OBJECTIVE To determine values of perfusion parameters determined via MRI in the brains of healthy dogs. ANIMALS 10 healthy adult Beagles. PROCEDURES Each dog was anesthetized for MRI examination of the brain, including standard sequences and a perfusion-weighted sequence. Gadoteric acid (0.2 mmol/kg) was injected IV at a rate of 5 mL/s. A dedicated workstation was used to measure the times from contrast medium injection to arrival at an ROI (TO) and peak contrast enhancement (TTP), mean contrast medium transport time (MTT), and cerebral blood flow (CBF) in the caudate nucleus, thalamus, piriform lobe, hippocampus, semioval center, and temporal cerebral cortex. A simple mathematical model was used to compare parameter values among the various brain regions. RESULTS T0 and time to peak contrast enhancement had a significant linear relationship. A significant negative correlation was identified between T0 and CBF and, to a lesser extent, between MTT and CBF. Differences among brain regions were significant for MTT and CBF. The CBF was lowest in the semioval center, and the piriform lobe had almost 2-fold the CBF of that region. No significant differences were identified between hemispheres of the brain. CONCLUSIONS AND CLINICAL RELEVANCE Findings obtained in this study involving healthy dogs may serve as a reference for MRI perfusion measurements in specific brain regions and may help in the characterization of various brain diseases in dogs.

OBJECTIVE To quantitatively analyze brain perfusion parameters in dogs with idiopathic epilepsy (IE) by use of MRI and to compare those findings with brain perfusion parameters for healthy dogs. ANIMALS 12 client-owned dogs with IE. PROCEDURES For each dog, standard MRI and perfusion-weighted imaging (before and after injection of gadoteric acid contrast medium) sequences of the brain were obtained during the interictal period by means of the same protocol used in a comparable study of healthy dogs. Time of contrast medium arrival, time to peak contrast enhancement, mean contrast transit time, and cerebral blood flow were calculated for the caudate nucleus, thalamus, piriform lobe, hippocampus, semioval center, and temporal cerebral cortex. Parameters for each structure were compared between dogs with IE and healthy dogs. RESULTS Dogs with IE had a significantly greater mean time of contrast arrival and lower mean cerebral blood flow than healthy dogs. Differences in cerebral blood flow between dogs with IE and healthy dogs were most pronounced in the piriform lobe, thalamus, and temporal cerebral cortex. The mean contrast transit time did not differ between dogs with IE and healthy dogs. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that, compared with healthy dogs, dogs with IE have decreased blood perfusion of the brain. Findings of this study can be used as a basis for further research into functional changes within the brains of epileptic dogs during the interictal phase.

A 3‐year‐old French bulldog was presented to the ophthalmology service of the Vetsuisse Faculty, University of Zurich with a 3‐day history of conjunctival swelling of the left eye (OS). Ophthalmologic examination revealed a moderate conjunctival hyperemia and chemosis. A migrating foreign body having entered the conjunctival fornix behind the nictitating membrane was suspected. Within the first 24 hours of medical management, OS developed a panuveitis and a scleral perforation was highly suspected. Ocular and orbital ultrasound as well as conventional magnetic resonance imaging (MRI) examinations failed to confirm the presence of a perforating foreign body. A High‐Resolution MRI (HR‐MRI) using a microscopy coil was then performed with findings consistent with a perforating and migrating foreign body. A grass awn of 12 mm length was surgically retrieved “ab externo” from its’ point of entry into the sclera. To the best of our knowledge, HR‐MRI has not yet been used to examine canine eyes. This case report supports the idea that orbital imaging can be greatly enhanced with the introduction of HR‐MRI using microscopy coils with clinically relevant implications.

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Bilateral carotid artery ligation has been reported as a lifesaving procedure to control severe hemorrhage. However, reports are sparse and little information is available regarding the potential risks associated with this procedure. We report an ischemic brain infarct as a complication after vascular surgery. A 3-year old, male intact border collie was presented for acute onset of forebrain signs 5 days after bilateral carotid artery ligation. Multimodal brain MRI including morphologic sequences, MR angiography, diffusion-and perfusion-weighted images were performed. MRI revealed a well-defined intra-axial lesion of the left caudate nucleus, with increased T2 and decreased T1 signal intensity and moderate heterogeneous peripheral contrast enhancement. The cerebral blood flow was reduced relative to the contralateral caudate nucleus. Images were consistent with a subacute lacunar ischemic infarct of the left striate artery. Additionally, multiple arterio-arterial anastomosis arising from the vertebral arteries were visible in the angiography sequences. Ischemic infarct due to thromboembolism should be considered as a possible complication associated with bilateral carotid artery ligation. Collateral blood supply can develop as early as 5 days after surgery.