title: Role of quantitative intravoxel incoherent motion parameters in the preoperative diagnosis of nodal metastasis in patients with rectal carcinoma.
abstract: To evaluate the diagnostic value of intravoxel incoherent motion imaging (IVIM) in differentiating metastatic and nonmetastatic lymph nodes in patients with rectal carcinoma.
  
  
  
  In all, 68 patients with histologically proven rectal carcinoma underwent an IVIM sequence (b = 0, 25, 50, 75, 100, 150, 200, 400, 600, 800, 1000, 1200, 1500, and 2000 s/mm(2) ) on a 3.0T MRI scanner. The IVIM parameters (D, D*, f, and apparent diffusion coefficient [ADC] values) in metastatic and nonmetastatic lymph nodes were measured and calculated. Receiver-operating characteristic (ROC) analyses were conducted to determine the optimal thresholds, the sensitivities, and specificities for differentiation.
  
  
  
  Mean D, f, and ADC values of metastatic lymph nodes were significantly greater than those of the normal lymph nodes (P < 0.01), whereas the mean D* value of metastatic lymph node was statistically lower (P = 0.03). The AUC, sensitivity, specificity, and the cutoff value, respectively, for differentiating metastatic from nonmetastatic lymph nodes for D, D*, f, and ADC were as follows: D, 0.9460, 89.25%, 91.04%, and 1.14 × 10(-3) mm(2) /s; D*, 0.6930, 64.18%, 82.80%, and 7.02 × 10(-3) mm(2) /s; f, 0.7810, 92.47%, 55.22%, and 0.27%; ADC, 0.8970, 87.10%, 88.06%, and 0.80 × 10(-3) mm(2) /s. The ROC curves demonstrated that the area under the ROC (AUC) of the D, ADC, f, and D* values successively decreased, and D had the highest AUC, with D* values being lowest.
  
  
  
  An IVIM sequence may be helpful in diagnosing metastatic lymph nodes of rectal carcinoma. Average D and ADC values are more sensitive than f and D* values in this differentiation. J. MAGN. RESON. IMAGING 2016;44:1031-1039.
authors.affiliation: Medical Imaging Center, First Affiliated Hospital, Jinan University, Guangzhou, Guangdong, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Qiu
authors.affiliation: Medical Imaging Center, First Affiliated Hospital, Jinan University, Guangzhou, Guangdong, China.
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Liu
authors.affiliation: Medical Imaging Center, First Affiliated Hospital, Jinan University, Guangzhou, Guangdong, China.
authors.forename: Si-Run
authors.initials: SR
authors.lastname: Liu
authors.affiliation: Department of Pathology, First Affiliated Hospital, Jinan University, Guangzhou, Guangdong, China.
authors.forename: Ze-Ping
authors.initials: ZP
authors.lastname: Weng
authors.affiliation: Medical Imaging Center, First Affiliated Hospital, Jinan University, Guangzhou, Guangdong, China.
authors.forename: Xiao-Qiao
authors.initials: XQ
authors.lastname: Chen
authors.affiliation: Medical Imaging Center, First Affiliated Hospital, Jinan University, Guangzhou, Guangdong, China.
authors.forename: You-Zhen
authors.initials: YZ
authors.lastname: Feng
authors.affiliation: Medical Imaging Center, First Affiliated Hospital, Jinan University, Guangzhou, Guangdong, China. caixran@jnu.edu.cn.
authors.forename: Xiang-Ran
authors.initials: XR
authors.lastname: Cai
authors.affiliation: Serviço de Imagiologia, Centro Hospitalar Conde de São Januário (CHCSJ), Estrada do Visconde de S. Januário, Macau. kuokcu@gmail.com.
authors.forename: Chang-Yu
authors.initials: CY
authors.lastname: Guo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging* / Q000473:pathology*; D008875:Middle Aged; D009038:Motion; D011300:Preoperative Care / Q000379:methods*; D011379:Prognosis; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: diffusion-weighted imaging (DWI); intravoxel incoherent motion (IVIM); lymph node metastasis; magnetic resonance imaging (MRI); rectal carcinoma