Trabecular bone imaging using a 3D adiabatic inversion recovery prepared ultrashort TE Cones sequence at 3T.

Abstract

To investigate direct imaging of trabecular bone using a 3D adiabatic inversion recovery prepared ultrashort TE cones (3D IR-UTE-Cones) sequence. The proposed 3D IR-UTE-Cones sequence used a broadband adiabatic inversion pulse together with a short TR/TI combination to suppress signals from long T2 tissues such as muscle and marrow fat, followed by multispoke UTE acquisition to detect signal from short T2 water components in trabecular bone. The feasibility of this technique for robust suppression of long T2 tissues was first demonstrated through numerical simulations. The proposed IR-UTE-Cones sequence was applied to a hip agarose bone phantom and to 6 healthy volunteers for morphologic and quantitative and proton density mapping of trabecular bone. Numeric simulation suggests that the IR technique with a short TR/TI combination provides sufficient suppression of long T2 tissues with a wide range of T1 s. High contrast imaging of trabecular bone can be achieved ex vivo and in vivo, with fitted values of 0.3-0.45 ms and proton densities of 5-9 mol/L. The 3D IR-UTE-Cones sequence with a short TR/TI combination provides robust suppression of long T2 tissues and allows both selective imaging and quantitative ( and proton density) assessment of short T2 water components in trabecular bone in vivo.