title: Use of diffusion tensor imaging in assessing superficial myometrial invasion by endometrial carcinoma: a preliminary study.
abstract: BACKGROUND
  Magnetic resonance imaging (MRI) remains the standard modality for local staging of gynecological malignancies, but it has several limitations, especially when differentiating a cancer limited to the endometrium from a cancer invading the superficial myometrium.
  
  
  OBJECTIVE
  To explore 1.5 T diffusion tensor imaging (DTI) in assessing superficial myometrial infiltration by endometrial carcinoma.
  
  
  METHODS
  We analyzed the sensitivity of apparent diffusion coefficient (ADC) versus fractional anisotropy (FA) in diagnosing superficial myometrial infiltration compared to DCE-MRI and T2-weighted imaging (T2WI) in 35 patients with endometrial cancer. For each patient, T2WI-DWI fusion images were generated, and five regions of interest (ROIs) were placed on corresponding DTI images. ADC and FA were calculated, and fiber tractography (FT) images for each level were obtained. ADC and FA values for the five ROIs were compared.
  
  
  RESULTS
  In distinguishing cancerous versus non-cancerous areas within superficial myometrium, median ADC values were significantly lower (1.16 vs. 1.48, respectively; P < 0.001) and median FA values were significantly higher (0.41 vs. 0.27; P < 0.001, respectively). ADC's versus FA's sensitivity, specificity, PPV, NPV, and accuracy for diagnosing superficial myometrial invasion were 74.3%, 88.6%, 86.7%, 77.5%, 81.4% versus 88.6%, 97.1%, 96.9%, 89.5%, 92.9%, respectively. T2WI and DCE-MR showed a sensitivity of 80.0% and 77.1%, respectively, in diagnosing myometrial invasion.
  
  
  CONCLUSIONS
  Both ADC and FA were able to distinguish between cancerous verss non-cancerous areas within superficial myometrium (although FA was more sensitive based on AUC values). In addition, FA was superior to ADC, and more sensitive than T2WI and DCE-MR, in evaluating myometrial invasion. FT images provided visual confirmation of irregular arrangement and direction of the fibers due to proliferation of stromal cells caused by superficial myometrial invasion.
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Dalian Medical University, Dalian, PR China.
authors.forename: Longmin
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Dalian Medical University, Dalian, PR China Cjr.liuailian@vip.163.com.
authors.forename: Ailian
authors.initials: A
authors.lastname: Liu
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Dalian Medical University, Dalian, PR China.
authors.forename: Ting
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Dalian Medical University, Dalian, PR China.
authors.forename: Qingwei
authors.initials: Q
authors.lastname: Song
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Dalian Medical University, Dalian, PR China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wei
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Dalian Medical University, Dalian, PR China.
authors.forename: Heqing
authors.initials: H
authors.lastname: Wang
mesh_terms: D000368:Aged; D016880:Anisotropy; D003937:Diagnosis, Differential; D056324:Diffusion Tensor Imaging / Q000379:methods*; D016889:Endometrial Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008875:Middle Aged; D009215:Myometrium / Q000473:pathology*; D009361:Neoplasm Invasiveness / Q000473:pathology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014594:Uterine Neoplasms / Q000473:pathology*
keywords: Diffusion tensor imaging (DTI); apparent diffusion coefficient (ADC); endometrial cancer; fiber tractography (FT); fractional anisotropy (FA)