Intraoperative Ultrasonography versus Helical Computed Tomography and Computed Tomography with Arterioportography in Diagnosing Colorectal Liver Metastases: Lesion-by-lesion Analysis

Helical computed tomography with arterioportography (CTAP) and intraoperative sonography (IOUS) are both recognized to be extremely sensitive in the detection of liver metastases measuring 10 mm was missed by IOUS. CTAP presented an ideal sensitivity of 100%, but specificity was as low as 68%. IOUS sensitivity was 98% and specificity was 95%. IOUS and CTAP are of comparable value regarding the detection of liver metastases <10 mm. Both techniques may be used if resections of synchronous or metachronous metastases are planned in order not to miss limiting small lesions and to prevent superfluous liver surgery. Helical CT scan with dynamic intravenous contrast enhancement is considered the most cost-effective preoperative staging method, although local staging may not be achieved because of insufficient intraabdominal survey.