In vivo ¹H MR spectroscopic findings in traumatic contusion of ICR mouse brain induced by fluid percussion injury

Purpose: The purpose of this study was to investigate the proton metabolic differences of the right parietal cortex with experimental brain contusions of ICR mouse induced by fluid percussion injury (FPI) compared to normal controls and to test the possibility that ¹H magnetic resonance spectroscopy (MRS) findings could provide neuropathologic criteria in the diagnosis and monitoring of traumatic brain contusions. Materials and methods: A homogeneous group of 20 ICR male mice was used for MRI and in vivo ¹H MRS. Using image-guided, water-suppressed in vivo ¹H MRS with a 4.7 T MRI/MRS system, we evaluated the MRS measurement of the relative proton metabolite ratio between experimental brain contusion of ICR mouse and healthy control subjects. Results: After trauma, NAA/Cr ratio, as a neuronal marker decreased significantly versus controls, indicating neuronal loss. The ratio of NAA/Cr in traumatic brain contusions was 0.90 ± 0.11, while that in normal control subjects was 1.13 ± 0.12 (P = 0.001). The Cho/Cr ratio had a tendency to rise in experimental brain contusions (P = 0.02). The Cho/Cr ratio was 0.91 ± 0.17, while that of the normal control subjects was 0.76 ± 0.15. However, no significant difference of Glx/Cr was established between the experimental traumatic brain injury models and the normal controls. Discussion and conclusions: The present ¹H MRS study shows significant proton metabolic changes of parietal cortex with experimental brain contusions of ICR mouse induced by FPI compared to normal controls. In vivo ¹H MRS may be a useful modality for the clinical evaluation of traumatic contusions and could aid in better understanding the neuropathologic process of traumatic contusions induced by FPI.