- view fewer
Acute changes in MRI diffusion, perfusion, T, and T in a rat model of oligemia produced by partial occlusion of the middle cerebral artery.
Magnetic Resonance in Medicine
706 - 712.
Oligemic regions, in which the cerebral blood flow is reduced without impaired energy metabolism, have the potential to evolve toward infarction and remain a target for therapy. The aim of this study was to investigate this oligemic region using various MRI parameters in a rat model of focal oligemia. This model has been designed specifically for remote-controlled occlusion from outside an MRI scanner. Wistar rats underwent remote partial MCAO using an undersize 0.2 mm nylon monofilament with a bulletshaped tip. Cerebral blood flow (CBF(ASL)), using an arterial spin labeling technique, the apparent diffusion coefficient of water (ADC), and the relaxation times T and T were acquired using an 8.5 T vertical magnet. Following occlusion there was a decrease in CBF(ASL) to 35 ± 5% of baseline throughout the middle cerebral artery territory. During the entire period of the study there were no observed changes in the ADC. On occlusion, T rapidly decreased in both cortex and basal ganglia and then normalized to the preocclusion values. T values rapidly increased (within approximately 7 min) on occlusion. In conclusion, this study demonstrates the feasibility of partially occluding the middle cerebral artery to produce a large area of oligemia within the MRI scanner. In this region of oligemic flow we detect a rapid increase in T and decrease in T. These changes occur before the onset of vasogenic edema. We attribute the acute change in T to increased amounts of deoxyhemoglobin; the mechanisms underlying the change in T require further investigation. (C) 2000 Wiley-Liss, Inc.
|Title:||Acute changes in MRI diffusion, perfusion, T, and T in a rat model of oligemia produced by partial occlusion of the middle cerebral artery|
|UCL classification:||UCL > School of Life and Medical Sciences > Faculty of Brain Sciences > Institute of Neurology > Brain Repair and Rehabilitation
UCL > School of Life and Medical Sciences > Faculty of Medical Sciences > Medicine (Division of) > Metabolism and Experimental Therapeutics
UCL > School of BEAMS > Faculty of Engineering Science > Medical Physics and Bioengineering
Archive Staff Only