Diagnostic performance of dual-energy CT with electron-density reconstruction for lumbar disc herniation.

Background: Magnetic resonance imaging (MRI) is used for the evaluation of degenerative spinal disease. However, its utility is restricted in routine practice because of contraindications and a lack of widespread availability. Dual-energy computed tomography (DECT) is a newer technique for the evaluation of degenerative spinal disease.

Objectives: This study aimed to evaluate the diagnostic performance of DECT with electron-density (ED) image reconstruction compared to standard CT for the detection of lumbar disc herniation, with MRI as the gold standard.

Method: The retrospective study included 84 patients between 01 July 2023 to 31 December 2023 who underwent DECT and 1.5-T MRI within 1 week. Four radiologists, blinded to the clinical and MRI information, independently evaluated the standard CT series and DECT series with ED reconstructions for lumbar disc herniation and spinal nerve root impingement. The gold standard for comparison was lumbar spine MRI, and diagnostic accuracy was measured with sensitivity and specificity.

Results: MRI revealed 417 lumbar disc herniations. Dual-energy computed tomography with ED reconstruction showed higher sensitivity (86.36% [532/616] vs. 57.79% [356/616]) and specificity (96.86% [1019/1052] vs. 95.82% [1008/1052]) for the detection of lumbar disc herniation compared to standard CT.

Conclusion: Dual-energy computed tomography with ED reconstruction shows better diagnostic performance for the detection of lumbar disc herniation compared to standard CT and can be a useful alternative imaging modality when MRI is contraindicated or unavailable.

Contribution: This study shows the usefulness of DECT as an alternative imaging technique for screening of degenerative spinal disease whenever MRI is contraindicated or unavailable.