Intracaval and intracardiac extension of malignant thymoma: CT diagnosis

There is disagreement about the ability of CT to detect isolated invasion of mediastinal vessels by malignant thymoma. Diagnosis usually depends on the absence of intact fat planes between the tumor mass and the adjacent vessel. We describe a rare case of CT demonstration of direct intraluminal invasion of a malignant thymoma into the superior vena cava and the right atrium.     

Pelvic lipomatosis: diagnosis using computed tomography.

Pelvic lipomatosis is a rare, benign disease in which the characteristic roentgenographic findings may mimic those of pelvic malignancy. In the past more than two-thirds of reported cases have been explored surgically for diagnosis. We present 2 cases to demonstrate how the definitive diagnosis of pelvic lipomatosis can be made with the aid of computed tomography to avoid invasive techniques.     

CT urography

With the advent of multi-detector row CT scanners, evaluation of the urothelium of the entire urinary tract with high-resolution thin sections during a single breath-hold has become a reality. Multidetector CT urography (MDCTU) is a single examination that allows evaluation of potential urinary tract calculi, renal parenchymal masses, and both benign and malignant urothelial lesions. Initial results with this new technique are encouraging. Current investigations of MDCTU focus on methods to improve opacification and distension of the upper urinary tract-the collecting systems, pelvis, and ureters. The role of abdominal compression, infusion of saline and/or furosemide, and optimal time delay of excretory phase imaging is being explored. Upper tract urothelial malignancies, including small lesions less the 5 mm in diameter, can be detected with high sensitivity. Methods to reduce radiation exposure are being explored, including split-bolus contrast injection techniques that combine nephrographic and excretory phases into a single phase. It is likely that in the near future, radiological evaluation of significant unexplained hematuria or of known or prior urothelial malignancy will consist of a single examination--MDCTU.     

CT appearance of abdominal thorotrast deposition and Thorotrast-induced angiosarcoma of the liver

Although the clinical and radiographic manifestations of Thorotrast and its complications have been described, the computed tomographic (CT) appearance of Thorotrast deposition in the abdomen is less well known. Thorotrast produces a characteristic opacification of the liver, spleen, and abdominal lymph nodes. We report two cases of patients with Thorotrast-induced angiosarcoma of the liver detected by CT. Computed tomography in both cases demonstrated space-occupying lesions in the liver, which were readily detectable because of distortion of the Thorotrast-produced opacification.     

CT diagnosis of tumor thrombosis of the renal vein and inferior vena cava.

Four cases of tumor thrombosis of the inferior vena cava and renal veins were diagnosed by computed tomography. In two, the thrombus itself was demonstrated within the vascular lumen after intravenous injection of urographic contrast material. The diagnosis was made in the other two patients by identification of massive enlargement of the vascular diameter.