TY - JOUR T1 - The Usefulness of Diffusion MRI in Detection of Lymph Node Metastases of Colorectal Cancer JF - Anticancer Research JO - Anticancer Res SP - 815 LP - 819 VL - 36 IS - 2 AU - MASAICHI OGAWA AU - NORIATSU ICHIBA AU - MICHIAKI WATANABE AU - KATSUHIKO YANAGA Y1 - 2016/02/01 UR - http://ar.iiarjournals.org/content/36/2/815.abstract N2 - The aim of this study was to assess the sensitivity and specificity of preoperative diagnosis by diffusion magnetic resonance imaging (D-MRI) for lymph node metastasis of colorectal cancer. The b-value represents the diffusion factor (measured in s/mm2) and the strength of the diffusion gradients. The b-value used in this study was 1,000 s/mm2. A total of 119 patients underwent D-MRI before resection of primary colorectal cancer (52 of the rectum, 67 of the colon) at our hospital between February 2005 and April 2006. Lymph node metastases judged by D-MRI were compared with postoperative pathological results. The form of lymph node metastasis was classified either as abundant or scarce type. The predictive values for lymph-node metastasis (sensitivity and specificity) by D-MRI were calculated from the result of this classification and lymph-node size. The study was divided into two periods: before the consensus meeting in January 2006, (n=79) (P-I), and after the adjustment of the criteria to improve the sensitivity and specificity based on the results of P-I (n=40) (P-II). Detection of lymph node metastasis using D-MRI in P-I had sensitivity of 61%, specificity of 73%, positive predictive value (PPV) of 55%, and negative predictive value (NPV) of 77%, while in P-II, these values improved to 79%, 95%, 94%, and 83%, respectively. Specificity and PPV for P-II were significantly higher than those for P-I (p<0.05). The diameter of lymph nodes judged to be metastatic on D-MRI (P-I vs. P-II: n=32 vs. 16) was 10.3±5.4 (3-28) vs. 9.1±3.0 (4-14) mm; 11.5±6.2 (4-28) vs. 9.2±3.1 (4-14) mm for truly positive nodes (n=18 vs. 15), and 6±3.8 (3-14) vs. 8 mm for false-positive nodes (n=14 vs. 1). On the other hand, lymph nodes judged negative by D-MRI (n=47 vs. 24) was 5.9±2.4 (3-16) vs. 5.7±2.8 (2-15) mm; 5.9±2.1 (3-16) vs. 5.3±2.1 (2-8) mm for truly negative (n=36 vs. 20), and 5.7±2.7 (3-12) vs. 7.8±4.9 (4-15) mm for false negative (n=11 vs. 4). As to the form of metastasis, all truly positive nodes were of the abundant type, and 6/11 (55%) in P-I and 1/4 (25%) in P-II false-negatives were of the scarce type. In conclusion, D-MRI seems useful for preoperative detection of metastatic lymph nodes in colorectal cancer, especially if the node is hyperintense and more than 9 mm in diameter. ER -