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Purpose: To compare the performance of virtual and conventional colonoscopy for the detection of colorectal polyps using a multislice spiral CT scanner (MSCT). Materials and Methods: 48 patients (20 women, 28 men, mean age 61.5 5 years) with clinical indication for conventional colonoscopy were prospectively studied using a MSCT (Somatom Volume Zoom, Siemens, Forchheim). Examination was performed after standard oral preparation for colonoscopy and colonic distension with room air and i.v. butylscopolamin. Images were obtained in prone and supine position using a detector configuration of 4 × 1 mm, a table feed of 5 mm/rotation at 140 mAs and 120 kV. Slice thickness and reconstruction increment were 3 and 1.5 mm, respectively. CT data were assessed by two blinded radiologists on a Vitrea workstation (Vital Images, USA) using a software with multiplanar and volume-rendering capabilities. Results: 33 patients had normal findings on conventional colonoscopy. In 15 patients a total of 30 polyps and one carcinoma with stenosis were identified. MSCT-colonography identified the carcinoma and 23 polyps (77%). 3 of 3 polyps were 10 mm or more (100%), 6 of 7 were 5.1 to 9.9 mm (86%) and 14 of 20 were 5 mm or smaller (70%). There were 13 false positive findings for polyps (10 lesions < 6 mm in 5 patients) and no false positive finding of carcinoma. Conclusions: MSCT colonography allows accurate detection of polyps larger than 10 mm. Compared to published results of single-slice CT, multislice CT colonography increases the rate of detection of small colorectal polyps in particular. However, false positive results still remain a problem.

The value of colour Doppler sonography in the diagnosis of renal artery stenosis has been studied retrospectively. 17 patients were examined (34 main renal arteries and 7 accessory renal arteries; ages 37 to 84 years; 7 males and 10 females). We studied 1) ability to study the main renal arteries, 2) visibility of accessory renal arteries and 3) the sensitivity and specificity of colour Doppler sonography for the diagnosis of renal artery stenosis. The results were compared with intraarterial angiography. Demonstration of the main renal arteries with colour Doppler sonography was possible in 23 of the 34 vessels. Not a single of the 7 accessory renal arteries was demonstrated by colour Doppler sonography. Of 8 angiographically demonstrated stenoses (more than 50% narrowing) 2 were missed by colour Doppler sonography. One stenosis was correctly diagnosed and 5 were incorrectly evaluated by sonography. 16 out of 18 angiographically normal main renal arteries were correctly evaluated by colour Doppler sonography but 2 showed a false positive finding. This results in a sensitivity of 17% and a specificity of 89% per kidney. Colour Doppler sonography cannot be recommended as a screening method for renal artery stenosis in view of its limited accuracy.

CT was carried out in 50 patients with clinical suspicion of hyperparathyroidism, in order to localise the adenoma. In 45 patients, the diagnosis was confirmed at operation and adenomas or hyperplastic glands were removed. In the remaining five patients the diagnosis was not confirmed at operation, nor by the subsequent clinical course. On four occasions, CT correctly turned out to be negative and in one patient a false positive finding was obtained. Amongst the 45 patients, a total of 59 enlarged glands (adenomas or hyperplastic glands) were found at operation and removed. Pre-operative CT was positive and correct in 78% and negative and incorrect in 22%. Of eight adenomas in the mediastinum, seven could be recognised pre-operatively. Previous operations on the neck did not reduce diagnostic accuracy. The techniques and results are described and discussed.

Between 1965 and 1968, 6500 lymphograms were performed at the University of Gottingen. Amongst these, there were 412 patients with malignant testicular tumours. In 81 patients the results of lymphography could be checked histologically. There was agreement between the lymphographic and histological findings in 65 patients (80.3%), sensitivity of 98.1% (51 out of 52) and specificity of 48.3% (14 out of 29). In 50 patients CT was performed in addition. The findings agreed in 31 cases; in eight patients lymphangiography resulted in a false positive finding and CT was incorrect in 12 patients. In all patients with proven retroperitoneal metastases, one or the other method produced a correct diagnosis.

Selective venous sampling for parathormone estimations has become an important method in the diagnosis of primary hyperparathyroidism and, together with thyroid phlebography, is an accurate means for localising hormone active parathyroid tissue. Thirty-three patients were examined by this technique and in 25 of these an exploration was carried out subsequently. Twenty-one had primary hyperparathyroidism. In one case hormone analysis lead to a false positive finding. In 18 of these 21 patients, the hormone-active parathyroid tissue was correctly localised. Phlebography showed evidence of an adenoma in five patients, but is of most use for localising the source of the hormone.