Validation of Quantitative Bound and Pore Water Imaging in Cortical Bone

Abstract

Clinically compatible ultra-short echo time (UTE) imaging sequences for quantitative T2-based bound and pore water imaging in bone were implemented and validated on a 3T human scanner and a 4.7T small bore system. Pore water images were generated by selectively saturating bound water signals with a T2-selective double adiabatic inversion pulse. Bound water images were generated by nulling the pore water signals with a T2-selective adiabatic inversion recovery preparation. In both cases, the magnetization preparation was integrated into a 3D UTE acquisition, with 16 radial spokes acquired per preparation. Images were acquired from human cadaveric femoral mid-shafts, from which isolated bone samples were subsequently extracted for non-imaging analysis using T2 spectroscopic measurements. The results showed a strong correlation between imaging-derived concentrations of bound and pore water and those determined from the isolated bone samples.