Guanshu Liu1, 2, Kannie WY Chan2, 3, Xiaolei Song2, 3, Jiangyang Zhang2, 4, Assaf A. Gilad2, 3, Jeff WM Bulte2, 3, Peter CM van Z
1F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Instittute , Baltimore, MD, United States; 2Department of Radiology, Johns Hopkins University School of Medicine, baltimore, MD, United States; 3Cellular Imaging Section, Institute for Cell Engineering, Johns Hopkins University School of Medicine, baltimore, MD, United States; 4F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, baltimore, MD, United States
Signal contamination and partial volume effects significantly influence in vivo CEST quantification. To improve upon this, we propose a simple magnetization transfer (MT) based segmentation method based on adding two MT weighted images at offsets of -12.5 and -50 ppm to CEST acquisitions. These are used to calculate a NOrmalizedMAgnetization Ratio (NOMAR) allowing pixels containing fat or fluids to be separated from target tissues using a global threshold determined by histogram analysis. As a first application, we demonstrate that this technique can significantly improve the detection of DIACEST liposomes injected into live mice.