Spinal neurilemmomas and neurofibromas: central dot sign in postgadolinium MRI.

The MR studies of three histologically proven spinal neurilemmomas and neurofibromas were reviewed retrospectively. There were two benign neurilemmomas (schwannomas) and one neurofibroma. The common characteristic of these cases was a central low intensity focus ("dot") seen on postcontrast T1-weighted imaging. The low intensity foci corresponded histologically to a congeries of changes including edema, microcysts, foam cells, hyalinization of blood vessels, old hemorrhage, and dystrophic calcification.

Water as contrast medium for computed tomography study of colonic wall lesions.

A tap water enema combined with intravenous iodine contrast medium was used for computed tomographic (CT) study of the entire clean colon in 35 patients. Thirty of them showed a high suspicion of rectal, colon, or cecal pathology at either clinical examination, barium enema study, or endoscopy. The remaining five patients were examined for suspected local recurrence of carcinoma. This CT technique detected the wall abnormality in all but one case with two small adenomatous polyps. This procedure, which is simple, inexpensive, and has a good acceptance and tolerance, can accurately detect mural wall abnormalities.

Use of water or air as oral contrast media for computed tomographic study of the gastric wall: comparison of the two techniques.

Thirty-four patients with a high suspicion of gastric lesion at endoscopy were studied by two computed tomographic (CT) techniques: one using a gas-producing agent and the other using water as an oral contrast media. Intravenous contrast medium was also given in all patients who underwent the water technique. Final histologic proof was obtained either by endoscopy or at surgery. Both CT techniques detected the wall abnormality in 32 of the 34 patients, and both techniques missed the same lesion in two patients. The water technique showed more gastric wall details and the lesion's limits could be defined more accurately. The acceptance and tolerance of the gas-producing agent was better in severely ill patients than tap water.

CT demonstration of normal gastric wall thickness: the value of administering gas-producing and paralytic agents.

The authors analysed the CT-findings in 100 normal subjects who underwent a modified double-contrast technique (D.C.). The mean gastric wall thickness in four areas was measured and the contribution of the D.C. technique is discussed.