Abdominal ImagingTechnical Note. Do Arterial Phase Helical CT Images Improve Detection or Characterization of Colorectal Liver Metastases?Ch'en, Ian Y.; Katz, Douglas S.; Jeffrey, R. Brooke Jr.; Daniel, Bruce L.; Li, King C. P.; Beaulieu, Christopher F.; Mindelzun, Robert E.; Yao, Dorcas; Olcott, Eric W.Author Information From the Department of Diagnostic Radiology, Stanford University Medical Center, 300 Pasteur Dr., Rm. H1307, Stanford, CA 94305, U.S.A. Address correspondence and reprint requests to Dr. R. B. Jeffrey, Jr. Journal of Computer Assisted Tomography: May-June 1997 - Volume 21 - Issue 3 - p 391-397 Buy Abstract Our goal was to determine if arterial phase images from dual phase helical CT improve either the detection or the characterization of hepatic metastases in patients with colorectal carcinoma. Sixty-two patients with known colorectal cancer underwent 65 dual phase helical CT examinations to evaluate for possible liver metastases. Three blinded reviewers independently evaluated the portal venous phase images alone to determine if hepatic metastases were present or absent. Arterial phase images were then analyzed to determine if they identified additional lesions or aided in characterizing small hepatic lesions. Scores of the two methods for diagnosing metastases were compared with the “gold standard” established by a consensus panel of three other radiologists who reviewed all images together with clinical, pathologic, and other imaging data. The addition of arterial phase imaging did not detect any new metastases. However, in 6 of the 64 technically adequate examinations, hepatic arterial phase images increased lesion conspicuity and significantly increased diagnostic confidence when compared with portal vein phase scans alone. In patients with colorectal cancer, the addition of arterial phase imaging does not increase sensitivity, but improves the specificity in diagnosing liver metastases in a small number of cases. Dual phase helical CT does not appear to be indicated in the evaluation of liver metastases from colorectal cancer. © Lippincott-Raven Publishers.