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Principal Investigator Sorensen, Gregory A. , Radiology
Arterial Spin Labeling MR: Brain Perfusion Imaging
To effectively use the ASL technique for CBF calculation in both healthy subjects and patients, it is necessary to optimize a relatively large number of MRI instrument parameters and subsequently develop an appropriate experimental procedure. Primary instrumentation parameters that need to be optimized include the two critical inversion times (TI1 and TI2), pixel bandwidth, tagging band thickness, diffusion weighting strength, and matrix size. While suggested parameter values and ASL protocols have been published for older MR systems, recent preliminary investigations have shown that the optimization will be different for ASL performed on state of the art, high-field MR scanners, equipped with whole body excitation coils, specialized head array coils, and improved ASL pulse sequences. Furthermore, parameter values will also vary considerably in disease states, primarily due to the vast changes in flow within lesions. Optimization of the ASL parameter space and improvement of the experimental design thus requires characterization of the perfusion response. The set of experiments described in this protocol aim to perform such optimizations by studying ASL in normal and diseased humans.

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