title: Converted lumbar BMD values derived from sagittal reformations of contrast-enhanced MDCT predict incidental osteoporotic vertebral fractures.
abstract: We obtained baseline and follow-up bone mineral density (BMD) values of the lumbar spine from sagittal reformations of routine abdominal contrast-enhanced multidetector computed tomography (MDCT) using a reference phantom and assessed their performance in differentiating patients with no, existing, and incidental osteoporotic fractures of the spine. A MDCT-to-QCT (quantitative computed tomography) conversion equation for lumbar BMD measurements was developed by using 15 postmenopausal women (63 ± 12 years), who underwent standard lumbar QCT (L1-L3) and afterward routine abdominal contrast-enhanced MDCT. Sagittal reformations were used for corresponding lumbar BMD measurements. The MDCT-to-QCT conversion equation was applied to baseline and follow-up routine abdominal contrast-enhanced MDCT scans of 149 postmenopausal women (63 ± 10 years). Their vertebral fracture status (no, existing, or incidental osteoporotic fracture) was assessed in the sagittal reformations. A correlation coefficient of r = 0.914 (p < 0.001) was calculated for the BMD values of MDCT and standard QCT with the conversion equation BMD(QCT) = 0.695 × BMD(MDCT) - 7.9 mg/mL. Mean follow-up time of the 149 patients was 20 ± 12 months. Fifteen patients (10.1 %) had an existing osteoporotic vertebral fracture at baseline. Incidental osteoporotic vertebral fractures were diagnosed in 13 patients (8.7 %). Patients with existing and incidental fractures showed significantly (p < 0.05) lower converted BMD values (averaged over L1-L3) than patients without fracture at baseline and at follow-up. In this longitudinal study, BMD values of the lumbar spine derived from sagittal reformations of routine abdominal contrast-enhanced MDCT predicted incidental osteoporotic vertebral fractures.
authors.affiliation: Institut für Radiologie, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany. thbaum@gmx.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Baum
authors.forename: Dirk
authors.initials: D
authors.lastname: Müller
authors.forename: Martin
authors.initials: M
authors.lastname: Dobritz
authors.forename: Petra
authors.initials: P
authors.lastname: Wolf
authors.forename: Ernst J
authors.initials: EJ
authors.lastname: Rummeny
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Link
authors.forename: Jan S
authors.initials: JS
authors.lastname: Bauer
mesh_terms: D000368:Aged; D015519:Bone Density; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000293:injuries; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D015663:Osteoporosis, Postmenopausal / Q000000981:diagnostic imaging / Q000473:pathology; D058866:Osteoporotic Fractures / Q000000981:diagnostic imaging*; D016103:Spinal Fractures / Q000000981:diagnostic imaging