MR Imaging of Schmorl's Nodes and Several Factors Influencing Enhancement of Schmorl's Nodes

Abstract

Retrospective analysis of Schmorl's nodes on L-spine MRI performed between May, 1995 and September, 1996 was done in 516 patients. In 516 patients, 117 patients(M: F = 48: 69, mean age: 46 yrs.) had 231 Schmorl's nodes. Contrast enhancements were performed in 84 patients (154 cases). 231 Schmorl's nodes were noted in 117 patients (mean number per patient: 1.9, maximum number per patient: 9). Mean AP diameter of nodes was 7.1 mm and mean height was 5.2 mm. The locations of nodes were L3 (24.9%), L4 (22.2%), L2 (21.3%), L1 (12.7%), T12 (7.7%), and S1 (1.2%). 55% of nodes were located in lower endplates and 45% were located in upper endplates. Also the common locations on endplates were mid. 1/3 portion (39%) and mid-Posterior junction (34.2%). The frequencies of intervertebral disc herniations with nodes were 33.3% at L4–5, 23.7% at L3–4, 21% at L5-S1, 12.8% at L2–3 and 7% at L1–2. The changes of adjacent vertebral bodies were noted in 75 patients (33%). Fatty marrow change (80%) was the most frequent findings. Contrast enhancements were visible in 54 cases (34%) among 154 cases. Statistical correlations were significant (p<.05, Chi-Square test) between height of Schmorls' nodes and enhancements/age and enhancements/age and height of Schmorl's nodes. Also there were trends of enhancements in the lower endplate than upper endplate and toward lower vertebral body (especially L5). The most frequent location of Schmorl's node were L3, the lower endplate, and mid. 1/3 portion of endplate. There were significant correlations (p<.05) between height of Schmorl's node and enhancement/ age and enhancement/age and height of Schmorl's node. The trends of enhancements in the lower endplate than upper endplate and toward lower vertebral body (especially L5) were noted.