Quantitative characterization of hepatocellular carcinoma and metastatic liver tumor by CT perfusion

Purpose: To evaluate the diagnostic value of computed tomography perfusion (CTP) in the distinction of hepatocellular carcinomas (HCCs) from metastatic liver tumors. Materials and methods: CTP data from 90 liver tumors (HCC 38, metastasis 52) in 31 patients (16 men and 15 women; mean age 60.3 years) were studied. CTP was performed on a 16/64 multidetector-row CT scanner using a 30-s duration cine acquisition after rapid bolus injection (5-7 ml/s) of 50-70 ml of iodinated contrast medium. The CTP data were analyzed using a deconvolution model. Metastatic tumors were grouped into hypovascular (n=36) and hypervascular (n=16) tumors. Results and conclusion: The hypovascular metastases showed a significantly lower blood flow (BF) and blood volume (BV), and higher mean transit time (MTT) than HCC (all P<0.0001). BF, BV, and MTT of HCCs were substantially lower than those of hypervascular metastases (P=0.02, P< 0.0001, P=0.03, respectively). A receiver-operating characteristic analysis showed that BV was a useful marker to distinguish HCCs from hypervascular metastases.