Page 271 - Atlas of Small Animal CT and MRI

Sella and Parasellar Region 261

Figure 2.9.18 Meningioma (Canine) MR

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

(d) T1+C, TP (e) T1+C, TP (f) T1+C, SP
7y MC Golden Retriever with recent onset of blindness. Images a–c are representative transverse images just rostral to the pituitary
fossa. Images d and e are additional representative contrast‐enhanced images rostral and caudal to image c, respectively. Image f is a
comparable image oriented in the sagittal plane. A large sessile mass is evident, centered on the region of the optic chiasm. The mass has
mixed T1 and T2 signal intensity (a,b) and is nonuniformly but intensely contrast enhancing (c–f). The mass appears to fill the pituitary
fossa (e,f), and the pituitary gland is not delineated from the mass. Although this lesion has some imaging features similar to those of a
primary pituitary neoplasm, the sessile appearance, with extension well beyond the pituitary fossa and hypothalamus, and the intense
contrast enhancement suggest an extraaxial neoplasm, such as meningioma. CT‐guided biopsy was interpreted as probable
meningioma.

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