Fig. 1

Magnetic resonance imaging (MRI) of a calf with SSCM type II (diplomyelia) (Case 4: 9-day-old, male, Holstein Friesian). a-e: MRI T2weighted (T2w) of calve with diplomyelia. f-g: MRI T1weighted (T1w) of calve with diplomyelia. a, f: Sagittal image of the spinal cord from L3 to the sacrum. At the level of L4 the spinal cord contains a structure filled with cerebrospinal-like fluid (asterisk *) in the dorsal funiculi. A slight dorsal narrowing (hash #) of the vertebral canal causes a slight compression of the spinal cord. Blue lines indicate the level of the transversal images shown below (B-E). b-e, g: transverse sections of the spinal cord at the level of L4-L6. b: Ventral aspect of cranial part of the fluid-filled structure (asterisk *) two small hyperintense (B-E), respectively hypointense (G) dots indicate the presence of two central canals (arrows ↑). c: The caudal end the fluid filled structure (asterisk *) is divided by a midline septum. Ventral of the structure the spinal cord shows a partial division and two central canals on each half are visible (arrows ↑). The left one seems slightly delated. d: The division of the spinal cord is more obvious. Both central canals are clearly visible (arrows ↑). e: A slight right dorsal narrowing (hash #) of the vertebral canal causes a slight compression of the spinal cord. Both central canals are still appreciable (arrows ↑). i-ii: MRI T2w of a healthy calf. i: transverse sections of the spinal cord at the level of L3. ii: Sagittal image of the spinal cord from L3 to the sacrum