Hyunyeol Lee1, Xia Zhao1, Hee Kwon Song1, Rosaline Zhang2, Scott P Bartlett2,3, Felix W Wehrli1. 1. Laboratory for Structural, Physiologic, and Functional Imaging, Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. 2. Department of Plastic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. 3. Division of Plastic and Reconstructive Surgery, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
Abstract
PURPOSE: To develop a dual-radiofrequency (RF), dual-echo, 3D ultrashort echo-time (UTE) pulse sequence and bone-selective image reconstruction for rapid high-resolution craniofacial MRI. METHODS: The proposed pulse sequence builds on recently introduced dual-RF UTE imaging. While yielding enhanced bone specificity by exploiting high sensitivity of short T2 signals to variable RF pulse widths, the parent technique exacts a 2-fold scan time penalty relative to standard dual-echo UTE. In the proposed method, the parent sequence's dual-RF scheme was incorporated into dual-echo acquisitions while radial view angles are varied every pulse-to-pulse repetition period. The resulting 4 echoes (2 for each RF) were combined by view-sharing to construct 2 sets of k-space data sets, corresponding to short and long TEs, respectively, leading to a 2-fold increase in imaging efficiency. Furthermore, by exploiting the sparsity of bone signals in echo-difference images, acceleration was achieved by solving a bone-sparsity constrained image reconstruction problem. In vivo studies were performed to evaluate the effectiveness of the proposed acceleration approaches in comparison to the parent method. RESULTS: The proposed technique achieves 1.1-mm isotropic skull imaging in 3 minutes without visual loss of image quality, compared to the parent technique (scan time = 12 minutes). Bone-specific images and corresponding 3D renderings of the skull were found to depict the expected craniofacial anatomy over the entire head. CONCLUSION: The proposed method is able to achieve high-resolution volumetric craniofacial images in a clinically practical imaging time, and thus may prove useful as a potential alternative to computed tomography.
PURPOSE: To develop a dual-radiofrequency (RF), dual-echo, 3D ultrashort echo-time (UTE) pulse sequence and bone-selective image reconstruction for rapid high-resolution craniofacial MRI. METHODS: The proposed pulse sequence builds on recently introduced dual-RF UTE imaging. While yielding enhanced bone specificity by exploiting high sensitivity of short T2 signals to variable RF pulse widths, the parent technique exacts a 2-fold scan time penalty relative to standard dual-echo UTE. In the proposed method, the parent sequence's dual-RF scheme was incorporated into dual-echo acquisitions while radial view angles are varied every pulse-to-pulse repetition period. The resulting 4 echoes (2 for each RF) were combined by view-sharing to construct 2 sets of k-space data sets, corresponding to short and long TEs, respectively, leading to a 2-fold increase in imaging efficiency. Furthermore, by exploiting the sparsity of bone signals in echo-difference images, acceleration was achieved by solving a bone-sparsity constrained image reconstruction problem. In vivo studies were performed to evaluate the effectiveness of the proposed acceleration approaches in comparison to the parent method. RESULTS: The proposed technique achieves 1.1-mm isotropic skull imaging in 3 minutes without visual loss of image quality, compared to the parent technique (scan time = 12 minutes). Bone-specific images and corresponding 3D renderings of the skull were found to depict the expected craniofacial anatomy over the entire head. CONCLUSION: The proposed method is able to achieve high-resolution volumetric craniofacial images in a clinically practical imaging time, and thus may prove useful as a potential alternative to computed tomography.
Authors: Jiang Du; Michael Carl; Mark Bydder; Atsushi Takahashi; Christine B Chung; Graeme M Bydder Journal: J Magn Reson Date: 2010-09-25 Impact factor: 2.229
Authors: Jiang Du; Mark Bydder; Atsushi M Takahashi; Michael Carl; Christine B Chung; Graeme M Bydder Journal: Magn Reson Imaging Date: 2011-05 Impact factor: 2.546
Authors: Carrie E Zimmerman; Pulkit Khandelwal; Long Xie; Hyunyeol Lee; Hee Kwon Song; Paul A Yushkevich; Arastoo Vossough; Scott P Bartlett; Felix W Wehrli Journal: Acad Radiol Date: 2021-04-24 Impact factor: 3.173