Measurement of bound and pore water T 1 1 relaxation times in cortical bone using three‐dimensional ultrashort echo time cones sequences

摘要

Purpose We present three‐dimensional ultrashort echo time Cones (3D UTE Cones) techniques for quantification of total water T 1 ( T 1 TW ), bound water T 1 ( T 1 BW ), and pore water T 1 ( T 1 PW ) in vitro and in vivo using a 3 Tesla (T) scanner. Methods T 1 TW , T 1 BW , and T 1 PW were measured with three‐dimensional (3D) Cones and adiabatic inversion recovery Cone (IR‐Cone) sequences. Two‐dimensional (2D) nonselective ultrashort echo time (UTE) techniques, including saturation recovery, variable repetition times (TRs), and inversion recovery (IR) preparation approaches were compared with 3D‐Cones techniques on bovine cortical bone samples (n?=?8). The 3D Cones sequences were used to measure T 1 TW , T 1 BW , and T 1 PW in the tibial midshaft of healthy volunteers (n?=?8). Results Comparable T 1 images were achieved for cortical bone between 3D Cones and 2D UTE techniques as well as those published in the literature. The 3D Cones sequences showed a mean T 1 TW of 208?±?22 ms, a mean T 1 PW of 545?±?28 ms, and a mean T 1 BW of 131?±?12 ms for bovine cortical bone; and a mean T 1 TW of 246?±?32 ms, a mean T 1 PW of 524?±?46 ms, and a mean T 1 BW of 134?±?11 ms for the tibial midshaft of healthy volunteers. Conclusions The 3D Cones sequences can be used for fast volumetric assessment of bound and pore water T 1 images in vitro and in vivo. Magn Reson Med 77:2136–2145, 2017. ? 2016 International Society for Magnetic Resonance in Medicine