Comparison of T2-weighted Magnetic Resonance Imaging findings with histological findings in degenerated lumbar discs in patients with lumbar disc herniation

Abstract

Diagnosis of disc degeneration and herniation largely depends on Magnetic Resonance Imaging (MRI) and X-rays which fails to detect early disc degeneration. This study was conducted to compare the degenerative changes seen in histological assessment with T2-weighted MRI findings. The study recruited 104 patients with lumbar disc herniation undergoing lumbar discectomy. Excised lumbar disc fragments were taken for histology and T2-weighted MRI was conducted prior to the surgery. Excised disc fragments were subjected to routine histology procedure and van Gieson stain for collagen was performed on each specimen.  Disc degeneration was assessed by histological parameters and T2-weighted MRI findings. The majority of subjects (94.2%) showed degenerative changes of the excised portion of the lumbar discs in histological assessment of the disc. However, T2-weighted MRI findings of degenerative changes of the discs were comparatively less (35.6%). According to the histological assessment, higher percentage (61.5 %) of discs were moderately degenerated while 7.7 % had severely degenerated discs. All patients who were confirmed for disc degeneration with T2-weighted MRI (n=37) had confirmed degenerative changes in the histological assessment as well. Histological degenerative alterations were observed in the majority of patients when compared to detectable degenerative changes in T2-weighted MRI suggesting the importance of histological assessment of degeneration in the excised intervertebral disc fragments. As early degenerative changes are not detected by the standard T2weighted MRI technique, if neglected, can progress to severe stages resulting in more discomfort and pain to the patients.

KEYWORDS:    Disc degeneration, Histology, Magnetic Resonance Imaging