Lumbar spinal muscles and spinal canal study by MRI three-dimensional reconstruction in adult lumbar spinal stenosis

Abstract

Background: Lumbar spinal stenosis is degenerative disc disease most common manifestation. If stenosisdegree seems poorly related to symptom severity, lumbar muscles role is recognized. Many studiesreport imaging methods, to analyze muscle volumes and fat infiltration (FI), but remain limited due tothe difficulty to represent entire muscle volume variability. Recently a 3D muscle reconstruction protocol(using the deformation of a parametric specific object method (DPSO) and three-point Dixon images) wasreported. It offers the ability to evaluate, muscles volumes and muscle FI.Purpose: To describe, in a lumbar spinal stenosis population, muscle volumes, muscle FI and lumbarspinal canal volume with 3D MRI images reconstructions.Materials and methods: Ten adults presenting L4–L5 lumbar stenosis, were included. After specific MRIprotocol, three-dimensional, muscle and spinal canal, reconstructions were performed. Muscle (psoasand paraspinal muscles) volumes and fat infiltration (FI), the spinal canal volume, age, and height werecorrelated one to each other with Spearman correlation factor. An ANOVA was performed to evaluate theintervertebral level influence (P ≤ 0.05).Results: Muscle volumes correlated with height (r = 0.68 for psoas). Muscles FI correlated with age (r = 0.66for psoas) and lumbar spinal canal volume (r = 0.91). Psoas and paraspinal volumes were maximum atL3–L4 level whereas FI increased from L1–L2 to L5–S1 level.Discussion: These first results illustrate the importance to consider muscles entirely and report correla-tions between muscles FI, lumbar spinal canal volume and age; and between muscle volumes and patientsheight. Muscle degeneration seems more related to muscle FI than muscle volume.Level of evidence: 3.