Effect of prostaglandin E1 on contrast enhanced CT of the liver: statistical analysis during arterial portography.

PURPOSE To determine the diagnostic effect of prostaglandin E(1) on contrast enhancement quality of CT during arterial portography (CTAP). MATERIALS AND METHODS Our patients population included 30 patients (11 women, 19 men; age range, 41 approximately 81 years) with liver tumors (23 hepatocellular carcinoma and 7 metastatic liver tumor) who had undergone angiography. We divided the 30 patients, who had undertaken CTAP twice, into two groups at random (group A; n=15, group B; n=15). In group A, first CTAP was performed without prostaglandin E(1). Approximately 5 minutes later, a second CTAP was again initiated 30 seconds after injection of prostaglandin E(1) under the same conditions. In group B, prostaglandin E(1) was injected before the first CTAP only. We measured the mean CT numbers and standard deviation (SD) numbers of anterior, posterior, medial and lateral segments in the liver at the same section of the CTAP using the same size and location of the regions of interest, and these values with and without prostaglandin E(1) were compared. RESULTS 1) CT numbers: The CT numbers were significantly increased in the medial segment after the injection of prostaglandin E(1) (p<0.05) in all cases of both groups. On the other hand, they were clearly decreased in the posterior segment after the injection of prostaglandin E(1) (p<0.05) in both groups. There were no statistical differences in the CT numbers in the anterior and lateral segments in all patients. In addition, the CT numbers of anterior and posterior segments showed high attenuation compared with the medial and lateral segments in group A without prostaglandin E(1). 2) SD numbers: The SD numbers, which are an index of the homogeneous enhancement, were significantly decreased in the posterior, medial and lateral segments after the injection of prostaglandin E(1) (p<0.01, p<0.05, p<0.01, respectively) in both groups. There were no significant differences in the SD numbers in the anterior segment regardless of the injection of prostaglandin E(1) in all cases. CONCLUSION CTAP with injection of prostaglandin E(1) makes contrast enhancement of liver parenchyma more homogeneously than the conventional procedure, and it may be a useful technique for the detection of liver tumors.