~1H-MRS in assessment of metabolic function of striatum and substantia nigra in normal middle-aged and elder people

Objective To explore the normal value range of 1 H-MRS parameters of striatum and substantia nigra in normal middle-aged and elder people.Methods Totally 32 healthy middle-aged and elder volunteers underwent 1 H-MRS with single-voxel PRESS for the striatum and multiple-voxel PRESS for the substantia nigra.The metabolite content,including N-acetylaspartate(NAA),choline(Cho),creatinine(Cr)and their ratio were analyzed.Results There was no significant difference of NAA/Cr,Cho/Cr,NAA/Cho,NAA/(Cho+Cr)between right and left striatum,nor between bilateral substantia nigra(all P0.05).Combining results of both sides,the mean value(95% CI)of NAA/Cr,Cho/Cr,NAA/Cho and NAA/(Cho+Cr)was 1.39(1.33—1.45),0.90(0.86—0.94),1.58(1.50—1.66),0.73(0.70—0.76)in striatum and 2.36(1.85—2.87),1.38(1.12—1.65),1.70(1.59—1.81),0.93(0.86—1.00)in substantia nigra,respectively.Among above parameters,NAA/(Cho+Cr)value was the most stable one.Conclusion Among 1 H-MRS parameters of striatum and substantia nigra in normal middle-aged and elder people,NAA/(Cho+Cr)is the most stable one,which can provide normal reference data for further study of diseases involving the striatum and substantia nigra.