title: Opportunistic screening for osteoporosis by routine CT in Southern Europe.
abstract: Feasibility evaluation of early detection of osteoporosis in oncologic patients by bone mineral density (BMD) on abdominal computed tomography (CT) scans performed for other clinical indications, by using dual-energy X-ray absorptiometry (DXA) as reference. Abdominal CT images can identify patients with osteoporosis BMD without additional radiation exposure or cost.
  
  
  
  The purpose of the study is to evaluate the feasibility of early detection of osteoporosis by bone mineral density (BMD) on abdominal computed tomography (CT) scans performed in oncologic patients, comparing calibrated and uncalibrated measurements by using dual-energy X-ray absorptiometry (DXA) as reference. We also performed an external validation of a threshold of 160 Hounsfield units (HU), proposed as highly sensitive.
  
  
  
  Cohort comprised CT-DXA pairs within a 6-month period performed for any indication on 326 consecutive adults, aged 62.4 ± 12.38 years (mean ± standard deviation). CT attenuation of trabecular bone in HU was measured at the axial cross sections of L1, L2, L3, and L4 vertebrae. Vertebral compression fractures were assessed by sagittal reconstruction view. Diagnostic performance measures and the area under the receiver operator characteristic curve (AUC) for diagnosing osteoporosis were calculated.
  
  
  
  BMD values were statistical significantly lower at any vertebral level from L1 to L4 for patients with osteoporosis defined by DXA (p < 0.001). Calibrated and uncalibrated BMD values were significantly correlated (R2= 0.833, p < 0.01). An uncalibrated L1 CT attenuation threshold of 160 HU was more than 90 % sensitive, and a threshold of 73 HU was more than 90 % specific for distinguishing osteoporosis BMD. Fifty-nine percent of patients with vertebral compression fracture had non-osteoporotic DXA T-scores.
  
  
  
  Abdominal CT images obtained for other reasons can identify patients with osteoporosis BMD without additional radiation exposure or cost. Uncalibrated values at L1 can detect more osteoporosis patients with spinal compression fractures than DXA in oncologic patients.
authors.affiliation: Center for Biomaterials and Tissue Engineering, Universitat Politècnica de València, Cami de Vera, s/n, 46022, Valencia, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Alacreu
authors.affiliation: Center for Biomaterials and Tissue Engineering, Universitat Politècnica de València, Cami de Vera, s/n, 46022, Valencia, Spain. dmoratal@eln.upv.es.
authors.forename: David
authors.identifier: http://orcid.org/0000-0002-2825-3646
authors.initials: D
authors.lastname: Moratal
authors.affiliation: Department of Radiology, Fundación Instituto Valenciano de Oncología, C/ Profesor Beltrán Báguena, 19, 46009, Valencia, Spain. aranae@uv.es.
authors.forename: Estanislao
authors.initials: E
authors.lastname: Arana
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000368:Aged; D015519:Bone Density / Q000502:physiology; D001851:Bone Diseases, Metabolic / Q000000981:diagnostic imaging / Q000503:physiopathology; D000071556:Cancellous Bone / Q000000981:diagnostic imaging / Q000503:physiopathology; D042241:Early Diagnosis; D005240:Feasibility Studies; D005260:Female; D006621:Hip Joint / Q000503:physiopathology; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D010024:Osteoporosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012372:ROC Curve; D013030:Spain; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Bone density; Computed tomography; External validation; Lumbar vertebrae; Osteoporosis; Screening; Spinal fractures