To avoid partial volume effects and thus improve data quality and data analysis, highest resolution is desired. However, if the signal in the individual voxels of the investigated subject is not large enough, the resulting low SNR prohibits analysis of the images. The greater SNR obtainable with Ultra High Field (UHF) instruments, therefore can be directly carried over into higher resolution. This enables researchers to push the resolution in the direction of “in vivo MRI histology” as well as to benefit from the increased data quality in a range of disease models [1,2].
In addition to anatomical imaging, many MRI methods benefit from the sensitivity increase. For example, in BOLD fMRI more refined stimulation paradigms can be defined, as the increased SNR places less demands on the strength of the stimulations. Furthermore, with increasing resolution, fMRI accuracy becomes less and less limited by voxel size but rather by how particularly minutely (both spatially and temporally) the blood flow to the point of neuronal activity is regulated . Furthermore, for high resolution fMRI the reduced partial volume effect promises to lead to further improvement in SNR . High resolution fMRI with small voxel sizes will additionally benefit from UHF since it operates in the thermal noise-dominated regime and thus, in this case, a significant sensitivity gain compared to lower magnetic fields is expected .