Disk injury in patients with vertebral fractures—a prospective diagnostic accuracy study using dual-energy computed tomography

OBJECTIVES: Using magnetic resonance imaging (MRI) as the standard of reference, we aimed to evaluate the diagnostic accuracy of dual-energy computed tomography (DECT) in assessing disk injuries in patients aged more than 50 years with vertebral fractures. METHODS: This prospective study was approved by the local ethics committee (EA1/372/14), and all patients gave written informed consent. Patients with suspected fractures underwent spinal DECTs and MRIs. Three readers scored DECT collagen maps for the presence or absence of disk injuries and also scored MR images according to the Sander classification (0–3). Only disks at risk (target disks) were included in the analysis. Sensitivity and specificity were calculated. Fleiss’s κ was used to evaluate interrater agreement. Attenuation, in Hounsfield units, was compared between affected and unaffected disks in DECT. RESULTS: Analyzing 295 disks in 67 patients, DECT was both sensitive (0.85) and specific (0.75). Sensitivity varied with the severity of disk damage, as assessed using the Sander scale (grade 1, 0.80; 2, 0.85; and 3, 0.98). Fleiss’s κ was 0.41 for MRI and 0.51 for DECT. In the DECT collagen maps, attenuation was lower in injured disks compared to that in normal disks (80.3 ± 35.2 vs. 97.9 ± 41.0, p < 0.001). CONCLUSIONS: Compared to conventional CT, DECT collagen maps can yield more diagnostic information, allowing identification of disk injuries in elderly patients with vertebral fractures. KEY POINTS: • Dual-energy computed tomography allows vertebral disk injuries to be detected in elderly patients with vertebral fractures. • Dual-energy computed tomography yields more diagnostic information about vertebral disks compared to conventional CT. • Dual-energy computed tomography can be used as an alternative imaging modality for patients unwilling or unable to undergo MRI. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00330-018-5963-4) contains supplementary material, which is available to authorized users.