Radiological Factors Associated with Increased Intramedullary Signal Intensity Based on X-ray and MRI – Implications in our understanding of Degenerative Spondylomyelopathy

Purpose: Increased intramedullary signal intensity (IISI) on T2 weighted MRI scan (T2WI) in patients with Degenerative Cervical Myelopathy (DCM) can be a radiological feature of spinal cord damage. However, the association of IISI to degeneration of the spinal column remains unclear in literature. The purpose of this study was to determine the prevalence of IISI and analyze the independent relationship between IISI and cervical degenerative parameters in patients with and without DCM. Methods A retrospective review of MRI, X-ray, and radiology data for 144 adult patients with DCM with both cervical MRI and X-ray scans was conducted. A total of 39 patients with IISI was identified. The remaining 105 patients without IISI made up the control group. Results IISI was prevalent in 27.1% of patients and most frequent in C6-C7 cervical levels. The likelihood of having IISI was 1.947 (Exp(B) 1.947, 95%CI [1.004–3.776]) times higher in segmental levels with facet joint degeneration. There was an increased likelihood of IISI within the spinal cord with increasing age (Exp(B) 1.034, 95%CI [1.008–1.060]), maximum spinal cord compression (MSCC) (Exp(B) 1.038, 95%CI [1.003–1.075]), rotational angle (Exp(B) 1.082, 95%CI [1.020–1.148]) and posterior herniation width (Exp(B) 1.333, 95%CI [1.017–1.747]) and decreasing Torg-Pavlov ratio (Exp(B) 0.010, 95%CI [0.001–0.068]). Conclusion IISI had a prevalence in 27.1% of DCM patients. Increased age, facet joint degeneration, MSCC, rotational angle, posterior herniation width and decreasing Torg-Pavlov angle were found to be independently associated with IISI. Radiological degenerative changes associated with IISI indicate value in the assessment of patients with possible DCM.