Primary malignant melanoma of the anterior mediastinum: CT and MR findings.

Malignant melanoma presenting in the mediastinum without an extrathoracic primary is extremely rare. To our knowledge, its imaging findings have not been described in the radiologic literature. We report a case of primary malignant melanoma of the anterior mediastinum and discuss its imaging findings on computed tomography and magnetic resonance imaging.

Mycotic pulmonary artery aneurysm diagnosed 18 years after bacterial endocarditis.

A 21-year-old woman with a history of bacterial endocarditis and ventricular septum defect repair was referred for evaluation of a mass in the right mid-lung field. A contrast-enhanced computed tomography scan of the chest showed an aneurysm of the right lateral pulmonary artery. The aneurysm was considered to be mycotic in origin. The aneurysm was treated by coil embolization using 19 detachable coils measuring 425 cm in overall length.

Perforated colonic diverticulitis mimicking urachal carcinoma: computed tomography and magnetic resonance findings.

We report on a case of perforated diverticulitis of the sigmoid colon, which mimicked urachal carcinoma, and discuss its radiological findings.

Diffusion-weighted magnetic resonance imaging in pituitary abscess.

Pituitary abscess is a rare but potentially life-threatening disease. The correct preoperative diagnosis of pituitary abscess is difficult and rarely made. We present a case of pituitary abscess where diffusion-weighted magnetic resonance imaging was useful in making the preoperative diagnosis of pituitary abscess.

Ectopic thyroid in the adrenal gland: Computed tomography findings.

Ectopic thyroid in the adrenal gland is extremely rare, and its radiologic findings have not been reported in the radiologic literature. A case of ectopic thyroid in the adrenal gland is reported, and its imaging findings on computed tomography are discussed.

Serial diffusion-weighted magnetic resonance imaging in methanol intoxication.

We report the serial magnetic resonance imaging (MRI) findings in a case of methanol intoxication. A 50-year-old man who had accidentally ingested methanol was admitted to our institution. The patient was almost blind, and became comatose. The MRI showed bilateral putaminal lesions with restricted diffusion. The MRI, which was performed on the third day after admission, showed new lesions in the subcortical white matter. The patient's general condition improved. His visual acuity, however, did not improve.

Temporal subtraction of thin-section thoracic computed tomography based on a 3-dimensional nonlinear geometric warping technique.

The authors developed a computer system that automatically produces temporal subtraction images on thin-section thoracic computed tomography based on a 3-dimensional nonlinear geometric warping technique. The automated subtraction system was applied to data from 20 subjects with lung diseases. Nineteen (95%) of 20 results showed good or excellent image quality. The remaining 1 (5%) showed adequate image quality. Our preliminary computer system demonstrates the potential for a clinically useful automated subtraction system.

Cerebral lipiodol embolism after transcatheter arterial chemoembolization of hepatocellular carcinoma.

A case of cerebral lipiodol embolism after transcatheter arterial chemoembolization (TACE) of hepatocellular carcinoma is presented. A 76-year-old man underwent TACE for advanced hepatocellular carcinoma. Immediately after chemoembolization, his level of consciousness deteriorated. Computed tomography revealed deposition of iodized oil in the cerebral cortex, basal ganglia, and thalami. Magnetic resonance imaging showed restricted diffusion within the thalami and basal ganglia. The patient's level of consciousness gradually improved, and all neurologic symptoms disappeared over 6 weeks.

Coil embolization of an arteriobiliary fistula caused by hepatic intra-arterial chemotherapy.

Arteriobiliary fistula is a rare complication of hepatic intra-arterial chemotherapy. We report successful coil embolization of an arteriobiliary fistula. An 80-year-old woman underwent percutaneous placement of an indwelling catheter into the replaced right hepatic artery for intra-arterial chemotherapy of liver metastases. Coil embolization of the left hepatic artery was not performed. The patient complained of abdominal pain during intra-arterial chemotherapy. Angiography revealed a fistula between the replaced right hepatic artery and the common bile duct. The fistula was successfully treated by coil embolization via the indwelling catheter, and the indwelling catheter was removed. Although such complications usually herald the termination of intra-arterial chemotherapy, the patient underwent percutaneous implantation of a new catheter-port system, and intra-arterial chemotherapy was restarted.

Gastrointestinal stromal tumor of the retroperitoneum: CT and MR findings.

Gastrointestinal stromal tumor (GIST) is a non-epithelial neoplasm arising from the wall of the gastrointestinal (GI) tract. Although the majority of GISTs are located in the GI tract, some GISTs occur in the omentum, mesentery and retroperitoneum. GIST arising in the retroperitoneum is extremely rare, and its radiological findings have not been well described. We report a case of primary retroperitoneal GIST and discuss its imaging findings.