Objective: To compare the consistency between contrast-enhanced CT and contrast-enhanced magnetic resonance imaging (CE-MRI) for determining the volume of tumor in the same patient with hepatocellular carcinoma (HCC) by 3D segmentation technique. 
Methods: The data of 60 HCC patients with initial diagnosis in the Second Xiangya Hospital of Central South University without any previous treatment from November 2014 to December 2018 were retrospectively collected. All patients underwent both contrast-enhanced CT scan and CE-MRI examination. The tumor volume corresponding to each imaging examination was calculated by the 3D lesion segmentation technique using region-based active and contour model, and then their consistency was analyzed.
Results: Fifteen cases were excluded for atypical imaging manifestations, so a total of 60 target lesions in 60 patients were analyzed (the largest lesion was selected in cases with multiple lesions). The mean volume of tumor in the 60 patients measured by enhanced CT was (22.72±7.49) cm3, by CE-MRI image was (23.53±7.64) cm3. There was no statistical difference between the two imaging methods in measuring tumor volume (t=0.59, P=0.55). The results of linear regression model showed that there was a strong correlation between the lesion volumes measured by the two imaging methods (r=0.99, 95% CI=0.97–0.99).
Conclusion: In determination of the lesion volume of HCC with 3D segmentation technique, the results obtained by contrast-enhanced CT and CE-MRI are highly consistent.