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

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.