Biomedical subjects

E M James

Publications and source records attributed to E M James.

At least 19 recordsLinked to original sources

PubMed1995

Blood flow velocity measurements: a comparison of 25 clinical ultrasonographic units.

A blood-mimicking flow phantom was used to evaluate the precision of velocity measurements acquired using 25 pulsed Doppler ultrasonographic units from four vendors. Measurements were made at four constant flow rates (12 to 50 cm/s peak velocity). The average standard deviation values of the peak and time-averaged velocities among all units and all flow rates were found to be 7 and 9% of the mean, respectively, while the corresponding values for a subgroup of 20 identical units were 5 and 8%. Considered in conjunction with other published data, this suggests that units should be calibrated to an institutional standard at the time of acceptance testing.

Blood Flow Velocity↗

PubMed1994

Diagnosis of acute deep venous thrombosis of the lower extremities: prospective evaluation of color Doppler flow imaging versus venography.

PURPOSE: To determine the value of color Doppler flow imaging in identification of deep venous thrombosis (DVT) of the femoropopliteal system without use of venous compression. MATERIALS AND METHODS: Color Doppler flow imaging was compared with venography in 103 lower extremities in 101 patients. Results of each examination were recorded as positive or negative for acute DVT or consistent with chronic DVT. RESULTS: Color Doppler flow imaging in 97 of 103 cases had a sensitivity of 95%, specificity of 99%, positive and negative predictive values of 95% and 99%, respectively, and accuracy of 98% in detection of acute DVT and was also helpful in differentiation of chronic from acute DVT. Color Doppler flow imaging prospectively identified six of eight patients with chronic DVT and correctly identified acute DVT in two patients with underlying chronic DVT. No results were false-positive for acute DVT in a patient with chronic DVT. CONCLUSION: Color Doppler flow imaging is complementary to compression ultrasonography in evaluation of suspected acute DVT and may be helpful in evaluation of suspected DVT in patients with previous or chronic DVT.

Acute Disease↗

PubMed1994

Intraoperative color Doppler sonography during renal artery revascularization.

Intraoperative color Doppler sonography is emerging as a useful procedure for evaluating renal arteries during transaortic renal endarterectomy or bypass grafting. Technical difficulties encountered during surgical renal revascularization, such as intimal defects or flaps, partial or complete thrombosis, and anastomotic stenosis of the renal artery, can be difficult to defect and evaluate. Intraoperative color Doppler sonography allows evaluation at a time when the problem is often correctable. We have been performing intraoperative sonographic studies of the renal artery for several years and have studied 151 vessels. In this pictorial essay, we present some of our observations on these cases.

Blood Vessel Prosthesis↗

PubMed1993

Portal vein thrombosis associated with pregnancy. A case report.

This report illustrates a case of portal vein thrombosis that developed in the second trimester of pregnancy. The patient did not have any of the known associations or predisposing factors for portal vein thrombosis or any past medical history of thrombosis or bleeding disorders. Antepartum and postpartum laboratory studies showed no evidence of a coagulation disorder; therefore, it seems that the sole cause of this thrombotic event was the hypercoagulable state of pregnancy.

Adult↗

PubMed1992

Prediagnostic malakoplakia presenting as a chronic inflammatory mass in the soft tissues of the neck.

Malakoplakia presenting in the head and neck is very rare. We present a case of an inflammatory mass in the neck, clinically mimicking actinomycosis in a 67-year-old man. Repeated culture of E. coli and histological and electron microscopic examination of biopsy material showed an infiltration of granular macrophages and intracellular gram negative bacilli, but no classical Michaelis-Gutmann bodies. The clinical and pathological findings and criteria for the diagnosis of malakoplakia are discussed.

Aged↗

PubMed1991

Oxalate, silicon and vanadium in acquired cystic kidney disease.

We have investigated the importance of several clinical and laboratory parameters on the development of acquired cystic kidney disease (ACKD) as detected by ultrasonography in 19 patients who had received dialysis therapy for at least three years. We were particularly interested on the possible effect of the serum levels of oxalate and silicon, which can produce tubular obstruction, and that of vanadium, which can affect cell proliferation. The severity of ACKD increased with the duration of dialysis and was greater in men than in women. Positive correlations were observed between the grades of ACKD and the levels of hemoglobin, hematocrit, and parathyroid hormone, while there was a negative correlation between ACKD and serum ferritin levels. The serum levels of oxalate, silicon, and vanadium, pre- and postdialysis, were markedly and significantly higher than those in normal controls, but there was no significant correlation between these levels and the duration of dialysis therapy or severity of ACKD. The pre- and postdialysis levels of vanadium were not significantly different, while the levels of oxalate and silicon were significantly lower in the postdialysis samples. No significant correlations were detected between ACKD and age of the patients, blood pressure, protein catabolic rate, efficiency of dialysis index, or the serum levels of iron, sodium, potassium, calcium, phosphorus, aluminum, and beta 2-microglobulin.

Dialysis Solutions↗

PubMed1991

Vasculogenic impotence. Duplex and color Doppler imaging.

Varicoceles, although only occasionally symptomatic, are reported to occur in 20% to 50% of infertile or subfertile men. Ligation or occlusion of the spermatic vein in these patients has improved semen quality in many instances. Recently, it has been recognized that varicoceles can be bilateral or subclinical and thus detected only by imaging. Sonographic diagnosis of varicoceles and percutaneous occlusive therapy are reviewed in this article.

Color↗

PubMed1990

Intraoperative ultrasonographically guided biopsy in testicular sarcoidosis: a case report.

We present a case of sarcoidosis with involvement of a solitary testis that was discovered incidentally on an ultrasonogram of the scrotum. This appears to be case 8 of sarcoidosis with genitourinary involvement limited to the testis. We believe it is the second report of intraoperative ultrasonography used to locate and perform a biopsy of impalpable testicular lesions. We consider this technique to be useful in instances of solitary gonads or in cases of bilateral lesions.

Adult↗

PubMed1990

Applications of duplex ultrasonography in the liver transplant patient.

Duplex ultrasonography plays an important role in the preoperative and postoperative assessment of liver transplant patients. Before surgical intervention, the principal use of sonography is to assess the patency of the extrahepatic portal vein because a narrowed or thrombosed portal vein may preclude transplantation. Postoperatively, several potential complications can lead to allograft dysfunction (rejection, infection, vascular thromboses, and biliary tract complications). Because these complications often manifest with variable and nonspecific symptoms, diagnosing them can be difficult. Sonography is a valuable noninvasive means of evaluating postoperative complications in liver transplant patients. When vascular complications are suspected, duplex sonography is the optimal screening procedure for assessment of the vascular anastomoses. Focal parenchymal abnormalities (hematomas, infarcts, and bilomas) and localized collections of abdominal fluid are readily detected by ultrasonography and can be safely aspirated and, when infected, percutaneously drained under sonographic guidance. Sonography is less useful in the detection of biliary tract complications early after transplantation.

Humans↗

PubMed1990

Positive predictive value of clinical suspicion of abdominal aortic aneurysm. Implications for efficient use of abdominal ultrasonography.

Although selective screening for an abdominal aortic aneurysm (AAA) by abdominal palpation aimed at detecting AAAs has engendered considerable support, no population-based data pertaining to the positive predictive value (PPV) of the clinical assessment of AAAs in routine clinical practice are available. Therefore, we used the unique resources of the Rochester (Minn) Epidemiology Project and the Mayo Clinic computerized abdominal ultrasonography database to identify all residents of Olmsted County, Minnesota,who underwent ultrasound examination for a clinically suspected AAA between November 1, 1985, and October 31, 1987. Of 116 residents who were suspected of having an AAA on abdominal palpation and were referred for an ultrasound examination for confirmation, 17 patients had a 3.5-cm or greater AAA by ultrasound examination (PPV = 14.7%). The probability of AAA by ultrasound examination (PPV = 14.7%). The probability of AAA documentation by ultrasound examination given clinical suspicion of an AAA was associated with higher body mass index, older age,and presence of other macrovascular disease. In 17 patients aged 70 years or younger, without other macrovascular disease and with body mass index of 24 or less, only 1 had an AAA of 3.5 cm or greater (PPV = 6%), while 10 of 20 patients aged 70 years or older, with macrovascular disease,and with body mass index greater than 24 had an AAA of 3.5 cm or greater (PPV = 50%). These population-based data that highlight the poor PPV of the clinical assessment for AAAs indicate that abdominal palpation aimed at detecting AAAs as part of a periodic health examination may lead to a much higher rate of false-positive results than indicated by previous referral-based data. Further research is needed to identify patient subgroups in whom abdominal palpation for detection of AAAs will be cost-effective with respect to reduction in AAA mortality.

Aged↗

PubMed1989

Current applications of duplex and color Doppler ultrasound imaging: carotid and peripheral vascular system.

Recent advances in ultrasound technology have made possible the development of diagnostic instruments that combine cross-sectional imaging and Doppler analysis. These instruments have expanded the role of diagnostic ultrasonography to the assessment of carotid and peripheral vascular disease. The current applications of duplex Doppler and color Doppler imaging in evaluating the extracranial carotid arteries, vertebral artery, peripheral venous system, and peripheral arterial system are reviewed. The indications for and limitations of these examinations, as well as the potential future uses, are discussed.

Arteries↗

PubMed1989

Current applications of duplex and color Doppler ultrasound imaging: abdomen.

Duplex ultrasound studies and color Doppler imaging have substantially enhanced the diagnostic capabilities of abdominal ultrasonography. The status of the flow in the major abdominal vessels is routinely obtainable along with anatomic information about the organs that they supply. The current applications of duplex and color Doppler imaging in evaluating the hepatic vascular system, hepatic transplants, aorta, splanchnic arterial system, renal artery and vein, renal transplants, and penile arterial system are reviewed. The indications for and limitations of these examinations, as well as the potential future uses, are discussed.

Abdomen↗

PubMed1989

Current applications of color Doppler imaging in the abdomen and extremities.

Recent advances in ultrasound technology have resulted in the development of diagnostic instruments that combine cross sectional imaging with spectral and color flow Doppler analysis. These instruments have expanded the role of diagnostic ultrasonography in the assessment of disease states involving the extracranial carotid artery, the peripheral vascular system, and the major abdominal vessels. The current applications of color Doppler imaging (CDI) combined with conventional spectral Doppler are demonstrated.

Abdomen↗

PubMed1989

Duplex and color Doppler sonographic evaluation of vasculogenic impotence.

One hundred eighty patients with suspected vasculogenic impotence were evaluated with conventional penile duplex sonography with spectral analysis and color Doppler imaging. Measurements of mean peak systolic and end-diastolic velocities were obtained from the cavernosal arteries before and after intracavernosal injections of papaverine. Sixty-one patients were examined with dynamic cavernosography and cavernosometry, and 12 patients were studied with selective internal pudendal and penile arteriography. All five patients with abnormal arteriography had mean peak systolic velocities in the cavernosal arteries of less than or equal to 25 cm/sec (sensitivity, 100%; 95% confidence interval, 48-100%) after the injection of papaverine. Six of the seven patients with normal arteriography had mean peak systolic velocities of greater than 25 cm/sec (specificity, 85.7%; 95% confidence interval, 42-100%) after injection of papaverine. By using data from a receiver-operating-characteristic curve, we determined that end-diastolic velocities in the cavernosal arteries of greater than or equal to 5 cm/sec after the injection of papaverine correctly identified patients with excessive venous leakage on cavernosometry; the sensitivity was 90% (95% confidence interval, 77-97%) and the specificity was 56% (95% confidence interval, 30-80%). The addition of color Doppler sonography made the detection of vessels easier and the correction of the Doppler angle more accurate, resulting in more rapid and accurate acquisition of data. Penile duplex sonography with spectral analysis and color Doppler imaging are sensitive and noninvasive means of examining patients with potential vasculogenic impotence.

Adolescent↗

PubMed1988

Reoperative parathyroid surgery.

Reoperation for persistent or recurrent primary hyperparathyroidism immediately connotes a complex clinical management problem. Successful cure of hypercalcemia is less frequent whereas complications are more common compared to initial explorations. Of 212 patients operated on at the Mayo Clinic from 1978 through 1986, 189 (89%) were cured. Sporadic disease, multiple endocrine neoplasia, and familial hyperparathyroidism were found in 183 (87%), 20 (9%), and 9 (4%) patients, respectively. Prior to the most recent reoperation, these patients had undergone from one to five operations. Preoperative localization examinations were performed in 192 patients (91%). Cervical high-resolution, real-time ultrasonography, computed tomography, and thallium-technetium scintigraphy had sensitivity rates of 87%, 56%, and 71%, respectively. When the tumor was localized preoperatively, the operative time and cost were significantly reduced compared to nonlocalized tumors. Cervical reexploration only was required in 154 (72%), combined cervical and mediastinal exploration occurred in 46 (22%), and mediastinal exploration only was performed in 12 (6%). There was no perioperative mortality; permanent hypoparathyroidism developed in 33 patients (16%), and six patients (2.9%) suffered permanent unilateral vocal cord paralysis. Anatomically, the most frequent site to find a missed parathyroid adenoma was in the normal location. The large majority of these glands were removed through a cervical incision although, on occasion, they were retracted from the anterior superior mediastinum or the low tracheoesophageal space. These data confirm that reoperative parathyroid surgery can be performed safely, with a rather high degree of success, but too-frequently results in a lifetime morbidity of hypoparathyroidism.

Adolescent↗

PubMed1988

Insulinoma: the value of intraoperative ultrasonography.

Ideally, surgical exploration for insulinomas would be met with uniform success in both finding and removing the tumor, incurring no postoperative mortality or morbidity. In reality, however, insulinomas remain undetected by even experienced surgeons in 10 to 20% of patients, including present-day series. Additionally, postoperative complications may occur in 10 to 25% of patients, principally related to the pancreatic dissection. Although dispensing with any attempt to preoperatively localize the tumor has been advocated, most authors agree that localization efforts are necessary and helpful. To review the results and surgical implications of current localization techniques, 41 adult patients who were surgically treated for insulinomas at the Mayo Clinic from 1980 through June 1987, were reviewed. Tumor size ranged from 5 mm to 4 cm, and the sensitivity of tumor localization using arteriography, computed tomography, preoperative and intraoperative ultrasonography were 55%, 27%, 59%, and 90%, respectively. Since the introduction of intraoperative ultrasonography into our clinical practice in 1982, all 29 of our adult patients' insulinomas have been identified with a combination of this technique and palpation by an experienced surgeon. There were no false positive interpretations with intraoperative ultrasonography, and tumors were imaged in four patients that were not palpable. In 18 of these 29 (62%) patients, the information gleaned from the images appeared to influence the surgical management. While there is no substitute for exploration by an experienced surgeon, his ability is enhanced by the addition of both preoperative and intraoperative ultrasonography.

Adenoma, Islet Cell↗

PubMed1988

Insulinoma. The value of intraoperative ultrasonography.

After establishing the diagnosis of an insulinoma, most surgeons prefer preoperative localization. Selective arteriography has long remained the gold standard for this purpose, but its use has been met with variable success. Despite various attempts at localization, insulinomas remain undetected in 10% to 20% of patients, and there may be a postoperative complication rate of at least 10% to 25%. To review the results and surgical implications of current localization techniques, 36 adult patients who were surgically treated for insulinomas at the Mayo Clinic, Rochester, Minn, from July 1982 through June 1987 were studied. The sensitivities of tumor localization using arteriography, computed tomography, and preoperative and intraoperative ultrasonography were 53%, 36%, 59%, and 90%, respectively. A subset of 29 patients underwent intraoperative ultrasonography, and all of these patients' insulinomas were identified with a combination of this technique and intraoperative palpation, with nonpalpable tumors being imaged in four patients. In 18 patients (62%), information obtained from the images appeared to influence the surgical management. While there is no substitute for exploration by an experienced surgeon, exploration appears to be enhanced by the addition of intraoperative ultrasonography, particularly during reoperation.

Adenoma, Islet Cell↗

PubMed1988

Localization of pancreatic insulinoma: comparison of pre- and intraoperative US with CT and angiography.

Methods of preoperative radiologic localization of insulinoma were compared in 52 patients, 44 of whom had solitary tumors. Examinations performed in these 44 patients were preoperative ultrasonography (US) in 28, angiography in 26, and computed tomography in 23. Prospective sensitivities were 61%, 54%, and 30%, respectively. Imaging sensitivities were lower for the eight patients with multiple insulinomas. In 28 of the 44 patients, intraoperative US was performed without the examiner being aware of the surgical findings. The sensitivity was 84%. Four insulinomas were not palpable but were visualized sonographically. The combined sensitivity of intraoperative US and surgical palpation for detecting solitary insulinomas was 100%. High-frequency intraoperative US is valuable for detecting occult solitary insulinomas and considerably useful for determining the proximity of insulinomas to the pancreatic and bile ducts.

Adenoma, Islet Cell↗