PURPOSE:This study was designed to compare diagnostic accuracies of measuring liver enzymes, preoperative ultrasonography, surgical examination, and intraoperative ultrasonography for detection of liver metastases from colorectal cancer.METHODS:Blind, prospective comparisons of diagnostic examinations mentioned above were performed in 295 consecutive patients with colorectal cancer. An experienced ultrasonologist performed the preoperative examinations, nd results were unknown to the other experienced ultrasonologist who performed the intraoperative examinations. The latter, also was unaware of the findings by the surgeon. The presence of metastases was further assessed by ultrasonography three months postoperatively, as well as additional surgery and liver biopsy in some of the patients.RESULTS:The sensitivity of intraoperative ultrasonography (62/64) was significantly superior to that of surgical exploration (54/64) and that of preoperative ultrasonography (45/64). The lowest sensitivity was presented by liver enzymes. Bilobar metastases were detected in 42 of 46 patients by intraoperative ultrasonography but in only 33 patients by the surgeon. Intraoperative ultrasonography demonstrated the highest specificity of all examinations.CONCLUSIONS:Intraoperative ultrasonography reduces the number of patients with liver metastases from being subjected to superfluous or even harmful liver surgery, and it may increase the number in whom liver surgery will prolong life.