Brain Tissue Flow Measurement using Arterial Spin Labeling with Flow Discrimination by Cumulative Readout Pulses

Background The Pennes' perfusion term in the Pennes bioheat transfer equation (BHTE) depicts the rate at which blood flow removes heat from a point and can play an important role in tissue heat dissipation. Because tissue perfusion is known to change over the course of a thermal therapy treatment [1, 2], the ability to perform multiple flow assessments to detect perfusion changes during magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU) treatment is of high importance. In this work, we present a method to use arterial spin labeling (ASL) to determine the Pennes' perfusion term in brain tissue and evaluate performance as a function of various imaging parameters, such as flip angle (FA), bandwidth (BW), and resolution. The results indicate that the proposed technique could be applied in MRgHIFU to provide an efficient estimate of the Pennes' perfusion term. Although demonstrated on brain tissue, this technique could be applied to other tissue types.