title: Performance of statistical models of shape and appearance for semiautomatic segmentations of spinal vertebrae T4-L4 on digitized vertebral fracture assessment images.
abstract: BACKGROUND
  Despite its clinical importance, accurate identification of vertebral fractures is problematic and time-consuming. There is a recognized need to improve the detection of vertebral fractures so that appropriate high-risk patients can be selected to initiate clinically beneficial therapeutic interventions.
  
  
  OBJECTIVE
  To develop and evaluate semiautomatic algorithms for detailed annotation of vertebral bodies from T4 to L4 in digitized lateral spinal dual-energy X-ray absorptiometry (DXA) vertebral fracture assessment (VFA) images.
  
  
  METHODS
  Using lateral spinal DXA VFA images from subjects imaged at University Hospital fracture liaison service, image algorithms were developed for semiautomatic detailed annotation of vertebral bodies from T4 to L4.
  
  
  METHODS
  Two hundred one women aged 50 years or older with nonvertebral fractures.
  
  
  METHODS
  Algorithm accuracy and precision.
  
  
  METHODS
  Statistical models of vertebral shape and appearance from T4 to L4 were constructed using VFA images from 130 subjects. The resulting models form a part of an algorithm for performing semiautomatic detailed annotation of vertebral bodies from T4 to L4. Algorithm accuracy and precision were evaluated on a test-set of 71 independent images.
  
  
  RESULTS
  Overall accuracy was 0.72 mm (3.00% of vertebral height) and overall precision was 0.26 mm (1.11%) for point-to-line distance. Accuracy and precision were best on normal vertebrae (0.65 mm [2.67%] and 0.21 mm [0.90%], respectively) and mild fractures (0.78 mm [3.18%] and 0.32 mm [1.39%], respectively), but accuracy and precision errors were higher for moderate (1.07 mm [4.66%] and 0.48 mm [2.15%], respectively) and severe fractures (2.07 mm [9.65%] and 1.10 mm [5.09%], respectively). Accuracy and precision results for the algorithm were comparable with other reported results in the literature.
  
  
  CONCLUSIONS
  This semiautomatic image analysis had high overall accuracy and precision on normal vertebrae and mild fractures, but performed less well in moderate and severe fractures. It is, therefore, a useful tool to identify normality of vertebral shape and to identify mild fractures.
authors: Department of Internal Medicine, VieCuri MC Noord-Limburg, Tegelseweg 210, 5912 BL Venlo, The Netherlands. Electronic address: robertvandervelde@planet.nl.
authors: Robert
authors: R
authors: van der Velde
authors: Mellor House, 26 Mellor Rd, Cheadle Hulme, Cheadle, SK8 5AU, United Kingdom.
authors: Takouhi
authors: T
authors: Ozanian
authors: Internal Medicine, Department of Rheumatology, University Hospital, Maastricht University, Debeyelaan 25, 6229 HX Maastricht, The Netherlands; University of Medicine and Pharmacy "Carol Davila" Bucharest, Romania Bulevardul Eroii Sanitari 8, Bucuresti 050474, Romania.
authors: Bianca
authors: B
authors: Dumitrescu
authors: Mellor House, 26 Mellor Rd, Cheadle Hulme, Cheadle, SK8 5AU, United Kingdom.
authors: Jane
authors: J
authors: Haslam
authors: Mellor House, 26 Mellor Rd, Cheadle Hulme, Cheadle, SK8 5AU, United Kingdom.
authors: Joes
authors: J
authors: Staal
authors: Mellor House, 26 Mellor Rd, Cheadle Hulme, Cheadle, SK8 5AU, United Kingdom.
authors: Alan
authors: A
authors: Brett
authors: Department of Internal Medicine, VieCuri MC Noord-Limburg, Tegelseweg 210, 5912 BL Venlo, The Netherlands; Department of Internal Medicine, Maastricht University Medical Centre/NUTRIM, Debeyelaan 25, 6229 HX Maastricht, The Netherlands.
authors: Joop
authors: J
authors: van den Bergh
authors: Internal Medicine, Department of Rheumatology, University Hospital, Maastricht University, Debeyelaan 25, 6229 HX Maastricht, The Netherlands.
authors: Piet
authors: P
authors: Geusens
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000293:injuries; D008875:Middle Aged; D015233:Models, Statistical; D011857:Radiographic Image Interpretation, Computer-Assisted; D016103:Spinal Fractures / Q000000981:diagnostic imaging*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging* / Q000293:injuries
keywords: DXA; Fractures; Morphometry; Osteoporosis; VFA; Vertebral