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Published on: September 7, 2018
MRI characteristics of cerebral microbleeds in four dogs
Caroline V Fulkerson1, Benjamin D Young, Nicolette D Jackson
1Department of Large Animal Clinical Sciences, Texas A&M University, College Station, TX 77843, USA. cvantass@purdue.edu
Abstract:
Cerebral microbleeds in people are small foci of hemosiderin-containing macrophages in normal brain parenchyma. They are the remnant of previous hemorrhage and occur with greater frequency in older individuals. Our purpose was to describe the magnetic resonance (MR) appearance of cerebral microbleeds in four dogs. These lesions appeared as round, hypointense foci measuring ≤4 mm on T2*-gradient-recalled echo images. They were less conspicuous or absent on T2-weighting, being iso- or hypointense, and uniformly invisible on T1-weighted images. No contrast enhancement was seen in any of the cerebral microbleeds. Necropsy-derived histopathologic analysis of one brain confirmed these lesions to be chronic cerebrocortical infarcts containing hemosiderin. The MR changes seen in dogs were analogous to what has been described in people and will be helpful in distinguishing cerebral microbleeds from other brain lesions.
Insights
Cerebral microbleeds, small brain hemorrhages, appear similarly on MRI in dogs and humans. This finding aids in differentiating these lesions from other abnormalities in canine brains.
Area of Science:
- Veterinary Neurology
- Neuroradiology
- Comparative Pathology
Background:
- Cerebral microbleeds are remnants of prior hemorrhages, characterized by hemosiderin-laden macrophages.
- These lesions are more prevalent in aging human populations.
- Understanding their appearance in veterinary patients is crucial for accurate diagnosis.
Purpose of the Study:
- To characterize the magnetic resonance (MR) imaging appearance of cerebral microbleeds in dogs.
- To compare the MR findings in dogs with those previously described in humans.
- To establish imaging criteria for identifying canine cerebral microbleeds.
Main Methods:
- Four dogs with suspected neurological conditions underwent MR imaging.
- Imaging sequences included T1-weighted, T2-weighted, and T2*-gradient-recalled echo (GRE).
- Histopathologic analysis of one brain specimen confirmed lesion composition.
Main Results:
- Cerebral microbleeds manifested as small (≤4 mm), round, hypointense foci on T2*-GRE sequences.
- Lesions were less conspicuous or isointense/hypointense on T2-weighted images and invisible on T1-weighted images.
- No contrast enhancement was observed, and histopathology confirmed chronic infarcts with hemosiderin.
Conclusions:
- The MR imaging appearance of cerebral microbleeds in dogs is analogous to that observed in humans.
- These findings provide valuable information for differentiating canine cerebral microbleeds from other intracranial lesions.
- This comparative imaging analysis enhances diagnostic capabilities in veterinary neurology.
