Fig. 2

Study measurements and observations a: Transverse T2-weighted image of spinal cord at C3/C4. Using Efilm ™ the transverse spinal cord is divided into quadrants (red lines) by first placing a vertical line bisecting the spinous process and then placing the horizontal line to bisect the spinal cord and the vertical line at 90°. The perpendicular diameters of the syrinx in each dorsal quadrant are measured (blue lines – 0.4 × 0.4 cm; green lines 0.3 cm × 0.2 cm). b: Transverse T2-weighted image of spinal cord at C1. The green arrow illustrates a syrinx which extends to the area of the SDH. c: Midsagittal T2-weighted spinal cord with SM. White dotted line indicates the transverse section at C3/C4 for 3a