Dual Energy Computed Tomography Collagen Material Decomposition for Detection of Lumbar Spine Disc Extrusion and Sequestration: A Comparative Study With Greyscale Computed Tomography

• Published in: Canadian Association of Radiologists journal 2023-02, Vol.74 (1), p.110-118
• Main Authors: Abdellatif, Waleed, Nugent, James P., Alballa, Faisal, Murray, Nicolas, Jalal, Sabeena, Ali, Ismail T., Nicolaou, Savvas
• Format: Article
• Language: English
• Subjects: Accuracy; Algorithms; Chi-square test; Collagen; Comparative studies; Computed tomography; Decomposition; Extrusion; Gray scale; Humans; Intervertebral discs; Low back pain; Lumbar Vertebrae - diagnostic imaging; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Retrospective Studies; Sensitivity; Sensitivity and Specificity; Spine; Spine (lumbar); Tendons; Tomography; Tomography, X-Ray Computed - methods
• ISSN: 0846-5371; 1488-2361
• DOI: 10.1177/08465371221118886

Purpose: To assess value of dual energy computed tomography (DECT) collagen material decomposition algorithm when combined with standard computed tomography (CT) in detection of lumbar disc extrusion and sequestration. Materials and Methods: Retrospective analysis of all patients with acute low back pain who had a diagnosis of lumbar spine disc extrusion and/or sequestration on Magnetic Resonance Imaging (MRI) (reference standard), and had undergone non-contrast DECT of the lumbar spine within 60 days of the MRI. Age and sex-matched control patients (n = 42) were included. Patients were grouped into standard, grey-scale CT only group and standard CT + DECT tendon images group. Two double-blinded radiologists reviewed both groups for presence of extrusion or sequestration. They also rated their diagnostic confidence on Likert 5-point scale. McNemar Chi-square test was used to compare diagnostic accuracy, unpaired t-test to compare reviewers diagnostic confidence, and Cohen’s k (kappa) test for interobserver agreement. Results: The combined group showed higher overall sensitivity (96.6% vs 87.2%), specificity (99% vs 95.4%), and diagnostic accuracy (98.7% vs 94.5%) with a lower false positive rate (1.1% vs 4.6%). McNemar Chi-square test confirmed statistical significance (P = .03 and P = .02 for Reviewers R1 and R2, respectively). The mean diagnostic confidence was also significantly higher on combined group (R1: 3.74 ± 1.1 vs 3.47 ± 1.15 (P < .01) and R2: 3.91 ± 1.15 vs 3.72 ± 1.16 [mean ± SD] (P = .02)). Conclusion: Utilizing MRI as a reference standard, DECT tendon application combined with standard CT increases the sensitivity, specificity, and accuracy of detection of lumbar spine disc extrusion and sequestration, when compared to standard CT alone.