General Session: Diagnostic Imaging
Presented by: W. Tian
W. Tian(1), J. Wang(1), X. Han(1), D. Li(1), G. Li(2), Q. Song(1)
(1) Fourth Clinical Medical College of Peking University, Beijing Jishuitan Hospital, Department of Spine Surgery, Beijing, China
(2) Tsinghua University, Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Beijing, China
Background data: Diffusion tensor imaging (DTI) parameters are correlated with the clinical assessment of preoperative degenerative cervical myelopathy (DCM) patients. But DTI parameters changed immediately after decompression surgery. The research on the value of DTI in postoperative DCM patients is still blank.
Purpose: To investigate the diagnostic and biomarker utility of DTI parameters in postoperative DCM patients.
Study Design: A case-control study. Subjects and
Methods: 59 postoperative DCM patients who were 222 to 727 days after surgery were recruited as case group, as well as 21 healthy volunteers as control group. Diffusion data were acquired on the axial view, with 17 slices in total covering the vertebral levels from C2 to C7. DTI parameters fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD) and mean diffusivity (MD), were measured at the levels of maximal compression (LMC) of case group and corresponding levels of control group. Regions of interest were drawn to match the outline of the whole spinal cord. Symptoms and signs were noted to identify myelopathy, JOA scale was used to assess spinal function status. Using one-tailed t-test to compare DTI parameters between two groups. Receiver-operator characteristic (ROC) analysis and spearman's correlation were used to determine the diagnostic and biomarker utility of DTI parameters. The level of significance was set at P< 0.05. All data analyses were performed using SPSS 20.
Results: All the patients were identified myelopathy, the JOA scores of patients range from 11.5 to 17 points. The one-tailed t-test showed that FA were significantly reduced, while AD, RD, MD were significantly increased at LMCs of patients when compared with corresponding levels of control group. ROC analysis showed that RD, MD and FA at LMC could identify subjects with myelopathy well (area under the cure more than 0.80), the diagnosis performance of AD is relatively weak. Spearman's correlation revealed a moderate positive correlation between FA at LMC and JOA scores (ρ=0.429). While RD、MD and AD at LMC were significantly negative correlated with JOA scores (ρ=-0.461, -0.461, -0.268 separately).
Conclusions: The DTI parameters RD, MD, and FA are valuable for the diagnosis of myelopathy and could be biomarkers for myelopathy severity in postoperative DCM patients.