Variation in Anisotropy of the Spinal Cord in Patients With Hyperkyphosis

Spinal cord compression is commonly seen in patients with severe kyphosis. However, conventional morphologic magnetic resonance imaging (MRI) was unable to detect the damage in microstructural integrity of the spinal cord around the apical vertebrae in these patients. The aim of the study was to evaluate the neuronal metrics/microstructure of the spinal cord around apical region in patients with hyperkyphosis using diffusion tensor imaging (DTI).

Twenty-four patients with hyperkyphosis aged 46.1±22.8 years who underwent 3.0T MRI examination with DTI sequence were prospectively enrolled from July 2022 to January 2023. Patients were divided into three groups according to spinal cord/cerebrospinal fluid architecture (CSF) on sagittal-T2 MRI of the thoracic apex: Type A-circular cord with visible CSF, Type B-circular cord but no visible CSF at apical dorsal, and Type C-spinal cord deformed without intervening CSF. The Fractional Anisotropy (FA) values acquired from DTI were compared among different groups. Correlations between DTI parameters and global kyphosis (GK)/sagittal deformity angular ratio (SDAR) were evaluated using Pearson correlation coefficients.

Inclusion criteria

• diagnosis of hyperkyphosis;
• the apex located at the thoracal region (T1-T12);
• full DTI data;
• records of detailed and systematic neurological physical examination.

Exclusion criteria

• any case with active infection, tumor, or trauma;
• any cases of comorbidity of neurofibromatosis type I;
• any cases combined with spinal syringomyelia, split cord malformations or diastematomyelia, tethered cord syndrome;
• previous spinal surgery.