Figure 1.

(A) Sagittal T2-weighted 1.5 Tesla MR image demonstrates swelling of the spinal cord and dorsally pronounced hyperintense signal changes extending from C3 to Th1. (B) The axial T2-weighted sequence at C4/5 level (corresponding to line 1 in A) shows the increased signal dorso-laterally, mostly affecting the lateral columns including the corticospinal tract and sparing most of the gray matter and the dorsal columns. Swelling and homogeneous T2-weighted hyperintense signal of the spinalis cervicis, multifidus, semispinalis capitis, and semispinalis cervicis muscles on both sides is depicted. (C) At C6/7 level an axial T2-weighted image (corresponding to line 2 in A) shows a more diffuse pattern of hyperintense signal changes in the spinal cord with less pronounced signal changes in paraspinal muscles compared to B. (D) The axial fat-suppressed contrast-enhanced T1-weighted sequence at C4 level demonstrates the homogeneous contrast enhancement within these muscles. Of note, there is no contrast enhancement in the affected spinal cord. (E) The sagittal T2-weighted 14 weeks later shows reduced swelling of the spinal cord and a decrease in T2-weighted hyperintense changes. (F) Axial T2-weighted image at C4/5 level (corresponding to line 1 in E) shows hyperintense signal changes confined to the dorsal columns. Edema-like signal changes within the paraspinal muscles disappear and respective muscles are moderately atrophied (G) The axial T2-weighted image at C6/7 level (corresponding to line 2 in E) depicts areas of low signal intensity within the central spinal cord indicative of blood degeneration products. (H) In the axial contrast-enhanced T1-weighted sequence at C4 level 14 weeks later contrast enhancement within paraspinal muscles is hardly detectable. The size of affected muscles is reduced.