title: New dual-energy X-ray absorptiometry equipment in the assessment of vertebral fractures: technical limits and software accuracy.
abstract: OBJECTIVE
  The aim of this study was to investigate software accuracy and influence of body mass index on image quality of Lunar iDXA (Lunar, Madison, WI, USA; software enCORE 12.0) in vertebral fracture (VFs) assessment.
  
  
  METHODS
  We enrolled 65 normal or overweight patients (group 1) and 64 obese patients (group 2) with indication for morphometric evaluation of the spine. Patients underwent iDXA, with scans performed in the standard manner by an expert technologist. Lateral images of the spine were subsequently evaluated by a musculoskeletal radiologist as the gold standard. Our analysis considered five points: vertebral bodies missed or not assessable or wrongly labeled on T4-L4 segment, diagnostic performance of the automatic morphometric point-positioning system in the detection of VFs, upgrading and downgrading of fractures, radiologist intervention rate, and BMI influence.
  
  
  RESULTS
  In group 1, 57/845 (6.7%) vertebral bodies and 34/832 (4.1%) in group 2 were not assessable-the upper thoracic spine. enCORE failed to recognize vertebral levels in 5.4% of the patients (7.7% in group 1 vs. 3.1% in group 2). On a lesion-based analysis sensitivity, specificity and accuracy of the software were 81.4, 93.8, and 93.1% in group 1 and 69.1, 88.3, and 86.7% in group 2, respectively. For 52.7% of the vertebrae in group 1 (51/8 upgraded/downgraded) and 70.0% in group 2 (96/26 upgraded/downgraded), a point correction was necessary and this changed the diagnosis respectively in 29.2 and 50.0% of the patients. Differences in diagnostic performance and point correction rate were significantly different between the two groups; however, BMI did not significantly affect vertebral level labeling and was correlated with a better visualization of the whole T4-L4 spine segment.
  
  
  CONCLUSIONS
  This study provides new and interesting information about the accuracy, reliability, and imaging quality provided by iDXA in the assessment of VFs.
authors: Imaging Division, Clinical Department of Radiological and Histocytopathological Sciences, University of Bologna, Sant'Orsola - Malpighi Hospital, Via Massarenti 9, 40138, Bologna, Italy.
authors: Alberto
authors: A
authors: Bazzocchi
authors: Danila
authors: D
authors: Diano
authors: Giuseppe
authors: G
authors: Battista
authors: Ugo
authors: U
authors: Albisinni
authors: Cristina
authors: C
authors: Rossi
authors: Giuseppe
authors: G
authors: Guglielmi
mesh_terms: D015502:Absorptiometry, Photon / Q000295:instrumentation / Q000379:methods*; D000465:Algorithms; D001823:Body Composition; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012984:Software; D012986:Software Validation; D016103:Spinal Fractures / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D013673:Technology Assessment, Biomedical