Improved visualization of electron-density dual-energy computed tomography for lumbar disc disease over the standard gray-scale type and virtual noncalcium imaging.

Abstract

Background: Dual-energy computed tomography (DECT) enhances tissue imaging characterization. However, no studies have evaluated the diagnostic accuracy of electron density (ED) for simultaneously displaying the lumbar disc and disc calcification. This retrospective study aimed to investigate the ability of ED to visualize lumbar disc disease as compared with standard computed tomography (SC) and virtual noncalcium (VNCa) imaging in order to provide a viable alternative for lumbar disc disease.

Methods: From October 2023 to February 2024, we retrospectively analyzed data from 53 patients who underwent DECT and 3.0-T magnetic resonance imaging (MRI) within 2 weeks. The randomized SC, VNCa, and ED image sets were independently evaluated by four radiologists for visualization of the lumbar disc and disc calcification with an 8-week interval. Final disc calcification results were obtained by consensus, with the SC results serving as the reference standard. Two other experienced radiologists performed MRI evaluations as the lumbar disc reference standard. Diagnostic performance was compared for each image.

Results: Among the 298 included lumbar discs, 183 lumbar disc herniations and bulges were revealed on MRI. As compared with VNCa and SC, ED showed higher overall sensitivity (91.3% vs. 88.9% vs. 78.0%), specificity (94.8% vs. 93.3% vs. 88.0%), and accuracy (92.6% vs. 90.6% vs. 81.9%) in visualizing lumbar disc herniation and bulging. The ED area under the curve (AUC) was higher than that of VNCa and SC (all P values <0.05), and ED identified all 40 (40/183) calcified discs shown on SC. In addition, diagnostic confidence and image quality of ED were higher than those of VNCa and SC (all P values <0.001).

Conclusions: ED demonstrated higher diagnostic accuracy and confidence for visualizing the lumbar disc and disc calcification on the computed tomography (CT) images as compared to VNCa and SC.