SEGMENTAL ANATOMY OF THE LIVER - POOR CORRELATION WITH CT

PURPOSE: To evaluate qualitatively and qualitatively the current proce dures for radiologic delineation of the segmental and subsegmental ana tomy of the liver. MATERIALS AND METHODS: Vascular casts of 10 livers were examined with helical computed tomography (CT). Liver segmental a nd subsegmental anatomy were determined on the CT scans according to c ustomary radiologic practice guidelines. CT anatomic findings were com pared with authentic anatomic territories seen at anatomic examination . The differences were assessed qualitatively in five of the 10 livers . RESULTS: For the marginal (cranial and caudal) portions of the liver , an average (+/- 1 standard deviation) of 17.3% +/- 6.5 of the hepati c area visualized on axial CT scans was attributed to an incorrect sub segment. For the central zones (those adjacent to the right and left b ranches of the portal vein), this error amounted to 51.6% +/- 19.9. Ex pressed in absolute numbers, the error amounted to 40 mm on axial CT s cans. CONCLUSION: The radiologic determination of portal venous territ ories within the liver must be revised. The indirect landmarks current ly used are not reliable for proper delineation. Only procedures that account for the portal venous distribution pattern, including peripher al branches, will result in correct depiction of the complex and varia ble anatomic reality.