Detection and Evaluation of Pelvic Lymph Nodes in Patients With Gynecologic Malignancies Using Body Diffusion-Weighted Magnetic Resonance Imaging

Abstract

Background: In this study, the potential in detecting and evaluating pelvic lymph node metastases on body diffusion-weighted (DW) images was evaluated in patients with gynecologic malignancies. Methods: This study included 18 patients with gynecologic malignancy who underwent magnetic resonance imaging in the pelvis using a 1.5-T superconductive magnet. The identification of pelvic nodes on only T2-weighted (T2W) axial images and on DW axial images in addition to T2W axial images was examined and compared. Moreover, we measured and calculated a short-axis diameter, a long-axis diameter, and a ratio of short- and long-axis diameter of nodes on the T2W images and the apparent diffusion coefficient (ADC) values of the nodes on the DW images. These results were compared with histopathologic results. Results: First, 136 (40%) of 340 dissected nodes were identified on T2W images, and 249 (73%) of 340 dissected nodes were identified on DW images in addition to T2W images. Second, the differences in the short-axis diameter, the long-axis diameter, and the ratio of short- and long-axis diameter on T2W images between metastatic and nonmetastatic nodes were not significant. The differences in the ADC values between metastatic and nonmetastatic nodes were not significant. Conclusions: Body DW images are useful in detection of pelvic lymph nodes in patients with gynecologic malignancy. However, the measurement of ADC values does not contribute to a diagnosis of metastatic nodes.