title: Fast volumetric imaging of bound and pore water in cortical bone using three-dimensional ultrashort-TE (UTE) and inversion recovery UTE sequences.
abstract: We report the three-dimensional ultrashort-TE (3D UTE) and adiabatic inversion recovery UTE (IR-UTE) sequences employing a radial trajectory with conical view ordering for bi-component T2 * analysis of bound water (T2 *(BW) ) and pore water (T2 *(PW) ) in cortical bone. An interleaved dual-echo 3D UTE acquisition scheme was developed for fast bi-component analysis of bound and pore water in cortical bone. A 3D IR-UTE acquisition scheme employing multiple spokes per IR was developed for bound water imaging. Two-dimensional UTE (2D UTE) and IR-UTE sequences were employed for comparison. The sequences were applied to bovine bone samples (n = 6) and volunteers (n = 6) using a 3-T scanner. Bi-component fitting of 3D UTE images of bovine samples showed a mean T2 *(BW) of 0.26 ± 0.04 ms and T2 *(PW) of 4.16 ± 0.35 ms, with fractions of 21.5 ± 3.6% and 78.5 ± 3.6%, respectively. The 3D IR-UTE signal showed a single-component decay with a mean T2 *(BW) of 0.29 ± 0.05 ms, suggesting selective imaging of bound water. Similar results were achieved with the 2D UTE and IR-UTE sequences. Bi-component fitting of 3D UTE images of the tibial midshafts of healthy volunteers showed a mean T2 *(BW) of 0.32 ± 0.08 ms and T2 *(PW) of 5.78 ± 1.24 ms, with fractions of 34.2 ± 7.4% and 65.8 ± 7.4%, respectively. Single-component fitting of 3D IR-UTE images showed a mean T2 *(BW) of 0.35 ± 0.09 ms. The 3D UTE and 3D IR-UTE techniques allow fast volumetric mapping of bound and pore water in cortical bone. Copyright © 2016 John Wiley & Sons, Ltd.
authors: Department of Orthopedics, Peking Union Medical College Hospital, Beijing, China.|Department of Radiology, University of California, San Diego, CA, USA.
authors: Jun
authors: J
authors: Chen
authors: Applied Science Laboratory, GE Healthcare, San Diego, CA, USA.
authors: Michael
authors: M
authors: Carl
authors: Department of Radiology, University of California, San Diego, CA, USA.
authors: Yajun
authors: Y
authors: Ma
authors: Department of Radiology, University of California, San Diego, CA, USA.
authors: Hongda
authors: H
authors: Shao
authors: Department of Radiology, University of California, San Diego, CA, USA.
authors: Xing
authors: X
authors: Lu
authors: Department of Radiology, University of California, San Diego, CA, USA.
authors: Bimin
authors: B
authors: Chen
authors: Department of Radiology, University of California, San Diego, CA, USA.|Radiology Service, VA San Diego Healthcare System, San Diego, CA, USA.
authors: Eric Y
authors: EY
authors: Chang
authors: Department of Orthopedics, Peking Union Medical College Hospital, Beijing, China.
authors: Zhihong
authors: Z
authors: Wu
authors: Department of Radiology, University of California, San Diego, CA, USA. jiangdu@ucsd.edu.
authors: Jiang
authors: J
authors: Du
mesh_terms: D000328:Adult; D000465:Algorithms; D000818:Animals; D001834:Body Water / Q000737:chemistry / Q000000981:diagnostic imaging*; D001842:Bone and Bones / Q000737:chemistry / Q000000981:diagnostic imaging*; D002417:Cattle; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D066298:In Vitro Techniques; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D016062:Porosity; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
keywords: IR-UTE; T2*; UTE; bone; bound water; cones; pore water