Bio

Clinical Focus


  • Menlo Clinic > Radiology
  • Radiology

Academic Appointments


Professional Education


  • Internship:Mount Zion Medical Center (1961) CA
  • Fellowship:Stanford University School of Medicine (1964) CA
  • Residency:Stanford University School of Medicine (1963) CA
  • Board Certification: Diagnostic Roentgenology, American Board of Radiology (1965)
  • Medical Education:SUNY Upstate Medical University (1960) NY

Publications

Journal Articles


  • What is the value of measuring coronary artery calcification? RADIOLOGY Wexler, L. 2008; 246 (1): 1-2

    View details for DOI 10.1148/radiol.2461071333

    View details for Web of Science ID 000252795300001

    View details for PubMedID 18096520

  • Ethical considerations in image-based screening for coronary artery disease. Topics in magnetic resonance imaging Wexler, L. 2002; 13 (2): 95-106

    Abstract

    Despite marked advances in the treatment and prevention of coronary artery disease (CAD) during the last decade, CAD and its complications continue to account for 20% of all deaths in the United States, more than other cause of death. Moreover, half of those who die suddenly of an acute myocardial infarction have no prior symptoms or overt manifestations of their underlying CAD. As our understanding of the pathophysiology of coronary atherosclerosis improves, diagnostic tests utilizing magnetic resonance (MR) imaging and gated computed tomography are being developed to screen for significant CAD in symptomatic individuals and in those who are preclinical or asymptomatic. Patients with known or suspected CAD might be candidates for MR studies of myocardial perfusion, myocardial contraction under stress, MR coronary arteriography, and plaque characterization. One rationale would be to uncover patients before they have a silent heart attack to institute preventative therapies. Although clinical studies have not definitively demonstrated the efficacy of these modalities, screening sites are proliferating and patients are demanding screening tests for CAD. Radiologists interpreting these tests should understand their underlying rationale, the data referenced to substantiate their use, and their responsibility to inform the patient of the results. This review describes current concepts of the pathophysiology of CAD, the rationale for the various screening tests for CAD that are in use or in development, and the potential value of the results of screening to individual patients. The ethical issues embodied in the performance of screening tests for CAD are placed in the context of the appropriate role of the radiologist as a physician interacting directly with a patient.

    View details for PubMedID 12055454

  • Digital storage phosphor chest radiography: An ROC study of the effect of 2K versus 4K matrix size on observer performance RADIOLOGY Miro, S. P., Leung, A. N., Rubin, G. D., Choi, Y. H., Kee, S. T., Mindelzun, R. E., Stark, P., Wexler, L., Plevritis, S. K., Betts, B. J. 2001; 218 (2): 527-532

    Abstract

    To compare observer performance in the detection of abnormalities on 1,760 x 2,140 matrix (2K) and 3,520 x 4,280 matrix (4K) digital storage phosphor chest radiographs.One hundred sixty patients who underwent dedicated computed tomography (CT) of the thorax were prospectively recruited into the study. Posteroanterior and lateral computed radiographs of the chest were acquired in each patient and printed in 2K and 4K formats. Six radiologists independently analyzed the hard-copy images and scored the presence of parenchymal (opacities 2 cm, and subtle interstitial), mediastinal, and pleural abnormalities on a five-point confidence scale. With CT as the reference standard, observer performance tests were carried out by using receiver operating characteristic (ROC) analysis.Analysis of averaged observer performance showed 2K and 4K images were equally effective in detection of all three groups of abnormalities. In the detection of the three subtypes of parenchymal abnormalities, there were no significant differences in averaged performance between the 2K and 4K formats (area below ROC curve [A(z)] values: opacities 2 cm, 0.86 +/-.025 and 0.85 +/- 0.030; subtle interstitial abnormalities, 0.73 +/- 0.041 and 0.72 +/- 0.041). Averaged performance in detection of mediastinal and pleural abnormalities was equivalent (A(z) values: mediastinal, 0.70 +/- 0.046 and 0.73 +/- 0.033; pleural, 0.85 +/- 0.032 and 0.86 +/- 0.033).Observer performance in detection of parenchymal, mediastinal, and pleural abnormalities was not significantly different on 2K and 4K storage phosphor chest radiographs.

    View details for Web of Science ID 000166728200033

    View details for PubMedID 11161174

  • A model for faculty mentoring in academic radiology ACADEMIC RADIOLOGY Illes, J., Glover, G. H., Wexler, L., Leung, A. N., Glazer, G. M. 2000; 7 (9): 717-724

    Abstract

    The purpose of this report is to describe the development and implementation of a faculty mentoring program in radiology designed to promote the career development of junior faculty and enhance communication in the department.The mentoring program was implemented in five stages: organizational readiness, participant recruitment, mentor matching and orientation, implementation, and evaluation. Evaluations were based on Likert scale ratings and qualitative feedback. A retrospective analysis was also conducted of the annual performance reviews of junior faculty in the areas of research, teaching, patient care, and overall performance.An average of 83% (19 of 23) of the junior faculty participated in the pilot phase of the mentoring program. During five rounds of testing, the median rating (1 indicates not important; 10, extremely important) from responding junior faculty was 10 for overall value of individual mentoring meetings; the median rating for the mentors responding was 8.75. Research and academic development were identified as the areas of greatest importance to the faculty. Research and patient care were most improved as assessed by faculty peers during performance reviews. The schedule of semiannual formal mentoring meetings was reported to be optimal.The program was implemented to the satisfaction of junior faculty and mentors, and longitudinal performance suggests positive effects. Issues to be contended with include confidentiality and the time needed for mentoring beyond already saturated schedules. Overall, the authors propose that mentoring programs can be an asset to academic radiology departments and a key factor in maintaining their vitality.

    View details for Web of Science ID 000089143200007

    View details for PubMedID 10987334

  • Congenital diaphragmatic hernia associated with aortic coarctation JOURNAL OF PEDIATRIC SURGERY Eghtesady, P., Skarsgard, E. D., Smith, B. M., Robbins, R. C., Wexler, L., Rhine, W. D. 1998; 33 (6): 943-945

    Abstract

    Congenital diaphragmatic hernia (CDH) may be associated with other anomalies, most frequently cardiovascular in nature. Despite fetal echocardiography, diagnosis of an accompanying cardiac malformation often is not made until after birth and sometimes not until after extracorporeal membrane oxygenation (ECMO) has been instituted. Aortic coarctation associated with CDH may occur as an isolated, surgically correctable malformation or it may be a component of the usually fatal left heart "hypoplasia" or "smallness" syndrome. The authors present two cases of aortic coarctation associated with CDH requiring ECMO that illustrate the management challenges of these coincident diagnosis. In one case, the accompanying coarctation was suspected and required precannulation angiography for confirmation, whereas in the other case, the diagnosis of coarctation was not made until after ECMO cannulation. Depending on its anatomic location and severity, an aortic coarctation associated with life-threatening CDH may limit the physiological efficacy of venoarterial ECMO. Furthermore, arterial cannulation for extracorporeal support requires that flow through the remaining carotid artery be maintained during aortic reconstruction, which may prove difficult for lesions best treated by subclavian flap angioplasty. When the diagnosis of coincident aortic coarctation and CDH is suspected or proven before institution of extracorporeal support, serious consideration should be given to venovenous bypass, because this may provide better postductal oxygenation and facilitate aortic repair with the option of left carotid artery inflow occlusion.

    View details for Web of Science ID 000074327400034

    View details for PubMedID 9660236

  • The use of magnetic resonance imaging in adult congenital heart disease. American journal of cardiac imaging Wexler, L., Higgins, C. B. 1995; 9 (1): 15-28

    Abstract

    Magnetic resonance (MR) imaging techniques have evolved sufficiently to produce clinically relevant studies that depict the anatomy and physiology of the heart. Applications to congenital cardiac disease in adult patients are numerous. MR imaging is particularly useful for noninvasive evaluation of the aorta in patients with aortic arch anomalies and coarctations and to study the results of palliative and corrective surgery for transposition of the great arteries and for reconstructive procedures that restore sufficient pulmonary blood flow. MR imaging is superior to transthoracic echocardiography in defining the anatomy of the central pulmonary arteries. Recent technological advances permit motion studies acquired during a single breath-hold and can be used to accurately measure stroke volume, ejection fraction, regional wall motion, and wall thickening from both ventricles. Functional parameters, such as the velocity and volume of blood flow in vessels, valve gradients, regurgitant flow, shunt flow, and pulmonary artery blood flow into each lung are readily performed. This review article documents the value of MR imaging in adult patients with congenital disorders of the heart, pulmonary arteries, and aorta, and includes illustrations of typical examples.

    View details for PubMedID 7894229

  • Magnetic resonance imaging in adult congenital heart disease. Journal of thoracic imaging Wexler, L., Higgins, C. B., Herfkens, R. J. 1994; 9 (4): 219-229

    Abstract

    Some patients with congenital cardiac anomalies develop their first symptoms as adults, and many more will survive to adulthood with congenital lesions that have been treated surgically. Magnetic resonance imaging (MRI) currently provides sufficient morphological information to allow the anatomical diagnosis of congenital abnormalities involving the heart and the great arteries. Newer MR techniques have also been developed that provide functional information such as measurements of valve gradients, stroke volumes, regurgitant volumes, and shunt volumes. Cardiac evaluation utilizing MR techniques may soon replace cardiac catheterization for the preoperative diagnosis of congenital heart disease and its long-term follow-up.

    View details for PubMedID 7830293

  • SPIRAL CT OF RENAL-ARTERY STENOSIS - COMPARISON OF 3-DIMENSIONAL RENDERING TECHNIQUES RADIOLOGY Rubin, G. D., Dake, M. D., Napel, S., Jeffrey, R. B., McDonnell, C. H., Sommer, F. G., Wexler, L., Williams, D. M. 1994; 190 (1): 181-189

    Abstract

    To evaluate the accuracy of computed tomographic (CT) angiography in the detection of renal artery stenosis (RAS).CT angiography was performed in 31 patients undergoing conventional renal arteriography. CT angiographic data were reconstructed with shaded surface display (SSD) and maximum-intensity projection (MIP). Stenosis was graded with a four-point scale (grades 0-3). The presence of mural calcification, poststenotic dilatation, and nephrographic abnormalities was also noted.CT angiography depicted all main (n = 62) and accessory (n = 11) renal arteries that were seen at conventional arteriography. MIP CT angiography was 92% sensitive and 83% specific for the detection of grade 2-3 stenoses (> or = 70% stenosis). SSD CT angiography was 59% sensitive and 82% specific for the detection of grade 2-3 stenoses. The accuracy of stenosis grading was 80% with MIP and 55% with SSD CT angiography. Poststenotic dilatation and the presence of an abnormal nephrogram were 85% and 98% specific, respectively.CT angiography shows promise in the diagnosis of RAS. The accuracy of CT angiography varies with the three-dimensional rendering technique employed.

    View details for Web of Science ID A1994MW25300036

    View details for PubMedID 8259402

  • PAH EXTRACTION AND ESTIMATION OF PLASMA-FLOW IN DISEASED HUMAN KIDNEYS AMERICAN JOURNAL OF PHYSIOLOGY Battilana, C., Zhang, H. P., Olshen, R. A., Wexler, L., Myers, B. D. 1991; 261 (4): F726-F733

    Abstract

    We have analyzed the efficiency with which p-amino-hippuric acid (PAH) is extracted (EPAH) by patients with healthy kidneys (n = 13) or kidneys damaged by chronic cyclosporin nephropathy (n = 21) or primary glomerulopathy (n = 12); respective values (mean +/- SE) for EPAH were 0.87 +/- 0.03, 0.77 +/- 0.03, and 0.69 +/- 0.04. Judged by a 131I-hippuran-to-PAH clearance ratio of 0.75 +/- 0.05, extraction ratio of hippuran was less efficient than EPAH in three glomerulopathic patients. A direct relationship was defined between EPAH and glomerular filtration rate (GFR) (r = 0.54) or calculated efferent oncotic pressure (IIE; r = 0.41, P less than 0.01). Curve fitting by means of quadratic spline functions revealed GFR and IIE to be additive in predicting EPAH (R2 = 0.45). Linear model prediction methods and a sample reuse technique failed to predict EPAH reliably from GFR and preglomerular oncotic pressure (IIA); however, 95% prediction intervals exceed 0.30 EPAH units in width. We conclude that oncotic pressure (presumably reflecting albumin concentration) along with GFR is predictive of EPAH depression in humans with chronic renal disease. However, even sophisticated curve-fitting techniques are too imprecise for accurate prediction of EPAH in a given individual. We submit that renal venous sampling to determine EPAH continues to be necessary for the accurate determination of the rate of plasma flow in the injured human kidney.

    View details for Web of Science ID A1991GK86900112

    View details for PubMedID 1928382

  • FREQUENCY AND MECHANISM OF BRADYCARDIA IN CARDIAC TRANSPLANT RECIPIENTS AND NEED FOR PACEMAKERS AMERICAN JOURNAL OF CARDIOLOGY Dibiase, A., Tse, T. M., Schnittger, I., Wexler, L., Stinson, E. B., Valantine, H. A. 1991; 67 (16): 1385-1389

    Abstract

    Orthotopic cardiac transplantation is occasionally complicated by unexplained bradyarrhythmias. Sinus node injury as a consequence of operation or acute rejection has anecdotally been linked to the development of bradycardia early after transplantation. These arrhythmias are empirically managed by pacemaker implantation, the indications for which remain poorly defined. This retrospective study examined the 20-year experience of our institution with bradyarrhythmias after transplantation to determine the predisposing factors and indications for pacemaker implantation. Forty-one of 556 patients in our cardiac transplant program (7.4%) received permanent pacemakers between 1969 and 1989. The predominant rhythm disturbances were junctional rhythm (46%), sinus arrest (27%) and sinus bradycardia (17%). Most patients were asymptomatic (61%), and presented in the early post-transplant period (73%). Four possible predisposing factors were evaluated: (1) graft ischemic time, (2) rejection history, (3) use of bradycardia-inducing drugs, and (4) anatomy of blood supply to the sinoatrial (SA) node. No significant differences existed between patients with and without pacemakers with regard to the first 3 variables. However, after transplantation angiograms showed that prevalence of abnormal SA nodal arteries was greater in patients with than without pacemakers (p less than 0.02). Pacemaker follow-up at 3, 6 and 12 months showed persistent bradycardia (60 to 90 beats/min) in 88, 75 and 50% of patients, respectively. The most common pacemaker complication (15%) was lead displacement at time of biopsy. These results suggest that disruption of the SA nodal blood supply may be an important predisposing factor in the development of bradycardias.

    View details for Web of Science ID A1991FR02000014

    View details for PubMedID 2042569

  • MONORAIL SYSTEM FOR PERCUTANEOUS REPOSITIONING OF THE GREENFIELD VENA-CAVAL FILTER RADIOLOGY GUTHANER, D. F., Wyatt, J. O., MEHIGAN, J. T., Wright, A. M., Breen, J. F., Wexler, L. 1990; 176 (3): 872-874

    Abstract

    The authors describe a technique for removing or repositioning a malpositioned Greenfield inferior vena caval filter. A "monorail" system was used, in which a wire was passed from the femoral vein through the apical hole in the filter and out the internal jugular vein; the wire was held taut from above and below and thus facilitated repositioning or removal of the filter. The technique was used successfully in two cases.

    View details for Web of Science ID A1990DV57900054

    View details for PubMedID 2389052

  • Angiographic implications of cardiac transplantation. American journal of cardiology Alderman, E. L., Wexler, L. 1989; 64 (9): 16E-21E

    Abstract

    Coronary vascular disease in the cardiac transplant recipient has become the third most frequent cause of death or retransplantation after infection and acute rejection. A unique pattern of concentric fibrointimal thickening develops within 1 year of cardiac transplantation; however, it is relatively inapparent on routine arteriography. The disease progresses primarily in distal vasculature, leading to progressive occlusion. Angiographically discrete lesions associated microscopically with advanced atherosclerotic plaques frequently occur in the more proximal vessels often associated with thrombus. The number of rejection episodes is somewhat predictive of the development of transplant coronary disease. Annual arteriograms performed in cardiac transplant recipients have revealed several distinctive angiographic features that include clockwise rotation of the heart, presence of coronary arterial-cameral fistulae, presumably resulting from right ventricular endomyocardial biopsy specimens and collateralization of the brachial anastomosis from coronary atrial branches. It is concluded that serial angiography in cardiac transplant recipients is important in the early detection of progressive graft atherosclerosis, a process that is clinically silent until such time as overt heart failure or cardiogenic shock occurs.

    View details for PubMedID 2672763

  • PULL-THROUGH APPROACH TO PERCUTANEOUS ANGIOPLASTY OF TOTALLY OCCLUDED COMMON ILIAC ARTERIES RADIOLOGY Ginsburg, R., Thorpe, P., BOWLES, C. R., Wright, A. M., Wexler, L. 1989; 172 (1): 111-113

    Abstract

    A method has been developed to increase the probability of success of percutaneous transluminal balloon angioplasty of total occlusions of the common iliac artery when conventional methods have failed. In 10 patients with a totally obstructed iliac artery, a guide wire was passed through a catheter placed from the contralateral side around the aortic bifurcation and antegrade through the total obstruction. The end of the wire was either snared by a retrieval basket or guided through a sheath in the ipsilateral common femoral artery, thus providing a firmly anchored pathway for subsequent manipulations. Balloons were then inserted retrograde through both common femoral arteries and dilated. In the first five patients, ipsilateral retrograde passage of a guide wire had failed despite multiple attempts with a variety of devices. In the other five patients, the contralateral antegrade approach was used initially. The new method was successful in all 10 patients with totally obstructed common iliac arteries.

    View details for Web of Science ID A1989AB75000022

    View details for PubMedID 2525789

  • NATURAL-HISTORY OF THE FALSE CHANNEL OF TYPE-A AORTIC DISSECTION AFTER SURGICAL REPAIR - CT STUDY RADIOLOGY Yamaguchi, T., GUTHANER, D. F., Wexler, L. 1989; 170 (3): 743-747

    Abstract

    To evaluate the false channel after surgical repair of a type A aortic dissection, postoperative computed tomographic (CT) scans were retrospectively reviewed in 33 patients. Initial CT demonstrated persistence of a double channel distal to the site of surgical repair in 26 patients (79%). In four of these patients serial CT demonstrated enlargement of the false channel, a finding that contributed to the decision to repeat surgery. Progression of thrombus was noted in five patients. Peripheral calcification within the aortic wall of the false channel, presumably located on the "pseudointima," was found in six patients. Because of the progressive nature of type A dissections in the postoperative period, serial CT examinations can provide important information on patients who have undergone surgical correction of a type A dissection.

    View details for Web of Science ID A1989T273400027

    View details for PubMedID 2916028

  • THE VASCULAR WAR OF 1988 JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION Wexler, L., Ginsburg, R., Mitchell, R. S., MEHIGAN, J. T. 1989; 261 (3): 418-419

    View details for Web of Science ID A1989R767700031

    View details for PubMedID 2521257

  • ECHOCARDIOGRAPHIC-LIKE ANGLED VIEWS OF THE HEART BY MR IMAGING JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Burbank, F., Parish, D., Wexler, L. 1988; 12 (2): 181-195

    Abstract

    Cardiac magnetic resonance (MR) imaging has developed rapidly to rival echocardiography as a noninvasive imaging modality. Anatomic detail may exceed that currently available using echocardiography techniques, and the ability to image moving protons may compete with Doppler color flow mapping in detecting valvular diseases and shunts. Because of the considerable clinical experience with echocardiography, as angled MR imaging planes become available as standard software packages, it may be useful for MR cardiac imaging to use standard, accepted echocardiographic nomenclature and imaging planes. This article describes the principles used to obtain long and short axis MR images that are comparable with echocardiographic imaging planes. Diagrams and illustrations are provided to orient the viewer using nomenclature common to echocardiography. These views may eventually be useful for functional analysis of the left ventricle and for detection and evaluation of valvular heart disease and intracardiac shunts.

    View details for Web of Science ID A1988M543100001

    View details for PubMedID 3351027

  • Six-year clinical and angiographic follow-up of patients with previously documented complete revascularization. Circulation ROBERT, E. W., GUTHANER, D. F., Wexler, L., Alderman, E. L. 1978; 58 (3): I194-9

    Abstract

    Relatively little information is available concerning the late clinical and angiographic status of patients with initially successful coronary bypass surgery. From 72 patients who had angiography 1 year after bypass surgery, we restudied at 6 years 19 patients with complete revascularization. At 1 year, 14 patients were asymptomatic and five had minimal anginal symptoms. Five years later, eight patients had redeveloped angina, and 11 retained their initial postoperative status. Overall graft patency at 6 years was 86%; 52% of the patients had atherosclerotic progression to > or = 70% luminal narrowing in a major unbypassed vessel or in a major vessel distal to bypass. The patients with unchanged symptoms all had patent grafts, while 11 of the 15 (73%) grafts were patent in patients with symptomatic deterioration (NS). However, progression of coronary disease occurred in seven of eight patients (88%) with worsened symptoms, as opposed to three of 11 patients with unchanged symptoms (P < 0.05). We conclude that late symptomatic deterioration following coronary bypass surgery is common, and that it usually reflects progression of coronary artery disease.

    View details for PubMedID 14740702

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