title: Semi-automated quantitative intravoxel incoherent motion analysis and its implementation in breast diffusion-weighted imaging.
abstract: BACKGROUND
  To optimize and validate intravoxel incoherent motion (IVIM) modeled diffusion-weighted imaging (DWI) compared with the apparent diffusion coefficient (ADC) for semi-automated analysis of breast lesions using a multi-reader setup.
  
  
  METHODS
  Patients (n = 176) with breast lesions (≥1 cm) and known pathology were prospectively examined (1.5 Tesla) with DWI (b = 0, 50, 200, 500, 800, 1000 s/mm(2) ) between November 2008 and July 2014 and grouped into a training and test set. Three independent readers applied a semi-automated procedure for setting regions-of-interest for each lesion and recorded ADC and IVIM parameters: molecular diffusion (Dslow ), microperfusion (Dfast ), and the fraction of Dfast (ffast ). In the training set (24 lesions, 12 benign), a semi-automated method was optimized to yield maximum true negatives (TN) with minimal false negatives (FN): only the optimal fraction (Fo) of voxels in the lesions was used and optimal thresholds were determined. The optimal Fo and thresholds were then applied to a consecutive test set (139 lesions, 23 benign) to obtain specificity and sensitivity.
  
  
  RESULTS
  In the training set, optimal thresholds were 1.44 × 10(-3) mm(2) /s (Dslow ), 18.55 × 10(-3) mm(2) /s (Dfast ), 0.247 (ffast ) and 2.00 × 10(-3) mm(2) /s (ADC) with Fo set to 0.61, 0.85, 1.0, and 1.0, respectively, this resulted in TN = 5 (IVIM) and TN = 1 (ADC), with FN = 0. In the test set, sensitivity and specificity among the readers were 90.5-93.1% and 43.5-52.2%, respectively, for IVIM, and 94.8-95.7% and 13.0-21.7% for ADC (P ≤ 0.0034) without inter-reader differences (P = 1.000).
  
  
  CONCLUSIONS
  The presented semi-automated method for breast lesion evaluation is reader independent and yields significantly higher specificity for IVIM compared with the ADC.
authors.affiliation: University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands, Groningen, The Netherlands.|University of Groningen, University Medical Center Groningen, Department of Radiology, Groningen, The Netherlands.
authors.forename: Hildebrand
authors.initials: H
authors.lastname: Dijkstra
authors.affiliation: University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands, Groningen, The Netherlands.|University of Groningen, University Medical Center Groningen, Department of Radiology, Groningen, The Netherlands.
authors.forename: Monique D
authors.initials: MD
authors.lastname: Dorrius
authors.affiliation: University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands, Groningen, The Netherlands.|University of Groningen, University Medical Center Groningen, Department of Radiology, Groningen, The Netherlands.
authors.forename: Mirjam
authors.initials: M
authors.lastname: Wielema
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Radiology, Groningen, The Netherlands.
authors.forename: Karolien
authors.initials: K
authors.lastname: Jaspers
authors.affiliation: University of Utrecht, University Medical Center Utrecht, Department of Radiology, Utrecht, The Netherlands.
authors.forename: Ruud M
authors.initials: RM
authors.lastname: Pijnappel
authors.affiliation: University of Groningen, University Medical Center Groningen, Center for Medical Imaging - North East Netherlands, Groningen, The Netherlands.
authors.forename: Matthijs
authors.initials: M
authors.lastname: Oudkerk
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Radiology, Groningen, The Netherlands.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Sijens
mesh_terms: D000328:Adult; D000368:Aged; D001331:Automation; D001940:Breast / Q000000981:diagnostic imaging* / Q000473:pathology; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D044584:Carcinoma, Ductal / Q000000981:diagnostic imaging / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D018450:Disease Progression; D005188:False Negative Reactions; D005260:Female; D018226:Fibroadenoma / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008875:Middle Aged; D009038:Motion; D010363:Pattern Recognition, Automated; D012372:ROC Curve; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: breast; cancer; diagnostic techniques and procedures; diffusion weighted MRI