Diagnostic Accuracy of Dual-Layer Spectral CT Using Electron Density Images to Detect Post-Traumatic Prevertebral Hematoma of the Cervical Spine

Abstract

Purpose  To investigate the diagnostic value of dual-layer spectral detector computed tomography (SDCT) in detecting posttraumatic prevertebral hematoma of the cervical spine by including electron density images. Methods  38 patients with post-traumatic imaging of the cervical spine were included in this study and received both SDCT and MRI examinations. MRI was set as the reference and combined conventional/electron density (CED) images were compared to conventional CT (CCT) images alone. Results  A total of 18 prevertebral hematomas were identified. Reader 1 identified 14 of 18 and reader 2 15 of 18 prevertebral hematomas by using CED reconstructions. Readers 1 and 2 detected 6 and 9 of 18 hematomas on CCT, respectively. CCT showed a sensitivity of 33-50% and a specificity of 75-80%, while for CED reconstructed images the sensitivity was 77-83% and the specificity was 85-90%. Accuracy increased from 55-66% to 84% by using CED images. The minimum thickness for detecting hematoma on CED images was 3mm. The sizes of prevertebral hematoma on CCT/CED were not significantly under- or overestimated compared to the MRI reference. There was a significant difference between the two readers for measuring hematoma sizes on CCT (p=0.04). Readers showed an excellent inter-rater reliability (kappa=0.82) for CED images and a moderative inter-rater reliability (kappa=0.44) for CCT. Conclusion  With SDCT, the diagnostic accuracy for detecting post-traumatic prevertebral hematoma is improved by using combined conventional and electron density reconstructions compared to conventional images alone. Key Points:   SDCT has a high potential for detecting post-traumatic prevertebral hematomas of the cervical spine by using combined conventional and electron density images. Prevertebral hematomas with a thickness of less than 3mm cannot be reliably identified by SDCT. There is no discernible value of conventional SDCT images for diagnosing prevertebral hematoma. Citation Format Sedaghat S, Langguth P, Larsen N etal. Diagnostic Accuracy of Dual-Layer Spectral CT Using Electron Density Images to Detect Post-Traumatic Prevertebral Hematoma of the Cervical Spine. Fortschr Röntgenstr 2021; 193: 1445-1450.