Feasibility of in-vivo semi-LASER renal magnetic resonance spectroscopy (MRS): Pilot study in healthy volunteers

Abstract

PurposeTo evaluate the feasibility of semi-LASER renal magnetic resonance spectroscopy (MRS) in healthy volunteers and establish signature chemical composition of normal renal tissue towards future application for renal carcinoma characterization and grading. Materials and methods14 healthy volunteers were recruited after informed consent. Single voxel 1H spectra were acquired on a 3T MRI system using a semi-LASER sequence, employing outer-volume suppression and VAPOR water suppression with multiple averages in multiple breath-holds. Off-line processing and automatic correction for zero-order phase and frequency using the water resonance or residual water resonance for water-suppressed acquisitions was performed. Results11 volunteers successfully completed the entire examination. Phase and frequency correction was necessary to obtain optimal data quality prior to signal summation in few datasets. No lipid resonance was observed in any spectra from the unsuppressed water acquisitions, either in individual transients or in corrected summed spectra opposed to previously reported studies. No signal from other metabolites, such as choline-containing compounds, was observed in any dataset. ConclusionSemi-LASER renal MRS is technically feasible. Normal renal parenchyma does not demonstrate detectable levels of lipid or choline. This may provide a reference point for future application of this technique for noninvasive renal carcinoma histologic subtype characterization and grade.