Objective: To evaluate the signal intensity (SI) of the intervertebral discs of the cervical spine on magnetic resonance (MR) fluid sensitive sequences, and correlate this to secondary signs of degeneration on MR and radiographs as well as to age.
Material and methods: A total of 265 patients aged ≥16 with back pain (≥3-months, <2-year, onset <45-years) from the SPondyloArthritis Caught Early (SPACE) cohort were included. Sagittal 1.5 T MR images and lateral radiographs of the cervical spine were independently evaluated by two readers for: SI of the intervertebral discs using a grading system based of Pfirrmann (grade 1 normal/bright SI; 2 inhomogeneous/bright SI; 3 inhomogeneous/mildly decreased SI; 4 inhomogeneous/markedly decreased SI; 5 signal void), disc herniation and Modic changes (MRI) and disc space narrowing, osteophytes and sclerosis (radiograph). Readers were blinded for clinical information. Descriptive statistics were used for characteristics and prevalence of findings, and regression analysis was used for age and grades.
Results: Of 265 patients (36% male, mean age 30), 221 (83%) patients had 1 to 6 discs (median 4) with decreased SI. Of 1,590 discs, 737 (46%) were grade 1; 711 (45%) grade 2; 133 (8%) grade 3; 8 (1%) grade 4 and 1 (0%) grade 5. Secondary signs of degeneration were rare and seen predominantly in C5-C7 and appear to be related to signal loss grade 3 and 4.
Conclusion: Low signal intensity of intervertebral discs in absence of secondary degenerative signs in the cervical spine on fluid sensitive MR images might be pre-existing and part of the natural course.
Keywords: Cervical spine; Fluid sensitive MR; Signal intensity of intervertebral discs.