Page 188 - Atlas of Small Animal CT and MRI

Figure 2.4.5 Chronic Intracranial Hemorrhage (Canine) MR

(a) T1, TP (b) T2, TP (c) T2*, TP

(d) T1, TP, 6 wk follow-up (e) T2, TP, 6 wk follow-up (f) T2*, TP, 6 wk follow-up
12y FS Poodle with 5‐day history of right forebrain deficits. The initial MR examination (a–c) was acquired 5 days following the onset of
clinical signs. The follow‐up MR examination (d–f) was acquired approximately 6 weeks later, at which time the dog had clinically
improved. On the initial examination, there is a large mass within the right frontal lobe that is T1 iso‐ to hyperintense (a) and of mixed T2
intensity (b). A prominent susceptibility effect is present on the T2* image (c). This constellation of imaging features is consistent with an
acute to subacute intracranial hemorrhage, supported by the 5‐day duration of clinical signs. The marked reduction in lesion volume and
the uniform hypointensity evident on all imaging sequences on the second examination acquired 6 weeks later are consistent with a
resolving chronic hematoma (d–f). A postmortem examination performed 1 year later for an unrelated cause of death revealed extensive
neuropil loss and other chronic degenerative changes of the right frontal lobe consistent with residual effects of a healed infarct.

Figure 2.4.6 Acute Epidural Hemorrhage (Canine) CT

10y FS Labrador Retriever with lymphoplasmacytic encephalitis. The CT image was acquired
immediately following CT‐guided brain biopsy. Epidural hemorrhage is evident involving
the left parietal region. The biconvex shape is consistent with an epidural hemorrhage.
Although acute hemorrhage is hyperattenuating on unenhanced CT images, the increased
attenuation in this patient is due, in part, to enhancement following intravenous contrast
medium administration.

(a) CT+C, TP
178