In vivo measurement of T2 relaxation times in mouse brain at 17.6 Tesla

Introduction: Transverse (T2) proton (H) magnetic resonance (MR) relaxation time plays an important role in clinics since it has a potential to distinguish different tissue types such as healthy tissue from pathological tissue [1, 2, 3]. Mice are routinely used as models for studying human brain disorders and the present trend in in vivo mouse brain MRI is to move toward ultra-high magnetic field, which can provides greater signal to noise ratio (S/N), increased resolution, sensitivity and specificity [4]. While the values for T2 relaxation time in different parts of the mouse brain have been published in different field strength, there are no established values of T2 relaxation times in mouse brain at 17.6T magnet. In this study, we aimed to establish the values of regional T2 relaxation time for mouse brain in vivo at 17.6 T and to determine whether the T2 value shows any changes at different magnetic field strengths. Phantom solutions were used to validate changes in T2 at different field strengths and to explore sources of errors when using a multi slice multi echo sequence (MSME) to measure T2.