T1ρ relaxation and its application to MR histology

Abstract

AbstractThe application of T1P as an alternative contrast parameter in high‐field magnetic resonance histology (MRH) has been investigated. Spectroscopic measurements of T1P were performed on 5.75% agar and 1.0 mM MnCl2 phantoms at 9.4 T to validate the accuracy of the imaging measurements. Image studies were performed at 2.0 and 9.4 T on perfusion‐fixed 17.5‐day‐old mouse embryos. T1′ T2′ and T1P relaxation times were calculated for the phantoms and muscle, diencephalon, and liver tissues. The 5.75% agar phantom and all tissues showed T1P dispersion with B1L, whereas the 1.0 mM MnCl2 phantom showed no significant B1L dependence. T1P dispersion with B0 was observed arising from the effects of diffusion through susceptibility‐induced gradients. T1P shows promise as a contrast parameter in high‐field MRH because it is capable of producing T2‐like contrast without the susceptibility artifacts associated with T2‐weighted images.