Bio

Clinical Focus


  • Nuclear Medicine

Academic Appointments


Administrative Appointments


  • Chief, Nuclear Medicine Service, VA Palo Alto Health Care System (1998 - Present)

Honors & Awards


  • Commendation, Department of Veterans Affairs Palo Alto Health Care System (2004)
  • Taplin Lecturer, Western Regional Chapters Society of Nuclear Medicine (2005)
  • Distinguished Service Award, Western Regional Chapters Society of Nuclear Medicine (2006)
  • Presidential Distinguished Educator Award, Society of Nuclear Medicine (2010)

Professional Education


  • Residency:Kaiser Foundation Hospital (1982) CA
  • Residency:Stanford University School of Medicine (1986) CA
  • Board Certification: Nuclear Medicine, American Board of Nuclear Medicine (1986)
  • Board Certification: Internal Medicine, American Board of Internal Medicine (1982)
  • Internship:Kaiser Foundation Hospital (1980) CA
  • Medical Education:USC Keck School of Medicine (1979) CA
  • MD, University Southern California, Medicine (1979)

Community and International Work


  • Board of Directors

    Partnering Organization(s)

    American Board of Nuclear Medicine

    Location

    US

    Ongoing Project

    No

    Opportunities for Student Involvement

    No

  • President

    Partnering Organization(s)

    Society of Nuclear Medicine

    Populations Served

    Professional community

    Location

    International

    Ongoing Project

    No

    Opportunities for Student Involvement

    No

Research & Scholarship

Current Research and Scholarly Interests


Scintigraphic evaluation of coronary blood flow and myocardial function using single photon emission computed tomography (SPECT) and positron emission tomography (PET). Tumor imaging and characterization of pulmonary nodules with PET/CT.

Clinical Trials


  • Cervical Nodal Mets in Squamous Cell Carcinoma of H&N - MRI, FDG-PET, & Histopathologic Correlation Not Recruiting

    The purpose of this study is to determine the value of novel non-invasive medical imaging methods for detecting the spread of head and neck squamous cell carcinoma to the lymph nodes in the neck by comparing their results to findings at the time of surgery.

    Stanford is currently not accepting patients for this trial. For more information, please contact Quynh-Thu Le, (650) 498 - 6184.

    View full details

  • Correlation of PET-CT Studies With Serum Protein Analysis Not Recruiting

    To correlate serum proteomics patterns with PET/CT findings to improve cancer diagnosis, staging, prognosis, and therapy monitoring.

    Stanford is currently not accepting patients for this trial. For more information, please contact Erik Mittra, (650) 725 - 4711.

    View full details

Teaching

2013-14 Courses


Publications

Journal Articles


  • A comparison of the diagnostic accuracy of F-18-FDG PET and CT in the characterization of solitary pulmonary nodules JOURNAL OF NUCLEAR MEDICINE Fletcher, J. W., Kymes, S. M., Gould, M., Alazraki, N., Coleman, R. E., Lowe, V. J., Marn, C., Segall, G., Thet, L. A., Lee, K. 2008; 49 (2): 179-185

    Abstract

    CT and PET are widely used to characterize solitary pulmonary nodules (SPNs). However, most CT accuracy studies have been performed with outdated technology and methods, and previous PET studies have been limited by small sample sizes and incomplete masking. Our objective was to compare CT and PET accuracy in veterans with SPN.Between January 1999 and June 2001, we recruited 532 participants with SPNs newly diagnosed on radiography and untreated. The SPNs were 7-30 mm. All patients underwent (18)F-FDG PET and CT. A masked panel of 3 PET and 3 CT experts rated the studies on a 5-point scale. SPN tissue diagnosis or 2-y follow-up established the final diagnosis.A definitive diagnosis was established for 344 participants. The prevalence of malignancy was 53%. The average size was 16 mm. Likelihood ratios (LRs) for PET and CT results for combined ratings of either definitely benign (33% and 9% of patients, respectively) or probably benign (27% and 12%) were 0.10 and 0.11, respectively. LRs for PET and CT results for combined ratings of indeterminate (1% and 25%), probably malignant (21% and 39%), or definitely malignant (35% and 15%) were 5.18 and 1.61, respectively. Area under the receiver operating characteristic curve was 0.93 (95% confidence interval, 0.90-0.95) for PET and 0.82 (95% confidence interval, 0.77-0.86) for CT (P < 0.0001 for the difference). PET inter- and intraobserver reliability was superior to CT.Definitely and probably benign results on PET and CT strongly predict benign SPN. However, such results were 3 times more common with PET. Definitely malignant results on PET were much more predictive of malignancy than were these results on CT. A malignant final diagnosis was approximately 10 times more likely than a benign final diagnosis in participants with PET results rated definitely malignant.

    View details for DOI 10.2967/jnumed.107.044990

    View details for Web of Science ID 000252866300023

    View details for PubMedID 18199626

  • Concurrent metabolic and osseous metastatic disease on a Tc99m-MDP bone scan EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING Mittra, E., Segall, G. 2007; 34 (12): 2150-2150

    View details for DOI 10.1007/s00259-007-0535-x

    View details for Web of Science ID 000251370400034

    View details for PubMedID 17874099

  • A case of three synchronous primary tumors demonstrated by F-18FDG PET CLINICAL NUCLEAR MEDICINE Mittra, E., Vasanawala, M., Niederkohr, R., Rodriguez, C., Segall, G. 2007; 32 (8): 666-667

    Abstract

    We present an F-18 FDG PET scan which demonstrates 3 synchronous primary malignancies. The patient is a 61-year-old man who presented with weight loss and dysphagia. He was initially diagnosed with squamous cell carcinoma of the midesophagus, and was then found to have an adenocarcinoma in the right lung. A staging PET scan additionally showed increased left tonsillar uptake. Subsequent biopsy confirmed squamous cell carcinoma of the left tonsil. The demonstration of 3 synchronous primaries by PET is probably rare.

    View details for Web of Science ID 000248382000022

    View details for PubMedID 17667450

  • F-18 FDG PET visualization of urinary leak after nephrostomy tube removal CLINICAL NUCLEAR MEDICINE Iagaru, A., Gamie, S., Segall, G. 2007; 32 (2): 168-169

    View details for Web of Science ID 000243782800025

    View details for PubMedID 17242582

  • F-18FDG PET imaging of urinary bladder oat cell carcinoma with widespread osseous metastases CLINICAL NUCLEAR MEDICINE Iagaru, A., Gamie, S., Segall, G. 2006; 31 (8): 476-478

    View details for Web of Science ID 000241026700010

    View details for PubMedID 16855436

  • F-18FDG PET evaluation of bronchial plasmacytoma with CT and MRI correlation CLINICAL NUCLEAR MEDICINE Iagaru, A., Mari, C., Segall, G. 2006; 31 (5): 279-280

    View details for Web of Science ID 000237077700009

    View details for PubMedID 16622337

  • Oral administration of F-18FDG to evaluate a single pulmonary nodule by positron emission tomography in a patient with poor intravenous access CLINICAL NUCLEAR MEDICINE Franc, B., Carlisle, M. R., Segall, G. 2003; 28 (7): 541-544

    Abstract

    F-18 fluorodeoxyglucose (FDG) is typically administered intravenously for positron emission tomography. The authors present a case of oral administration of FDG for evaluation of a pulmonary nodule and review the limited literature on this subject. Oral administration of FDG is a useful alternative to intravenous administration in patients with difficult intravenous access when the alimentary tract is not involved in the clinical diagnosis.

    View details for Web of Science ID 000183782800001

    View details for PubMedID 12819404

  • Positron emission tomography is superior to computed tomography for metastatic detection in melanoma patients ANNALS OF SURGICAL ONCOLOGY Swetter, S. M., Carroll, L. A., Johnson, D. L., Segall, G. A. 2002; 9 (7): 646-653

    Abstract

    Whole-body positron emission tomography (PET) provides diagnostic information not currently available with traditional imaging and may improve the accuracy of staging melanoma patients.A retrospective cohort review was performed of 104 patients with primary or recurrent melanoma who underwent PET to determine sensitivity/specificity for metastatic detection compared with body computed tomography (CT). One hundred fifty-seven PET and 70 CT scans were analyzed, with a median patient follow-up of 24 months. Metastases were confirmed with positive histology (87.5%) or documented disease progression (12.5%). Fifty-three patients prospectively underwent consecutive studies within a mean 3-week interval for direct comparative analysis.PET demonstrated 84% sensitivity (95% confidence interval [CI],.78 to.89) and 97% specificity (95% CI,.91 to.99), whereas CT showed 58% sensitivity (95% CI,.49 to.66) and 70% specificity (95% CI,.51 to.84). Exclusion of areas not evaluated on CT (head, neck/supraclavicular, extremities) increased CT sensitivity to 69% (95% CI,.59 to.77). Sixty-six consecutive PET and CT scans were performed with 81% and 57% of metastases detected, respectively.PET is more sensitive and specific than CT for detection of melanoma metastasis and should be considered the primary staging study for recurrent disease. PET shows greater ability to detect soft tissue, small-bowel, and lymph node metastasis that do not meet criteria designated as abnormal by CT. PET is superior to CT even when sites not routinely evaluated by CT are excluded from comparative analysis.

    View details for Web of Science ID 000177327500008

    View details for PubMedID 12167578

  • Positron emission tomography of the thyroid, with an emphasis on thyroid cancer NUCLEAR MEDICINE COMMUNICATIONS McDougall, I. R., Davidson, J., Segall, G. M. 2001; 22 (5): 485-492

    Abstract

    The role of Positron Emission Tomography (PET) using 18F-fluorodeoxyglucose (FDG) in the management of thyroid cancer is discussed. It is important to ensure that patients are relaxed because uptake of FDG in tense or active muscles in the neck and larynx can be misinterpreted as metastases. The major role for PET is in patients where the stage of disease is uncertain, usually the result of discordant negative 131I scan and a positive serum thyroglobulin (Tg) values. PET identifies the source of Tg production in 50-80% of patients. PET scan can be negative in well differentiated cancers which retain the ability to trap iodine. This can result in a 'flip/flop', with negative PET, positive radio-iodine scan, or positive PET, negative radioiodine scan. PET is also valuable in identifying the source of calcitonin production in patients with medullary thyroid cancer. When focal uptake is seen in the thyroid of patients who are scanned for non thyroidal reasons, the likelihood of primary thyroid cancer is high. In contrast diffuse uptake of FDG in the thyroid is usually the result of auto-immune thyroid disorders.

    View details for Web of Science ID 000168832200004

    View details for PubMedID 11388568

  • FDG PET imaging in patients with lymphoma: A clinical perspective - Invited commentary JOURNAL OF NUCLEAR MEDICINE Segall, G. M. 2001; 42 (4): 609-610

    View details for Web of Science ID 000168000500017

    View details for PubMedID 11337550

  • 9:45-10:00. Positron Emission Tomography (PET) is Superior to Computerized Tomography (CT) for Metastatic Staging in Melanoma Patients. Clinical positron imaging : official journal of the Institute for Clinical P.E.T Swetter, S., Carroll, L., Johnson, D., Segall, G. 2000; 3 (4): 154

    Abstract

    PET provides diagnostic information currently not available with traditional imaging. Retrospective analysis was performed of 104 patients with primary or recurrent melanoma who underwent PET for staging to determine sensitivity/specificity compared to body CT. 157 PET and 70 CT scans were analyzed with a mean follow up of 26 months. Metastatic events were confirmed with positive histology (73%) or documented disease progression.PET demonstrated 86% sensitivity and 97% specificity in 41 patients with metastasis. CT showed 57% sensitivity and 70% specificity in 30 patients with metastasis. Exclusion of areas not evaluated on CT (head, neck/supraclavicular, and extremities) increased CT sensitivity to 68%. Fifty-three patients underwent 67 consecutive CT and PET scans that detected 132 metastases in 30 individuals. PET detected a greater percentage of metastases (83%) compared to CT (56%), and specifically, in the soft tissue, neck, peripheral/mediastinal/intraabdominal lymph nodes, and small bowel. PET detected 100% of mediastinal metastasis while CT detected only 67%. Surprisingly, PET detected 84% of lung parenchymal metastasis compared to 72% with CT.PET is more sensitive and specific than CT for detection of melanoma metastasis and should be considered the primary staging study upon suspicion of recurrent disease. PET shows greater ability to detect soft tissue, small bowel, and lymph node metastasis that do not meet criteria designated as abnormal by CT. Likewise, CT does not routinely evaluate the supraclavicular area, neck, or upper/lower extremities. However, even when these sites are excluded from comparative analysis, PET is superior to CT in detecting melanoma metastasis.

    View details for PubMedID 11150757

  • Comparison of FDG-PET and Bone Scans for Detecting Skeletal Metastases in Patients with Non-small Cell Lung Cancer. Clinical positron imaging : official journal of the Institute for Clinical P.E.T Durski, J. M., Srinivas, S., Segall, G. 2000; 3 (3): 97-105

    Abstract

    Purpose: Positron Emission Tomography (PET) with F18-fluorodeoxyglucose has been proven useful for staging non-small cell lung cancer. Bone scans are frequently performed for suspected skeletal metastases. The purpose of this study was to evaluate if bone scans compared to PET scans provide additional information that changes the stage of disease.Procedures: Nineteen patients with non-small cell lung cancer had PET and bone scans done for staging of the malignancy. The results of both studies were compared.Results: Bone and PET scans agreed on the presence or absence of skeletal metastases in all nineteen patients. The addition of a bone scan to a PET scan did not change the stage of the disease or the management in any of the patients. Bone scans allowed for more precise localization of the lesions in some patients.Conclusions: Bone scans do not change the stage of disease when performed in addition to PET scans, but provide more precise localization of skeletal abnormalities.

    View details for PubMedID 11008099

  • Physiologic Source of Intestinal FDG Uptake. Effect of Atropine and Sincalide. Clinical positron imaging : official journal of the Institute for Clinical P.E.T Jadvar, H., Schambye, R. B., Segall, G. M. 1999; 2 (6): 318

    View details for PubMedID 14516615

  • Psychological stress and myocardial perfusion in coronary disease patients and healthy controls JOURNAL OF PSYCHOSOMATIC RESEARCH BENIGHT, C. C., Segall, G. M., Ford, M. E., Goetsch, V. L., Hays, M. T., Taylor, C. B. 1997; 42 (2): 137-144

    Abstract

    This study examined the effect of two different psychological stressors on regional cardiac perfusion in six men with coronary heart disease (CHD) and nine healthy controls. Subjects recalled an anger experience and an anger plus helpless (i.e., Desperation Recall Task) experience during positron emission tomography (PET). Emotional reactivity, blood pressure, and heart rate were also assessed. Experimental manipulations generated significant emotional and cardiovascular reactivity. Cardiac perfusion to diseased myocardial segments failed to show any significant differences between CHD patients' diseased segments and controls' healthy segments for the Anger Recall task or the Desperation Recall Task. Results failed to confirm previous findings of coronary artery constriction while reliving an angry experience, yet are consistent with other studies utilizing mental arithmetic. Vasoactive medication use, sample size, and perfusion variability may have contributed to these findings.

    View details for Web of Science ID A1997WK44200003

    View details for PubMedID 9076641

  • Low probability lung scan in a patient at high risk for pulmonary embolism JOURNAL OF NUCLEAR MEDICINE Kwok, C. G., SKIBO, L. K., Segall, G. M. 1996; 37 (1): 165-170

    View details for Web of Science ID A1996TP05200036

    View details for PubMedID 8543989

  • REST EXERCISE THALLIUM MYOCARDIAL PERFUSION IMAGING - A NEW AND RAPID TECHNIQUE TO EVALUATE CORONARY-ARTERY DISEASE NUCLEAR MEDICINE COMMUNICATIONS Segall, G. M., ZIPKIN, R. E. 1993; 14 (6): 465-470

    Abstract

    Twenty-six patients underwent conventional exercise/4-h redistribution thallium myocardial perfusion imaging as well as rest/exercise imaging on different days. For the rest/exercise study, patients were imaged 10 min after receiving 1 mCi thallium at rest. The resting study was immediately followed by symptom-limited treadmill exercise. Patients were injected with 2 mCi thallium at peak exercise and imaged 10 min later. The entire rest/exercise study was completed in 2 h. There was a high degree of correlation between the two studies. Of the 130 segments analysed, 84 were normal and 46 were abnormal by exercise/redistribution imaging whereas 88 were normal and 42 were abnormal by rest/exercise imaging. Among the 14 patients who had coronary arteriography, both exercise/redistribution and rest/exercise imaging correctly identified 23/35 segments as abnormal (sensitivity [pi003] 66%) and 34/35 segments as normal (specificity = 97%). Furthermore, abnormal segments were more likely to be reversible on the rest/exercise study. The results suggest that the accuracy of rest/exercise thallium imaging is equal to conventional exercise/redistribution imaging in the evaluation of coronary artery disease. The significant time economy and possible improvement in assessing myocardial viability are important potential advantages of this new technique.

    View details for Web of Science ID A1993LF94700009

    View details for PubMedID 8321485

  • EFFECTS OF ANGER ON LEFT-VENTRICULAR EJECTION FRACTION IN CORONARY-ARTERY DISEASE AMERICAN JOURNAL OF CARDIOLOGY Ironson, G., Taylor, C. B., BOLTWOOD, M., BARTZOKIS, T., Dennis, C., Chesney, M., Spitzer, S., Segall, G. M. 1992; 70 (3): 281-285

    Abstract

    This study examined the comparative potency of several psychological stressors and exercise in eliciting myocardial ischemia as measured by left ventricular (LV) ejection fraction (EF) changes using radionuclide ventriculography. Twenty-seven subjects underwent both exercise (bicycle) and psychological stressors (mental arithmetic, recall of an incident that elicited anger, giving a short speech defending oneself against a charge of shoplifting) during which EF, blood pressure, heart rate and ST segment were measured. Eighteen subjects had 1-vessel coronary artery disease (CAD), defined by greater than 50% diameter stenosis in 1 artery as assessed by arteriography. Nine subjects served as healthy control subjects. Anger recall reduced EF more than exercise and the other psychological stressors (overall F [3.51] = 2.87, p = .05). Respective changes in EF for the CAD patients were -5% during anger recall, +2% during exercise, 0% during mental arithmetic and 0% during the speech stressor. More patients with CAD had significant reduction in EF (greater than or equal to 7%) during anger (7 of 18) than during exercise (4 of 18). The difference in EF change between patients with CAD and healthy control subjects was significant for both anger (t25 = 2.23, p = 0.04) and exercise (t25 = 2.63, p = 0.01) stressors. In this group of patients with CAD, anger appeared to be a particularly potent psychological stressor.

    View details for Web of Science ID A1992JE54300003

    View details for PubMedID 1632389

  • EFFECT OF FLOW-RATE ON ADHERENCE OF UNLABELED AND IN-111 OXINE-LABELED LEUKOCYTES INVESTIGATIVE RADIOLOGY Lang, E. V., Lang, J. H., Segall, G. M. 1992; 27 (1): 50-54

    Abstract

    Uptake of radioactively labeled leukocytes has been observed in ischemic noninfected regions. Since this may be a flow-related phenomenon, the authors investigated the effect of flow rate on adherence of indium-111 oxine-labeled leukocytes with a model based on the elution patterns of radioactivity and granulocytes from nylon fiber columns. Relative radioactivity adherence (%RA) and relative granulocyte adherence (%GA) agreed closely, indicating that radioactivity retained by the columns is predominantly in the form of viable labeled granulocytes, and that labeled and unlabeled granulocytes have the same adherence characteristics. When other conditions were held constant, but passage speed was varied, %GA and %RA were related to the flow rate in an inverse linear fashion. Decrease in flow rate can lead to increased accumulation of leukocytes.

    View details for Web of Science ID A1992GX89400007

    View details for PubMedID 1733881

  • SAFETY OF DIPYRIDAMOLE-THALLIUM IMAGING IN HIGH-RISK PATIENTS WITH KNOWN OR SUSPECTED CORONARY-ARTERY DISEASE JOURNAL OF NUCLEAR MEDICINE PERPER, E. J., Segall, G. M. 1991; 32 (11): 2107-2114

    Abstract

    The effects of an oral dipyridamole suspension were studied in 400 consecutive patients to determine if certain subsets of patients were at greater risk of suffering major complications. Most patients (69%) experienced at least one side effect. Severe chest pain, severe hypotension, and severe dyspnea occurred in 9%, 2.5%, and 0.3% of patients respectively. Two patients were hospitalized for persistent chest pain but none suffered a myocardial infarction, malignant ventricular arrhythmia, or death. The test was found to be safe for patients over 70 yr old. Severe dyspnea was rare even among patients with lung disease who were withdrawn from theophylline prior to testing. Patients with three-vessel coronary artery disease were more likely to experience severe chest pain and those with significant left ventricular dysfunction were more likely to develop severe hypotension. In 99.5% of patients, side effects were promptly reversed by aminophylline. Dipyridamole-thallium imaging has an acceptable safety profile for a wide variety of patients, including those with severe coronary disease and/or left ventricular dysfunction.

    View details for Web of Science ID A1991GP12700023

    View details for PubMedID 1941146

  • EXERCISE WHOLE-BODY THALLIUM SCINTIGRAPHY IN THE DIAGNOSIS AND EVALUATION OF OCCLUSIVE ARTERIAL-DISEASE IN THE LEGS JOURNAL OF NUCLEAR MEDICINE Segall, G. M., LENNON, S. E., STEVICK, C. D. 1990; 31 (9): 1443-1449

    Abstract

    Whole-body thallium scintigraphy can be used to diagnose and evaluate occlusive arterial disease in patients with leg claudication. We performed exercise and redistribution scans in 36 healthy individuals and 17 patients with claudication. Regions of interest were drawn around the whole body, as well as each buttock, thigh, and calf. Counts in each region were expressed as a percentage of whole-body activity, as well as an interextremity activity ratio for each level. Significant differences due to gender and age were found. The sensitivity and specificity of the test in men was 94% and 71%, respectively, using the criterion of percentage regional uptake and 81% and 90%, respectively, using interextremity comparison. We conclude that exercise whole-body thallium imaging is a simple and accurate test for the evaluation of suspected occlusive arterial disease in the legs.

    View details for Web of Science ID A1990DX50300005

    View details for PubMedID 2118563

  • KINETICS OF LEUKOCYTE SEQUESTRATION IN THE LUNGS OF ACUTELY SEPTIC PRIMATES - A STUDY USING IN-111 LABELED AUTOLOGOUS LEUKOCYTES JOURNAL OF SURGICAL RESEARCH HANGEN, D. H., Segall, G. M., HARNEY, E. W., Stevens, J. H., McDougall, I. R., Raffin, T. A. 1990; 48 (3): 196-203

    Abstract

    To further clarify the role of leukocytes in the pathogenesis of ARDS, we studied the localization and kinetics of leukocyte migration using 111In-labeled autologous white cell scans (111In wbc scans) in four primates made acutely septic with infusions of Escherichia coli. Whole body images were obtained with a gamma camera and were acquired on computer every 15 min beginning immediately after the E. coli infusion. Simultaneous measurements of C5a and peripheral blood leukocyte count were also obtained. Within 5 min of initiating sepsis, three major events occurred: complement activation as measured by the production of C5a, a profound fall in peripheral leukocyte count, and a significant increase in the sequestration of leukocytes in the lungs. The pulmonary sequestration reached a peak at 15 min with a mean of 152% of baseline activity. This sequestration consisted of a population that was predominantly neutrophils. Damage to the pulmonary capillary endothelium was demonstrated by an increase in extravascular lung water. The results support a role for neutrophils and complement as mediators in the pathogenesis of ARDS.

    View details for Web of Science ID A1990CV60600003

    View details for PubMedID 2314092

  • SEQUENTIAL ASSESSMENT OF PULMONARY EPITHELIAL DIETHYLENE TRIAMINE PENTA-ACETATE CLEARANCE AND INTRAPULMONARY TRANSFERRIN ACCUMULATION DURING ESCHERICHIA-COLI PERITONITIS AMERICAN REVIEW OF RESPIRATORY DISEASE Ishizaka, A., Stephens, K. E., Segall, G. M., HATHERILL, J. R., McDougall, I. R., Wu, Z. H., Raffin, T. A. 1990; 141 (3): 631-639

    Abstract

    The individual roles of pulmonary capillary endothelial and alveolar epithelial permeability in the pathogenesis of the adult respiratory distress syndrome (ARDS) are unclear. We developed a method for the sequential assessment of pulmonary macromolecule accumulation and small solute clearance in vivo using a gamma camera. We measured the exponential clearance coefficient of 111In-labeled diethylene triamine penta-acetate (111In-DTPA) to assess airway clearance of small solutes. We also calculated the exponential equilibration coefficient of 111In-labeled transferrin (111In-TF) to assess intrapulmonary accumulation of transferrin. We determined these parameters in guinea pigs with Escherichia coli peritonitis and compared them with a saline-treated control group, oleic-acid-treated groups, and a group treated with low molecular weight dextran Ringer solution. The pulmonary DTPA clearance and the intrapulmonary transferrin accumulation were significantly increased in the peritonitis group (29.4 +/- 8.2 x 10(-3) min-1, p less than 0.02, and 15.1 +/- 3.1 x 10(-3) min-1, p less than 0.02) when compared with the control group (3.1 +/- 0.8 x 10(-3) min-1 and 4.5 +/- 0.5 x 10(-3) min-1). These changes developed within 5.5 h of the initial insult. Neither increased extravascular lung water nor elevated pulmonary artery and left atrial pressures were detected in the peritonitis group. The low molecular weight dextran Ringer group did not show a significant increase in the pulmonary DTPA clearance and the intrapulmonary transferrin accumulation.(ABSTRACT TRUNCATED AT 250 WORDS)

    View details for Web of Science ID A1990CT66700020

    View details for PubMedID 2178527

  • PRONE VERSUS SUPINE THALLIUM MYOCARDIAL SPECT - A METHOD TO DECREASE ARTIFACTUAL INFERIOR WALL DEFECTS JOURNAL OF NUCLEAR MEDICINE Segall, G. M., Davis, M. J. 1989; 30 (4): 548-555

    Abstract

    Artifactual inferior wall defects as a result of diaphragmatic attenuation of activity are a frequent source of error in thallium myocardial single photon emission computed tomography (SPECT) studies. Thirty-four patients and 11 clinically normal volunteers were studied prospectively to see if specificity of inferior wall defects for right coronary artery disease could be improved by scanning patients prone versus supine. All individuals were scanned both prone and supine, in random order, following symptom limited treadmill exercise. Images were acquired at 3 degrees steps, 25 sec per frame, in a 180 degrees elliptical orbit always beginning in the 45 degrees right anterior oblique position relative to the patient. Polar maps generated from the short axis slices were used to calculate the average regional activity. The prone studies showed consistently higher inferior wall activity compared to the supine studies on both the exercise (182 +/- 22 vs. 160 +/- 23, p less than or equal to 0.001) and 4-hr delay studies (183 +/- 20 vs. 175 +/- 21, p less than or equal to 0.001). Prone imaging resulted in a significantly higher specificity for RCA disease compared to supine imaging (90% vs. 66%, p less than 0.05) with an improvement in accuracy from 71% to 82%. Sensitivity, specificity, and accuracy for left anterior descending and left circumflex artery disease were not significantly affected by patient position during imaging. All patients having SPECT thallium myocardial perfusion studies should be imaged prone to minimize artifactual inferior wall defects and improve accuracy.

    View details for Web of Science ID A1989T939600019

    View details for PubMedID 2661750

  • Noninvasive detection of human cardiac transplant rejection with indium-111 antimyosin (Fab) imaging. Circulation FRIST, W., Yasuda, T., Segall, G., Khaw, B. A., Strauss, H. W., Gold, H., STINSON, E., Oyer, P., Baldwin, J., Billingham, M. 1987; 76 (5): V81-5

    Abstract

    Diagnosis of rejection after cardiac transplantation is currently made by right ventricular endomyocardial biopsy. To evaluate antimyosin imaging as a noninvasive means of detecting human cardiac rejection, the Fab fragment of murine monoclonal antimyosin antibodies was labeled with indium-111 and given intravenously to 18 patients (age 45 +/- 12 years) in 20 studies 7 days to 9 years after transplantation. Endomyocardial biopsy specimens were obtained at the time of each imaging study. Eight patients had positive scans confirmed by biopsy as rejection, and eight patients had negative scans and no evidence of rejection on biopsy. Discordance was observed in four studies, two with positive scans and no rejection on biopsy and two with negative scans and positive biopsy. The sensitivity, specificity, and overall accuracy of the technique were each 80%. Imaging with radiolabeled antimyosin antibody Fab fragments may be of value in the noninvasive identification of rejection in the cardiac transplant recipient.

    View details for PubMedID 3311460

Conference Proceedings


  • SPECT and PET in the evaluation of coronary artery disease Jadvar, H., Strauss, H. W., Segall, G. M. RADIOLOGICAL SOC NORTH AMERICA. 1999: 915-926

    Abstract

    Cardiac positron emission tomography (PET) is an accurate method for assessing myocardial perfusion and metabolism in the evaluation of coronary heart disease. PET allows more accurate detection of myocardial ischemia than single photon emission tomography (SPECT). In addition, PET has higher spatial resolution and allows attenuation correction and the quantification of various physiologic parameters. PET with 2-(fluorine-18) fluoro-2-deoxy-D-glucose is considered the standard of reference for predicting improvement in regional or global left ventricular function after revascularization by identifying hibernating viable myocardium that shows diminished perfusion and preserved metabolism. Other less commonly used clinical applications of cardiac PET include assessment of myocardial oxygen consumption and fatty acid metabolism. The use of PET in myocardial imaging is expected to increase in the near future with the regional distribution of positron-emitting radiotracers and the emergence of relatively low-cost PET systems.

    View details for Web of Science ID 000081364000012

    View details for PubMedID 10464799

  • Uses and limitations of FDG positron emission tomography in patients with head and neck cancer Hanasono, M. M., Kunda, L. D., Segall, G. M., Ku, G. H., Terris, D. J. JOHN WILEY & SONS INC. 1999: 880-885

    Abstract

    Numerous authors have reported the potential usefulness of positron emission tomography (PET). These studies have had conflicting results, at least partly owing to limited sample sizes. The objective of this study is to define not only the uses, but also the limitations of PET in patients with head and neck cancer.Nonrandomized, retrospective analysis of PET at an academic institution.The authors performed 146 PET scans on 133 patients with head and neck cancer. Eighteen patients (19 PET scans) with thyroid disorders were excluded. A minimum 1 year of follow-up was available in 84 patients, who were separated into groups based on whether the PET was used to detect unknown primary cancers (n = 20), stage neck nodal and distant metastases (n = 8), monitor response to nonsurgical therapy (n = 22), or detect recurrent or residual cancers (n = 34). The results of PET were compared with results from computed tomography (CT) and magnetic resonance imaging (MRI) performed in the same patients.Of the unknown primary cancers, PET correctly identified 7 of 20 primary sites, giving a sensitivity of 35%. When combined with CT or MRI, the sensitivity increased to 40%. When used for detection of metastatic disease, PET demonstrated five of five nodal metastases (100%) and two of four distant metastases (50%). In evaluating the response to nonsurgical therapy, PET had a sensitivity of 50% and a specificity of 83% for detecting tumor at the primary site and a sensitivity of 86% and a specificity of 73% for detecting nodal disease. When used for evaluation of recurrent/residual disease, PET identified seven of seven cases of local recurrences/residual disease and had a specificity of 85%. PET also detected seven of seven cases of nodal disease and had a specificity of 89%.For staging purposes, PET is limited by its lack of anatomic detail. However, PET compares favorably with CT and MRI in detecting recurrent/residual cancers. PET imaging complements the more traditional imaging modalities (CT or MRI), especially for an unknown primary cancer.

    View details for Web of Science ID 000080716900007

    View details for PubMedID 10369275

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