Dai, WeiyingGarcia, Daironde Bazelaire, CedricAlsop, David2022-07-152008-12Dai, Weiying, Dairon Garcia, Cedric de Bazelaire, David Alsop. "Continuous Flow-Driven Inversion for Arterial Spin Labeling Using Pulsed Radio Frequency and Gradient Fields." Magnetic Resonance in Medicine 60, no. 6 (2008): 1488-1497. DOI: 10.1002/mrm.217900740-31941522-2594https://nrs.harvard.edu/URN-3:HUL.INSTREPOS:37372632Continuous labeling by flow driven adiabatic inversion is advantageous for arterial spin labeling (ASL) perfusion studies, but details of the implementation, including inefficiency, magnetization transfer, and limited support for continuous-mode operation on clinical scanners has restricted the benefits of this approach. Here a new approach to continuous labeling that employs rapidly repeated gradient and RF pulses to achieve continuous labeling with high efficiency is characterized. The theoretical underpinnings, numerical simulations, and in-vivo implementation of this pulsed continuous ASL (PCASL) are described. In-vivo PCASL labeling efficiency of 96% relative to continuous labeling with comparable labeling parameters far exceeded the 33% duty cycle of the PCASL RF pulses. Imaging at 3 Tesla with body coil transmission was readily achieved. This technique should help to realize the benefits of continuous labeling in clinical imagers.en-USResearch Subject Categories::MEDICINE::Physiology and pharmacology::Radiological research::RadiologyJournal Article2022-07-1510.1002/mrm.21790