Eun Soo Kim, Presenter: Nothing to Disclose

Seung-Koo Lee MD, PhD, Abstract Co-Author: Nothing to Disclose

Hye Jeong Kim MD, Abstract Co-Author: Nothing to Disclose

Kwanseop Lee, Abstract Co-Author: Nothing to Disclose

To evaluate effect of local brain cooling by quantification of the permeability parameters (Ktrans, Kep, Ve, and Vp) presenting the microvascular BBB permeability using dynamic contrast enhanced MRI at a transient middle cerebral artery occlusion(MCAO) rat model

31 Adult Sprague-Dawley rats (280-300 gram) were used in transient middle cerebral artery occlusion (MCAO) and underwent DCE-MRI on a 3T MRI scanner with 8-channel SENSE wrist coil. MCAO was induced by an intra-luminal filament. For one hour, middle cerebral artery was occluded at rat model. In the stroke control group without treatment, a 1-h MCA occlusion was induced and followed by 3 hour of reperfusion. Immediate MRI was performed and 24 hour of reperfusion was followed. The next day, the second MRI was done. In the local saline infusion group, after a 1-h MCA occlusion, 6ml of cold and warm saline (20°C or 37°C) through the hollow filament for about 10 minutes was infused before the onset of 3 hour of reperfusion. Immediate MRI was also performed and 24 hour of reperfusion was followed. The next day, following MRI was done. In all animals, the rotarod test was performed before MCAO and after MCAO for 1 to 9 days. The following day, all animals were euthanized and their brains were sectioned. To detect BBB breakdown after MCAO, we performed immunehistochemistry for myeloperoxidase (MPO) to identify infiltrating neutrophils associated with the inflammatory response. Data post-processing of permeability parameter was performed using Pride tools provided by Philips Medical system.

There was a statistically significant decrease of Ktrans and Kep at infarction area in cold saline (20°C) group compared with no treatment control group and a borderline decrease of Kep in cold saline (20°C) group, compared with warm saline (37°C) group. The behavior test was no statistically significance between three groups. Compared to total mixed inflammatory cells, the number of MPO-positive cells was significantly higher in control group than in cold and warm saline (20°C or 37°C) groups. In addition, the MPO-positive cells in cold saline (20°C) group are statistically lower than warm saline (37°C) group.

Local brain hypothermia induced by local saline infusion at stroke make a stable environment as decrease of BBB breakdown.

DCE MRI can demostrate the microvascular BBB permeability in stroke research.

Kim, E, Lee, S, Kim, H, Lee, K, Assessment of Brain-blood Barrier (BBB) Permeability after Local Brain Cooling with Dynamic Contrast Enhanced MRI in Transient Middle Cerebral Artery Occlusion (MCAO) Rat Model.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14006924.html