Page 786 - Clinical Small Animal Internal Medicine

754 Section 8 Neurologic Disease

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Figure 69.11 A lateral skull radiograph shows a frontal bone
fracture (arrow) in this dog after being bitten by another dog.

Figure 69.13 A transverse T2‐weighted MRI of the dog in
Fig. 69.11 confirms the extent of the soft tissue injury associated
with frontal bone fractures. Hyperintensity seen in the brain
(arrow) is compatible with edema secondary to the bite injury.

density decreases, with clot resorption creating a hypoat-
tenuating lesion similar to edema. A CT can provide
images for surgical planning, but should only be pursued
in patients who are severely affected or deteriorating
requiring surgical intervention.
Magnetic resonance imaging allows superior soft
tissue detail and is preferred for evaluation of the brain,
especially the caudal fossa which does not image well
with CT (Figure 69.13). MRI can detect more subtle
parenchymal changes that may be missed on a CT and
may provide information about prognosis. Hematomas
or hemorrhage, parenchymal contusions, and edema
Figure 69.12 A transverse bone windowed CT scan of the dog in are readily apparent on MRI images. Although CT is
Fig. 69.11 confirms a comminuted frontal bone fracture associated preferred for evaluation of bony structures, fractures can
with soft tissue damage and air pockets dorsal to the skull. also be identified on an MRI, most proficiently using
STIR and gradient echo sequences.
radiography, especially considering the 3D reconstruc- Typically, CT and MRI are only pursued in patients
tion capabilities (Figure 69.12). Additionally, CT can be who fail to respond to aggressive medical therapy or who
used to diagnose intracranial hemorrhage, alterations in deteriorate and may require surgical intervention. Both
ventricular size or shape, midline shift of the falx cerebri, MRI and CT findings were recently correlated with
and edema. CT does not provide good soft tissue detail prognosis in veterinary head trauma patients so their use
of the brain parenchyma, but is frequently the preferred may be of specific additional benefit.
modality for evaluation of human head trauma patients
for surgical intervention because of the speed of image Intracranial Pressure Monitoring
acquisition. Typically, hemorrhage is hyperattenuating Intracranial pressure may be monitored through place-
(hyperdense) on a CT in the acute stages. Over time, the ment of a pressure transducer or fiberoptic transducer