Hepatic vessel segmentation on contrast enhanced CT image sequence for liver transplantation planning

Abstract

The structure and morphology of the hepatic vessels and their relationship between tumors and liver seg-ments are major interests to surgeons for liver surgi-cal planning. In case of living donor liver transplan-tation (LDLT), the most important step in determin-ing donor suitability is an accurate assessment of the liver volume available for transplantation. In addition, the mutual principles of the procedures include dis-section in the appropriate anatomic plane without portal occlusion, minimization of blood loss, and avoi-dance of injury to the remaining liver. It is essential first step to identify and evaluate the major hepatic vascular structure for liver surgical planning. In this paper, the threshold was determined to segment the liver region automatically based on the distribution ratio of intensity value; and the hepatic vessels were extracted with mathematical morphology transfor-mation, which called hit operation, that is slightly modified version of hit-and-miss operation on con-trast enhanced CT image sequence. We identified the vein using the preserved voxel connectivity between two consecutive transverse image sequences, followed by resection into right lobe including right hepatic vein, middle hepatic vein branches andleft lobe in-cluding left hepatic vein. An automated hepatic vessel segmentation scheme is recommended for liver sur-gical planning such as tumor resection and trans-plantation. These vessel extraction method combined with liver region segmentation technique could be ap-plicable to extract tree-like organ structures such as carotid, renal, coronary artery, and airway path from various medical imaging modalities.