Low-dose hepatic computed tomography perfusion imaging and its preliminary study.

Objective: Computed tomography perfusion imaging (CTPI) is a rapid and non-invasive functional imaging method that reflects hemodynamic changes of liver diseases. However, its large radiation dosage limits its clinical application. We aimed to evaluate the feasibility of low-dose CTPI in normal liver and its preliminary application in hepatocellular carcinoma (HCC).

Methods: CTPI was performed in 34 healthy volunteers randomly divided into three groups with different applications of tube current, including a conventional dose group, a median-dose group and a low-dose group. The perfusion parameters of each group were compared and a low-dose CTPI was performed in 13 patients with HCC.

Results: Relatively satisfying images and perfusion parameters of liver CTPI were acquired with the different tube currents. There were no significant differences between the parameters of the three groups (P>0.05). The effective dosage of conventional, median and low-dose liver CTPI were 19.62 mSv, 12.61 mSv, and 7.01 mSv, respectively. The radiation dosage of low-dose liver CTPI was reduced to 64.27% compared with that of the conventional group. The hepatic blood flow, hepatic blood volume and hepatic perfusion index of HCC were higher than background liver parenchyma and normal liver.

Conclusions: Low-dose liver CTPI obtained similar perfusion parameters result to that of the conventional-dose, whereas the radiation dosage was reduced by 2/3. Low-dose liver CTPI can reflect the hemodynamic change of HCC. Low-dose liver CTPI has potential clinical value for diagnosis and differential diagnosis of liver diseases.