COMPUTED-TOMOGRAPHY OF EXPERIMENTAL LIVER METASTASES USING AN IODINATED HEPATOCYTE-SPECIFIC LIPID EMULSION - A CORRELATIVE STUDY IN THE NUDE RAT

RATIONALE AND OBJECTIVES. A hepatocyte-specific iodinated lipid emulsion, NRI 757, was used for detection of experimental hepatic metastases. MATERIALS AND METHODS. The study was performed in a correlative model of multiple hepatic metastases from a human colonic cancer implanted in the nude rat. RESULTS. After intravenous injection, normal liver parenchyma remained enhanced for several hours, whereas the uptake in hepatic metastases was negligible, A liver-to-lesion contrast of 45 Hounsfield units (HU) was obtained at a dose of 1 mt NRI 757/kg body weight (BW). In a lesion-by-lesion analysis of 177 metastases ranging in size from 1 to 32 mm, the mean +/- standard deviation overall detection rate for native scanning and contrast-enhanced scanning in vivo and post mortem, 20 +/- 0.4%, 53 +/- 5.2%, and 55 +/- 4.0%, respectively and 28%, 84%, and 82%, retrospectively. When metastatic size also was considered, for native scanning the maximum detection rate of 61% was reached for 8- to 10-mm lesions, whereas for contrast-enhanced computed tomography scanning, 100% of the 5- to 7-mm lesions and 42% of the 1- to 2-mm nodules were detected. CONCLUSION. The use of NRI 757 improved the diagnostic yield considerably.