Figure 4. Box plot shows relationship between signal intensity on intermediate-weighted MR images and axonal number (ie, axonal density) in cervical spinal cord in control specimens and MS specimens. (MS specimens were categorized as showing high-signal-intensity lesions [HISIL], intermediate-signal-intensity lesions [IMSIL], and NAWM). NAWM showed extensive axonal loss, although this was not clearly detected on intermediate-weighted MR images. Results of statistical analysis between subgroups are listed in Table 3.