Helical scanning CT for hepatocellular carcinoma.

To evaluate the clinical usefulness of helical scanning CT for hepatocellular carcinoma, 39 patients were examined using a Toshiba CT system, the Xforce. Helical scanning CT data were acquired using up to 20 continuous 1.5-sec rotations, with contrast medium bolus injection of 100-150 ml at a rate of 1.5-3 ml/sec, and during a single breath-hold. Scanning was begun 35 to 50 sec after the start of injection. Helical scanning CT permits axial images to be reconstructed at any desired position within the scanned area, and provides images without interslice gaps caused by respiratory movement. Contrast enhanced helical scanning CT permits blood vessels to be clearly displayed following the bolus injection of contrast medium using an automatic injector. Furthermore, the shorter scanning time makes it possible to scan the target area in the desired vascular phase. In all 39 patients who were examined using contrast enhanced helical scanning CT, high-quality three-dimensional images were obtained. Such images were particularly useful for assessing the three-dimensional relationships among high density tumors and vascular structures. In conclusion, helical scanning CT was considered to be useful for hepatocellular carcinoma.