The Application Value Of Diffusion Weighted Imaging And Enhanced Magnetic Resonance Imaging In The Diagnosis Of Peritoneal Carci- Nomatosis

Objective:To explore the efficacy of conventional magnetic resonance imaging(MRI), diffusion-weighted magnetic resonance imaging(DWI), and enhanced magnetic resonance imaging in diagnosing peritoneal carcinomatosis(PC), and summarize the MRI findings of PC.Methods: From September in 2013 to March in 2015, 43 patients with peritoneal carcinomatosis were included, which confirmed by surgical pathology or clinical follow-up in Gansu cancer hospital. All patients underwent MR examination(including T1 WI, T2 WI, DWI and enhanced magnetic resonance imaging). All of sequences were reviewed by two radiologists independently who were blinded to the results of the pathology and clinical follow-up. The following subjects were analyzed and recorded:(1) the lesion distribution and the MRI findings;(2) the sensitivity, specificity, positive predictive value and negative predictive of common MR sequences, common MR+DWI, common MR+DWI+ enhanced in diagnosing PC were calculated. And the corresponding receiver operator characteristic(ROC) curve were drawn by SPSS 20.0.Results: 1) Total of 28 patients with peritoneal carcinomatosis were enrolled. The MR findings of PC were as following: irregular linear thinckeing of parietal and visceral peritoneum(20), serosal thinckeing of the intestinal surface(2), omental stranding and caking(10); mesentery stranding thickening(9); masses and nodules in the abdnominal cavitys(22); ascites(26); lymphadenopathy(8). The total number of lesion locations was 240, with the common sites of bilateral diaphragm, bilateral paracolic sulci(right more than left), omental, small omentum, peritoneum, and pot wall of uterine / bladder-rectal pouch. 2) The Kappa value of the three methods by two radiologists were 0.852、0.850、0.846 respectively. They achieved good consistency.The sensitivity and specificity value of the three modes estimated by radiologist. A were 80.0% and 55.6%, 85.7% and 73.3%, 92.9% and 80.0% respectively, and the AUC value were 0.690(P=0.041), 0.795(P=0.002) and 0.864(P=0.000), respectively. The 95% of confidence interval in the AUC values of the three scanning modes has overlapped, indicating that there is no statistically significant difference(P>0.05) among the three scanning modes. Reviewer B achieved respective sensitivety, specificity were78.2% and 50.0%, 82.1% and 74.2%, and 92.9% and 81.2% on conventional MRI,conventional MRI+DWI, conventional MRI+DWI+enhanced MRI, AUC were respectvely 0.688(P=0.044),0.777(P=0.003) and 0.831(P=0.000). The 95% of confidence interval in the AUC values of the three scanning modes has overlapped, indicating that there is no statistically significant difference(P>0.05) among the three scanning modes.Conclusions: All the conventional MRI, DWI, and enhanced scanning sequences can diagnose peritoneal carcinomatosis. MRI can find the primary peritoneal carcinomatosis and extents. The diagnostic efficiency of conventional MRI for PC was inferior, and the diagnostic efficiency of conventional MRI+DWI and conventional MRI+DWI+ enhanced were medium. The combination of the three modes obtained the maximum AUC value, significantly improving the sensitivity and specificity for PC diagnosis, which will provide a reasonable iconography methods basis for clinic accurate detection of PC.