Tailored CT: primum non nocere.

Despite its vital diagnostic utility, the ionizing radiation used in CT is not benign. Patients have an increased risk of dying from a radiation-induced cancer for every pass through a CT scanner. One way to reduce this risk is to tailor CT, especially follow-up scans, to specific areas of concern.

Differential density of normal renal parenchyma on nonenhanced CT: a new observation.

Purpose: Nonenhanced CT scans through the kidneys commonly show a difference in radiopacity between the inner peripelvic portion of the renal parenchyma and the more peripheral regions of the renal parenchyma. This normal observation has not been described.

Method: We reviewed 50 nonenhanced CT scans.

Testicular feminization: radiologic considerations in a unique form of cryptorchidism.

A case report of complete testicular feminization is presented. The medical and radiological characteristics of this condition which distinguish it from male cryptorchidism and other disorders of sexual differentiation are discussed. To our knowledge, only three previous case reports have been published in the radiology literature.

Case report: intermittent sciatic herniation of the ureter.

Sciatic herniation is the rarest form of pelvic hernia. Herniation of the ureter into the sciatic foramen is extremely uncommon with only 11 cases reported in the literature. We describe an unusual case of intermittent herniation of the ureter during an intravenous urogram.

A survey of radiology clerkships at teaching hospitals in the United States.

Rationale And Objectives: The nature and extent of medical school radiology clerkships were qualified.

Methods: Questionnaires were sent to 126 medical school radiology departments in the United States. Queries were made regarding length and requirements for clerkships, methods of teaching, methods of student evaluation, and responsibility for these functions.

Loculated mediastinal chylothorax resulting from esophagogastrectomy: a case report.

The thoracic duct is closely related to the esophagus and the pleura. During an esophagogastrectomy, the thoracic duct is at risk for injury, which usually results in chylous pleural effusions. We present an uncommon situation, however, where the pleura was not violated and a large mediastinal lymph collection resulted.

Radiocontrast-associated renal dysfunction: a comparison of lower-osmolality and conventional high-osmolality contrast media.

Nephropathy is an established untoward event associated with intravascular administration of conventional high-osmolality contrast media (HOM). It has not been shown previously that lower-osmolality contrast media (LOM) are less nephrotoxic in a clinical setting. We evaluate the ability to replace HOM with LOM (in lower-extremity angiography) to reduce the incidence of nephropathy.

Radiocontrast-associated renal dysfunction: incidence and risk factors.

Contrast-induced nephropathy is a potentially serious untoward reaction to radiologic contrast media. The incidence of this nephropathy and the predisposing conditions are not well established, possibly because of methodologic differences between studies. We evaluated the incidence of contrast-induced nephropathy after femoral arteriography in 394 patients by using multiple definitions (different increases in serum creatinine or blood urea nitrogen levels at various times).

Stress incontinence secondary to a vesicourethral fistula: case report.

A previously unreported case of vesicourethral fistula in a female is presented. Its possible etiology and recommendations are discussed.

Excessive accumulation of normal retroperitoneal fat mimicking a neoplasm: urographic/CT correlations.

Computed tomography (CT) was performed on four patients in whom excretory urograms revealed marked displacement of the kidneys and/or ureters. CT in each case was remarkable for the presence of excessive accumulation of normal retroperitoneal fat and failed to document the existence of a retroperitoneal neoplasm, lymphadenopathy, or other pathological mass.

CT diagnosis of circumcaval ureter.

Variability in the normal course of the ureter makes it difficult to differentiate a normal variant from a congenital anomaly or deviation caused by a mass. CT can be useful in making this distinction. We present five cases of circumcaval ureter in which contrast-enhanced CT, by showing the ureter passing posterior and medial to the inferior vena cava (IVC), provided the definitive diagnosis.

Hyperbaric therapy for the removal of an obstructing intestinal tube balloon.

Gaseous distention of the mercury bag of intestinal long tubes has been known to result in small bowel obstruction. In the case presented, hyperbaric therapy was used to reduce the size of the impacted balloon and facilitate its removal. Hyperbaric therapy provides a safe, effective alternative to more invasive methods of balloon removal.

Renal oncocytoma: new observations.

Renal oncocytomas are uncommon, benign tumors that can be treated by local excision or heminephrectomy; their preoperative differentiation from renal cell carcinoma, treated by radical nephrectomy, would be invaluable. A particularly important finding, a central scar--not stressed in previous reports, is frequently demonstrated by CT examination. We evaluated radiographic studies of 18 pathologically confirmed cases of oncocytoma and compared findings with results of CT, sonography, and angiography studies of 18 renal cell carcinoma cases.

Mach bands and pneumomediastinum.

A thin line of apparent radiolucency is a frequent companion outline of the heart borders and the aortic knob. This usually represents a "negative" Mach band. On occasion, such lines can be confused with pneumomediastinum or pneumopericardium, especially if only a single postero-anterior (PA) film is available.

Computed tomography of abdominal fatty masses.

Computed tomographic (CT) scans of 34 cases of abdominal fatty masses were reviewed retrospectively in order to establish criteria for distinguishing benign conditions from malignant tumors. By evaluating location, attenuation, internal consistency, and margination, it is possible not only to make this distinction but frequently to suggest a specific diagnosis. Abdominal fatty masses that are sharply marginated, homogeneous, and that show CT numbers less than or equal to the patient's normal fat can be considered benign.

Radionuclide imaging and computed tomography in renal oncocytoma.

Renal oncocytoma is an apparently benign neoplasm that is being reported with increasing frequency. It is important to differentiate it from renal-cell carcinoma prior to surgery. Angiographic, CT, and ultrasound studies may suggest the diagnosis but are not pathognomonic.