title: Reproducibility of dynamic contrast-enhanced MR imaging. Part II. Comparison of intra- and interobserver variability with manual region of interest placement versus semiautomatic lesion segmentation and histogram analysis.
abstract: OBJECTIVE
  To compare the inter- and intraobserver variability with manual region of interest (ROI) placement versus that with software-assisted semiautomatic lesion segmentation and histogram analysis with respect to quantitative dynamic contrast material-enhanced (DCE) MR imaging determinations of the volume transfer constant (K(trans)).
  
  
  METHODS
  The study was approved by the institutional review board and compliant with HIPAA. The requirement to obtain informed consent was waived. Fifteen DCE MR imaging studies of the female pelvis defined the study group. Uterine fibroids were used as a perfusion model. Three varying types of lesion measurements were performed by five readers on each study by using DCE MR imaging perfusion analysis software with manual ROI placement and a semiautomatic lesion segmentation and histogram analysis solution. Intra- and interreader variability of measurements of K(trans) with the different measurement types was calculated.
  
  
  RESULTS
  The overall interobserver variability of K(trans) with manual ROI placement (mean, 28.5% ± 9.3) was reduced by 42.5% when the semiautomatic, software-assisted lesion measurement method was used (16.4% ± 6.2). Whole-lesion measurement showed the lowest interobserver variability with both measurement methods (20.1% ± 4.3 with the manual method vs 10.8% ± 2.6 with the semiautomatic method). The overall intrareader variability with the manual ROI method (7.6% ± 10.6) was not significantly different from that with the semiautomatic method (7.3% ± 10.8), but the intraclass correlation coefficient for intrareader reproducibility improved from 0.86 overall with the manual method to 0.99 with the semiautomatic method.
  
  
  CONCLUSIONS
  A semiautomatic lesion segmentation and histogram analysis approach can provide a significant reduction in interobserver variability for DCE MR imaging measurements of K(trans) when compared with manual ROI methods, whereas intraobserver reproducibility is improved to some extent.
authors.affiliation: Department of Radiology and Duke Multi-Dimensional Image Processing Laboratory, Duke University Medical Center, Box 3808, Durham, NC 27710, USA.
authors.forename: Tobias
authors.initials: T
authors.lastname: Heye
authors.forename: Elmar M
authors.initials: EM
authors.lastname: Merkle
authors.forename: Caecilia S
authors.initials: CS
authors.lastname: Reiner
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Davenport
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Horvath
authors.forename: Sebastian
authors.initials: S
authors.lastname: Feuerlein
authors.forename: Steven R
authors.initials: SR
authors.lastname: Breault
authors.forename: Peter
authors.initials: P
authors.lastname: Gall
authors.forename: Mustafa R
authors.initials: MR
authors.lastname: Bashir
authors.forename: Brian M
authors.initials: BM
authors.lastname: Dale
authors.forename: Atilla P
authors.initials: AP
authors.lastname: Kiraly
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Boll
mesh_terms: D000328:Adult; D001185:Artificial Intelligence; D003198:Computer Simulation; D003287:Contrast Media / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007889:Leiomyoma / Q000378:metabolism* / Q000473:pathology*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008875:Middle Aged; D008954:Models, Biological; D010363:Pattern Recognition, Automated / Q000379:methods*; D010388:Pelvis / Q000473:pathology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014594:Uterine Neoplasms / Q000378:metabolism* / Q000473:pathology*
chemical_list: D003287:Contrast Media