Journal Article

Assessment of thoracic disk herniation by using virtual noncalcium dual-energy CT in comparison with standard grayscale CT

Lenga, Lukas, Ascenti, Giorgio, Wichmann, Julian L., Burck, Iris, D’Angelo, Tommaso, Yel, Ibrahim, Martin, Simon S., Beckers, Sebastian, Mader, Christoph, Grünewald, Leon D., Albrecht, Moritz H., Koch, Vitali, Eichler, Katrin, Gruber-Rouh, Tatjana, Vogl, Thomas J., Mazziotti, Silvio, Booz, Christian

2021

Overview

Objectives To determine the diagnostic accuracy of dual-energy CT (DECT) virtual noncalcium (VNCa) reconstructions for assessing thoracic disk herniation compared to standard grayscale CT. Methods In this retrospective study, 87 patients (1131 intervertebral disks; mean age, 66 years; 47 women) who underwent third-generation dual-source DECT and 3.0-T MRI within 3 weeks between November 2016 and April 2020 were included. Five blinded radiologists analyzed standard DECT and color-coded VNCa images after a time interval of 8 weeks for the presence and degree of thoracic disk herniation and spinal nerve root impingement. Consensus reading of independently evaluated MRI series served as the reference standard, assessed by two separate experienced readers. Additionally, image ratings were carried out by using 5-point Likert scales. Results MRI revealed a total of 133 herniated thoracic disks. Color-coded VNCa images yielded higher overall sensitivity (624/665 [94%; 95% CI, 0.89–0.96] vs 485/665 [73%; 95% CI, 0.67–0.80]), specificity (4775/4990 [96%; 95% CI, 0.90–0.98] vs 4066/4990 [82%; 95% CI, 0.79–0.84]), and accuracy (5399/5655 [96%; 95% CI, 0.93–0.98] vs 4551/5655 [81%; 95% CI, 0.74–0.86]) for the assessment of thoracic disk herniation compared to standard CT (all p < .001). Interrater agreement was excellent for VNCa and fair for standard CT ( ϰ = 0.82 vs 0.37; p < .001). In addition, VNCa imaging achieved higher scores regarding diagnostic confidence, image quality, and noise compared to standard CT (all p < .001). Conclusions Color-coded VNCa imaging yielded substantially higher diagnostic accuracy and confidence for assessing thoracic disk herniation compared to standard CT. Key Points • Color-coded VNCa reconstructions derived from third-generation dual-source dual-energy CT yielded significantly higher diagnostic accuracy for the assessment of thoracic disk herniation and spinal nerve root impingement compared to standard grayscale CT. • VNCa imaging provided higher diagnostic confidence and image quality at lower noise levels compared to standard grayscale CT. • Color-coded VNCa images may potentially serve as a viable imaging alternative to MRI under circumstances where MRI is unavailable or contraindicated.

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V
• Subject: Accuracy / Aged / Bone Marrow / Color / Computed Tomography / Diagnostic Radiology / Diagnostic systems / Edema / Female / Gray scale / Humans / Image processing / Image quality / Imaging / Impingement / Internal Medicine / Interventional Radiology / Intervertebral discs / Magnetic resonance imaging / Medical imaging / Medicine / Medicine & Public Health / Neuroradiology / Noise levels / Noise standards / Radiography, Dual-Energy Scanned Projection / Radiology / Retrospective Studies / Sensitivity and Specificity / Spinal nerves / Thorax / Tomography, X-Ray Computed / Ultrasound