Detection of lumbar disc herniation and degeneration using photon-counting detector CT with virtual non-calcium imaging.

Abstract

This study aimed to compare the diagnostic performance of virtual non-calcium (VNCa) imaging using photon-counting detector CT (PCD-CT) with MRI in assessing lumbar disc herniation (LDH) and intervertebral disc degeneration (IDD). Patients with low back pain underwent PCD-CT and MRI within 2 h. Quantitative analysis included VNCa-derived CT values and T2 relaxation times in manually placed regions of interest. Qualitative assessment focused on diagnostic accuracy for LDH and root impingement using grayscale and color-coded VNCa images. A total of 68 participants (51.8% female; mean age, 48 ± 14 years) were included. A significant negative correlation was observed between VNCa CT and MRI T2 values (r = -0.705, p < 0.001), strongest in the nucleus pulposus. Compared with grayscale CT, color-coded VNCa imaging significantly improved sensitivity (81-94%), specificity (84-95%), and accuracy (84-95%) for detecting LDH (all comparisons, p < 0.001); and improved sensitivity (82-94%), specificity (96-97%), and accuracy (93-96%) for diagnosing root impingement (all comparisons, p < 0.05). PCD-CT with VNCa imaging enables reliable quantification of disc water content and significantly improves diagnostic accuracy for LDH and root impingement. It offers a valuable alternative to MRI, especially in clinical settings where MRI is limited or unavailable. Question Can PCD-CT-based virtual non-calcium (VNCa) imaging serve as a reliable alternative to MRI for diagnosing lumbar disc herniation and assessing disc degeneration? Findings VNCa CT values strongly correlated with MRI T2 values, and VNCa images significantly improved diagnostic accuracy for lumbar disc herniation and nerve root impingement. Clinical relevance PCD-CT with VNCa imaging provides an accurate, rapid, and accessible assessment of lumbar disc herniation and disc degeneration, offering a valuable diagnostic alternative for patients unable to undergo MRI.