title: Dual-energy CT virtual non-calcium technique for detection of bone marrow edema in patients with vertebral fractures: A prospective feasibility study on a single- source volume CT scanner.
abstract: OBJECTIVE
  Dual-energy computed tomography (DECT) is a recent development for detecting bone marrow edema (BME) in patients with vertebral compression fractures. The aim of this pilot study was to determine the reliability of single-source DECT in detecting vertebral BME using magnetic resonance imaging (MRI) as standard of reference.
  
  
  METHODS
  Nine patients with radiographic thoracic or lumbar vertebral compression fractures underwent both, DECT on a 320-row single-source scanner and 1.5T MRI. Virtual non-calcium (VNC) images were reconstructed from the DECT volume datasets. Three blinded readers independently scored images for the presence of BME. Only vertebrae with loss of height in radiography (target vertebrae) were included in the analysis. A vertebra was counted as positive if two readers agreed on the presence of BME. Cohen's kappa was calculated for interrater comparison. Intervertebral ratios of target and the reference vertebra were compared for CT attenuation and MR signal intensity in a reference vertebra using Spearman correlation. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated.
  
  
  RESULTS
  Fourteen target vertebrae with a radiographic height loss were identified; eight of them showed BME on MRI, while DECT identified BME in 7 instances. There were no false positive virtual non-calcium images, resulting in a sensitivity of 0.88 (0.75-1.0 among all readers) and specificity of 1.0 (0.81-1.0). Interrater agreement was inferior for DECT (κ=0.63-0.89) compared to MRI (κ=0.9-1.0). Intervertebral ratio in VNC images strongly correlated with short-tau inversion recovery (r=0.87) and inversely with T1 (-0.89). SNR (0.2+/- 0.2 in VNC and 16.7+/- 7.3 in STIR) and CNR (0.2+/- 0.3 and 7.1+/- 6.3) values were inferior in VNC.
  
  
  CONCLUSIONS
  Detecting BME with single-source DECT is feasible and allows detection of vertebral compression fractures with reasonably high sensitivity and specificity. However, image quality of VNC reconstructions has to be improved to achieve better interrater agreement. Nonetheless, DECT might accelerate the diagnostic work-flow in patients with vertebral compression fractures in the future and reduce the number of additional MRI examinations.
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin Campus Mitte, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin, Germany. Electronic address: torsten.diekhoff@charite.de.
authors.forename: T
authors.initials: T
authors.lastname: Diekhoff
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin Campus Mitte, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin, Germany.
authors.forename: K G
authors.initials: KG
authors.lastname: Hermann
authors.affiliation: Department of Spine Surgery, Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin Campus Mitte, Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Pumberger
authors.affiliation: Department of Radiology, Charité - Universitätsmedizin Berlin Campus Mitte, Humboldt-Universität zu Berlin, Freie Universität Berlin, Berlin, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Hamm
authors.affiliation: Department of Spine Surgery, Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin Campus Mitte, Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Putzier
authors.affiliation: Department of Spine Surgery, Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin Campus Mitte, Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Fuchs
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000000981:diagnostic imaging* / Q000473:pathology; D004487:Edema / Q000000981:diagnostic imaging* / Q000473:pathology; D005240:Feasibility Studies; D005260:Female; D050815:Fractures, Compression / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D059629:Signal-To-Noise Ratio; D016103:Spinal Fractures / Q000000981:diagnostic imaging* / Q000473:pathology; D013131:Spine / Q000000981:diagnostic imaging / Q000473:pathology; D015898:Tomography Scanners, X-Ray Computed; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods*
keywords: Bone marrow edema; Dual-energy computed tomography; Image quality assessment; Magnetic resonance imaging; Vertebral compression fracture