Page 286 - Atlas of Small Animal CT and MRI

276 Atlas of Small Animal CT and MRI

Figure 2.10.12 Cavernous Sinus Syndrome (Canine) MR

(a) T2, TP (b) T1, TP (c) T1+C, TP

(d) T1+C+FS, DP (e) T1+C, SP
8y FS Shepherd cross with cranial nerve III, IV, V, VI, and ocular sympathetic innervation deficits consistent with cavernous sinus syndrome.
There is a large, well‐defined, T1 isointense, T2 hyperintense ovoid mass arising from the pituitary fossa (a,b: arrow). The carotid arteries are
identified in cross‐section and appear to be surrounded by the mass (a,b: arrowheads). Following contrast administration, the mass uniformly
and intensely enhances, and the basilar part of the mass can be seen to invade the cavernous sinus bilaterally. Carotid arteries are confirmed
to be incorporated into the mass (c: arrowheads). The cavernous sinus contains the carotid arteries, its sympathetic plexus, and the third,
fourth, sixth, and some branches of the fifth cranial nerves. The invasion of the mass within the sinus explains the clinical signs.

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