Academic Appointments

  • Clinical Professor, Radiology

Research & Scholarship

Current Research and Scholarly Interests

Acute traumatic and non traumatic abdominal emergencies
Postoperative abdominopelvic complications
Errors in radiology


All Publications

  • Imaging of Cosmetic Plastic Procedures and Implants in the Body and Their Potential Complications AMERICAN JOURNAL OF ROENTGENOLOGY Yahyavi-Firouz-Abadi, N., Menias, C. O., Bhalla, S., Siegel, C., Gayer, G., Katz, D. S. 2015; 204 (4): 707-711


    Cosmetic plastic surgery procedures, as well as implants, are increasingly being performed. These implants are often encountered on routine imaging examinations, and radiologists are often asked to evaluate for complications or evidence of failure. Pectoral augmentation, gluteal augmentation, body lift and abdominoplasty, and penile and testicular prostheses are reviewed in this article.The typical appearance of common cosmetic implants and cosmetic techniques used in the human body is presented, along with the imaging spectrum of their potential complications.

    View details for DOI 10.2214/AJR.14.13516

    View details for Web of Science ID 000351614700023

    View details for PubMedID 25794060

  • Imaging of Abdominal and Pelvic Surgical and Postprocedural Foreign Bodies RADIOLOGIC CLINICS OF NORTH AMERICA Gayer, G., Lubner, M. G., Bhalla, S., Pickhardt, P. J. 2014; 52 (5): 991-?


    Every form of medical and surgical treatment, even the most trivial one, carries with it some chance of complications. This risk is usually small, and the benefit of the treatment should clearly outweigh the risk. Treatment-related complications may occur, however, presenting either soon after the intervention or remote from it. In this review, the focus is on imaging findings of surgical materials used in abdominal surgery, and of a wide array of implanted abdominal devices. The pertinent complications of these devices and of retained surgical objects are highlighted and illustrated.

    View details for DOI 10.1016/j.rcl.2014.05.006

    View details for Web of Science ID 000342882500005

    View details for PubMedID 25173655

  • Imaging of Iatrogenic Complications of the Urinary Tract Kidneys, Ureters, and Bladder RADIOLOGIC CLINICS OF NORTH AMERICA Patel, B. N., Gayer, G. 2014; 52 (5): 1101-?


    Iatrogenic complications of various severities may arise from many, if not all, forms of medical and surgical treatment. Most of these occur in spite of proper precautions. Every system in the human body may be affected, and the urinary tract is no exception. Radiologists are often the first to suspect and identify such iatrogenic injuries and, therefore, awareness of the pertinent imaging findings is vital. This review explores and illustrates many of the common and less common iatrogenic complications affecting the kidney, ureters, and bladder.

    View details for DOI 10.1016/j.rcl.2014.05.013

    View details for Web of Science ID 000342882500011

    View details for PubMedID 25173661

  • Metastatic Melanoma in the Chest and Abdomen: The Great Radiologic Imitator SEMINARS IN ULTRASOUND CT AND MRI Chang, S. T., Desser, T. S., Gayer, G., Menias, C. O. 2014; 35 (3): 272-289


    Metastatic melanoma causes an unpredictable variety of manifestations in the chest and abdomen that may be indistinguishable from other diseases by imaging alone. Melanoma metastases commonly involve the lymph nodes, lungs, liver, and small bowel, but virtually any organ can be affected. Newer modalities, such as contrast-enhanced ultrasound and whole-body magnetic resonance imaging, may provide more sensitive detection of metastatic melanoma for diagnosis, staging, and surveillance. An understanding of the predominantly hematogenous nature of metastatic spread by melanoma as well as a high index of suspicion in any patient with a history of melanoma may allow for more precise and confident diagnosis.

    View details for DOI 10.1053/j.sult.2014.02.001

    View details for Web of Science ID 000338268300008

    View details for PubMedID 24929267

  • The Renal Sinus-Transitional Cell Carcinoma and its Mimickers on Computed Tomography SEMINARS IN ULTRASOUND CT AND MRI Gayer, G., Zissin, R. 2014; 35 (3): 308-319


    The renal sinus is a deep recess located at the medial aspect of the kidney surrounded by the renal parenchyma. It contains within it the collecting system of the kidney, lymphatics, nerves, and renal blood vessels. The remainder of the sinus is filled with adipose and fibrous tissue. A variety of pathological conditions arise from the different tissues in this site. The aim of this review is to explore and illustrate the common and less common processes affecting the renal pelvis.

    View details for DOI 10.1053/j.sult.2014.02.004

    View details for Web of Science ID 000338268300010

    View details for PubMedID 24929269

  • Traumatic injury of the thoracic aorta treated with stent-graft: is long-term CT angiography follow-up justified? Clinical radiology Rimon, U., Shinfeld, A., Gayer, G. 2014; 69 (5): e207-10


    To report the results of long-term (>5 years) computed tomography (CT) angiography follow-up after thoracic endovascular aortic repair in patients with traumatic thoracic aortic injury.All follow-up CT angiographies performed in patients with traumatic thoracic aorta injury treated by endovascular stent-graft between 2002 and 2008 were reviewed. Of the 14 patients treated, seven patients had CT angiography follow-up examinations for more than 5 years. All patients were men with a mean age of 26 years. The Talent device was used in four patients and Gore TAG device in three patients. The mean device diameter and length were 24.6 mm and 103 mm, respectively. Follow-up included annual outpatient clinic surveillance and CT angiography examinations, which were reviewed for any device-related complications. The radiation effective dose was calculated from the CT dose report.Thirty-three CT examinations performed 64-110 months (mean 76) after stent-graft implementation were reviewed. The mean follow-up number of examinations per patient was 4.7 (range 2-8). Intra-graft circular mural tissue at the distal part of the stent-graft was seen in one patient. Stable lack of proximal device apposition was seen in all patients. No other radiological complications (e.g., aortic infection, dilatation, aneurysm or pseudoaneurysm, device struts breakage, migration, collapse, endoleak) were detected. None of the patients developed hypertension. The average effective dose was 77.01 mSv (range 34.11-128.84 mSv).CT angiography did not reveal any complications developing throughout the long-term follow-up. These results suggest that long-term CT angiography follow-up may not be required.

    View details for DOI 10.1016/j.crad.2013.12.013

    View details for PubMedID 24565646

  • Appendicitis in adults with incidental midgut malrotation: CT findings CLINICAL RADIOLOGY Ben Ely, A., Gorelik, N., Cohen-Sivan, Y., Zissin, R., Carpineta, L., Osadchy, A., Gayer, G. 2013; 68 (12): 1212-1219


    To report the computed tomography (CT) findings of acute and complicated appendicitis in adults with incidental midgut malrotation.The medical records and CT studies of eight patients with appendicitis and incidental midgut malrotation who presented to two medical centres between 1998 and 2009 were reviewed.All patients presented with 1-5 days of acute abdominal pain, which was diffuse in two, left-sided in two, lower abdominal in two, and in the right lower quadrant in two patients. The inflamed appendix was right-sided in three, left-sided in three, and in the midline in two patients. Three cases were complicated by a peri-appendicular abscess, and one patient also had a small bowel obstruction. All patients had a complete non-rotation with right-sided duodenum and jejunum, and left-sided colon. All eight patients had an abnormal superior mesenteric artery-superior mesenteric vein (SMA/SMV) relationship and a dysplastic uncinate process of the pancreas. Urgent surgery was performed in six patients and the remaining two were treated conservatively.Altered anatomy in malrotation affects the typical clinical and CT findings of acute appendicitis, therefore delaying diagnosis. When CT shows focal inflammation anywhere within the abdomen, along with an abnormal SMA/SMV relationship, the position of the caecum should be ascertained and acute appendicitis ruled out.

    View details for DOI 10.1016/j.crad.2013.07.001

    View details for Web of Science ID 000327922000003

    View details for PubMedID 23937823

  • Dropped gallstones: spectrum of imaging findings, complications and diagnostic pitfalls BRITISH JOURNAL OF RADIOLOGY Nayak, L., Menias, C. O., Gayer, G. 2013; 86 (1028)


    Spillage of gallstones into the abdominal cavity, referred to as "dropped gallstones" (DGs), occurs commonly during laparoscopic cholecystectomy. The majority of these spilled stones remain clinically silent; however, if uncomplicated DGs are not correctly identified on subsequent imaging, they may mimic peritoneal implants and cause unduly concern. A small percentage of DGs cause complications, including abscess and fistula formation. Recognising the DG within the abscess is critical for definitive treatment. This pictorial review illustrates the imaging appearances and complications of DGs on CT, MRI and ultrasound and emphasises pitfalls in diagnosis.

    View details for DOI 10.1259/bjr.20120588

    View details for Web of Science ID 000324101700001

    View details for PubMedID 23747395

  • Letter From the Editor: The Pulmonary Vasculature SEMINARS IN ULTRASOUND CT AND MRI Gayer, G. 2012; 33 (6): 471-472

    View details for DOI 10.1053/j.sult.2012.08.002

    View details for Web of Science ID 000312179300001

    View details for PubMedID 23168058

  • Changes in spleen volume after resection of hepatic colorectal metastases CLINICAL RADIOLOGY Jacobs, K. E., Visser, B. C., Gayer, G. 2012; 67 (10): 982-987


    To identify and describe changes in spleen volume occurring in patients with colorectal metastases to the liver after partial hepatectomy.Forty-one consecutive patients (20 men, 21 women) with histopathology-proven colorectal liver metastases who underwent partial hepatectomy between August 2007 and April 2011 were included. Liver and spleen volumes were measured by computed tomography (CT) volumetry on the most recent CT prior to surgery and on all CTs obtained within a year after partial hepatectomy. Patients were carefully evaluated for and excluded if they had co-morbid conditions known to cause splenomegaly or risk factors for portal hypertension such as underlying liver disease and portal vein thrombosis.Thirty-two (78%) patients demonstrated an increase in spleen volume on the first post-operative CT, with more than a double increase in volume amongst five patients. Spleen volume increased by an average of 43% within 3 months of partial hepatectomy (p < 0.0001) and remained increased through 6 months after surgery, returning to near baseline thereafter. In the remaining nine (22%) patients, the spleen was observed to decrease an average of 11% in volume on first postoperative CT (p < 0.005).Splenic enlargement after partial hepatectomy of colorectal metastases is a common finding on CT. Increased familiarity amongst radiologists of this phenomenon as likely reflecting physiological changes is important in order to avoid unnecessary evaluation for underlying conditions causing interval enlargement of the spleen.

    View details for DOI 10.1016/j.crad.2012.03.013

    View details for Web of Science ID 000309094900007

    View details for PubMedID 22608244

  • Enlargement of the spleen as an incidental finding on CT in post-partum females with fever BRITISH JOURNAL OF RADIOLOGY Gayer, G., Ben Ely, A., MAYMON, R., Hertz, M. 2012; 85 (1014): 753-757


    The aim was to evaluate whether enlargement of the spleen on CT in a post-partum female with fever is a common phenomenon.In this retrospective institutional review board-approved study, the spleen was measured by CT in 77 females (average age 30.7 years) examined for post-partum fever and a control group of 58 febrile females imaged for suspected appendicitis (average age 29.7 years). The splenic length, width and thickness were measured and used to calculate the splenic index. The measurements of both groups of patients were compared. The size of the spleen was assessed again in 12 of the 77 post-partum female who had a follow-up CT for unrelated reasons. Continuous variables were compared, by groups, using analysis of variance (ANOVA). ANOVA with repeated measures was used to evaluate changes over time. A p-value <0.05 was considered significant.The length, thickness and width of the spleen were significantly larger in the patients imaged after delivery compared with those in the control group (p<0.001 for all three comparisons). The mean splenic index was 686.6 cm(3) in the post-partum group and 408.1 cm(3) in the control group (p<0.001). The splenic dimensions and index were significantly smaller in the 12 post-partum females who had a follow-up study.An enlarged spleen in febrile females undergoing CT in the puerperium may reflect physiological changes occurring during pregnancy.

    View details for DOI 10.1259/bjr/92126864

    View details for Web of Science ID 000305509200029

    View details for PubMedID 21976628

  • Letter from the Editor: Imaging of the Aorta SEMINARS IN ULTRASOUND CT AND MRI Gayer, G. 2012; 33 (3): 167-168

    View details for DOI 10.1053/j.sult.2012.03.001

    View details for Web of Science ID 000305094700001

    View details for PubMedID 22624963

  • Spontaneous Suburothelial Hemorrhage in Coagulopathic Patients: CT Diagnosis AMERICAN JOURNAL OF ROENTGENOLOGY Gayer, G., Desser, T. S., Hertz, M., Osadchy, A., Daniel, B. L., Zissin, R. 2011; 197 (5): W887-W890


    The objective of our study was to identify and describe the spectrum of CT findings in patients with coagulopathy-induced suburothelial hemorrhage involving the renal collecting system.CT findings of suburothelial hemorrhage are often subtle and are best appreciated on unenhanced CT scans because of the high density of the hemorrhage. After contrast injection, uniformly thickened soft tissue enveloping the collecting system is suggestive of this condition. Clinical information regarding the presence of coagulopathy is essential for the radiologist to entertain this relatively rare diagnosis.

    View details for DOI 10.2214/AJR.11.6474

    View details for Web of Science ID 000296512800013

    View details for PubMedID 22021537

  • Retroperitoneal Sarcomas SEMINARS IN ULTRASOUND CT AND MRI Kumarasamy, N. A., Gayer, G. 2011; 32 (5): 422-432


    Retroperitoneal sarcomas are a rare and highly malignant group of tumors. Because of their anatomical location, they often reach a large size before detection and are difficult to diagnose clinically because of nonspecific symptoms. After surgical resection, the tumors display a high rate of recurrence, thus requiring long-term and often indefinite follow-up. Consequently, imaging plays a central role in the diagnosis and management of these tumors. This review article examines the epidemiology, staging criteria, histologic subtypes, diagnosis, treatment, and general imaging principles for all retroperitoneal sarcomas, with detailed focus on the most common subtype, retroperitoneal liposarcomas.

    View details for DOI 10.1053/j.sult.2011.06.002

    View details for Web of Science ID 000295817700005

    View details for PubMedID 21963163

  • Foreign Objects Encountered in the Abdominal Cavity at CT RADIOGRAPHICS Gayer, G., Petrovitch, I., Jeffrey, R. B. 2011; 31 (2): 409-U156


    Foreign objects are not infrequently seen at computed tomography (CT) of the abdomen and pelvis and may pose a diagnostic challenge to the radiologist, who must recognize the object, characterize its nature and location, and determine its clinical significance. Most foreign objects are incidentally detected at CT, but they may mimic a wide range of pathologic conditions. Some foreign objects (eg, an object that has been swallowed either intentionally or unintentionally) are the cause of the patient's signs and symptoms and require prompt medical attention. Other objects, such as a sponge or surgical instrument that has been retained postoperatively, may have medicolegal consequences. Furthermore, certain objects, such as intentionally concealed drug packets, may go undetected unless a high degree of suspicion exists and appropriate window settings are used to review the study. The radiologist should be familiar with the wide range of foreign objects that may be encountered at abdominopelvic CT, be able to recognize them promptly, and understand their implications for patient treatment.

    View details for DOI 10.1148/rg.312105123

    View details for Web of Science ID 000288533500011

    View details for PubMedID 21415187

  • Letter from the editor: the great mimickers in radiology. Seminars in ultrasound, CT, and MR Gayer, G. 2014; 35 (3): 193-4

    View details for DOI 10.1053/j.sult.2014.03.001

    View details for PubMedID 24929260

  • Ovarian Carcinoma Metastasis to Breast: Role of PET/CT ISRAEL MEDICAL ASSOCIATION JOURNAL Gayer, G., Ben-Haim, S. 2013; 15 (12): 784-784

    View details for Web of Science ID 000329474300016

    View details for PubMedID 24449989

  • Letter From the Editor: Radiologic Imaging in Hematological Disorders SEMINARS IN ULTRASOUND CT AND MRI Gayer, G. 2013; 34 (6): 491-492

    View details for DOI 10.1053/j.sult.2013.10.009

    View details for Web of Science ID 000328656800001

    View details for PubMedID 24332201

  • Images in clinical medicine. Abdominal ectopic pregnancy. New England journal of medicine Gayer, G. 2012; 367 (24): 2334-?

    View details for DOI 10.1056/NEJMicm1111814

    View details for PubMedID 23234516

  • The Role of Readily Available Clinical, Laboratory and Radiologic Findings in Distinguishing A/H1N1/2009 Influenza from Other Causes of Acute Febrile Respiratory Illness under Pandemic Conditions ISRAEL MEDICAL ASSOCIATION JOURNAL Karplus, R., Weinberger, M., Zaidenstein, R., Goldshtein, L., Natif, N., Gayer, G. 2012; 14 (10): 613-619


    During an influenza pandemic, clinicians need easily available clinical and laboratory criteria to distinguish influenza from similar respiratory illnesses. We compared A/H1N1/2009-polymerase chain reaction (PCR)-positive and matched PCR-negative hospitalized patients with suspected H1N1 influenza to identify factors that could assist physicians at patient admission.To identify factors significantly associated with A/ H1N1/2009 infection.A group of 145 patients with PCR-confirmed A/H1N1 2009 influenza admitted between 27 May 2009 and 3 December 2009 was matched with 145 PCR-negative patients by age, epidemiological week and pregnancy status. Epidemiological and clinical parameters and radiological findings on initial chest X-ray were compared between the two groups.Asthma (PCR+ 26%, PCR- 12%, P = 0.006) and military service (PCR+ 13%, PCR- 4%, P = 0.15) were associated with PCR-positive status in non-pregnant patients. At presentation, fever, cough, myalgia and fulfilling the pandemic influenza case definition were significantly more frequent in nonpregnant PCR+ patients (62/90/43/59% in PCR+ versus 38/69/30/35% in PCR-). In pregnant patients, fever and fulfilling the case definition were significantly associated with PCR-positive status. Mean leukocyte and absolute lymphocyte counts were significantly lower in both pregnant and nonpregnant PCR-positive patients. Significantly more PCR-negative non-pregnant patients (43% vs. 22% PCR+, P = 0.004) had abnormal chest X-ray (CXR) findings on presentation. In PCR-positive patients, patchy consolidation and interstitial infiltrates were the most common abnormalities.Under the conditions generated by the A/ H1 1/2009 pandemic, radiological findings did not distinguish reliably between influenza and other febrile respiratory illnesses. Asthma, military service, the pandemic case definition (particularly fever, cough and myalgia)

    View details for Web of Science ID 000310929600005

    View details for PubMedID 23193782

  • An uncommon cause of abdominal pain following blunt abdominal trauma BRITISH JOURNAL OF RADIOLOGY Laeseke, P. F., Gayer, G. 2012; 85 (1015): 1025-1026

    View details for DOI 10.1259/bjr/20841300

    View details for Web of Science ID 000306995300043

    View details for PubMedID 22745207

  • Letter From the Editor: Sarcomas SEMINARS IN ULTRASOUND CT AND MRI Gayer, G. 2011; 32 (5): 363-364

    View details for DOI 10.1053/j.sult.2011.06.003

    View details for Web of Science ID 000295817700001

    View details for PubMedID 21963159

  • Musculoskeletal ultrasonography. Seminars in ultrasound, CT, and MR Gayer, G. 2011; 32 (2): 65-?

    View details for DOI 10.1053/j.sult.2010.12.004

    View details for PubMedID 21414542

  • CT diagnosis of a large peritoneal loose body: a case report and review of the literature BRITISH JOURNAL OF RADIOLOGY Gayer, G., Petrovitch, I. 2011; 84 (1000): E83-E85


    We report a case of a large peritoneal loose body (LPLB), diagnosed on CT. The loose body appeared as a round pelvic mass with central calcifications and a distinct fat plane separating it from adjacent organs. The mass changed its location from the left to the right side of the pelvis within 9 days on repeat imaging. The typical cross-sectional characteristics of a LPLB include a mobile well-circumscribed soft-tissue mass usually with coarse central calcifications. The accurate diagnosis of a LPLB is vital to prevent unnecessary surgical intervention in an asymptomatic patient with an incidentally discovered LPLB.

    View details for DOI 10.1259/bjr/98708052

    View details for Web of Science ID 000288499000005

    View details for PubMedID 21415299

  • Ultrasound, computed tomography, and magnetic resonance: the "central nervous system" of every radiology practice. Seminars in ultrasound, CT, and MR Gayer, G. 2010; 31 (2): 65-66

    View details for DOI 10.1053/j.sult.2010.01.007

    View details for PubMedID 20304315

  • Sealed rupture of abdominal aortic aneurysms: CT features in 6 patients and a review of the literature ABDOMINAL IMAGING Apter, S., Rimon, U., Konen, E., Erlich, Z., Guranda, L., Amitai, M., Portnoy, O., Gayer, G., Hertz, M. 2010; 35 (1): 99-105


    To assess the CT features of sealed rupture of abdominal aortic aneurysm.We reviewed the CT scans of six index cases obtained over a 3 year period with a sealed rupture of an abdominal aortic aneurysm and those reported in the literature over a 21 year period. CT scans were reviewed for aneurysm size, the presence of a draped aorta and adjacent vertebral erosion. A group of consecutive patients with non-ruptured abdominal aortic aneurysm, referred for endovascular aneurysm repair during the same 3 year period constituted the control group.In the study group of 31 patients the mean size of the aneurysm was 6.24 +/- 2.01 cm, compared to 6.01 +/- 0.99 cm in the control group, without statistically significant difference (t = 0.75, df = 97, P = 0.46). A draped aorta was detected in all patients with a sealed rupture. Vertebral erosion was present in all our six, but mentioned in only 14 of the cases reported.A sealed rupture of an abdominal aortic aneurysm can occur in relatively small aneurysms. A draped aorta and adjacent vertebral erosion are characteristic CT signs of such a rupture.

    View details for DOI 10.1007/s00261-008-9488-1

    View details for Web of Science ID 000274263900015

    View details for PubMedID 19082650

  • Image-guided therapy. Seminars in ultrasound, CT, and MR Gayer, G. 2009; 30 (2): 47-48

    View details for PubMedID 19358436

  • Abdominal CT findings in small bowel perforation BRITISH JOURNAL OF RADIOLOGY Zissin, R., Osadchy, A., Gayer, G. 2009; 82 (974): 162-171


    Small bowel perforation is an emergent medical condition for which the diagnosis is usually not made clinically but by CT, a common imaging modality used for the diagnosis of acute abdomen. Direct CT features that suggest perforation include extraluminal air and oral contrast, which are often associated with secondary CT signs of bowel pathology. This pictorial review illustrates the CT findings of small bowel perforation caused by various clinical entities.

    View details for DOI 10.1259/bjr/78772574

    View details for Web of Science ID 000263462800011

    View details for PubMedID 18852210

  • Superior mesenteric artery to superior mesenteric vein arteriovenous fistula presenting as abdominal pain and gastrointestinal bleeding 3 years after an abdominal gunshot wound: report of a case and review of the literature. journal of trauma Weinstein, D., Altshuler, A., Belinki, A., Peer, A., Gayer, G., Halevy, A., Bass, A. 2009; 66 (1): E13-6

    View details for DOI 10.1097/01.ta.0000221791.73326.fb

    View details for PubMedID 18277282

  • Positive Intraluminal Bowel Contrast on Computed Tomography Following Oral Ingestion of Kayexelate CANADIAN ASSOCIATION OF RADIOLOGISTS JOURNAL-JOURNAL DE L ASSOCIATION CANADIENNE DES RADIOLOGISTES Zissin, R., Stackievicz, R., Osadchy, A., Gayer, G. 2008; 59 (5): 264-267


    Our study presents the computed tomography (CT) manifestations of orally ingested kayexelate (a powdered form of sodium polystyrene sulphonate) used to treat hyperkalemia. Five patients with whom kayexalate appeared as high-attenuating intraluminal enteric content, similar to oral contrast material or leakage of intravascular contrast, are reported. Radiologists should be familiar with its appearance as it may mimic oral or vascular contrast within the gastrointestinal tract, a finding that may lead to a diagnostic error or misinterpretation.

    View details for Web of Science ID 000269024000005

    View details for PubMedID 19385154

  • Acute abdominal pain is one of the most common presenting complaints in the emergency department. Seminars in ultrasound, CT, and MR Gayer, G. 2008; 29 (5): 291-292

    View details for PubMedID 18853836

  • Recent advances in CT technology have enabled us, radiologists, to rediscover a fascinating organ, the heart. Seminars in ultrasound, CT, and MR Gayer, G. 2008; 29 (3): 165-166

    View details for PubMedID 18564539

  • Familial wandering spleen: a first instance JOURNAL OF PEDIATRIC SURGERY Ben Ely, A., Seguier, E., Lotan, G., Strauss, S., Gayer, G. 2008; 43 (5)


    We report on 2 sisters presenting with acute torsion of a wandering spleen within a 3-year interval. The diagnosis was made preoperatively by computed tomography (CT) in both cases. A high index of suspicion because of our experience with the first patient, who underwent splenectomy, enabled a correct early diagnosis in the sibling. On urgent surgery, reversible ischemic changes were found, and detorsion and splenopexy resulted in preservation of the spleen.

    View details for DOI 10.1016/j.jpedsurg.2007.12.077

    View details for Web of Science ID 000256551300050

    View details for PubMedID 18485931

  • Iatrogenic splenic injury in postoperative patients: a series of case reports. Emergency radiology Gayer, G., Galperin-Aizenberg, M. 2008; 15 (2): 109-113


    The purpose of this study was to report case studies of iatrogenic splenic injuries on computed tomography (CT) in symptomatic postsurgical patients. The medical records and CT studies of all patients with injury to the spleen after abdominal surgery were reviewed. CT was performed in the postoperative period, urgently in all patients. Unsuspected splenic injuries were found on CT performed in the early postoperative period in seven symptomatic patients (five women and two men, age range 21-81 years) after various abdominal surgical procedures. Injuries as detected on CT included splenic infarct in five, subcapsular hematoma in two, and laceration of the spleen in one. These findings were the only abnormal abdominal findings in four of the patients and were probably the source of the postoperative abdominal pain and fever. Splenic injury is a rare complication of abdominal surgery. It is often the radiologist who diagnoses the injury, and awareness of this possible complication can obviate further investigations.

    View details for PubMedID 18095010

  • Abdominal CT findings in nontraumatic colorectal perforation EUROPEAN JOURNAL OF RADIOLOGY Zissin, R., Hertz, M., Osadchy, A., Even-Sapir, E., Gayer, G. 2008; 65 (1): 125-132


    Colorectal perforation is an emergent medical condition in which the diagnosis and the etiology are often established on CT, the common imaging modality used for evaluating the acute abdomen. The cardinal, direct CT features suggesting perforation are extraluminal air and enteric contrast, added by secondary signs of bowel pathology, such as focal bowel wall thickening and bowel wall defect. This pictorial review will illustrate the CT findings of colorectal perforation caused by various clinical entities.

    View details for DOI 10.1016/j.ejrad.2007.03.014

    View details for Web of Science ID 000253086400017

    View details for PubMedID 17466477

  • Pseudoaneurysm of the renal artery following partial nephrectomy: Imaging findings and coil embolization CLINICAL RADIOLOGY Cohenpour, M., Strauss, S., Gottlieb, P., Peer, A., Rimon, U., Stav, K., Gayer, G. 2007; 62 (11): 1104-1109


    To present the imaging findings of five patients with renal artery pseudoaneurysm (RAP) after partial nephrectomy.Five patients (four men and one woman) with RAP as a complication of partial nephrectomy were studied. The diagnosis of RAP was established using contrast-enhanced computed tomography (CT) in three patients and renal angiography in two patients. In two cases, the diagnosis was evident on ultrasound with colour Doppler.The indication for partial nephrectomy (open approach in four patients and laparoscopic in one patient) was a space-occupying lesion, which proved to be a renal cell carcinoma. All patients presented with macroscopic haematuria, 1-21 days (mean 12.2 days) after surgery. In three of patients the definitive diagnostic imaging method was contrast-enhanced CT. The arterial phase of CT showed a well-circumscribed dense collection of contrast material located within the renal parenchyma. In two other patients the initial and conclusive diagnostic imaging method was renal angiography. All patients underwent selective renal angiography with therapeutic coil embolization. The procedure failed in one patient, which necessitated nephrectomy.Pseudoaneurysm of the renal artery should be considered in patients presenting with macrohaematuria after nephron-sparing surgery. The diagnosis can be established using contrast-enhanced CT, ultrasound with colour Doppler, or angiography. Renal angiography with selective embolization is a safe and efficacious technique for managing the condition.

    View details for DOI 10.1016/j.crad.2007.06.004

    View details for Web of Science ID 000250714300012

    View details for PubMedID 17920871

  • Abdominal CT Findings of Delayed Postoperative Complications CANADIAN ASSOCIATION OF RADIOLOGISTS JOURNAL-JOURNAL DE L ASSOCIATION CANADIENNE DES RADIOLOGISTES Zissin, R., Osadchy, A., Gayer, G. 2007; 58 (4): 200-211

    View details for Web of Science ID 000207169500001

    View details for PubMedID 18186431

  • Transcatheter arterial embolisation in anticoagulant-related haematoma - a current therapeutic option: a report of four patients and review of the literature INTERNATIONAL JOURNAL OF CLINICAL PRACTICE Zissin, R., Gayer, G., Kots, E., Ellis, M., Bartal, G., Griton, I. 2007; 61 (8): 1321-1327


    The aim of this study is to present the computed tomography (CT) and angiographic findings of life-threatening extraperitoneal haemorrhage complicating anticoagulant therapy, treated with transcatheter arterial embolisation (TAE). CT and angiographic studies of four consecutive patients with large, extraperitoneal anticoagulant-related haematomas (ACH) treated by TAE were retrospectively reviewed. Attention was directed to the location of the haematoma and to the possible presence of active arterial extravasation on CT. Four women (mean age 70 years) with large extraperitoneal ACH's demonstrated on CT as extended rectus sheath haematoma in three and expanding iliopsoas haematoma in one, were successfully treated by TAE of the inferior epigastric (n=3) and lumbar artery (n=1). Two patients were diagnosed by contrast-enhanced CT as having active arterial bleeding within the haematoma requiring TAE. The other two were referred to angiography because of haemodynamic instability. We also reviewed the imaging findings of 26 patients with extraperitoneal ACH's requiring TAE described in the literature. In the reviewed cases, a female predominance was found, the retroperitoneum was the most frequent site and most patients recovered. To conclude, unenhanced CT has proved an excellent modality for the diagnosis of ACH's. TAE has been shown to be an effective and safe method for managing such haematomas when conservative treatment is insufficient. We suggest that whenever a large extraperitoneal ACH is seen on unenhanced CT, a subsequent contrast-enhanced dynamic scan should be performed, unless contraindicated. Enhanced CT has a supplementary role in detecting active bleeding that provides an indication for angiographic therapy. Awareness of this optional treatment improve patient's outcome.

    View details for DOI 10.1111/j.1742-1241.2006.01207.x

    View details for Web of Science ID 000247906500015

    View details for PubMedID 17343658

  • Pelvis architecture and urinary incontinence in women EUROPEAN UROLOGY Stav, K., Alcalay, M., Peleg, S., Lindner, A., Gayer, G., Hershkovitz, I. 2007; 52 (1): 239-244


    To examine anatomic features in the pelvic bones and muscles in women with urinary incontinence (UI).Between October 2005 and January 2006, 212 consecutive women underwent pelvic computerized tomography in our center. Preceding the examination, all women completed a clinical and demographic questionnaire including detailed questions about UI. Several anatomic parameters using multiplanar reformation and three-dimensional techniques (volume rendering) were examined. We specifically evaluated different bony parameters, pelvic floor muscle angles, densities, and cross-sectional areas. Ninety-three women (46.5%) had UI; the remaining women served as the control group. A logistic regression model was used to evaluate risk factors for UI.The mean age was 55.5 yr (range: 19-90). Women who suffered from UI were older (60.97 vs. 50.77 yr, p<0.0001), had higher body mass index (27.65 vs. 25.49, p<0.01), had more previous hysterectomies (21.5% vs. 6.5%, p<0.005), underwent more pelvic irradiation (9.7% vs. 1.8%, p<0.05), and had more diabetes mellitus (31.2% vs. 13.1%, p<0.005). Patient's age and previous hysterectomy were found to be the major clinical risk factors for UI (OR: 1.029, p=0.002; OR: 2.94, p=0.024, respectively). Logistic regression analysis on all clinical and morphologic variables yielded the following risk factors: pelvic-inlet diameter (OR: 1.216, p<0.0001), pelvic-inlet anterior-posterior diameter (OR: 1.109, p=0.003), pelvic-outlet diameter (OR: 1.077, p=0.011) and transverse perineal muscle cross-section diameter (OR: 0.773, p<0.0001).Pelvic inlet and outlet dimensions are major risk factors for developing UI in women. These findings may lead to a better comprehension of the pathophysiology of UI in women.

    View details for DOI 10.1016/j.eururo.2006.12.026

    View details for Web of Science ID 000247281400037

    View details for PubMedID 17207915

  • Computed Tomography Findings of Early Abdominal Postoperative Complications CANADIAN ASSOCIATION OF RADIOLOGISTS JOURNAL-JOURNAL DE L ASSOCIATION CANADIENNE DES RADIOLOGISTES Zissin, R., Osadchy, A., Gayer, G. 2007; 58 (3): 136-145

    View details for Web of Science ID 000207169400001

    View details for PubMedID 17718297

  • Gas in the kidney: CT findings. Emergency radiology Portnoy, O., Apter, S., Koukoui, O., Konen, E., Amitai, M. M., Sella, T., Gayer, G., Hertz, M. 2007; 14 (2): 83-87


    Gas in the renal parenchyma is a rare finding seen best with computed tomography (CT). It can be encountered in a wide range of clinical conditions, some of them life-threatening like emphysematous pyelonephritis, whereas in others, it may represent a postoperative or procedure outcome. The latter are not usually a clinical emergency (for example, after nephrostomy insertion or in a urinary intestinal connection). Due to the increasing use of abdominal CT examinations, radiologists, especially in emergency setting, should be aware of this rare finding and be familiar with its differential diagnosis.

    View details for PubMedID 17431695

  • Rebound thymic enlargement on CT in adults INTERNATIONAL JOURNAL OF CLINICAL PRACTICE Yarom, N., Zissin, R., Apter, S., Hertz, M., Rahimi-Levene, N., Gayer, G. 2007; 61 (4): 562-568


    The objective of this study is to report the development of thymic enlargement in adults, mainly associated with chemotherapy for malignancy. The typical CT features of this phenomenon are described. The clinical data and CT studies of 13 adult patients with newly appearing thymic enlargement on CT were reviewed. These patients were followed-up mainly for malignancy. Further follow-up CTs were studied when available. Medical records were reviewed as to the primary disease, its medical treatment and the time of initial appearance of the enlarged thymus in relation to treatment. The study group included 13 adult patients, 12 with malignant disease and one with a slowly resolving pneumonia. The enlarged thymus appeared as a triangular, arrowhead-shaped structure, with a bilobed configuration and convex borders. Density measurements were consistent with homogeneous soft tissue. Location was in the anterior mediastinum, in the normal site of the thymus. In nine patients, follow-up studies were available. The observation period ranged from 5 months to 8 years from the initial appearance of the enlarged thymus. In five of the nine patients, the thymic enlargement resolved after 1-4.5 years. In four of the nine patients, the thymus remained enlarged during a follow-up ranging from 5 months to 2.5 years. Thymic enlargement, while a rare phenomenon in adults, may occur, mainly after chemotherapy. This phenomenon should be included in the differential diagnosis of a soft tissue mass appearing in the anterior mediastinum on follow-up CT in adult patients particularly following treatment for malignancy.

    View details for DOI 10.1111/j.1742-1241.2006.00950.x

    View details for Web of Science ID 000245051600010

    View details for PubMedID 17263694

  • Anatomic and pathologic computed tomographic findings following splenectomy SEMINARS IN ULTRASOUND CT AND MRI Zissin, R., Gutman, M., Even-Sapir, E., Gayer, G. 2007; 28 (1): 67-78


    Computed tomography (CT) is frequently used for postoperative evaluation in patients who have undergone splenectomy, on either an elective or an emergency basis. This pictorial article reviews and demonstrates the CT findings of postoperative anatomic changes, as well as various postoperative complications following splenectomy.

    View details for DOI 10.1053/j.sult.2006.10.009

    View details for Web of Science ID 000244256900011

    View details for PubMedID 17366711

  • Iatrogenic injury to the spleen - CT appearance SEMINARS IN ULTRASOUND CT AND MRI Galperin-Aizenberg, M., Blachar, A., Gayer, G. 2007; 28 (1): 52-56


    Splenic injury is a well-known but rare complication of various abdominal surgical and invasive procedures, and even of cardiac surgery. The true incidence of iatrogenic splenic trauma is, however, difficult to assess and is probably underestimated. Overt injuries diagnosed during surgery are usually immediately treated by splenectomy without imaging. This review focuses on missed splenic injuries that are diagnosed on imaging following surgery or an invasive procedure.

    View details for DOI 10.1053/j.sult.2006.10.007

    View details for Web of Science ID 000244256900008

    View details for PubMedID 17366708

  • Maternal spleen size throughout normal pregnancy SEMINARS IN ULTRASOUND CT AND MRI Maymon, R., Zimerman, A. L., Strauss, S., Gayer, G. 2007; 28 (1): 64-66


    Ultrasonography (US) is an accurate method with reproducible results for calculating splenic dimensions. Standards of normal spleen sizes have been developed for the general adult population, for children, and even for tall healthy athletes, thereby enabling US diagnosis of splenomegaly. Extrapolation of data from the normal population to pregnant women might, however, be inaccurate because of the physiological changes throughout gestation. We have recently reported a prospective study evaluating the size of the maternal spleen throughout pregnancy and hereby review the results and their implications.

    View details for DOI 10.1053/j.sult.2006.10.005

    View details for Web of Science ID 000244256900010

    View details for PubMedID 17366710

  • Normal sonographic values of maternal spleen size throughout pregnancy ULTRASOUND IN MEDICINE AND BIOLOGY Maymon, R., Strauss, S., Vaknin, Z., Weinraub, Z., Herman, A., Gayer, G. 2006; 32 (12): 1827-1831


    This study aims to establish normal range of sonographically measured maternal spleen size throughout pregnancy. Currently, 288 healthy pregnant women between 6 and 42 weeks' gestation underwent ultrasonographic measurements of spleen length and width. The relationships between ultrasound measurements with prepregnancy body mass index (BMI) and gestational age were assessed using the Pearson correlation coefficient. A linear regression model was applied to construct the appropriate equation for measuring the spleen area relative to BMI and gestational age. A significant correlation (R) was found between gestational age and spleen dimensions length (R = 0.486; p < 0.001), width (R = 0.455; p < 0.001) and area (R = 0.522; p < 0.001)) as well as between prepregnancy BMI and spleen length [(R = 0.314; p < 0.001), width (R = 0.380; p < 0.001) and area (R = 0.413; p < 0.001)]. We divided the spleen area by the BMI, thus enabling to perform a linear regression analysis with gestational age (weeks) as an independent continuous variable. A high multiple correlation (R) between spleen area and this variable was found (R(2) = 0.47; p < 0.001). The equation [spleen area/BMI = 1.598 + 0.032 x gestational age in weeks] was performed for calculating the spleen area throughout pregnancy. A significant overall growth pattern of spleen area in pregnancy with increasing gestational age was found. Normograms from these data can be used to evaluate splenomegaly throughout pregnancy.

    View details for DOI 10.1016/j.ultrasmedbio.2006.06.017

    View details for Web of Science ID 000243171400004

    View details for PubMedID 17169694

  • The wandering spleen: CT findings and possible pitfalls in diagnosis CLINICAL RADIOLOGY Ben Ely, A., Zissin, R., Copel, L., Vasserman, M., Hertz, M., Gottlieb, P., Gayer, G. 2006; 61 (11): 954-958


    To report the CT features of wandering spleen, a rare condition which can be incidentally detected as an abdominal or pelvic mass or can present with torsion, causing an acute abdomen.The CT studies of seven patients, two children and five adults, with wandering spleen were reviewed. CT was performed urgently in three patients for acute abdomen, and electively in four.CT findings of wandering spleen included absence of the spleen in its normal position and a mass located elsewhere in the abdomen or pelvis, i.e. an ectopic spleen, enhancing homogeneously in four cases and failing partially or completely to enhance in the other three, indicating infarction. A "whirl" appearance representing the twisted splenic pedicle was seen in the three cases with torsion. Urgent splenectomy confirmed infarction secondary to torsion.The possible diagnosis of wandering spleen should be kept in mind when CT shows the spleen to be absent from its usual position and a mass is found elsewhere in the abdomen or pelvis. When, in addition, a "whirl" or partial or no enhancement of this mass are seen in a case presenting with acute abdomen, torsion of a wandering spleen is a likely diagnosis.

    View details for DOI 10.1016/j.crad.2006.06.007

    View details for Web of Science ID 000241713300008

    View details for PubMedID 17018308

  • Extrarenal manifestations of severe acute pyelonephritis: CT findings in 21 cases. Emergency radiology Zissin, R., Osadchy, A., Gayer, G., Kitay-Cohen, Y. 2006; 13 (2): 73-77


    The aim of this study is to report the extrarenal computerized tomography (CT) findings in patients with acute pyelonephritis (APN). Twenty-one CT examinations of 20 patients [19 women and one man, with ages ranging from 18 to 57 years (mean -35.2 years)], presenting either with a clinical diagnosis of APN (n=17) or with a suspected acute appendicitis, fever of unknown origin, and adult respiratory distress syndrome, one in each, were retrospectively reviewed. None had a known preexisting systemic disease. Results showed that renal abnormalities were seen on CT in all patients. In addition, ascites was detected in all women patients associated with subcutaneous edema in five of them. A thickened gallbladder wall was found in 19 cases, all were women, and periportal tracking and a dilated inferior vena cava in 17 CTs. Pleural effusion and thickened interlobular septa were present in 16 and 15 studies, respectively. Relevant laboratory findings included hypoalbuminemia in 14, elevated liver enzymes in 11, hypocholesterolemia in nine, and elevated LDH levels in six cases. In conclusion, radiologists should be familiar with the extrarenal imaging features of APN that may be seen on CT, and on ultrasonography as well, and should look for renal abnormalities to diagnose a clinically unsuspected APN. Alternatively, APN should be included in the differential diagnosis of systemic diseases that cause gallbladder wall thickening to avoid misdiagnosing it as acute cholecystitis.

    View details for PubMedID 16941112

  • Congenital anomalies of the spleen SEMINARS IN ULTRASOUND CT AND MRI Gayer, G., Hertz, M., Strauss, S., Zissin, R. 2006; 27 (5): 358-369


    Various congenital anomalies may affect the spleen, starting with common anomalies, such as an accessory spleen, up to rare conditions such as a wandering spleen and polysplenia. Most of these anatomic variants have no clinical significance; they need, however, to be recognized by the radiologist as such. Awareness of these variants is important for the radiologist to interpret the findings correctly and avoid mistaking them for a clinically significant abnormality. In this review we illustrate the spectrum of congenital anomalies of the spleen and stress pitfalls and possible complications resulting from these anomalies.

    View details for DOI 10.1053/j.sult.2006.06.002

    View details for Web of Science ID 000241312600002

    View details for PubMedID 17048452

  • Renal extramedullary haematopoiesis mimicking renal lymphoma on computed tomography CLINICAL RADIOLOGY Galperin-Aizenberg, M., Volchek, Y., Even Sapir, E., Vasserman, M., Maizlin, Z. V., Cohenpour, M., Gayer, G. 2006; 61 (10): 896-898
  • The CT findings of abdominal anticoagulant-related hematomas SEMINARS IN ULTRASOUND CT AND MRI Zissin, R., Ellis, M., Gayer, G. 2006; 27 (2): 117-125


    Spontaneous bleeding is a serious complication of anticoagulation that should be promptly recognized and treated. The clinical manifestations vary and are related to the site of the hemorrhage. CT, a simple and safe imaging modality, plays an important role in the accurate determination of the presence or absence of an anticoagulant-related bleed, its extent, and its precise location. This pictorial article reviews and demonstrates the CT findings of a variety of anticoagulant-related hematomas at various anatomical locations in the abdomen.

    View details for DOI 10.1053/j.sult.2006.01.008

    View details for Web of Science ID 000236788300005

    View details for PubMedID 16623366

  • Minimally invasive management of urolithiasis SEMINARS IN ULTRASOUND CT AND MRI Gayer, G., Hertz, M., Stav, K., Zissin, R. 2006; 27 (2): 139-151


    The management of urolithiasis has radically changed over the last two decades. Open surgery has been almost completely replaced by minimally invasive procedures, mainly extracorporeal shock wave lithotripsy (ESWL) and ureteroscopy (URS). Although these treatment modalities have been proven to be very safe and effective, serious complications can occur. Prompt diagnosis is often essential and may even be lifesaving. Radiologists play an important role in this setting, since many of these complications can be readily diagnosed by imaging. Awareness of the wide spectrum of complications may be crucial in interpreting imaging studies of patients who have undergone one of these procedures. This article reviews the contemporary management of ureteric stones with ESWL and URS and illustrates the radiological findings of complications of these procedures.

    View details for DOI 10.1053/j.sult.2006.01.006

    View details for Web of Science ID 000236788300007

    View details for PubMedID 16623368

  • CT findings of latrogenic complications following gastrointestinal endoluminal procedures SEMINARS IN ULTRASOUND CT AND MRI Zissin, R., Konikoff, F., Gayer, G. 2006; 27 (2): 126-138


    Abdominal CT, a simple and safe imaging modality, plays an important role in evaluating patients suspected of having abdominal complications following nonsurgical gastrointestinal procedures, to accurately determine the presence or absence of such insults. This pictorial article reviews and demonstrates the CT findings of various complications following upper endoscopy, percutaneous endoscopic gastrostomy, endoscopic retrograde cholangiopancreatography, endoscopic US, colonoscopy, and enemas (barium as well as cleansing).

    View details for DOI 10.1053/j.sult.2006.01.007

    View details for Web of Science ID 000236788300006

    View details for PubMedID 16623367

  • Anomalous origin of left main coronary artery: the value of myocardial scintigraphic and spiral computed tomography scans. Nuclear medicine review. Central & Eastern Europe Cohenpour, M., Tourovski, A., Zyssman, I., Friedensohn, A., Gayer, G., Horne, T. 2006; 9 (1): 69-71


    Anomalous origin of the left main coronary artery (LMCA) from the right sinus of the Valsalva or the proximal right coronary artery (RCA) is one of the most clinically important anomalies of coronary circulation. We report the case of a patient with chest pain and abnormal thallium myocardial perfusion scan in whom the anomaly was first detected on invasive coronary arteriography. The exact anatomic course of anomalous LMCA was confirmed using contrast enhanced computed tomography.

    View details for PubMedID 16791809

  • To biopsy or not to biopsy: An 82-year-old patient with a retroperitoneal mass and severe low back pain EUROPEAN JOURNAL OF INTERNAL MEDICINE Horowitz, M., Gayer, G., Itzchak, Y., Rapoport, M. J. 2006; 17 (1): 55-56


    An 82-year-old patient was admitted to our ward due to disabling severe low back pain. Computed tomography of the spine revealed a retroperitoneal space-occupying lesion encroaching on two adjacent lumbar vertebrae and causing destruction of the cortex of their anterior aspect. The patient was scheduled for a biopsy of the mass. Magnetic resonance (MR) of the lumbar spine, however, suggested that the mass was most probably an aortic aneurysm. The biopsy was cancelled and the patient was referred for surgical intervention. MR is indicated in the evaluation of a solid mass causing vertebral destruction in order to achieve an accurate preoperative diagnosis and prevent a hazardous invasive procedure.

    View details for DOI 10.1016/j.ejim.2005.08.004

    View details for Web of Science ID 000242854500012

    View details for PubMedID 16378888

  • Wandering spleen - the challenge of ultrasound diagnosis: Report of 7 cases JOURNAL OF CLINICAL ULTRASOUND Karmazyn, B., Steinberg, R., Gayer, G., Grozovski, S., Freud, E., Kornreich, L. 2005; 33 (9): 433-438


    To summarize our experience with sonographic diagnosis of wandering spleen in children and assess for the typical sonographic findings of wandering spleen, complications, and possible diagnostic pitfalls.We identified all pediatric patients from 1998-2003 with a surgically confirmed diagnosis of wandering spleen. All sonographic examinations were reviewed for splenic position, size, echotexture, and parenchymal blood flow.Seven children were identified with a mean age of 9.7 years (range 4.2-15.3 years). All presented with abdominal pain. Abdominal sonography, performed in all children demonstrated a low position of the spleen (n = 6), splenomegaly (n = 4), and absence of parenchymal flow in the three patients with splenic torsion and infarction. The diagnosis was made preoperatively via sonography in five children; three required repeated hospital admissions before the correct diagnosis was established. Complications occurred in five patients (gastric obstruction [n = 1], splenic infarction [n = 3], and recurrent pancreatitis [n = 1]).The most specific sonographic finding for wandering spleen is low position of the spleen. However, if the spleen regains its normal or near-normal position, the diagnosis may be missed and the condition may recur, and result in complications.

    View details for Web of Science ID 000233580200001

    View details for PubMedID 16281274

  • Fallopian tube carcinoma presenting as tubo-ovarian abscess: a report of two cases with literature review INTERNATIONAL JOURNAL OF GYNECOLOGICAL CANCER Halperin, R., Zehavi, S., Gayer, G., Herman, A., Schneider, D. 2005; 15 (6): 1131-1134


    Preoperative diagnosis of fallopian tube carcinoma is difficult, with fewer than 5% being diagnosed preoperatively. We describe tubal carcinoma, presenting as a tubo-ovarian abscess in two 47-year-old women. Both patients presented with abdominal pain, pelvic mass, and fever. Both patients were treated as having a tubo-ovarian abscess but failed to respond to therapy. During surgery a metastatic right tubal carcinoma was found. A definite operation was performed in both patients. Three additional cases of fallopian tube carcinoma, presenting as acute pelvic inflammatory disease, were found while reviewing the English literature. Actually all these three cases presented as tubo-ovarian abscess because of the existence of tender pelvic mass. Carcinoma of the fallopian tube should be considered in the differential diagnosis of tubo-ovarian abscess in those who failed to respond to a previously unreported clinical presentation.

    View details for Web of Science ID 000233289200021

    View details for PubMedID 16343195

  • Congenital internal hernia as a cause of small bowel obstruction: CT findings in 11 adult patients BRITISH JOURNAL OF RADIOLOGY Zissin, R., Hertz, M., Gayer, G., Paran, H., Osadchy, A. 2005; 78 (933): 796-802


    The aim of this study is to report the CT findings in patients proved to have congenital internal hernia (CIH) as a cause of small bowel obstruction (SBO). The CT scans of 11 patients (9 men and 2 women, with ages ranging from 20 years to 95 years (mean 60.7 years), presenting with clinical symptoms and signs of SBO without previous abdominal surgery or trauma, were retrospectively reviewed. In all patients features of SBO were seen. In addition, in nine of them a saclike mass, containing dilated small bowel loops with mesenteric vessels converging toward its orifice was demonstrated and a pre-operative diagnosis of an incarcerated internal hernia was suggested. In the other two, a closed loop obstruction was seen without an identifiable cause. Mural thickening of the entrapped loops within the hernial sac was seen in five patients, with hypoperfusion in four of them, blurring of the mesenteric vessels with localized mesenteric fluid was demonstrated in seven and free peritoneal fluid in 10. All patients were operated on following the CT and an incarcerated CIH was confirmed. Gangrenous bowel was present at exploration in seven cases. One patient died. In conclusion, in patients with intact abdomen and SBO, CT may be the first imaging modality to discover a clinically unsuspected CIH, which requires prompt surgical intervention. Radiologists should be aware of the CT features suggestive of a SBO caused by CIH, i.e. a saclike mass of dilated small bowel loops, as a correct diagnosis will influence patient management and prognosis.

    View details for DOI 10.1259/bjr/87050272

    View details for Web of Science ID 000231664200005

    View details for PubMedID 16110100

  • Letter from the guest editor. Magnetic resonance imaging of the abdomen--part I. Seminars in ultrasound, CT, and MR Gayer, G. 2005; 26 (3): 115-?

    View details for PubMedID 15987061

  • Bilateral pelvic urinomas following ureteral injury from surgery: lymphocele look-alikes on computed tomography. Emergency radiology Gayer, G., Halperin, R., Vasserman, M., Siegel, Y. 2005; 11 (3): 167-169


    Postoperative fluid collections are a not-infrequent finding on computed tomography (CT), and their causes are numerous. One of the more rare etiologies is a urinoma resulting from a ureteral injury. Such an injury is one of the most serious complications of abdominal, mainly gynecological, surgery. This complication is often clinically unsuspected, as symptoms are nonspecific and the patient may present weeks and even months after the injury. We present a patient in whom clinically unsuspected bilateral pelvic urinomas were diagnosed on a baseline CT 8 weeks after radical hysterectomy. We want to emphasize the crucial role of CT, especially with delayed scanning, in reaching this diagnosis.

    View details for PubMedID 16028322

  • Computed tomographic features of afferent Loop syndrome: Pictorial essay CANADIAN ASSOCIATION OF RADIOLOGISTS JOURNAL-JOURNAL DE L ASSOCIATION CANADIENNE DES RADIOLOGISTES Zissin, R., Hertz, M., Paran, H., Osadchy, A., Gayer, G. 2005; 56 (2): 72-78


    ALS, a rare condition, is often difficult to diagnose clinically but has a characteristic CT appearance as a U-shaped, fluid-filled tubular structure crossing the midline between the abdominal aorta and the superior mesenteric artery. Radiologists should be familiar with this rare entity, as awareness of its pathognomonic CT features will aid in establishing the correct diagnosis as well as in offering a tentative etiology as a guide for treatment.

    View details for Web of Science ID 000229314500003

    View details for PubMedID 15957273

  • CT appearance of a retained "fish" in the abdomen AMERICAN JOURNAL OF ROENTGENOLOGY Gayer, G., Karni, T., Vasserman, M. 2005; 184 (3): S75-S77

    View details for Web of Science ID 000227522800027

    View details for PubMedID 15728030

  • Computed tomographic findings of abdominal complications of Crohn's disease - Pictorial essay CANADIAN ASSOCIATION OF RADIOLOGISTS JOURNAL-JOURNAL DE L ASSOCIATION CANADIENNE DES RADIOLOGISTES Zissin, R., Hertz, M., Osadchy, A., Novis, B., Gayer, G. 2005; 56 (1): 25-35

    View details for Web of Science ID 000229835400005

    View details for PubMedID 15835588

  • Postoperative anatomic and pathologic findings at CT following colonic resection SEMINARS IN ULTRASOUND CT AND MRI Zissin, R., Gayer, G. 2004; 25 (3): 222-238


    CT is frequently used for postoperative evaluation in patients who have undergone colonic resection. This pictorial article reviews and demonstrates the CT findings of normal postoperative anatomic changes, as well as different postoperative complications following various colonic operative techniques.

    View details for DOI 10.1053/j.sult.2004.03.004

    View details for Web of Science ID 000222223600003

    View details for PubMedID 15272547

  • Postoperative pneumoperitoneum: Prevalence, duration, and possible significance SEMINARS IN ULTRASOUND CT AND MRI Gayer, G., Hertz, M., Zissin, R. 2004; 25 (3): 286-289


    Free intraperitoneal air after abdominal surgery is a confounding finding with uncertain significance. A diagnostic dilemma often arises as to its origin: does it merely represent residual postoperative pneumoperitoneum (PP), which will need no intervention, or does it indicate a complication such as an anastomotic leak or a perforation of the gastrointestinal tract. Residual PP is usually well tolerated, as it will be absorbed over time and requires no therapy. On the other hand, air escaping through a gastrointestinal tract perforation or leak usually represents an intra-abdominal catastrophe requiring urgent intervention. This intriguing subject has been dealt with quite extensively based on plain film radiography findings in the past 50 years, and has lately also been studied on CT. This review discusses factors influencing the prevalence of PP and its range of duration.

    View details for DOI 10.1053/j.sult.2004.03.009

    View details for Web of Science ID 000222223600008

    View details for PubMedID 15272552

  • Ureteral injuries: CT diagnosis SEMINARS IN ULTRASOUND CT AND MRI Gayer, G., Hertz, M., Zissin, R. 2004; 25 (3): 277-285


    Ureteral injury is a rare, yet very serious, complication of various abdominal, pelvic, and even spinal procedures. It is often clinically unsuspected as symptoms are nonspecific and the patient may present weeks and even months after the injury. Therefore the diagnosis of ureteral injury is often delayed, leading to more serious morbidity. A ureteral injury may be first diagnosed on CT in a patient evaluated after surgery. A high index of suspicion is essential and a CT study should then include a delayed scan in order to establish the diagnosis of ureteral injury resulting in a urinoma. This may obviate the need for additional invasive imaging studies or unnecessary exploration.

    View details for DOI 10.1053/j.sult.2004.03.008

    View details for Web of Science ID 000222223600007

    View details for PubMedID 15272551

  • Small bowel obstruction secondary to Crohn disease: CT findings ABDOMINAL IMAGING Zissin, R., Hertz, M., Paran, H., Bernheim, J., Shapiro-Feinberg, M., Gayer, G. 2004; 29 (3): 320-325


    We investigated the computed tomographic (CT) findings in patients with small bowel obstruction (SBO) and Crohn disease (CD). Fourteen patients, seven men and seven women (mean age, 41.3 years), were retrospectively reviewed. All presented with clinical symptoms and signs of SBO. Eleven had a history of CD, whereas three experienced the bowel obstruction as the first manifestation of the disease. On CT, features of complete SBO were seen in nine patients, whereas incomplete obstruction was found in the other five. One patient had CT findings of an adhesive obstruction. The other 13 were diagnosed as having CD-related SBO; a markedly stenotic bowel segment caused the obstruction in one patient, and a thickened-wall small bowel segment with luminal narrowing was evident at the transition zone in the other 12. The mural thickening had a target appearance in seven and homogeneous thickening in the other five. Additional thickened bowel segments were found in five patients and mesenteric involvement was found in 10. Five patients were treated conservatively, and the other nine underwent surgery (one with adhesiolysis only). Resection of the stenotic bowel was performed in six patients and stricturoplasty was done in the other two, with associated intestinal biopsy in one of these two patients. Histopathology revealed findings of active on chronic disease in all. CT is frequently performed for suspected SBO, so radiologists should be aware of the diagnosis of CD, because SBO may be its first manifestation. Alternatively, radiologists can accurately diagnose a CD-related obstruction in a patient with known CD and differentiate it from an obstruction due to adhesions. Patient management in these cases, however, is based most often on the clinical condition.

    View details for DOI 10.1007/s00261-003-0111-1

    View details for Web of Science ID 000221223000005

    View details for PubMedID 15354340

  • Dense ascites: CT manifestations and clinical implications. Emergency radiology Gayer, G., Hertz, M., Manor, H., Strauss, S., Klinowski, E., Zissin, R. 2004; 10 (5): 262-267


    Ascites is a not infrequent finding on CT. Causes of ascites include congestive heart failure, hypoalbuminemia, cirrhosis, inflammation, and neoplasm. In most cases the attenuation of ascites is that of clear fluid, measuring around 0 HU. Rarely, however, a considerably higher density of ascites is seen. This finding may be a challenge for the radiologist, particularly since some of the conditions associated with it are of major clinical importance requiring prompt intervention.

    View details for PubMedID 15290474

  • CT findings in patients with small bowel obstruction due to phytobezoar. Emergency radiology Zissin, R., Osadchy, A., Gutman, V., Rathaus, V., Shapiro-Feinberg, M., Gayer, G. 2004; 10 (4): 197-200


    The role of CT in evaluating patients with small bowel obstruction (SBO) has been extensively described in the current literature. We present the CT findings of SBO due to a phytobezoar, afterwards surgically confirmed, in 5 men and 1 woman (aged 32-89 years) out of 95 patients diagnosed by CT as having SBO in a 44-month period. These six patients underwent abdominal CT prior to operation and the CT findings were retrospectively reviewed. All six patients presented with clinical symptoms and signs of SBO; three of them had undergone gastric surgery 13, 17, and 22 years earlier, respectively. In all six cases, CT showed an ovoid intraluminal mass, 3 x 5 cm in size and of a mottled appearance, at the transition zone between dilated and collapsed small bowel loops. This was in contrast to feces-like material (the "small bowel feces sign"), seen within dilated small bowel loops in nine patients with SBO, and was typically longer. As CT is frequently performed for suspected SBO, an ovoid, short intraluminal mottled mass seen at the site of an obstruction may be regarded as a pathognomonic preoperative sign of an obstructing phytobezoar.

    View details for PubMedID 15290490

  • Computed tomographic features of intraperitoneal fat-containing lesions: pictorial essay CANADIAN ASSOCIATION OF RADIOLOGISTS JOURNAL-JOURNAL DE L ASSOCIATION CANADIENNE DES RADIOLOGISTES Zissin, R., Osadchy, A., Gayer, G., Shapiro-Feinberg, M., Rathaus, V. 2003; 54 (5): 281-288


    Abdominal CT, which is a common imaging modality performed for a variety of clinical indications, provides an important tool in the diagnosis and evaluation of various lesions with fatty components affecting the peritoneal cavity and its contents.

    View details for Web of Science ID 000187206500003

    View details for PubMedID 14689802

  • Vascular lesions of the renal sinus. Emergency radiology Gayer, G., Zissin, R., Rimon, U., Guranda, L., Apter, S., Hertz, M. 2003; 10 (3): 135-141


    The renal sinus contains within it the collecting system of the kidney as well as lymphatics, nerves, and renovascular structures. This area may be affected by a large variety of pathological conditions arising from the various tissues in this site. Vascular lesions of the renal sinus are uncommon and may present clinically with acute symptoms and on imaging as a mass lesion. Awareness of the different vascular lesions affecting this area is essential for establishing the correct diagnosis and for appropriate treatment. The role of computed tomography is emphasized because it is the most commonly used modality to evaluate acute abdominal conditions as well as suspected renal masses, and the diagnosis can usually be made without the need for additional imaging modalities.

    View details for PubMedID 15290501

  • Traumatic rupture of the diaphragm: CT diagnosis ISRAEL MEDICAL ASSOCIATION JOURNAL Ringler, L., Lavy, R., Gayer, G. 2003; 5 (12): 899-900

    View details for Web of Science ID 000187242200019

    View details for PubMedID 14689767

  • CT findings of intussusception in adults SEMINARS IN ULTRASOUND CT AND MRI Gayer, G., Hertz, M., Zissin, R. 2003; 24 (5): 377-386


    Intussusception is rare in adults, in contrast to its frequent occurrence in infants. The clinical presentation is variable, consisting mainly of abdominal pain that may be chronic, intermittent, or acute. The classic triad of nausea and vomiting, bloody diarrhea, and an abdominal mass typically present in children with intussusception does not usually appear in adults. This diagnosis is, therefore, rarely included in the differential diagnosis of adult patients with vague abdominal complaints. However, with increasing use of CT scanning in the evaluation of patients with abdominal pain, the diagnosis of intussusception can be readily suggested by the radiologist because of its virtually pathognomonic appearance on CT.

    View details for DOI 10.1053/S0887-2171(03)00073-8

    View details for Web of Science ID 000186313900006

    View details for PubMedID 14620719

  • Congenital pulmonary venolobar syndrome: Spectrum of helical CT findings with emphasis on computerized reformatting RADIOGRAPHICS Konen, E., Raviv-Zilka, L., Cohen, R. A., Epelman, M., Boger-Megiddo, I., Bar-Ziv, A., Hegesh, J., Ofer, A., Konen, S., Katz, M., Gayer, G., Rozenman, U. 2003; 23 (5): 1175-1184


    The term congenital pulmonary venolobar syndrome refers to a wide spectrum of pulmonary developmental anomalies that may appear singly or in combination. The main components of congenital pulmonary venolobar syndrome are hypogenetic lung (including lobar agenesis, aplasia, or hypoplasia), partial anomalous pulmonary venous return, absence of pulmonary artery, pulmonary sequestration, systemic arterialization of lung, absence of inferior vena cava, and accessory diaphragm. The recent introduction of multisection helical computed tomography (CT), combined with use of advanced postprocessing graphic workstations, allows improved noninvasive delineation of complex congenital anomalies. A single fast (5-15-second) CT scan now enables the radiologist to (a) generate angiogram-like images of the anomalous pulmonary arteries and veins; (b) demonstrate tracheobronchial abnormalities by generating simulated bronchographic or bronchoscopic images; and (c) depict associated parenchymal abnormalities on axial, coronal, or sagittal images, which once represented an important advantage of magnetic resonance imaging over CT. Multisection helical CT is a helpful diagnostic tool in the preoperative evaluation of patients with suspected congenital pulmonary venolobar syndrome.

    View details for Web of Science ID 000185333900010

    View details for PubMedID 12975508

  • IVC anomalies and right renal aplasia detected on CT: a possible link? ABDOMINAL IMAGING Gayer, G., Zissin, R., Strauss, S., Hertz, M. 2003; 28 (3): 395-399


    We report the occurrence of congenital anomalies of the inferior vena cava (IVC) and right renal aplasia in three patients as detected on computed tomography (CT).The medical records and imaging studies of three patients with congenital anomalies of the IVC and right renal aplasia were studied. We also reviewed eight reported cases with such an association.Eleven patients, nine adults and two girls, were included in the series. Indications for imaging included deep vein thrombosis (n = 5), hypertension (n = 2), failure to advance a femoral vein catheter cranially (n = 1), dilated veins along the abdominal wall (n = 1), endstage renal failure (n = 1), and jaundice (n = 1). CT was performed in seven patients, and venography, aortography, and other imaging modalities were performed in four. IVC anomalies included partial or complete absence of the IVC in nine patients and a double vena cava in two. The azygos vein was very prominent in all patients in whom the IVC was absent. The right kidney was absent or very small in all patients.The association between IVC anomalies and absence of the right kidney as detected on CT probably was not incidental. Although most patients had symptoms deriving from the anomalies, these might have been clinically silent. The radiologist should be aware of the possible association between these anomalies, which can be detected on CT.

    View details for DOI 10.1007/s00261-002-0090-7

    View details for Web of Science ID 000182610300016

    View details for PubMedID 12719912

  • Pulmonary embolism-the initial manifestation of renal cell carcinoma in a young woman. Emergency radiology Gayer, G., Mini, S., Olchovsky, D., Leibovitch, I., Apter, S., Weitzen, R., Hertz, M. 2003; 10 (1): 43-45


    We report a case of massive pulmonary embolus demonstrated on CT in a young woman presenting with dyspnea, with no known risk factors for embolism. Abdominal CT on further investigation showed a renal tumor invading the left renal vein and the inferior vena cava as the cause of the pulmonary embolus. In a patient presenting with pulmonary artery embolism without venous thrombosis, the differential diagnosis should include an occult tumor as the cause of the embolus.

    View details for PubMedID 15290530

  • Delayed rupture of abdominal aortic false aneurysm following blunt trauma. Emergency radiology Gayer, G., Bass, A. 2003; 10 (1): 64-66


    Blunt injury of the abdominal aorta resulting in pseudoaneurysm formation is very rare. Such a pseudoaneurysm may rupture at any time, usually with fatal outcome. We report the case of a 32-year-old man with a clinically unsuspected ruptured abdominal aorta pseudoaneurysm, which had probably formed 3 years earlier, and emphasize the CT features.

    View details for PubMedID 15290537

  • Spontaneous rupture of the spleen detected on CT as the initial manifestation of infectious mononucleosis. Emergency radiology Gayer, G., Zandman-Goddard, G., Kosych, E., Apter, S. 2003; 10 (1): 51-52


    Spontaneous splenic rupture after infectious mononucleosis (IM) is a rare, potentially fatal complication of IM, occurring in 0.1-0.5% of patients with proven IM. It usually occurs several weeks after the onset of symptoms, but may, rarely, be the initial manifestation of the disease. The patient is usually examined as an emergency due to severe abdominal pain and a falling hematocrit. The radiologist should be aware of the pathologic conditions involving the spleen which may lead to its spontaneous rupture.

    View details for PubMedID 15290533

  • Granulomatous appendicitis presenting as right lower quadrant pain: CT findings. Abdominal imaging Zissin, R., Gayer, G., Bernheim, J., Kots, E., Shapiro-Feinberg, M., Hertz, M. 2003; 28 (2): 280-283


    We present the computed tomographic (CT) findings of granulomatous appendicitis.Five of 652 (0.9%) patients who had undergone appendectomy for clinically suspected acute appendicitis over a 19-month period proved to have granulomatous appendicitis. One patient had surgery based on a clinical diagnosis of acute appendicitis. Four patients (three men and one woman; age range = 14-39 years) underwent abdominal CT. The CT findings were retrospectively reviewed with special attention to the appendiceal abnormalities.All four patients presented with subacute clinical presentation. Enlarged appendices of 4.5 and 2 cm in diameter with thickened walls of soft tissue density were found in two patients, and periappendicular inflammatory masses were found in the other two. Enlarged mesenteric lymph nodes and right lower quadrant fat stranding was seen in all four patients. Histopathology showed numerous granulomas within the inflamed appendix.Radiologists should be familiar with the rare entity of granulomatous appendicitis in patients examined by CT for suspected acute appendicitis. An insidious clinical presentation with CT findings of an exceptionally large appendix and associated periappendiceal inflammatory changes should raise the possibility of granulomatous appendicitis or carcinoma or lymphoma of the appendix.

    View details for PubMedID 12592479

  • Congenital anomalies of the inferior vena cava revealed on CT in patients with deep vein thrombosis AMERICAN JOURNAL OF ROENTGENOLOGY Gayer, G., Luboshitz, J., Hertz, M., Zissin, R., Thaler, M., Lubetsky, A., Bass, A., Korat, A., Apter, S. 2003; 180 (3): 729-732


    We describe a possible relationship between inferior vena cava anomalies and extensive thrombosis of the inferior vena cava and the iliac and femoral veins.An anomaly of the inferior vena cava should be considered in young patients who present with deep vein thrombosis of the femoral and iliac veins. Coagulation abnormalities, frequently found in these patients, may be a contributory factor.

    View details for Web of Science ID 000181153400027

    View details for PubMedID 12591684

  • CT of a thickened-wall gall bladder BRITISH JOURNAL OF RADIOLOGY Zissin, R., Osadchy, A., Shapiro-Feinberg, M., Gayer, G. 2003; 76 (902): 137-143


    This pictorial article reviews the various clinical entities that may cause mural thickening of the gall bladder encountered on contrast enhanced CT.

    View details for DOI 10.1259/bjr/63382740

    View details for Web of Science ID 000181843100011

    View details for PubMedID 12642285

  • CT findings in patients with familial Mediterranean fever during an acute abdominal attack BRITISH JOURNAL OF RADIOLOGY Zissin, R., Rathaus, V., Gayer, G., Shapiro-Feinberg, M., Hertz, M. 2003; 76 (901): 22-25


    The aim of this study is to present the abdominal CT findings of patients with familial Mediterranean fever (FMF) examined during an acute abdominal attack. CT scans of 17 patients (10 women and 7 men; age range 11-45 years) were retrospectively reviewed. Attention was directed to mesenteric or peritoneal abnormalities and to the presence of appendiceal pathology. Patients were divided into two groups; group A (n=14) consisted of patients with an acute abdominal attack caused by FMF, and group B (n=3) consisted of patients whose attack proved to be owing to a separate pathology requiring surgery. Characteristic CT findings of acute abdomen in FMF included mesenteric pathology (n=12), mainly of engorged vessels with thickened mesenteric folds, mesenteric lymphadenopathy (n=6) and ascites (n=6). Signs of focal peritonitis were found in four patients. Radiologists should be familiar with such CT findings of peritoneal irritation in patients with FMF during an acute attack, and may suggest this clinical diagnosis in the proper clinical setting in a patient who has not been previously diagnosed. Alternatively, the radiologist should be aware of the possibility of a concurrent acute appendicitis or other acute abdominal pathology in patients with known FMF and should search for it.

    View details for DOI 10.1259/bjr/3205183

    View details for Web of Science ID 000181353800004

    View details for PubMedID 12595321

  • Perirectal urinoma from ureteral injury incurred during spinal surgery mimicking rectal perforation on computed tomography scan. Spine Gayer, G., Caspi, I., Garniek, A., Hertz, M., Apter, S. 2002; 27 (20): E451-3


    A case of a perirectal urinoma from a ureteral injury incurred during spinal surgery is reported.To report ureteral injury as a rare complication of spinal surgery with misleading CT findings, and to emphasize the necessity of delayed scans in the diagnosis.A ureteral injury is a rare complication of spinal surgery. In such a case, extravasated urine collects in the retroperitoneum and pelvis. This fluid opacifies after intravenous contrast, and delayed scans are necessary in the diagnosis. As clinical findings are usually nonspecific, CT is essential for the correct diagnosis.A 55-year-old woman underwent discectomy and insertion of a disc prosthesis through an anterior left retroperitoneal approach. Fever and abdominal pain developed after 3 days. Computed tomography scan was performed to evaluate the patient's symptoms.Computed tomography with repeated delayed scans showed an opacifying fluid collection surrounding the rectum, remote from the site of surgery, yet compatible with a urinoma. Antegrade pyelography demonstrated an injury of the left ureter with extravasating urine, dissecting caudally. After a temporary nephrostomy, the patient recovered.Although ureteral injury after abdominal surgery is not so uncommon, it is very rarely incurred during spinal surgery. Because symptoms are usually nonspecific, the radiologist should be aware of this possible complication, and should perform CT with intravenous contrast material and with delayed scans because a rapid-sequence helical CT may not yet show opacification of the fluid present in the abdomen. This is the hallmark of the diagnosis.

    View details for PubMedID 12394917

  • Typhlitis as a rare cause of a psoas abscess ABDOMINAL IMAGING Gayer, G., Apter, S., Zissin, R. 2002; 27 (5): 600-602


    Typhlitis is a life-threatening necrotizing process of the cecum associated with leukemia patients who have undergone chemotherapy. We present a rare complication of typhlitis in a boy with leukemia, in whom a right psoas abscess developed secondary to the inflammatory process of the cecum, with an emphasis on the computed tomographic findings of this severe and potentially life-threatening complication. Typhlitis should be added to conditions of the gastrointestinal tract that cause a psoas abscess such as Crohn's disease, diverticulitis, appendicitis, colorectal carcinoma, and appendiceal tumor.

    View details for DOI 10.1007/s00261-001-0082-z

    View details for Web of Science ID 000177561500021

    View details for PubMedID 12173006

  • CT diagnosis of afferent loop syndrome CLINICAL RADIOLOGY Gayer, G., Barsuk, D., Hertz, M., Apter, S., Zissin, R. 2002; 57 (9): 835-839


    To report the computed tomography (CT) features of afferent loop syndrome which is often clinically unsuspected.The CT studies of five patients with afferent loop syndrome were reviewed. These patients had undergone gastroenterostomy and other surgical procedures, for malignant neoplasms in four and for peptic ulcer in one. Patients presented between 4 months and 15 years (average 5.5 years) after surgery. Symptoms were acute in all patients, the most common symptom being abdominal pain. In addition three of the patients had chronic symptoms including recurrent episodes of abdominal pain, recurrent ascending cholangitis, jaundice and bilious vomiting.The obstructed afferent loop appeared on CT as a fluid-filled tubular mass with an average diameter of 5.3cm. Valvulae conniventes were identified in all, and small intraluminal air bubbles in four. The dilated afferent loop was opacified with oral contrast material in only one patient. The loop was located in the subhepatic area in three patients and crossed the midline between the aorta and the superior mesenteric vessels in the other two. Additional findings included biliary dilatation in all five patients and signs of pancreatitis in one. Treatment was surgical in four patients (delayed for four months in one) and conservative in one.A fluid-filled tubular structure containing small air bubbles in the right upper quadrant or crossing the midline on CT in symptomatic patients after gastroenterostomy is characteristic of a dilated, possibly obstructed, afferent loop. The diagnosis is often not suspected clinically since patients may present many years after the initial surgery. Recognition of the characteristic CT findings will avoid both inappropriate procedures such as aspiration or drainage of an obstructed afferent loop and delay in treatment.

    View details for DOI 10.1053/crad.2002.0972

    View details for Web of Science ID 000178243000010

    View details for PubMedID 12384110

  • Torsion of a wandering spleen ISRAEL MEDICAL ASSOCIATION JOURNAL Gayer, G. 2002; 4 (8): 658-659

    View details for Web of Science ID 000182574500023

    View details for PubMedID 12183881

  • Laparoscopic splenectomy for torsion of wandering spleen associated with celiac axis occlusion. Surgical endoscopy Rosin, D., Bank, I., Gayer, G., Rimon, U., Gur, D., Kuriansky, Y., Morag, B., Pras, M., Ayalon, A. 2002; 16 (7): 1110-?


    Wandering spleen is a spleen lacking its normal ligamentous attachments, and thus subjected to free movement in the abdominal cavity, and even torsion around its pedicle. Surgical treatment includes either fixation (splenopexy) or resection (splenectomy). Both procedures can now be accomplished using the laparoscopic approach.We describe a case of a torsion of a wandering spleen, leading to recurrent episodes of abdominal pain, and eventually to splenic ischemia, necessitating splenectomy. The diagnosis was complicated by associated angiographic findings of celiac axis occlusion, possibly by median arcuate ligament compression. Laparoscopic splenectomy was successful, and led to complete resolution of symptoms.Although a rare condition, wandering spleen can be diagnosed accurately by imaging studies, mainly CT scan and angiography. Nowadays, the laparoscopic approach is preferred and enables the surgeon to perform either splenopexy or splenectomy, depending on the vascular status of the spleen.

    View details for PubMedID 12165835

  • Perforations of the rectosigmoid colon induced by cleansing enema: CT findings in 14 patients ABDOMINAL IMAGING Gayer, G., Zissin, R., Apter, S., Oscadchy, A., Hertz, M. 2002; 27 (4): 453-457


    We report the computed tomographic (CT) features of colorectal perforations caused by cleansing enema.We reviewed the medical records and CT studies of all patients with colorectal perforations caused by a cleansing enema.Fourteen patients (10 men, four women; average age = 80 years) were included in the study. The most common presenting symptoms were severe abdominal pain and fever. CT was performed within 48 h after the event in most patients. Extraluminal air in the perirectal fat was the most frequent finding on CT and was present in all patients. Additional findings were extraperitoneal ( n = 9), intraperitoneal ( n = 3) and /or subcutaneous ( n = 3) air, free fluid ( n = 9), extraluminal feces ( n = 8), and focal bowel wall thickening ( n = 4). No leak of contrast from the rectum was observed in any patient including the one patient in whom contrast was administered rectally. Ten patients were treated by surgery; five recovered and the other five died. The other four patients were treated conservatively and all four died.The diagnosis of colorectal perforation can be made on CT. Because the diagnosis is not always suspected by the clinician, the radiologist may be the first to suggest it. Therefore, the radiologist should be familiar with the CT features of a potentially lethal, rectally induced perforation.

    View details for DOI 10.1007/s00261-001-0104-x

    View details for Web of Science ID 000176363200015

    View details for PubMedID 12066245

  • Calcification in lymphoma occurring before therapy: CT features and clinical correlation AMERICAN JOURNAL OF ROENTGENOLOGY Apter, S., Avigdor, A., Gayer, G., Portnoy, O., Zissin, R., Hertz, M. 2002; 178 (4): 935-938


    Calcification in lymphoma occurring before therapy is rare. We assessed the prevalence, CT features, and clinical significance of calcification in nodes and masses in patients with lymphoma occurring before therapy.CT of the chest, abdomen, and pelvis of 956 newly diagnosed patients with lymphoma was evaluated prospectively for calcifications in enlarged lymph nodes and lymphoma masses. Findings were correlated with histologic type of disease, tissue parameters, and clinical course. Calcifications were further evaluated on follow-up CT.Of 956 patients with lymphoma (704 with non-Hodgkin's lymphoma and 252 with Hodgkin's lymphoma), eight patients (0.84%) showed calcifications in involved sites, seven of whom had non-Hodgkin's lymphoma and one of whom had Hodgkin's lymphoma. Calcifications were present in lymph nodes and masses in the mediastinum in five patients, in the retroperitoneum in two patients, and in the adrenal in one patient. All eight patients had the aggressive type of lymphoma. Four patients later relapsed, one of whom died. A fifth patient died after only minimal response to treatment.Calcification in patients with lymphoma occurring before therapy is rare as opposed to that in lymphoma after therapy. It occurred in our patients more often in the mediastinum, in patients with non-Hodgkin's lymphoma rather than in patients with Hodgkin's lymphoma, and only in patients with the aggressive type of disease.

    View details for Web of Science ID 000174558200027

    View details for PubMedID 11906877

  • Neurofibromatosis diagnosed on CT with MR correlation EUROPEAN JOURNAL OF RADIOLOGY Arazi-Kleinmann, T., Mor, Y., Brand, N., Gayer, G. 2002; 42 (1): 69-73


    We report a young man with asymptomatic neurofibromatosis type-1 initially diagnosed on CT. CT demonstrated the typical lesions of this disorder: extensive cervical, thoracic, abdominal and pelvic masses and spinal alterations. The symmetrical distribution and the location of the lesions as well as their attenuation are characteristic of NF-1 and may be considered diagnostic for this disease.

    View details for Web of Science ID 000175312400011

    View details for PubMedID 12039024

  • Unexpected subdiaphragmatic findings on CT of the chest in septic patients after cardiac surgery CLINICAL RADIOLOGY Apter, S., Amir, G., Taler, M., Gayer, G., Kuriansky, J., Amitai, M., Smolinsky, A. K., Hertz, M. 2002; 57 (4): 287-291


    to draw the attention to upper abdominal abnormalities, which may be revealed incidentally in patients referred for a chest computed tomography (CT) after cardiac surgery.We reviewed prospectively and retrospectively the CT results of all patients referred for a chest CT, with suspected sternal infection or for other reasons, after cardiac surgery, to assess possible upper abdominal disease as visualized on lower cuts of the chest CT with abdominal windows.Out of a total of 205 patients in the study 39 (19%) had unexpected abdominal abnormalities. The organs involved in decreasing order of frequency were the spleen (n = 18), gallbladder (n = 15), pancreas (n = 9), kidneys (n = 6) and bowel (n = 3). Many patients had involvement of more than one organ. The lesions were mainly ischaemic and/or infectious in origin. These findings led to interventional procedures in 13 (33%) of the patients with a good outcome.We found a relatively high prevalence of abdominal abnormalities on CT of the chest in patients referred with suspected thoracic problems after cardiac surgery. Major findings on CT led to changes in the management of these patients. We recommend therefore viewing lung bases with abdominal windows as well as adding sections through the upper abdomen in patients who are referred for a chest CT after cardiac surgery with suspected thoracic problems.

    View details for DOI 10.1053/crad.2001.0798

    View details for Web of Science ID 000175635700009

    View details for PubMedID 12014875

  • Perforated peptic ulcer masquerading as gallbladder disease: CT findings ISRAEL MEDICAL ASSOCIATION JOURNAL Gayer, G. 2002; 4 (4): 304-305

    View details for Web of Science ID 000182574000019

    View details for PubMedID 12001712

  • Granulomatous appendicitis presenting as right lower quadrant pain: CT findings ABDOMINAL IMAGING Zissin, R., Gayer, G., Bernheim, J., Kots, E., Shapiro-Feinberg, M., Hertz, M. 2002; 28 (2): 280-283
  • Pictorial review: adult intussusception--a CT diagnosis. British journal of radiology Gayer, G., Zissin, R., Apter, S., Papa, M., Hertz, M. 2002; 75 (890): 185-190


    Intussusception, usually thought of as a childhood condition, may be encountered in adults as well, and is then more often associated with underlying pathology. While the condition is mostly unsuspected clinically, as patients present with non-specific abdominal pain that is often of long duration, CT findings are characteristic. Examples are shown of intussusception both in the small bowel and colon. Awareness of these findings allows the radiologist to make the correct diagnosis.

    View details for PubMedID 11893645

  • Typhlitis: A computed tomography diagnosis ISRAEL MEDICAL ASSOCIATION JOURNAL Gayer, G., Zissin, R. 2002; 4 (2): 146-147

    View details for Web of Science ID 000182573800018

    View details for PubMedID 11875993

  • CT of duodenal pathology BRITISH JOURNAL OF RADIOLOGY Zissin, R., Osadchy, A., Gayer, G., Shapiro-Feinberg, M. 2002; 75 (889): 78-84


    This pictorial review presents the CT findings in different pathological entities of the duodenum. The aim of the article is to demonstrate the contribution of a common imaging modality, i.e. abdominal CT, in the diagnosis of various duodenal disorders.

    View details for Web of Science ID 000173746400015

  • Urinomas caused by ureteral injuries: CT appearance ABDOMINAL IMAGING Gayer, G., Zissin, R., Apter, S., Garniek, A., Ramon, J., Kots, E., Hertz, M. 2002; 27 (1): 88-92


    We report the computed tomographic (CT) features of urinomas caused by ureteral injuries which are often not clinically suspected, causing delay in diagnosis.CT studies of 12 patients with ureteral injury were reviewed. Ureteral injuries were iatrogenic in 9 patients and traumatic in the remaining three. CT was performed between 2 and 139 days (average = 33 days) after the insult. The most common presenting symptoms were severe abdominal pain and fever. All CT studies were performed before and after intravenous contrast administration. In 11 of 12 cases, delayed scanning was added 15 min to 5 h later.The sites of injury were the proximal ureter in two patients, the middle ureter in three, the distal ureter in two, and the ureteral anastomosis in five. The urinomas appeared as confined water-density fluid collections in seven patients, as free fluid (urinary ascites) in two, and as both in three. Extravasation of contrast from the ureter was observed on early scans in six patients and on delayed scanning only in the other six. The density of the opacified urinoma measured 80-200 HU. Ipsilateral hydronephrosis was observed in seven patients. Ureteral injuries were treated conservatively in eight patients and surgically in four.Ureteral injuries after iatrogenic or penetrating trauma often are diagnosed with considerable delay. The presence of ascites or localized fluid collections in symptomatic patients after abdominal surgery or penetrating trauma should raise the possibility of a ureteral injury and prompt delayed scanning.

    View details for Web of Science ID 000172942300019

    View details for PubMedID 11740616

  • Abdominal computerized tomography in the diagnosis of Meckel's diverticulitis in the adult. Israel Medical Association journal Portnoy, O., Gayer, G., Onaca, N., Heldenberg, E., Apter, S. 2001; 3 (12): 982-983

    View details for PubMedID 11794933

  • Intussusception - Not only a childhood disease ISRAEL MEDICAL ASSOCIATION JOURNAL Gayer, G. 2001; 3 (12): 962-962

    View details for Web of Science ID 000173516300022

    View details for PubMedID 11794926

  • Iliopsoas abscess: a report of 24 patients diagnosed by CT ABDOMINAL IMAGING Zissin, R., Gayer, G., Kots, E., Werner, M., Shapiro-Feinberg, M., Hertz, M. 2001; 26 (5): 533-539


    We wanted to define the role of computed tomography (CT) in the diagnosis, etiology, and treatment of iliopsoas abscess.Twenty-four patients (18 men, six women; age range = 17-86 years) with iliopsoas abscesses diagnosed over 8 years were retrospectively reviewed. All presented with fever and elevated white blood cell counts. Twenty-one had abdominal, flank or pelvic pain and nine had specific psoas signs suggesting the diagnosis.Seventeen of the abscesses were right-sided. Twenty were regarded as secondary to various underlying causes that were clearly demonstrated on CT and related to gastrointestinal (n = 12), skeletal (n = 5), or urinary tract (n = 3) diseases. All patients received appropriate antibiotic treatment. Thirteen also had their abscesses drained and eight had definitive surgical procedures.CT is an effective imaging technique for diagnosing iliopsoas abscess, even when classic clinical signs are absent. Treatment by percutaneous drainage under CT guidance is another advantage. When a psoas abscess is a complication of Crohn's disease, resection of the affected bowel segment is recommended in addition to drainage because drainage alone even in conjunction with appropriate medical therapy is usually not effective.

    View details for Web of Science ID 000170691900017

    View details for PubMedID 11503095

  • CT findings in congenital anomalies of the spleen BRITISH JOURNAL OF RADIOLOGY Gayer, G., Zissin, R., Apter, S., Atar, E., Portnoy, O., Itzchak, Y. 2001; 74 (884): 767-772


    There is a wide range of congenital anomalies of the spleen. Some are common, such as splenic lobulation and accessory spleen. Other less common conditions, such as wandering spleen and polysplenia, have particular clinical significance. Radiologists need to be aware of the various congenital variants of the spleen in order to recognize clinically important anomalies and to avoid mistaking less significant ones for an abnormality. In this pictorial review, the embryology of congenital anomalies of the spleen as well as their appearance on CT are described, diagnostic pitfalls are identified and complications of the anomalies are discussed.

    View details for Web of Science ID 000170612400018

    View details for PubMedID 11511506

  • Ovarian vein thrombosis - Computerized tomography diagnosis ISRAEL MEDICAL ASSOCIATION JOURNAL Gayer, G. 2001; 3 (8): 627-628

    View details for Web of Science ID 000171334800020

    View details for PubMedID 11519396

  • Widespread abdominal venous thrombosis in paroxysmal nocturnal hemoglobinuria diagnosed on CT ABDOMINAL IMAGING Gayer, G., Zandman-Goddard, G., Raanani, P., Hertz, M., Apter, S. 2001; 26 (4): 414-419


    Paroxysmal nocturnal hemoglobinuria is a rare disorder characterized by pancytopenia. One of the main manifestations of this disease is development of widespread life-threatening venous thrombosis, which may involve multiple abdominal veins. We describe two patients with paroxysmal nocturnal hemoglobinuria with clinically unsuspected portal, splenic, and mesenteric venous thromboses that were diagnosed on computed tomography. This complication should be clinically suspected in patients suffering from paroxysmal nocturnal hemoglobinuria who present with abdominal pain, and it should be sought by the radiologist on pre- and postcontrast computed tomography.

    View details for Web of Science ID 000169338200011

    View details for PubMedID 11441556

  • Computerized tomography findings of abdominal tuberculosis: Report of 19 cases ISRAEL MEDICAL ASSOCIATION JOURNAL Zissin, R., Gayer, G., Chowers, M., Shapiro-Feinberg, M., Kots, E., Hertz, M. 2001; 3 (6): 414-418


    Abdominal tuberculosis usually presents with general symptoms and obscure abdominal complaints for which computerized tomography is often the first imaging study.To evaluate the CT findings of abdominal tuberculosis.The CT scans of 19 patients (10 men and 9 women aged 20-85 years) with proven abdominal tuberculosis were retrospectively reviewed to define the location and extent of the disease. The patients were referred for the study mainly with general systemic symptoms. Additional abdominal complaints were present in four, including acute abdomen in one. Two had symptoms deriving from the urinary tract. Nine patients had recently arrived from high prevalence countries; five of them and two others were positive for human immunodeficiency virus. Three patients had a family history of tuberculosis; one had previously been treated for tuberculosis and four others had an underlying chronic disease. The diagnosis of tuberculosis was established by standard microbiological and histological techniques.We divided the disease manifestations into intraperitoneal (n = 13) and genitourinary involvement (n = 6). Peritoneal tuberculosis was fairly common, characterized by ascites, omental and mesenteric infiltration, and smooth thickening of the parietal peritoneum. One oncology patient had a false positive Tc-99m CEA isotope scanning, suggesting tumor recurrence. Genitourinary disease manifested mainly as hydronephrosis and calcifications. Three patients had pulmonary tuberculosis as well.The CT findings of abdominal tuberculosis may mimic various diseases, mainly diffuse peritoneal malignancy. We emphasize the need to consider tuberculosis in the differential diagnosis in patients with obscure abdominal symptoms, especially with multi-organ involvement. A high degree of clinical suspicion and familiarity with the abdominal CT manifestations allow early diagnosis of this treatable disease.

    View details for Web of Science ID 000172750000005

    View details for PubMedID 11433633

  • Appendicitis in an elderly woman: CT diagnosis ISRAEL MEDICAL ASSOCIATION JOURNAL Gayer, G. 2001; 3 (5): 386-387

    View details for Web of Science ID 000172749700017

    View details for PubMedID 11411210

  • Abdominal CT findings in nephropathic amyloidosis of familial Mediterranean fever AMYLOID-JOURNAL OF PROTEIN FOLDING DISORDERS Apter, S., Zemer, D., Terhakopian, A., Gayer, G., Langevitz, P., Amitai, M., Schwartz, T., Atar, E., Hertz, M., Pras, M., Livneh, A. 2001; 8 (1): 58-64


    To evaluate the abdominal CT features of reactive amyloidosis, abdominal CT scans of 20 patients with amyloidosis of familial Mediterranean fever (FMF) were reviewed and compared with abdominal CT scans of 2 control groups: 22 patients with chronic renal failure (CRF) due to non-amyloidotic kidney diseases and 40 patients with normal kidney function. The kidney size of patients with amyloidosis of FMF were found to vary during the course of the disease from normal or slightly larger than normal at the proteinuric phase, to smaller than normal and comparable to kidney size in CRF, at the uremic stage. Compared to kidney disease of other causes, more patients with FMF-amyloidosis had dense kidneys with coarse parenchymal calcification and calcification in other abdominal organs. Patients with FMF-amyloidosis had fewer aortic calcifications than patients with non-amyloidotic kidney disease. These findings suggest that kidney disease of reactive amyloidosis may have abdominal CT findings distinguishing it from other types of kidney diseases.

    View details for Web of Science ID 000169107300007

    View details for PubMedID 11293826

  • Renal duplication with associated complications in adults: CT findings in 26 cases CLINICAL RADIOLOGY Zissin, R., Apter, S., Yaffe, D., Kots, E., Gayer, G., Nissenkorn, I., Hertz, M. 2001; 56 (1): 58-63


    To review the computed tomography (CT) findings in 26 adult patients with complicated renal duplication, and to assess whether the complications were anomaly-related or superimposed by acquired disease.Fifteen women and 11 men, aged 17-83 years took part in the study. All CT studies were reviewed to define the moieties affected.The duplication was unilateral in 18 cases and bilateral in six, one patient had a single left kidney and the remaining one a horseshoe kidney. In 14 patients the pathology was related only to the anomaly. Upper pole abnormalities were seen in 13 patients (seven related to the anomaly) and lower pole abnormalities in five (all related to duplication). Both systems were affected in eight cases, six of them by pathological processes unrelated to duplication. Hydronephrosis of the affected collecting system was the most common imaging finding.Computed tomography is often used to evaluate abdominal conditions in adults and may therefore be the first imaging modality to reveal a duplex kidney complicated by a pathological process. Involvement of only one moiety was frequently related to the duplication, with a predilection for the upper moiety, while involvement of both systems was used unrelated to the duplication. Zissin, R. (2001). Clinical Radiology, 56, 58-63.

    View details for Web of Science ID 000166454900011

    View details for PubMedID 11162699

  • CT findings in tell patients with failed renal allografts: comparison with findings in functional grafts EUROPEAN JOURNAL OF RADIOLOGY Gayer, G., Apter, S., Katz, R., Ben-David, A., Katzir, Z., Hertz, M. 2000; 36 (3): 133-138


    Our aim is to report the computed tomography (CT) features of the long-term failed renal allograft. Ten patients with failed renal transplants in whom the graft was left in situ underwent CT for various unrelated indications. The majority of the failed grafts showed marked shrinkage and coarse punctate diffuse parenchymal calcifications. Small cysts were seen in four grafts. A long-term failed renal transplant appeared on CT as a small rounded soft tissue mass. The graft was almost always heavily calcified. Lack of awareness of the nature of such a mass may mislead the radiologist in interpreting it as a space-occupying lesion.

    View details for Web of Science ID 000165851900004

    View details for PubMedID 11091012

  • Paraffin oil bezoar impacted in the small bowel: CT findings BRITISH JOURNAL OF RADIOLOGY Gayer, G., Gotlieb, W. H., Apter, S. 2000; 73 (875): 1213-1214


    A case of a paraffin oil bezoar impacted in the small bowel, resulting from the prolonged use of paraffin oil as treatment for increasing constipation in a patient with metastatic ovarian carcinoma, is described. Although pharmacobezoars are reported in the literature, we could not find a description of the CT findings of a paraffin oil bezoar.

    View details for Web of Science ID 000165710800013

    View details for PubMedID 11144801

  • CT diagnosis of malpositioned chest tubes BRITISH JOURNAL OF RADIOLOGY Gayer, G., Rozenman, J., Hoffmann, C., Apter, S., Simansky, D. A., Yellin, A., Itzchak, Y. 2000; 73 (871): 786-790


    Insertion of a chest tube into the pleural space is standard management for various pleural disorders. Malpositioning of chest tubes in extrathoracic, intraparenchymal and mediastinal locations and in the fissures is common. Malpositioning results not only in inadequate drainage of air and fluid but may also result in increased morbidity and mortality. Diagnosis of a malpositioned tube is sometimes difficult to establish on a chest radiograph. CT, however, has proven to be extremely accurate in evaluating the position of a chest tube and has often provided additional valuable information with significant therapeutic impact.

    View details for Web of Science ID 000088323400017

    View details for PubMedID 11089474

  • Complications after laparoscopic gynecologic procedures: CT findings ABDOMINAL IMAGING Gayer, G., Apter, S., Garniek, A., Portnoy, O., Schiff, E. 2000; 25 (4): 435-439


    Laparoscopic gynecologic surgery has gained worldwide popularity in the past few years, but complications of this new technique do occur. We encountered three patients who developed major complications after laparoscopic gynecologic procedures including perforation of the sigmoid colon, urinary bladder, and ureter. We report the computed tomographic findings of these cases and the diagnostic dilemmas they posed.

    View details for Web of Science ID 000087871300017

    View details for PubMedID 10926200

  • Postoperative pneumoperitoneum as detected by CT: prevalence, duration, and relevant factors affecting its possible significance ABDOMINAL IMAGING Gayer, G., Jonas, T., Apter, S., Amitai, M., Shabtai, M., Hertz, M. 2000; 25 (3): 301-305


    To determine the prevalence and duration of postoperative pneumoperitoneum as detected on computed tomography (CT) and to evaluate factors that influence postoperative pneumoperitoneum.One hundred three CT examinations of 89 patients performed after abdominal surgery for various indications were prospectively collected and reviewed. The presence and volume of free air were noted and correlated with patients' sex, age, and habitus, with the time interval between surgery and CT, with the type of surgery, and with the presence of drains.Pneumoperitoneum was seen in 44% of examinations performed in the first 3 days after surgery and in 30% between the 4th and 18th postoperative days. The prevalence and volume of free air decreased with the time interval between surgery and CT. It was not detected in any of the 11 examinations performed beyond the 18th postoperative day. The volume of free air in the majority of examinations did not exceed 10 mL and ranged from 0.2 to 10 mL in 19 patients (66% of patients with free air). Larger volumes of free air, ranging from 10 to 20 mL and from 20 to 40 mL, were observed in 5 (17%) and 4 (14%) patients, respectively, and only one patient had more than 40 mL of free air. Free air was found significantly more often in male and in asthenic patients; age had no significant effect. Free air was more prevalent in the presence of drains. The type of surgery did not significantly influence the prevalence of postoperative pneumoperitoneum, although it was noted slightly less often after laparoscopic surgery than after open laparotomy.Pneumoperitoneum is a common phenomenon after abdominal surgery, decreasing in frequency with time. The air is most often residual and not a sign of disruption of the gastrointestinal tract. Obesity, female sex, and occurrence of free air several weeks after surgery are factors suggestive of a leak, but the significance of a postoperative pneumoperitoneum on CT should be determined mainly by the clinical setting.

    View details for Web of Science ID 000086812700020

    View details for PubMedID 10823456

  • Synchronous mucinous tumors of the ovary and the appendix associated with pseudomyxoma peritonei: CT findings ABDOMINAL IMAGING Zissin, R., Gayer, G., Fishman, A., Edelstein, E., Shapiro-Feinberg, M. 2000; 25 (3): 311-316


    To present the computed tomographic (CT) findings of synchronous mucinous tumors of the ovary and the appendix associated with pseudomyxoma peritonei (PMP).Imaging studies, mainly abdominal CT scans, of three women aged 49-75 years were reviewed. Attention was directed to the ovarian masses, peritoneal seeding, and the presence of an appendiceal mucocele.The ovarian tumors and the appendiceal mucocele were clearly demonstrated in two cases, and they were part of the extensive PMP in the third patient. Ascites was found in all cases, with internal septation in one. Associated scalloping of the liver margins and hypodense peritoneal implants, with extensive bowel involvement, were seen in another one. Pathologically, there was one case of right ovarian mucinous cystadenoma and villous adenoma of the appendix, one case of right ovarian and appendiceal mucinous cystadenocarcinoma, and one case of bilateral metastatic ovarian implants of appendiceal mucinous cystadenocarcinoma. PMP was found in all. In the case with benign tumors of the ovary and the appendix, the PMP was classified as a benign mucinous spillage. This patient returned 33 months after surgery with PMP, in which epithelial cells were found.Radiologists should be familiar with the clinical occurrence of synchronous mucinous tumors of the ovary and the appendix associated with PMP and with the typical CT findings of the latter two entities. Alternatively, when the imaging findings suggest ovarian cystic tumor with PMP, the radiologist should be alerted to the probability of a clinically unsuspected appendiceal mucocele and should search for it.

    View details for Web of Science ID 000086812700022

    View details for PubMedID 10823458

  • Transient colocolic intussusception CLINICAL IMAGING Zissin, R., Gayer, G., Konen, O., Shapiro-Feinberg, M. 2000; 24 (1): 8-9


    We present the CT findings of a transient colocolic intussusception, related to an underlying colonic tumor, but remote from it. The resolving nature of intussusception was clearly demonstrated on delayed images and may explain the characteristic chronic clinical symptoms of intussusception in adult.

    View details for Web of Science ID 000165884000002

    View details for PubMedID 11120410

  • Imaging of mucocoele of the appendix with emphasis on the CT findings: A report of 10 cases CLINICAL RADIOLOGY Zissin, R., Gayer, G., Kots, E., Apter, S., Peri, M., Shapiro-Feinberg, M. 1999; 54 (12): 826-832


    Mucocoele of the appendix denotes an obstructive dilatation of the appendiceal lumen due to abnormal accumulation of mucus. It is sometimes associated with pseudomyxoma peritonei, which predicts a malignant origin. We present the CT findings and additional imaging studies of 10 patients with neoplastic appendiceal mucocoele and discuss the clinical implications.Abdominal CT findings from 10 patients with appendiceal mucocoele were reviewed. Barium enema, US and MRI were additionally performed in three patients. There were five men and five women aged 45-80 years. Special attention was directed to the shape and nature of the mass, its relation to the caecum and the presence of ascites or peritoneal implants, as well as possible additional ovarian tumours in female patients.The mucocoele was an incidental finding in five patients. They were either spherical or elongated cystic lesions, attached to the wall of the caecum, six of them with mural calcification. Ascites were present in six patients and hypodense large peritoneal implants representing pseudomyxoma peritonei in four. Pathologically the series included five cases of cystadenoma (in one, a malignant pseudomyxoma peritonei subsequently developed), four cases of cystadenocarcinoma and one villous adenoma (this patient later developed pseudomyxoma peritonei). Pseudomyxoma peritonei was found in five cases. Three women had associated ovarian cystic tumour.The appearance of an appendiceal mucocoele is quite characteristic and can be diagnosed on CT. CT can also depict additional findings suggesting pseudomyxoma peritonei. In women with an appendiceal mucocoele the ovaries should be examined closely for cystic tumour and vice versa.

    View details for Web of Science ID 000084680300009

    View details for PubMedID 10619300

  • Intestinal malrotation as an incidental finding on CT in adults ABDOMINAL IMAGING Zissin, R., Rathaus, V., Oscadchy, A., Kots, E., Gayer, G., Shapiro-Feinberg, M. 1999; 24 (6): 550-555


    Intestinal malrotation in adults is usually an incidental finding on computed tomography (CT). We present the CT findings of 18 adult patients with malrotation and discuss the clinical implications.Abdominal scans of 18 patients (12 women, six men; age range = 15-79 years) with intestinal malrotation were reviewed. Special attention was directed to the location of the superior mesenteric vessels, the location of the small and large bowels, the size of the uncinate process, the situs definition, and additional anomalies.The malrotation was an incidental finding in all but one patient. The malrotation was type Ia in 17 patients and IIc in the one symptomatic patient. The superior mesenteric vessels were vertically oriented in 10, inverted in two, normally positioned in four, and mirror imaged in two cases with situs ambiguus. All patients had aplasia of the pancreatic uncinate process, five had a short pancreas, and two had a preduodenal portal vein. Fourteen patients had a normal situs and four had heterotaxia. Seven patients had polysplenia, six of which with associated inferior vena cava anomalies.Intestinal malrotation can be diagnosed on CT by the anatomic location of a right-sided small bowel, left-sided colon, an abnormal relationship of the superior mesenteric vessels, and aplasia of the uncinate process. Awareness of these abnormalities is necessary to diagnose this anomaly. It should be sought in patients with a situs problem, inferior vena cava anomalies, polysplenia, or preduodenal portal vein. Although usually an incidental finding, it is important to diagnose such a malrotation because it may cause abdominal symptoms. Also, knowledge of associated vascular anomalies is important when abdominal surgery is planned.

    View details for Web of Science ID 000083351100004

    View details for PubMedID 10525804

  • Acute diverticulitis of the small bowel: CT findings ABDOMINAL IMAGING Gayer, G., Zissin, R., Apter, S., Shemesh, E., Heldenberg, E. 1999; 24 (5): 452-455


    We present the computed tomographic (CT) findings in two cases of small bowel diverticulitis, one affecting the jejunum and the other a Meckel's diverticulum. The main CT finding was that of a mass with an air-fluid collection in contiguity with small bowel loops.

    View details for Web of Science ID 000082193900005

    View details for PubMedID 10475926

  • Bezoars in the stomach and small bowel - CT appearance CLINICAL RADIOLOGY Gayer, G., Jonas, T., Apter, S., Zissin, R., Katz, M., Katz, R., Amitai, M., Hertz, M. 1999; 54 (4): 228-232


    The aim of this study was to present the computed tomography (CT) appearance of trichobezoars, phytobezoars and other unusual ingested material.Seven patients diagnosed on CT with bezoars in the stomach or small intestine were reviewed with special attention on the characteristics of the intraluminal mass and the presence of proximal dilatation.There were six women and one man aged 14-81 years. CT was performed because of abdominal pain and a palpable abdominal mass. In none of the cases was the diagnosis suspected clinically. Four patients had a trichobezoar occupying the entire lumen of the stomach. It appeared as a concentric inhomogeneous mass with entrapped air, surrounded by contrast material. In the other three patients the bezoar was confined to the small intestine and was composed respectively of vegetable fibres, ingested toilet paper and an olive stone. The first two had a mottled appearance whereas the last one was small, spherical and well defined. Variable proximal dilatation of the small bowel was present in all three.With the increased use of CT in the evaluation of patients with non-specific abdominal pain, it is important to recognize the CT appearance of bezoars, as this diagnosis is often not suspected clinically.

    View details for Web of Science ID 000079646500007

    View details for PubMedID 10210341

  • Polysplenia syndrome detected in adulthood: report of eight cases and review of the literature ABDOMINAL IMAGING Gayer, G., Apter, S., Jonas, T., Amitai, M., Zissin, R., Sella, T., Weiss, P., Hertz, M. 1999; 24 (2): 178-184


    To present the computed tomographic (CT) features of the abdominal anomalies consistent with polysplenia syndrome in adults. Awareness of these abnormalities may avoid misdiagnosing characteristic findings as separate pathological processes.Imaging studies, mainly abdominal CT scans, of eight patients were reviewed. Attention was directed to the location of the multiple spleens, stomach, and liver and to the possible presence of a short pancreas, malrotation of the intestine, and venous anomalies. We also reviewed the CT findings of 15 adult patients described in the literature.Three men and five women underwent CT for various unrelated conditions. The most common findings were multiple spleens along the greater curvature of the stomach, which were located in the right upper quadrant in six patients. The inferior vena cava was seen on the left side in seven subjects, with azygos/hemiazygos continuation in six. A preduodenal portal vein was present in seven subjects. The liver was in the midline in four patients and on the left side in two. A short pancreas was seen in four patients, intestinal nonrotation in five, and dextrocardia in two. The prevalence of these anomalies was similar to that of the reviewed cases.CT proved to be an excellent imaging modality in the diagnosis of the abdominal anomalies. Some of these (a short pancreas, multiple spleens, and azygos continuation) can simulate pathological processes. Hence the importance of recognizing these CT findings as part of a syndrome.

    View details for Web of Science ID 000078810300017

    View details for PubMedID 10024407

  • CT findings of glutaraldehyde colitis: A report of two cases CLINICAL RADIOLOGY Zissin, R., Gayer, G., Maor-Kendler, Y. 1999; 54 (2): 123-125


    The CT findings of two cases of gluteraldehyde colitis following flexible colonoscopy with normal results are described. Although the CT findings are non-specific, the diagnosis can be suggested by the radiologist who is aware of the previous endoscopy.

    View details for Web of Science ID 000078471600012

    View details for PubMedID 10050742

  • CT diagnosis of delayed presentation of congenital diaphragmatic hernia simulating massive pleuropneumonia EUROPEAN RADIOLOGY Gayer, G., Bilik, R., Vardi, A. 1999; 9 (8): 1672-1674


    A case of an 11-month-old infant with a delayed presentation of congenital diaphragmatic hernia is reported. Incarceration of the herniated colon caused a misleading appearance on the chest X-ray which was interpreted as massive pleuropneumonia. Computed tomography, performed because of continuing deterioration in the clinical condition, showed fluid-filled bowel loops in the chest and dilated bowel loops with air-fluid levels in the abdomen, suggesting the correct diagnosis.

    View details for Web of Science ID 000082906800035

    View details for PubMedID 10525888

  • CT angiography of superior mesenteric artery syndrome AMERICAN JOURNAL OF ROENTGENOLOGY Konen, E., Amitai, M., Apter, S., Garniek, A., Gayer, G., Nass, S., Itzchak, Y. 1998; 171 (5): 1279-1281


    Our purpose was to describe the use of CT angiography and three-dimensional (3D) reconstruction in the diagnosis of superior mesenteric artery syndrome in three patients.CT angiography combined with 3D reconstructions is a noninvasive technique that may have a complementary diagnostic role similar to that of angiography in patients with a classic clinical presentation suggestive of superior mesenteric artery syndrome. CT angiography combined with 3D reconstructions should be considered in patients who might otherwise require angiography.

    View details for Web of Science ID 000076580400020

    View details for PubMedID 9798861

  • Virtual CT angioscopy of pulmonary arteries in a patient with multiple pulmonary emboli AMERICAN JOURNAL OF ROENTGENOLOGY Konen, E., Rozenman, J., Amitai, M., Gayer, G., Garniek, A. 1998; 171 (2): 399-400

    View details for Web of Science ID 000074990700025

    View details for PubMedID 9694462

  • Urinary excretion of orally ingested gastrografin on CT ABDOMINAL IMAGING Apter, S., Gayer, G., Amitai, M., Hertz, M. 1998; 23 (3): 297-300


    Renal excretion of orally ingested gastrografin has rarely been reported on computed tomography (CT). We studied the unenhanced scans of 82 patients with bowel disorders or perforation to assess the prevalence of urinary contrast material (CM) in various bowel diseases. We also assessed the clinical significance of this sign. In addition, we reviewed the unenhanced CT scans of 100 randomly selected patients without bowel diseases as a control group. Twenty-nine of the 58 patients with bowel diseases, six of nine with free perforation, and one of 15 with covered perforation had CM in the urinary tract. None of the 100 without bowel disease showed urinary CM. Statistical analysis was done by using the Fisher's exact test. The prevalence of urinary CM was highest in inflammatory bowel disease, radiation enteritis, and free perforation (p < 0. 0001). This study shows that the CT finding of orally ingested gastrografin in the urinary tract differentiates patients with bowel disease from those without.

    View details for Web of Science ID 000073386500013

    View details for PubMedID 9569301

  • Pyelocalyceal diverticula containing milk of calcium - CT diagnosis CLINICAL RADIOLOGY Gayer, G., Apter, S., Heyman, Z., Morag, B. 1998; 53 (5): 369-371


    To present the computed tomography (CT) findings of pyelocalyceal diverticula containing milk of calcium in seven patients.Three patients were examined because of flank pain, one because a malignant lesion was suspected and the three others were examined for unrelated symptoms. Three repeated scans to the kidney area were performed in every patient: an unenhanced scan, post-contrast scan and a delayed scan.Unenhanced scans demonstrated an intraparenchymal round lesion with calcific material localized either at the inferior border or filling almost the entire cavity. On post-contrast scans a contrast-fluid level appeared, with some enhancement of the clear fluid in the upper part of the cyst. A further rise in the contrast-fluid level or total opacification with a density identical to that of the collecting system was obtained on delayed scans.Pyelocalyceal diverticula containing milk of calcium present on CT as a partially calcified renal mass. Slight opacification soon after injection may be mistaken for enhancement arousing suspicion of a tumour. However, a delayed scan will demonstrate a densely opacified cyst filled with contrast from the collecting system which is virtually pathognomonic of the lesion.

    View details for Web of Science ID 000073763200011

    View details for PubMedID 9630277

  • Reconstruction of the sternum and chest wall with methyl methacrylate: CT and MRI appearance EUROPEAN RADIOLOGY Gayer, G., Yellin, A., Apter, S., Rozenman, Y. 1998; 8 (2): 239-243


    The aim of our study was to define the appearance of methyl methacrylate grafts replacing resected sternum and ribs on CT and MRI and how the sternal graft may mimic an abnormally sclerotic sternum on CT images. We reviewed the CT scans of nine patients who had undergone chest wall resection (eight with malignant and one with benign disease) and reconstruction with a composite of methyl methacrylate and Marlex mesh graft. One of them had an MRI study as well. The size, shape and CT attenuation were assessed on mediastinal and bone window settings. The sternal graft was seen on mediastinal and even better on bone windows as an abnormally wide, irregularly shaped structure, somewhat denser than the normal sternum. The chest wall prosthesis replacing resected ribs was seen as a continuous dense structure and of similar attenuation as that of the sternal graft. On MRI the prosthesis appeared as a well-defined structure with no signal. Reconstruction of the chest wall with methyl methacrylate appears on CT as a diffusely dense sclerotic bone lesion not unlike a malignant lesion. The possibility of a graft has to be included in the differential diagnosis in these cases.

    View details for Web of Science ID 000072432900012

    View details for PubMedID 9477274

  • Intussusception in adults: CT diagnosis CLINICAL RADIOLOGY Gayer, G., Apter, S., Hofmann, C., Nass, S., Amitai, M., Zissin, R., Hertz, M. 1998; 53 (1): 53-57


    Intussusception in adults is nowadays usually diagnosed on computed tomography (CT), as CT is often the first modality for the investigation of prolonged abdominal pain from which these patients suffer. We wish to present the CT, clinical and pathological findings of 16 adult patients with intussusception seen over a 5-year period. MATERIALS andThe abdominal scans of 16 patients with intussusception were reviewed. Special attention was directed to the location of the mass, its shape and fat content, possible underlying pathology and dilatation of the bowel proximally. The findings were correlated with clinical and pathological data.Eight men and eight women, aged 34-81 years, were studied. The most frequent indication for CT was prolonged abdominal pain. CT findings included an inhomogeneous soft tissue mass, target or sausage-shaped, depending on the angle of the CT beam vs. the intussusception, with a fatty component in 14 of the 16. Intussusception was enteroenteric (six), ileocolic (three), or colocolic (seven). Complete small bowel obstruction was present only in one case and some bowel dilatation in three. The underlying pathology could be diagnosed on CT in only two cases of lipoma. Nine patients had an underlying malignant process, eight of them unsuspected. Of the other five, two had coeliac disease, two were classified as idiopathic and one had a necrotic polyp of undetermined pathology.Intussusception on CT presented a characteristic mass lesion containing fat stripes in almost all patients. Obstruction was rarely seen. Malignant lesions were the most common cause and therefore early diagnosis and prompt intervention are essential.

    View details for Web of Science ID 000075812700010

    View details for PubMedID 9464437

  • [Typhlitis]. Harefuah Strugo, R., Gayer, G., Olhovsky, D. 1997; 132 (3): 175-?


    Typhlitis (from Greek, "typhlon", cecum) is an inflammatory process involving the cecum and ascending colon--in neutropenic patients after chemotherapy. Early diagnosis and treatment is of great importance, since the mortality is high. In the past decade there has been an increasing number of reports, as well as impressive improvement in diagnosis, and treatment. We describe 2 patients treated in our department. We emphasize the evolving changes in the management of these patients, from early surgical intervention to conservative treatment, and the problem of prophylactic treatment for those who survive an episode of typhlitis.

    View details for PubMedID 9154722

  • [Computed tomography--new horizons]. Harefuah Apter, S., Konen, E., Gayer, G., Yitzchak, Y. 1995; 128 (7): 449-451

    View details for PubMedID 7750841



    Thirty two children with reflux into the lower pole of duplicated collecting systems, followed non-operatively for one to five years, were compared to a carefully selected control group of similar children who had reflux into a single collecting system. There were no significant differences between the two groups, either in the outcome of reflux or in the incidence of new renal scars. We conclude that reflux into the lower pole of a duplex kidney does not in itself constitute an indication for early surgical treatment.

    View details for Web of Science ID A1989AB08100007

    View details for PubMedID 2755742