Preoperative evaluation of future remnant liver function is critical for patients undergoing hepatic surgery. Overestimation of the remnant liver function can lead to life-threatening postoperative hepatic failure, and its underestimation can lead to a lost opportunity for potentially curative surgery. Conventionally, post-hepatectomy remnant liver function has been estimated preoperatively using computed tomography (CT) volumetry. CT can provide precise anatomical information, and the remnant liver volume, measured by CT volumetry, has been reported to be an effective predictor of hepatic dysfunction after hepatectomy. However, the indirect estimation of liver function by CT volumetry is reliable only when the function is assumed to be homogenous over the whole liver.

99mTc-galactosyl human serum albumin (99mTc-GSA) single-photon emission CT (SPECT) was developed to facilitate investigations of regional hepatic function. A disadvantage of conventional 99mTc-GSA SPECT was poor anatomical resolution, and this newly developed SPECT has a tremendously improved anatomical resolution owing to the fusion of CT and 99mTc-GSA SPECT. Recent reports have indicated that accurate regional function, based on precise anatomical information, could be evaluated using this technique.

Inclusion Criteria:

• All eligible patients were those surgically treated for hepato-biliary diseases.

Exclusion Criteria:

• Patient exclusion criteria included a body weight loss greater than 10% during the six months prior to surgery, the presence of distant metastases, or seriously impaired function of vital organs due to respiratory, renal or heart disease.