Page 369 - Atlas of Small Animal CT and MRI

Intervertebral disk disease and other degenerative disorders 359

Figure 3.5.1 Normal Intervertebral Disks (Canine) MR

(a) GA, LAT (b) GA, SP (c) T1&T2, SP
The gross appearance of the dorsal annulus fibrosis (a,b: small arrowhead), the nucleus pulposus (a,b: arrow), and ventral annulus
fibrosis (a,b: large arrowhead). Compare the appearance of the intervertebral disk in image b to the appearance on T1 (c: T1) and T2
(c: T2) images acquired in the same anatomic plane.

Figure 3.5.2 Mineralized Type I Extrusion (Canine) CT

5y MC Dachshund found acutely paretic
earlier in the day with neuroanatomic locali­
zation to T3–L3. Images a and b include
the T11–12 and T12–13 intervertebral disk
spaces. Images c and d are through the T11–
12 and T12–13 disks, respectively. CT images
were acquired as part of a CT myelogram. An
in situ mineralized nucleus pulposus is present
at the T11–12 intervertebral disk space (a–c:
small arrowhead). Mineralized disk material
from the T12–13 intervertebral disk space has
herniated into the ventral subdural space of
the vertebral canal, causing focal spinal cord
compression with attenuation of the contrast
(a) DX, LAT (b) CT+C, SP columns (b,d: arrow). The T12–13 disk space
is narrow and contains residual mineralized
disk material (a,b,d: large arrowhead).
A hemilaminectomy performed at T12–13
confirmed mineralized disk material within
the extradural space. Adjacent disks were
fenestrated.

(c) CT+C, TP (d) CT+C, TP

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