title: Quantitative Ultrasound Assessment of Duchenne Muscular Dystrophy Using Edge Detection Analysis.
abstract: OBJECTIVE
  The purpose of this study was to investigate the ability of quantitative ultrasound (US) using edge detection analysis to assess patients with Duchenne muscular dystrophy (DMD).
  
  
  METHODS
  After Institutional Review Board approval, US examinations with fixed technical parameters were performed unilaterally in 6 muscles (biceps, deltoid, wrist flexors, quadriceps, medial gastrocnemius, and tibialis anterior) in 19 boys with DMD and 21 age-matched control participants. The muscles of interest were outlined by a tracing tool, and the upper third of the muscle was used for analysis. Edge detection values for each muscle were quantified by the Canny edge detection algorithm and then normalized to the number of edge pixels in the muscle region. The edge detection values were extracted at multiple sensitivity thresholds (0.01-0.99) to determine the optimal threshold for distinguishing DMD from normal. Area under the receiver operating curve values were generated for each muscle and averaged across the 6 muscles.
  
  
  RESULTS
  The average age in the DMD group was 8.8 years (range, 3.0-14.3 years), and the average age in the control group was 8.7 years (range, 3.4-13.5 years). For edge detection, a Canny threshold of 0.05 provided the best discrimination between DMD and normal (area under the curve, 0.96; 95% confidence interval, 0.84-1.00). According to a Mann-Whitney test, edge detection values were significantly different between DMD and controls (P < .0001).
  
  
  CONCLUSIONS
  Quantitative US imaging using edge detection can distinguish patients with DMD from healthy controls at low Canny thresholds, at which discrimination of small structures is best. Edge detection by itself or in combination with other tests can potentially serve as a useful biomarker of disease progression and effectiveness of therapy in muscle disorders.
authors.affiliation: Laboratory for Manufacturing and Productivity, Massachusetts Institute of Technology, Cambridge, Massachusetts USA, Medical Electronic Device Realization Center, Massachusetts Institute of Technology, Cambridge, Massachusetts USA.
authors.forename: Sisir
authors.initials: S
authors.lastname: Koppaka
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center, Boston, Massachusetts USA.
authors.forename: Irina
authors.initials: I
authors.lastname: Shklyar
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center, Boston, Massachusetts USA.
authors.forename: Seward B
authors.initials: SB
authors.lastname: Rutkove
authors.affiliation: Department of Neurology, Boston Children's Hospital, Boston, Massachusetts USA.
authors.forename: Basil T
authors.initials: BT
authors.lastname: Darras
authors.affiliation: Laboratory for Manufacturing and Productivity, Massachusetts Institute of Technology, Cambridge, Massachusetts USA, Medical Electronic Device Realization Center, Massachusetts Institute of Technology, Cambridge, Massachusetts USA.
authors.forename: Brian W
authors.initials: BW
authors.lastname: Anthony
authors.affiliation: Departments of Neurology and Pediatrics, Washington University, St Louis Missouri USA.
authors.forename: Craig M
authors.initials: CM
authors.lastname: Zaidman
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, Boston, Massachusetts USA jswu@bidmc.harvard.edu.
authors.forename: Jim S
authors.initials: JS
authors.lastname: Wu
mesh_terms: D000293:Adolescent; D000465:Algorithms; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging* / Q000473:pathology*; D020388:Muscular Dystrophy, Duchenne / Q000000981:diagnostic imaging* / Q000473:pathology*; D010865:Pilot Projects; D011446:Prospective Studies; D014463:Ultrasonography / Q000379:methods*
keywords: Duchenne muscular dystrophy; edge detection; muscle; musculoskeletal ultrasound; quantitative ultrasound