title: [Diagnosis value of 3.0 T diffusion-weighted imaging with background suppression magnetic resonance for metastatic lymph nodes in rectal cancer].
abstract: OBJECTIVE
  To evaluate the diagnostic value of 3.0 T diffusion-weighted imaging with background suppression (DWIBS) magnetic resonance (MR) for lymph node metastasis in rectal cancer.
  
  
  METHODS
  Thirty-five patients with rectal cancer who underwent preoperative routine MRI+DWI examination were enrolled in the study and were treated by rectal cancer resection plus lymph node dissection. Metastatic and non-metastatic lymph nodes were confirmed by postoperative pathology. Apparent diffusion coefficient (ADC) values, long-axis and short-axis diameters of lymph nodes were measured. Receiver operating characteristic (ROC) curve was used to assess the diagnostic efficacy of ADC, long-axis and short-axis diameters for differentiating metastatic lymph nodes from non-metastatic lymph nodes.
  
  
  RESULTS
  A total of 151 lymph nodes were confirmed with exact location in 35 patients. Sixty-five metastatic lymph nodes and 86 non-metastatic lymph nodes were identified. The ADC values of metastatic lymph nodes and non-metastatic lymph nodes were(0.86±0.14)×10(-3) and (0.94±0.16)×10(-3) mm(2)/s respectively. The long-axis diameter were(9.78±3.13) and (7.90±1.77) mm, respectively. The short-axis diameter were (7.65±2.00) and (6.45±1.19) mm, respectively. There were statistically significant differences between metastatic and non-metastatic lymph nodes in ADC values, long-axis diameter, and short-axis diameter(all P<0.01). The areas under the ROC curve of ADC value, long-axis diameter, and short-axis diameter were 0.648, 0.706, and 0.692, respectively. Optimal cutoff values for these parameters were 1.05×10(-3) mm(2)/s, 7.95 mm, and 5.90 mm, respectively, and the corresponding sensitivities and specificities were 93.8% and 30.2%, 75.4% and 61.6%, 90.8% and 38.4%.
  
  
  CONCLUSIONS
  Quantitative measurement of ADC value may reflect the degree of diffusion restriction of metastatic lymph nodes by DWIBS at 3.0 T MR. Accurate diagnosis of metastatic lymph nodes in rectal cancer demands comprehensive evaluation combining ADC value with diameter measurement.
authors: Department of Radiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China.
authors: Xiao-zhao
authors: XZ
authors: Zhuang
authors: Shen-ping
authors: SP
authors: Yu
authors: Ji
authors: J
authors: Cui
authors: Chuang-qi
authors: CQ
authors: Chen
authors: Xiao-juan
authors: XJ
authors: Zhao
authors: Bi-tao
authors: BT
authors: Pan
authors: Zi-ping
authors: ZP
authors: Li
mesh_terms: D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D012004:Rectal Neoplasms / Q000175:diagnosis* / Q000473:pathology*