Dynamic contrast-enhanced MR imaging and dual-phase helical CT in the preoperative assessment of suspected pancreatic cancer: A comparative study with receiver operating characteristic analysis

OBJECTIVE. The purpose of this study was to compare dynamic contrast-enhanc ed MR imaging and dual-phase helical CT in the preoperative assessment of p atients with suspected pancreatic carcinoma. SUBJECTS AND METHODS, Thirty-three consecutive surgical candidates (20 men; 13 women: 39-81 years old) were included. MR imaging comprised fast spin-e cho (TR/TE 4000/91), fat-suppressed T1-weighted spin-echo (500/15), and T1- weighted breath-herd gradient-echo fast low-angle shot (100/4; flip angle, 80 degrees) images before and after the administration of gadopentetate dim eglumine. Helical CT used 5-mm collimation with a pitch of 1: 1.5-1.7; imag es were obtained 20 and 65-70 sec after injection of 150 ml of contrast mat erial. Two pairs of interpreters who were unaware of the results of the oth er imaging method independently scored each examination for the presence of a lesion and for surgical resectability using a five-point scale. Results were correlated with surgery (n = 25) or consensus review (n = 8). Receiver operating characteristic methodology was used to analyze the results for r esectability, and positive predictive values were calculated. RESULTS, Both MR imaging and helical CT revealed 29 of 31 lesions. In deter mining lesion resectability, the mean areas under the receiver operating ch aracteristic curves were 0.96 and 0.81 (p = .01) and the positive predictiv e values were 86.5% and 76% (p = .02) for MR imaging and helical CT, respec tively. CONCLUSION. MR imaging and helical CT performed equally well in lesion dete ction. MR imaging was significantly better in the assessment of resectabili ty of pancreatic tumors.