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Biomedical subjects

N R Dunnick

Publications and source records attributed to N R Dunnick.

At least 163 records · Page 9Linked to original sources

Intraarterial digital subtraction angiography in hypertensive azotemic patients.

Ten intraarterial digital subtraction angiography studies in nine azotemic patients were reviewed to assess the technical adequacy and the effect of contrast load on renal function. All studies were of diagnostic quality. In only two of 10 studies was there a mild transient deterioration in the degree of renal insufficiency. Intraarterial digital subtraction angiography is a reliable method that can be used to evaluate the renal arteries, even in the presence of azotemia.

Aged↗

Computed tomography of the normal mesentery.

Thirty patients were studied to evaluate the CT appearance of the normal mesentery and its vasculature. Mesenteric vessels were identified by determining their relations to segments of the small bowel and colon in the 30 patients. Jejunal and ileal branches supplying small bowel were identified in all patients. The ileocolic and right colic branches of the ascending colon were identified in 27 and 26 patients, respectively; middle colic vessels were identified in 29 patients. Left colic branches were identified in only 14 patients; sigmoid branches were identified in 23 patients. The vessels showed a characteristic wavy appearance as they coursed through mesenteric fat. The average attenuation of the mesenteric fat was -117.4 +/- 7.9 H. Normal lymph nodes were not routinely identified within the mesentery. Various pathologic processes altered the normal appearance of the components of the mesentery.

Adipose Tissue↗

Ventilation-perfusion scanning and pulmonary angiography: correlation in clinical high-probability pulmonary embolism.

During a 3-year period, 173 clinically selected patients underwent pulmonary angiography to confirm or exclude acute pulmonary embolism. All patients had undergone ventilation-perfusion (V/Q) scanning (167 patients) or perfusion scanning alone (six) before angiography. Angiography was done because the results of the V/Q scanning did not satisfy the clinician's needs for certainty. The results of the V/Q and studies were compared to determine the relative accuracy of V/Q scanning in this clinical setting. Pulmonary embolism was found in seven (15%) of 47 patients with low-probability scans, 11 (32%) of 34 patients with intermediate-probability scans, 22 (39%) of 57 patients with indeterminate scans, and 23 (66%) of 35 patients with high-probability scans. In this clinically selected population, low-probability scans were more accurate in excluding pulmonary embolism than were high-probability scans in establishing that diagnosis.

Humans↗

Computed tomography of the kidney.

Computed tomography has had a dramatic impact on the practice of uroradiology. The transverse image plane and excellent density differentiation allow more accurate diagnoses and often preclude the necessity for more invasive diagnostic tests or surgery. Refinements in equipment and diagnostic techniques promise further improvements in diagnosis and disease monitoring.

Adenocarcinoma↗

Computed tomography of renal oncocytoma.

Six patients with small solid renal tumors were evaluated by computed tomography (CT). Two patients had renal oncocytomas, three had small renal cell adenocarcinomas, and one had separate foci of each of these tumors in the same kidney. We describe several features that may alert the clinician to the possible presence of oncocytoma. We found, however, that unless the dense central scar that can be seen in larger oncocytomas is visualized on CT (as was the case in one of our patients), differentiation between oncocytomas and renal cell carcinomas by CT is not possible.

Adenocarcinoma↗

Subcapsular pancreatic pseudocyst of the kidney.

Pancreatic pseudocysts are a well-known complication of pancreatitis and may occur in unusual locations. We report a case of a child with hereditary pancreatitis who developed a subcapsular pseudocyst of the left kidney. The constellation of findings of calcific pancreatitis and a left renal subcapsular fluid collection should raise the possibility of a subcapsular pseudocyst.

Child↗

Perinephric hemorrhage from metastatic carcinoma to the kidney.

Retroperitoneal hemorrhage caused by a renal tumor is usually due to a renal cell carcinoma or angiomyolipoma. The authors report a case of computed tomographic (CT) demonstration of renal metastases from choriocarcinoma with an associated perinephric hemorrhage. The CT features indicated the acute nature of the hematoma and its confinement within the extracapsular compartment of the perirenal space.

Adolescent↗

The radiology of juxtaglomerular tumors.

Nine cases of proven juxtaglomerular tumor of the kidney are reviewed. Each patient presented with hypertension; elevated peripheral renin levels were found in four patients. As in past studies, this tumor occurred more frequently in women (7/9 cases). Although the patients tended to be younger (mean age, 31 years) than those with essential hypertension, all but two patients were more than 20 years of age. In all cases, the tumor was solitary, well-defined, and curable by surgery. The tumor was identified by excretory urography in 5/8 patients who underwent this procedure. A solid renal mass was detected in each of the seven patients examined by ultrasound. Since the tumor tends to be isodense with normal renal parenchyma, it is sometimes not seen on computed tomography without intravenous contrast material. Arteriography revealed a hypovascular mass in each of the nine patients. The combination of a hypovascular solid renal mass in a patient with elevated renin but no renal artery lesions should suggest the diagnosis of a juxtaglomerular cell tumor.

Adolescent↗

Primary lower extremity lymphedema: CT diagnosis.

The CT findings of two cases of primary lymphedema of the lower extremities are presented. CT showed a coarse, nonenhancing, reticular pattern in an enlarged subcutaneous compartment. CT excluded the diagnosis of secondary lymphedema from an obstructing mass by demonstrating a normal retroperitoneum and pelvis. The CT findings are correlated with pedal lymphangiograms.

Adult↗

The radionuclide renogram as a predictor of relative renal blood flow.

Radionuclide renograms obtained with Tc-99m-DTPA were used to calculate relative renal blood flow in 16 dogs. In 13 of these dogs, relative blood flow ratios (R:L) calculated from the renograms were correlated with ratios measured with an electromagnetic flowmeter or with radiolabeled microspheres. The results indicate that Tc-99m-DTPA renograms can be used to make an accurate prediction of relative renal blood flow.

Animals↗

Age-related changes in the thymus gland: CT-pathologic correlation.

Recent reports suggest that computed tomography (CT) is useful for thymoma detection in patients with myasthenia gravis. However, that usefulness may be conditioned by the state of the normal thymus. To examine this concept, the CT findings in 64 consecutive patients with histologic confirmation of thymic status after thymectomy or thymic biopsy during mediastinal exploration were reviewed. The normal thymus has a bilobed, arrowhead-shaped cross section at all ages, with gradual focal or diffuse fatty infiltration of the parenchyma usually occurring between 20 and 40 years of age. A thymoma is usually a spherical or oval mass, often producing a focal, distinct bulge in the adjacent pleural reflection. The differentiation of thymoma from normal thymus should be possible in most patients if age-related changes in the normal gland are appreciated.

Adolescent↗

Closed-system venography in the evaluation of angiodysplastic lesions of the extremities.

Closed-system venography is a minimally invasive, well tolerated method for diagnosing and delineating extremity angiodysplastic lesions. This method involves passive filling of the vascular tree after compressive exsanguination of an extremity and extrinsic occlusion of its arterial supply and venous drainage, thereby creating a static, closed system. Closed-system venography was done in 17 patients, where it correctly identified 11 of 12 surgically confirmed vascular abnormalities. There were no false-positive examinations. Whereas ateriography remains the examination of choice in studying arteriovenous malformations, closed-system venography has demonstrated a superior ability to diagnose and define lesions of capillary and venous origin.

Adolescent↗

Abdominal computed tomography in small cell lung cancer: assessment of extent of disease and response to therapy.

Abdominal computed tomography (CT) was performed as part of the initial staging evaluation in 77 patients with small cell carcinoma (SCC) of the lung. CT scans revealed mass lesions in 26 patients (34%). Abnormalities were confined to the liver in 15 patients and to retroperitoneal structures (lymph nodes, adrenal glands, psoas muscle region masses) in eight, and occurred in both areas in three. However, only three of 29 patients otherwise staged as having limited disease (confined to one hemithorax and regional nodes) had evidence of abdominal metastases on CT scan. Most (23/26) positive studies were in patients already known to have more extensive tumor dissemination. In 71 patients with pathologic confirmation of liver status, CT had a sensitivity of 63%, specificity of 91%, and overall accuracy of 85% in assessing the liver. Comparison of radionuclide liver scan findings with hepatic biopsies gave similar results. During therapy, 65 follow-up CT scans were obtained in 46 patients. Scan abnormalities improved or disappeared in 11/12 cases with tumor response documented in other ways, appeared or worsened in 5/13 cases of tumor progression that was diagnosed by other tests, and only rarely (2/65 scans) improved at the time of documented tumor progression, or vice versa. In only three patients, however, did CT scan provide the sole site of evaluable disease during treatment or detect either the only area of residual disease in a patient in otherwise complete remission or the initial evidence of tumor progression. Although abdominal CT scans in SCC can demonstrate metastatic dissemination not evaluable by other means, they provide relatively little therapeutically relevant information beyond that obtained with standard staging procedures.

Abdominal Neoplasms↗

Seminal vesiculography: limited value in vesiculitis.

Seminal vesiculograms were performed on 44 men being evaluated for chronic perineal pain consistent with seminal vesiculitis. The vesiculograms were performed prior to antibiotic instillation into the vas deferens. Vesiculograms were abnormal in 32 of the 44 patients (73%). The most common abnormality was the presence of multiple small diverticula producing a feathery appearance of the vas deferens (64%), a finding present in only 19 per cent of patients being evaluated for infertility and 20 per cent of normal patients. Asymmetry and incomplete filling of the seminal vesicles were less common abnormalities. Seventeen of these patients had seminal vesiculectomies for persistent or recurrent pain, and 15 have been followed long enough to assess the results. The histologic examination of the excised seminal vesicles was abnormal in only 3 patients (20%), despite radiographic abnormalities in 10 (67%) and improvement after surgery in 12 (80%). Seminal vesiculography may be useful to exclude anatomic abnormalities prior to instillation, but does not appear sufficiently specific to warrant use as the primary diagnostic examination for patients suspected of having seminal vesiculitis.

Adult↗