Comparison of Four-Channel Flexible and Eight-Channel Extremity Coils for Multivoxel Proton Magnetic Resonance Spectroscopy of the Canine Brain at 1.5 T.

To compare four-channel flexible and eight-channel extremity radiofrequency coils for measuring brain metabolite ratios using multivoxel proton magnetic resonance spectroscopy (1H-MRS) in dogs at 1.5 T. Sixteen healthy dogs (12 males, 4 females; age 6.19 ± 2.17 years; weight 23.43 ± 9.65 kg) underwent 1H-MRS using both coil types with identical protocols. Multivoxel point-resolved spectroscopy was performed on bilateral thalamic regions at short (TE = 30 ms) and long (TE = 135 ms) echo times. N-acetyl aspartate-to-creatine (NAA/Cr) and choline-to-creatine (Cho/Cr) ratios were compared between coils using Wilcoxon signed-rank tests. No significant differences were found between coil types. For long echo time, NAA/Cr ratios were right thalamus 1.29 ± 0.27 versus 1.32 ± 0.34 (p = 0.756) and left thalamus 1.22 ± 0.19 versus 1.22 ± 0.48 (p = 0.301) for four-channel versus eight-channel coils, respectively. Cho/Cr ratios were right thalamus 1.45 ± 0.28 versus 1.69 ± 0.68 (p = 0.056) and left thalamus 1.51 ± 0.41 versus 1.45 ± 0.41 (p = 0.215). Short echo time results were similarly nonsignificant. Both coil types provide comparable metabolite measurements for canine brain 1H-MRS at 1.5 T, allowing coil selection to be guided by practical considerations such as patient size and positioning ease rather than spectral quality concerns.