Improved detectability of VX2 carcinoma in the rabbit liver with contrast enhancement in computed tomography.

Detection of liver metastases by CT scanning depends on both size and difference in attenuation between the metastasis and the surrounding liver parenchyma. VX2 carcinoma cells were injected into the liver parenchyma of rabbits which were subsequently scanned under suspended respiration before, during and after infusion of iothalamate ethyl ester, a particulate contrast agent. The results demonstrate the greater attenuation difference between tumor and parenchyma required for the detection of smaller lesions. Contrast enhancement was most beneficial in the detection of tumors having diameters less than the scan section width.