Figure 2: MRI T2-weighted image of a 34-year-old female. (a) Sagittal view. (b) Axial view. The axial view of each disc was retrieved in correspondence with the center of each disc in sagittal view. A circle of one centimeter in radius, region of interest (ROI), was drawn in the geometrical center of each disc. The mean signal intensity of ROI was then measured and recorded. The mean signal intensity of ROI of each level (e.g., L4-5) divided with reference level (i.e., T12-L1) was called CDS.