[Segmental anatomy of the liver in computed tomography: do we localize the lesion accurately?].

Purpose: To evaluate if Couinaud's model using the planes of the major veins is an adequate tool for the presurgical localization of focal liver lesions.

Methods: Biphasic helical CT scans were performed on patients evaluated for liver resection using an increased IV bolus of contrast medium (180 ml lopamidol) and 2 mm image reconstruction increments. During the first evaluation, all liver lesions were localized in the conventional way using the planes of the 3 major hepatic veins and the portal trunks as segmental boundaries. In a second review, all lesions were attributed to the nearest peripheral portal branches. The path and the segmental attribution of the portal branches were analysed. Evaluations were performed using an interactive cine mode as well as three-dimensional reconstructions.

Results: 20 of 126 (16%) liver lesions had a different segmental location if the individual anatomy of the peripheral portal branch was used instead of the conventional technique. These different locations were due to the path of the portal trunks or the path of the peripheral portal branches crossing the planes of the major hepatic veins.

Conclusion: The segmental anatomy of the liver using the planes of hepatic veins and portal trunks according to Couinaud is not an accurate tool for the presurgical localization of liver lesions in many cases.