Asymmetry and increased dimensions of the muscles of the lumbar region on the left side compared to the contralateral side, as well as loss of the fibrillar pattern and contrast medium uptake, affecting the psoas muscle, quadratus lumborum, latissimus dorsi, erector spinae, longissimus thoracic and iliocostal with extension to the epidural space through the left neuroforamina from L1-L2 to L5-S1 compromising emerging nerve roots, causing compression of the dural sac.
The lumbosacral vertebral bodies with heterogeneous signal intensity, with a mottled appearance in all sequences, with heterogeneous enhancement after the application of intravenous contrast, also observed in the posterior elements and iliac bones.