Computed Tomography Of Experimental Liver Abscesses Using A New Liposomal Contrast Agent

RATIONALE AND OBJECTIVES. Evaluation of computed tomographic enhancement characteristics of a new liposomal contrast agent (liposomal iodixanol [LI]) in a pyogenic liver abscess model in 17 rabbits.METHODS. Eight to 14 days after abscess induction (Escherichia coli), density-time curves were calculated for regions of interest in liver, abscess nail and center, spleen, portal vein, abdominal aorta, inferior vena cava, and kidney. Images were obtained every minute between 1 and 10 minutes, every 5 minutes between 15 and 60 minutes, and 75 minutes after 200 mg/kg LI application (group A: 7 rabbits) and after 600 mg/kg iopentol application (group B: 10 rabbits), and 90, 105, and 120 minutes after LI.RESULTS. The abscess wall-liver contrast after LI lasted from 10 to more than 120 minutes with a maximum of 30 Delta Hounsfield Units (HU) at 45 minutes. For iopentol, the abscess wall-liver contrast lasted from 2 to 7 minutes with a maximum of 8 Delta HU at 5 minutes, The abscess wall-center contrast after LI lasted from 1 to more than 120 minutes with a maximum of 112 Delta HU at 40 minutes. For iopentol, the abscess wall-center contrast lasted from 1 to 75 minutes with a maximum of 79 Delta HU at 1 minute. The liver-portal vein contrast after LI lasted from 1 to more than 120 minutes with a maximum of 100 Delta HU at 20 minutes. For iopentol, the liver-portal vein contrast lasted from 1 to 8 minutes with a maximum of 38 Delta HU at 2 minutes. An abscess wall was detected in a higher percentage of the LT images (86% LI, 56% iopentol),CONCLUSIONS. The diagnostic value of LI exceeds that of iopentol in terms of overall abscess contrast and duration of the diagnostic interval. The higher hepatic vessel contrast allows better abscess localization.