BACKGROUNDA new lacunar infarction model was recently established in beagle dogs through proximal middle cerebral artery (MCA) occlusion by thrombus. This study aimed to characterize the model by multimodal magnetic resonance imaging (MRI) and to investigate its potential role for the future stroke research.

METHODSThe left proximal MCA was embolized with an autologous thrombus in six beagles. Diffusion-weighted imaging (DWI) and T2-weighted imaging (T2WI) were performed every half hour during the first six hours after occlusion, followed by three time points at 12 hours, 24 hours, and one week. Perfusion-weighted imaging (PWI) and magnetic resonance angiography (MRA) were carried out at six hours, 24 hours and one week. The PWI-DWI mismatch ratio was defined as (PWI-DWI)/DWI ischemic volume.

RESULTSLacunar infarcts induced by MCA occlusion were located in the left caudate nucleus and internal capsule. All the lesions could be detected within two hours by DWI. Lesion volume on DWI increased in a time dependent manner, from (87.19 ± 67.16) mm(3) at one hour up to (368.98 ± 217.05) mm(3) at 24 hours (P = 0.009), while that on PWI gradually decreased from (7315.00 ± 2054.38) mm(3) at six hours to (4900.33 ± 1319.71) mm(3) at 24 hours and (3334.33 ± 1195.11) mm(3) at one week (P = 0.002). The mismatch ratio was 41.93 ± 22.75 at six hours after ischemia, showing "extensive mismatch", and decreased to 18.10 ± 13.74 at 24 hours (P = 0.002). No MCA recanalization was observed within 24 hours after MCA occlusion.

CONCLUSIONSLacunar infarction induced by proximal MCA occlusion could be detected early by DWI and was characterized by extensive PWI-DWI mismatch. Multimodal MRI is useful to demonstrate the natural evolution of PWI-DWI mismatch. This ischemic model could be further used for investigating early thrombolysis in lacunar stroke showing extensive mismatch.

Animals ; Diffusion Magnetic Resonance Imaging ; methods ; Dogs ; Infarction, Middle Cerebral Artery ; complications ; Magnetic Resonance Angiography ; methods ; Male ; Stroke, Lacunar ; diagnosis

Posterior reversible encephalopathy syndrome (PRES) is usually a reversible clinical and radiological entity associated with typical features on brain MR or CT imaging. However, the not-so-uncommon atypical radiological presentations of the condition are also present and they may go unrecognised as they are confused with other conditions. Here, we report a very rare case of atypical, unilateral PRES in a 49-year-old uremic, post-transplant female patient who presented with seizures. Initial MRI showed high-grade occlusion of the left middle cerebral artery (MCA) and lesions suggestive of subacute infarction in the ipsilateral frontotemporoparietal lobe. Patient symptoms had resolved a day after the onset without any specific treatment but early follow-up CT findings suggested hemorrhagic transformation. Follow-up MRI performed 2 years later showed complete disappearence of the lesions and persisting MCA occlusion.
Acute Kidney Injury/complications ; Brain/radiography ; Diagnosis, Differential ; Female ; Humans ; Infarction, Middle Cerebral Artery/diagnosis/radiography ; Lung Transplantation ; Magnetic Resonance Imaging ; Middle Aged ; Posterior Leukoencephalopathy Syndrome/complications/*diagnosis ; Tomography, X-Ray Computed

We report a case of ophthalmic artery obstruction combined with brain infarction following periocular autologous fat injection. The patient, a 44-year-old woman, visited our hospital for decreased visual acuity in her left eye and dysarthria one hour after receiving an autologous fat injection in the periocular area. Her best corrected visual acuity for the concerned eye was no light perception. Also, a relative afferent pupillary defect was detected in this eye. The left fundus exhibited widespread retinal whitening with visible emboli in several retinal arterioles. Diffusion-weighted magnetic resonance imaging of the brain showed a hyperintense lesion at the left insular cortex. Therefore, we diagnosed ophthalmic artery obstruction and left middle cerebral artery infarction due to fat emboli. The patient was managed with immediate ocular massage, carbon dioxide, and oxygen therapy. Following treatment, dysarthria improved considerably but there was no improvement in visual acuity.
Adult ; Arterial Occlusive Diseases/diagnosis/*etiology ; Female ; Fluorescein Angiography ; Follow-Up Studies ; Fundus Oculi ; Humans ; Infarction, Middle Cerebral Artery/*complications/diagnosis ; Magnetic Resonance Imaging ; *Ophthalmic Artery ; Orbit ; Subcutaneous Fat/*transplantation ; Transplantation, Autologous/adverse effects ; Visual Acuity

No abstract available.
*Aorta, Thoracic/ultrasonography ; Aortic Diseases/*complications/diagnosis ; Catheterization, Peripheral/*adverse effects ; Cerebral Angiography/*adverse effects ; Electrocardiography ; Fatal Outcome ; *Femoral Artery ; Heart Arrest/diagnosis/etiology ; Humans ; Male ; Middle Aged ; Myocardial Infarction/diagnosis/*etiology ; Punctures ; *Sinus of Valsalva/ultrasonography ; Thrombosis/diagnosis/*etiology

No abstract available.
Angiography, Digital Subtraction ; Cerebral Angiography ; Cerebrovascular Circulation ; Collateral Circulation ; Female ; Humans ; Infarction, Middle Cerebral Artery/diagnosis/*etiology/physiopathology ; Intracranial Arteriosclerosis/diagnosis/*etiology/physiopathology ; Magnetic Resonance Angiography ; Middle Aged ; Moyamoya Disease/diagnosis/*etiology/physiopathology ; Predictive Value of Tests ; Scleroderma, Systemic/*complications ; Tomography, Emission-Computed, Single-Photon