Detection of Mesenteric Tumor Using Dynamic Contrast Enhanced MRI.

PURPOSE: This study was designed to evaluate the use of a novel imaging technique, dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI), for detecting mesenteric peritoneal metastases.

METHODS: Thirty-four patients underwent preoperative conventional MRI, including T1, T2, diffusion-weighted (DWI), and delayed gadolinium MRI, as well as DCE MRI. DCE MRI involved imaging the peritoneal cavity every 9 s for 6 min. DCE images were processed to generate parametric maps of tumor vascularity. Two oncologic surgeons and a radiologist reviewed conventional MRI for all tumor and then later reviewed the conventional MRI plus the DCE parametric maps. Images were reviewed for tumor of the parietal peritoneum, porta hepatis, bowel serosa, upper small bowel mesentery, lower small bowel mesentery, and pelvis. Conventional MRI and DCE + MRI findings were compared to operative and histopathologic reports for tumor detection. PCI scores were calculated for surgery, MRI, and DCE.

RESULTS: Upper mesenteric tumor was present in 21 patients. DCE images showed a sensitivity of 100%, specificity of 92%, and accuracy of 97% compared with conventional MRI sensitivity of 24%, specificity of 93%, and accuracy of 50% (p = 0.006). Lower mesenteric tumor was present in 22 patients. DCE images showed a sensitivity of 100%, specificity of 92%, and accuracy of 97% compared with conventional MRI sensitivity of 45%, specificity of 92%, and accuracy of 62% (p = 0.008). The mean surgical PCI for all 34 patients was 23.4 compared with MRI 20.0 (p = 0.003) and DCE MRI 24.1 (p = 0.26). The addition of the DCE images improved the accuracy of total PCI by > 10% in 16 (0.46) patients. For PCI regions 9-12, the mean surgical PCI was 6.0 compared with MRI 4.8 (p = 0.08) and DCE 6.6 (p = 0.02). The addition of DCE images improved the accuracy of the regional PCI > 10% in 15 (0.43) patients.

CONCLUSIONS: DCE MRI provides a novel contrast tool that improves detection of mesenteric tumor. Depicting small-volume mesenteric tumor is better on DCE MRI compared with conventional MRI.