Xenon-inhalation computed tomography for noninvasive quantitative measurement of tissue blood flow in hepatocellular carcinoma.

Abstract

The purpose of this study was to separately measure the arterial and portal venous tissue blood flow (TBF) of hepatocellular carcinoma (HCC) with a noninvasive method using xenon inhalation CT (xenon-CT) and to differentiate between well-differentiated HCCs and moderately and poorly differentiated HCCs. Total, arterial and portal venous TBFs of 38 surgically proven HCC nodules from 38 patients were measured by means of xenon-CT. Serial abdominal CT scans were obtained before and after inhalation of nonradioactive xenon gas. TBF was computed using the Fick principle, after which the correlation between TBF and pathologic features of the tumors was determined. Total, arterial, and portal venous TBFs of HCC were 125.7 +/- 59.9 mL/min/100g, 102.5 +/- 37.3, and 22.2 +/- 11.4, respectively, and the corresponding findings for hepatic parenchyma were 67.3 +/- 13.1, 25.2 +/-9.6, and 42.4 +/- 11.0. Total and arterial TBFs of HCC were significantly higher than those of the hepatic parenchyma (P < 0.01), whereas portal venous TBF of HCC was significantly lower than that of hepatic parenchyma (P < 0.01). Arterial TBF of moderately or poorly differentiated HCC (120.4 +/- 38.2) was significantly higher than that of well-differentiated HCC (60.4 +/- 43.5) (P < 0.01). Arterial and portal venous TBFs of HCC could be measured separately, noninvasively, and safely with xenon-CT. Correlation between TBF and pathologic features of tumors indicate that xenon-CT can be used to differentiate between well-differentiated HCCs and moderately and poorly differentiated HCCs.