Computerized tomographic appearance of renal cysts after extracorporeal shock wave lithotripsy.

We identified cysts in five kidneys of four patients who had lithotripsy. Three of these kidneys were evaluated with CT scans the day before and the day after lithotripsy and showed no change. The other two kidneys were studied by CT only after extracorporeal shock wave lithotripsy; hemorrhage was shown in one and cyst wall thickening in the other.

Acute bilateral diffuse pulmonary shadowing after evacuation of hydatid mole.

Acute bilateral diffuse pulmonary shadowing complicates the resection of hydatid mole approximately 10% of the time. Etiologic factors include trophoblastic emboli, pulmonary emboli, high output congestive failure, and DIC. Prompt recognition and emergency oxygen therapy with PEEP are imperative for survival.

Computed tomography of low periesophageal focal fat collections.

Focal fat collections in the middle compartment of the lower mediastinum are reported in the literature. However, this explanation for a mass in that location is not widely recognized. We found four cases of focal fat collections on routine computed tomography.

Computed tomography of isolated osteoblastic colon metastases in the bony pelvis.

Skeletal metastases from colorectal carcinoma are unusual and osteoblastic metastases are quite rare. Three cases are described in which an isolated recurrence of a previous colorectal carcinoma occurred within the pelvic bones, without evidence of skeletal metastases elsewhere so that local spread via portocaval anastomoses in the pelvis is postulated. In all three cases, proliferative calcification and new bone formation occurred within an expansile, destructive lesion, suggesting the occurrence of a synergistic effect between the underlying bone and a malignant neoplasm which has a propensity to calcify.

Liver metastases: optimization of MR imaging pulse sequences at 1.0 T.

Twenty patients with known liver metastases were examined with magnetic resonance imaging; four different pulse sequences were used and six different images were produced to allow comparison of pulse sequence performance at a 1.0-T field strength. Pulse sequence performance was in each case calculated by measuring contrast-to-noise ratios (C/N) comparing normal liver, metastatic tumors to liver, and background noise.

Epipericardial fat pad: CT findings.

Epicardial and mediastinal fat around the apex of the heart may produce the classic appearance of a cardiac fat pad filling in the anterior cardiophrenic angle on a lateral chest radiograph. A review of 50 computed tomographic (CT) scans of the chest that were normal save for possible cardiomegaly, together with chest radiographs obtained within a 14-day interval, revealed a wide variation in the configuration of this fat pad in 16 patients (32%). Depending on geometric circumstances, the fat pad may produce a well-marginated region of increased density, a region of increased density with poor margination, or an area of reduced density lying anterior to the heart.

Tumor invasion of the anterior skull base: a comparison of MR and CT studies.

Seven patients who had tumors arising in the anterior face or paranasal sinuses and invasion of the anterior skull base were evaluated with magnetic resonance (MR) and high resolution CT. Magnetic resonance was superior in evaluating tumor encasement of the carotid artery and invasion of the cavernous sinus; for assessing the relationship of the tumor to the anterior brain, optic nerves, and optic chiasm; in providing coronal images free from dental artifact; and in determining tumor extent within the infratemporal fossa. Bone destruction was more easily observed on CT than MR.

The variable nature of the mediastinal contour lines: CT/chest radiography correlation.

Interfacing of the lung with the mediastinum produces a number of mediastinal lines including those due to the innominate veins, left subclavian artery, paratracheal stripe, both anterior and posterior junction lines, the azygo-esophageal recess, descending aorta and paraspinal lines. Displacement or absence of one or more of these lines may be due to an abnormality of mediastinal contour or may indicate a mediastinal mass, but can occur in normal subjects. Correlative findings between chest radiography and chest computed tomography in 50 normal subjects illustrate the variable nature of these lines.

MRI vs. high-resolution CT scanning: evaluation of the anterior skull base.

While magnetic resonance imaging (MRI) is no longer a tool of the future, its availability is limited. Most hospitals still use high-resolution computed tomography (CT) scanning as their major imaging modality. Although numerous articles point to the improved diagnostic uses of MRI--as compared to high-resolution CT--a change from high-resolution CT scanning to MRI scanning throughout the United States would cost billions of dollars.

Tumor detection with phase-contrast imaging: an evaluation of clinical potential.

The conspicuity of a variety of human tumors outside the liver, with a broad spectrum of histologic types, was evaluated using phase-contrast imaging (proton chemical shift imaging, proton spectroscopy) and the results compared with the data obtained using routine T1- and T2-weighted magnetic resonance (MR) imaging sequences. In all cases, tumors were most conspicuous using the phase-contrast technique. In two instances, the tumors could be discerned only by this method, being undetectable by any routine MR pulse sequence.

Respiration artifacts in MR imaging: reduction by breath holding.

Respiratory motion commonly produces degradation of image quality on magnetic resonance scans of the upper abdomen due to artifacts produced in the direction of the phase encoding gradient. Such artifacts may be reduced, although not eliminated, on image sequences obtained with relatively short acquisition times by means of breath holding during the middle 20% of the sequence.

Quantitation of the prominent medullary pyramid: a reappraisal.

We propose a revised objective measurement of the size of the renal medullary pyramid in the assessment of the prominent renal pyramid: the medullary-renal ratio (MRR). (Formula: see text). This is a more accurate assessment of the size of the renal pyramid relative to the size of the kidney than the previously proposed medullary pyramid index, which fails to take into account the varying morphology of otherwise normal kidneys.

Efficacy of abdominal computed tomography in evaluation of possible abdominal abscess.

A retrospective analysis was made of all abdominal computed tomography scans performed because of clinical suspicion of an abscess at our institution over a 12-month period. Of 130 patients examined, 45 patients had had abdominal surgery within the previous 2-week period. Of these patients, 14 were found to have abscesses on computed tomography, with three known false-negative studies.

Lower lobe collapse due to pleural effusion: a CT analysis.

In the presence of a pleural effusion, volume loss is seen in the adjacent lung, primarily in the lower lobe. With a modest effusion a compliant lower lobe may show displacement and generalized volume loss without focal atelectasis, but more commonly segmental atelectasis does occur, typically in the posterior basal segment. Large effusions result in a major degree of lower lobe collapse.

Sonography of experimental acute renal vein occlusion.

Complete occlusion of the renal vein in five rabbits with the kidney in its normal position was followed by high-resolution ultrasound. Early changes consisted of moderate renal enlargement and a diffuse increase in renal echogenicity with a fine echo pattern. On the average, renal length increased by only 13%.

The sonographic evaluation of hydronephrosis with progressive ureteric obstruction. An experimental model.

An experimental animal model was set up to examine the interrelationship between urine flow and progressive ureteric stenosis in producing sonographically detectable hydronephrosis. In four rabbits with mild ureteric stenosis or no stenosis the renal pelvis showed little distension even with rapid diuresis. Progressively tighter ureteric stenoses resulted in progressive renal pelvic distension accentuated by diuresis.

Plexiform neurofibroma of the pelvis in neurofibromatosis: CT findings.

Three cases of intrapelvic plexiform neurofibromas are presented in patients with neurofibromatosis. In all three cases computed tomography demonstrated widespread sheets of nodular tissue lying in an extraperitoneal location in front of the sacrum or extending along the pelvic sidewalls . Symptomatology in these patients related to compression of either nerve roots or adjacent vessels.

Computed tomography of mural thrombosis in the hypereosinophilic syndrome.

The hypereosinophilic syndrome characteristically involves multiple organs. Its most severe debilities are associated with cardiac and central nervous system complications. Endothelial damage can result in intracardiac thrombosis, endocardial fibrosis, and progressive congestive failure.

The renal parenchymal stone: a benign calcified renal mass.

Five patients are described, each with a densely calcified solitary mass in a peripheral location in the kidney. There was exophytic projection of the calcification in 4 cases. Three lesions were so completely calcified as to be regarded as stones.

Spinal lipoma presenting as a mediastinal mass: diagnosis by CT.

Spinal lipomas account for less than 1% of all spinal tumors. Prior to the advent of computed tomography, the preoperative diagnosis could only be suggested on the basis of nonspecific clinical and radiographic findings. We report a case of an unusual spinal lipoma that presented as a mediastinal mass.

Necrotic tumor simulating intraabdominal abscess: a case report.

The appearance of gas was observed within a lymphomatous mass at the time of therapy, simulating an abscess on computed tomography and abdominal radiography. There was no evidence that the tumor was infected. No fistula could be demonstrated between the mass and a hollow viscus, and phlegmonous necrosis of the tumor is suggested as an etiology.

Gastric manifestations of North American Burkitt's lymphoma.

Stomach involvement is rare in American Burkitt's lymphoma. Three cases were noted in 66 patients, and all were associated with large left upper quadrant masses. The appearance of Burkitt's lymphoma of the stomach is similar to other lymphomas and consists of diffuse infiltration of the wall, mucosal thickening, ulcerations, and intra- and extragastric masses.

Adrenal involvement in non-Hodgkin lymphoma.

Adrenal masses are described in seven cases of non-Hodgkin lymphoma in a series of 173 patients. In all seven patients the lymphoma was diffuse rather than nodular. Three patients had adrenal masses at the time of presentation, whereas in four cases the adrenal gland was a site of tumor recurrence after therapy.