Increased detectability of liver metastases by the use of contrast enhancement in computed tomography. A comparison between the precontrast, the immediate postcontrast and the one hour postcontrast scan.

The precontrast, immediate postcontrast and the one hour postcontrast CT scans were analysed in search for liver metastases in 75 patients with malignant disease. The use of high dose intravenous contrast medium (42 g I) increased the number of hepatic metastases detected. The one hour postcontrast scan revealed a few more lesions than the immediate postcontrast scan. Further investigations on this subject are necessary before any definite conclusions can be made as our series of patients is small. In routine CT the most practical procedure in search for liver metastases is: 1) Scanning of the liver without contrast medium. 2) Incremental dynamic scanning during and immediately following injection of contrast medium. 3) If there is still uncertainty: Scanning at a later time, for example at one hour after injection of contrast medium.