Affiliation:
1. Emory National Primate Research Center Emory University Atlanta Georgia USA
2. Department of Radiology and Imaging Sciences Emory University School of Medicine Atlanta Georgia USA
3. Department of Computer Engineering Chonnam National University Gwangju South Korea
4. Department of ICT Convergence System Engineering Chonnam National University Gwangju South Korea
5. Department of Neurosurgery Emory University School of Medicine Atlanta Georgia USA
Abstract
AbstractPurposeTo integrate 3D CEST EPI with an unevenly segmented RF irradiation module and preliminarily demonstrate it in the clinical setting.MethodsA CEST MRI with unevenly segmented RF saturation was implemented, including a long primary RF saturation to induce the steady‐state CEST effect, maintained with repetitive short secondary RF irradiation between readouts. This configuration reduces relaxation‐induced blur artifacts during acquisition, allowing fast 3D spatial coverage. Numerical simulations were performed to select parameters such as flip angle (FA), short RF saturation duration (Ts2), and the number of readout segments. The sequence was validated experimentally with data from a phantom, healthy volunteers, and a brain tumor patient.ResultsBased on the numerical simulation and l‐carnosine gel phantom experiment, FA, Ts2, and the number of segments were set to 20°, 0.3 s, and the range from 4 to 8, respectively. The proposed method minimized signal modulation in the human brain images in the kz direction during the acquisition and provided the blur artifacts‐free CEST contrast over the whole volume. Additionally, the CEST contrast in the tumor tissue region is higher than in the contralateral normal tissue region.ConclusionsIt is feasible to implement a highly accelerated 3D EPI CEST imaging with unevenly segmented RF irradiation.
Funder
National Institute of Neurological Disorders and Stroke
Ministry of Science and ICT, South Korea
Subject
Radiology, Nuclear Medicine and imaging