Background During scanning of the right hypochondrium and right intercostal regions with an ultrasonic transducer,several ultrasonic images of oblique sections are obtained.It is still a challenge for ultrasonography to divide these nonconventional sections into an accurate hepatic segmentation patt.The aim of this research was to investigate the value of the virtual hepatic segment model (VHSM) in assisting the ultrasonic localization of space-occupying hepatic lesions.Methods VHSM was constructed via 3D reconstruction according to the first Chinese visible human dataset.Preoperative ultrasonography,contrast-enhanced CT scan and VHSM techniques were performed in 100 patients with spaceoccupying focal lesions in the liver parenchyma for segmental localization.The results of these three techniques were compared with the operative findings.Results VHSM was successfully detected on 2D sectional images by 3D reconstruction through surface rendering and volume rendering.The model could simulate ultrasonic directions to conduct a virtual dissection on any section plane,and fine liver segmentation could be displayed in any virtual plane.In 100 patients,there were 112 liver space-occupying focal lesions distributed in 148 liver segmentations.Regarding the positioning accuracies for lesions of different sizes and the lesion segmental distribution accuracies estimated using the three methods mentioned above,ultrasonography exhibited a significantly lower accuracy than VHSM for the segmental localization of lesions (P ＜0.05),and contrast-enhanced CT was not significantly different from ultrasonography plus VHSM (P ＞0.05).Conclusion VHSM increased the accuracy of ultrasonic localization of space-occupying hepatic lesions,particularly in hepatic hypovascular regions.