Page 260 - Atlas of Small Animal CT and MRI

250 Atlas of Small Animal CT and MRI

Figure 2.9.5 Pituitary Hemorrhage (Apoplexy) (Canine) MR

(a) T2, TP (b) T1, TP (c) T1+C, TP
10y MC Chow cross with neurologic signs consistent with increased intracranial pressure. The dog also had concurrent thrombocyto-
penia. A large, T1 and T2 hyperintense, heterogeneous mass is present involving the pituitary, hypothalamic, and thalamic regions
(a,b). The mixed‐signal pattern is consistent with intraparenchymal hemorrhage. The mass moderately and heterogeneously contrast
enhances (c). Postmortem examination found that the pituitary was expanded, and in some regions obliterated, by lakes of free red
blood cells and a mass composed of red blood cells, fibrin, and degenerate cells (hematoma).

Figure 2.9.6 Hypophysitis (Canine) MR
6y FS Greyhound with progressive obtunda-
tion. The meningeal lining of the pituitary
fossa is T2 hyperintense (b: arrowhead), and
the meninges of the fossa and dural septum
intensely contrast enhance (c,d: arrowhead).
More diffuse meningeal enhancement is
evident, involving the meninges of the falx
cerebri and the basilar regions of the piriform
lobes (c,d: arrows). Postmortem examination
revealed diffuse meningoencephalitis with
marked chronic granulomatous and lymphop-
lasmacytic hypophysitis.

(a) T1, SP (b) T2, SP

(c) T1+C, SP (d) T1+C, DP
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