Surgical Treatment of a Chronic Brain Abscess and Growing Skull Fracture in a Dog

Figure 1

Preoperative magnetic resonance (MR) images of the head. (a) T2-weighted right parasagittal image. There is a predominantly T2-hyperintense mass in the right cerebrum underlying a calvarial defect (arrow) and significant dilation of the right lateral ventricle (asterisk). Inset: note the multiple rims of alternating intensity surrounding the T2-hyperintense center, not suppressed on a T2-weighted FLAIR sequence. (b) T2-weighted transverse image at the level of the optic chiasm. The mass is causing midline shift toward the left and brain herniation through the calvarial defect (arrow). (c) T2-weighted FLAIR transverse image at the level of the midbrain. There is hyperintensity immediately surrounding the markedly dilated right lateral ventricle (asterisk) and descending transtentorial herniation of the right parahippocampal gyrus (arrow). (d) T2-weighted transverse image at the level of the caudal thalamus. There is subfalcine herniation of the right cingulate gyrus (arrow) and part of the right lateral ventricle (asterisk). (e) -weighted transverse image at the level of the optic chiasm. There are several irregular areas of signal void, one (arrow) that corresponds with the bone fragment seen on CT imaging. (f) Postcontrast T1-weighted gradient-recalled echo right parasagittal image. There are three pockets of T1-hypointense material surrounded by a strongly contrast-enhancing rim. Note the elevated bone flap that incompletely spans the calvarial defect (arrow).

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