Brain perfusion magnetic resonance imaging using pseudocontinuous arterial spin labeling in 314 dogs and cats.

BACKGROUND: Arterial spin labeling (ASL) is a noninvasive brain perfusion magnetic resonance imaging (MRI) technique that has not been assessed in clinical veterinary medicine. HYPOTHESIS/OBJECTIVES: To test the feasibility of ASL using a 1.5 Tesla scanner and provide recommendations for optimal quantification of cerebral blood flow (CBF) in dogs and cats. ANIMALS: Three hundred fourteen prospectively selected client-owned dogs and cats. METHODS: Each animal underwent brain MRI including morphological sequences and ≥1 ASL sequences using different sites of blood labeling and postlabeling delays (PLD). Calculated ASL success rates were compared. The CBF was quantified in animals that had morphologically normal brain MRI results and parameters of ASL optimization were investigated. RESULTS: Arterial spin labeling was easily implemented with an overall success rate of 95% in animals with normal brain MRI. Technical recommendations included (a) positioning of the imaging slab at the foramen magnum and (b) selected PLD of 1025 ms in cats and dogs <7 kg, 1525 ms in dogs 7 to 38 kg, and 2025 ms in dogs >38 kg. In 37 dogs, median optimal CBF in the cortex and thalamic nuclei were 114 and 95 mL/100 g/min, respectively. In 28 cats, median CBF in the cortex and thalamic nuclei were 113 and 114 mL/100 g/min, respectively. CONCLUSIONS AND CLINICAL IMPORTANCE: Our survey of brain perfusion ASL-MRI demonstrated the feasibility of ASL at 1.5 Tesla, suggested technical recommendations and provided CBF values that should be helpful in the characterization of various brain diseases in dogs and cats.

Brain abscess complicating ischemic embolic stroke in a patient with cardiac papillary fibroelastoma - Case report and literature review.

A 72-year-old man without obvious risk factors initially presented with acute ischemic stroke and fever, without concomitant infection. Broad spectrum antibiotic therapy was initiated. Transthoracic and Transesophageal echocardiography, and cardiac MRI revealed a 20 mm round mass attached to the anterior mitral valve leaflet, suggesting the diagnosis of a benign cardiac tumor or a vegetation. At the site of infarction an abscess of 11 mm in diameter developed 30 days later. The patient underwent surgical valve repair for the prevention of further embolic complications. Histology revealed a cardiac papillary fibroelastoma (PFE). He made complete clinical recovery. Secondary abscess formation after ischemic stroke is rare: 11 other cases have been reported. Because they develop at the site of a previous ischemic infarct, these abscesses usually do not manifest by additional neurologic deficits, making difficult their diagnosis. In most cases a concomitant infection cannot be individualized. Even if these abscesses are a rare entity, patients with cerebral infarct presenting with fever must be closely follow-up with cerebral imaging. Even if PFE is a rare cardiac source of embolic stroke, it should be considered in the differential diagnosis of stroke in a patient where an alternative etiology has not been established.