High Resolution in vivo preclinical 1H-FID-MRSI using Compressed Sensing : when acceleration leads to precipitation

Motivation: High-resolution preclinical magnetic resonance spectroscopic imaging applied in the rodent brain can offer a great deal of metabolite information, but at the cost of low temporal resolution. Goal(s): Our goal was to explore 1H-MRSI with compressed sensing (CS) acceleration to reach higher resolution on the rat brain and investigate its benefits and shortcomings. Approach: Free induction decay MRSI was acquired with a resolution of 31x31 and optimized CS was then used to reach 47x47 and 63x63 in an acceptable time. Results: While concentration estimates and maps were preserved with each resolution, the lipid contaminations and increase in effective voxel size limited the method. Impact: 1H-MRSI combined with CS could be useful for dynamic measurements over multiple repetitions. For higher resolution acquisition, the technique could be more suitable for 3D whole-brain acquisition or in combination with other acceleration techniques.