Page 202 - Atlas of Small Animal CT and MRI

192 Atlas of Small Animal CT and MRI

Figure 2.5.8 Late‐delayed Radiation Effects (Canine) MR

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

(d) T2*, TP (e) T2*, TP
10y MC Boston Terrier who underwent radiation therapy for a pituitary tumor 18 months previously. There is ill‐defined, bihemispheric,
white‐matter T2 hyperintensity and T1 hypointensity (a,b). There are multiple focal signal voids in the deep gray matter and at the
cerebral cortical gray–white matter interface, best seen on T2* images (d,e). The residual pituitary tumor is best seen on the contrast‐
enhanced T1 image (c). The signal voids represent susceptibility effect from multiple lacunar infarcts from the vascular effects of
irradiation. The white matter T2 hyperintensity is consistent with necrotizing leukoencephalopathy.

192