Stroke

Cerebrovascular disease refers to any abnormality of the brain caused by a pathologic process compromising blood supply. Pathologic processes that may result in cerebrovascular disease include occlusion of the lumen by a thrombus or embolus, rupture of a blood vessel wall, a lesion or altered permeability of the vessel wall, and increased viscosity or other changes in the quality of the blood. Stroke or cerebrovascular accident (CVA) is the most common clinical presentation of cerebrovascular disease and is defined as a sudden onset of nonprogressive focal brain signs secondary to cerebrovascular disease.

Ischemic stroke can have a T1W hyperintense appearance in absence of intralesional hemorrhage

Magnetic resonance imaging (MRI) signal changes associated with ischemic stroke are typically described as T2W and FLAIR hyperintense, and T1W isointense lesions. Intralesional T1W hyperintensity is generally attributed to either a hemorrhagic stroke, or an ischemic stroke with hemorrhagic transition, and has an associated signal void on gradient echo (GE) sequences.

This multicenter retrospective descriptive study investigates the presence of T1W hyperintensity in canine stroke without associated signal void on GE sequences. T1W hyperintensities are likely caused by partial tissue infarction or selective neuronal necrosis.

1.5 Tesla Magnetic Resonance Imaging Features of Canine Intracranial Intra-axial Hematomas

The MRI appearance of intracranial hemorrhage can be complex and has different signal intensity patterns, which depend on several factors including age of the hemorrhage which affect the state of oxidation of haemoglobin.

The aim of this study was to describe the 1.5 tesla MRI features of canine intra-axial hematomas and correlate these findings with the evolution of hemorrhages described in human brains. Retrospective evaluation of patient details, clinical signs, and MRI findings of dogs with intra-axial hematomas that were histopathologically confirmed or determined via repeat MRI study and/or resolution of neurological signs. Ten dogs met the inclusion criteria.

All 10 hemorrhagic lesions were comprised of two distinct regions; a relatively thin T1-weighted (T1W), T2-weighted (T2W) and gradient echo (GRE) hypointense peripheral border region and a large central region that was heterogenous but predominantly T1W, T2W and GRE hyperintense. The peripheral border region was complete in its integrity in all 10 cases on T2W and GRE sequences. Contrast enhancement was present in (6/10) hematoma lesions and was always peripheral in nature with no evidence of central enhancement associated with any of the lesions

Imaging Ischemic and Hemorrhagic Disease of the Brain in Dogs

A thorough understanding of the appearance of strokes at various stages can aid the clinician when presented with a patient who has developed a stroke in the days or weeks prior to evaluation. This review covers the vascular anatomy of the brain, the classification of stroke and the use of both CT and MRI for the diagnosis of both ischaemic and haemorrhagic stroke lesions.

Comparison of D‐dimer concentration and thromboelastography for diagnosis of cerebrovascular accidents in dogs: A retrospective study

The objective of this study was to assess the utility of blood D‐dimer concentration and TEG in supporting the imaging diagnosis of CVAs in 68 dogs.

Neither D‐dimer concentration nor TEG was significantly associated with a CVA. D‐dimer testing showed low sensitivity and high specificity for CVA diagnosis. Thromboelastography showed moderate sensitivity and specificity for CVA diagnosis. Abnormal D‐dimer concentration or TEG were not helpful in differentiating hemorrhagic from ischemic stroke.

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Stroke

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