Phase-encoding strategies for optimal spatial resolution and T1 accuracy in 3D Look-Locker imaging Export

@article{NK07, abstract = {The Look-Locker (LL) imaging method provides an accurate and efficient approach for mapping the spin-lattice relaxation time, T1. However, the same recovery of signal during LL image acquisition required to estimate T1 also results in unwanted modulation of k-space. This is particularly problematic with 3D LL imaging as the number of phase-encoding steps during the recovery interval (e.g., 16) increases in an effort to reduce imaging times. This modulation of k-space has the effect of introducing a point spread function (PSF), which can lead to either image blurring (if the earlier tip angles are assigned to the centre of k-space) or edge enhancement (if the earlier tip angles are assigned to the edges of k-space), thus corrupting T1 estimation, particularly for small objects. In this study, the PSF and its effect on the acquired images for four different interleaved phase-encode schemes (centric-in, centric-out, sequential and hybrid-sequential) are simulated for a range of T1, tip angle and 3D LL acquisition parameters expected in practice. It is shown by simulation and confirmed experimentally in phantoms that a hybrid sequential phase-encoding scheme reduces image blurring while maintaining T1 accuracy (\~{}2\%) and precision (2\%) over a range of object sizes down to 2 pixels (2 mm).}, author = {Nkongchu, Ken and Santyr, Giles}, citeulike-article-id = {3123765}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.mri.2007.02.020}, citeulike-linkout-1 = {http://www.sciencedirect.com/science/article/B6T9D-4NT24XB-2/2/22256b0339104162a399a97ee7e2765d}, doi = {10.1016/j.mri.2007.02.020}, journal = {Magnetic Resonance Imaging}, keywords = {3d, fastt1, nk07, tomrop}, month = {October}, number = {8}, pages = {1203--1214}, posted-at = {2008-08-14 15:19:43}, priority = {0}, title = {Phase-encoding strategies for optimal spatial resolution and T1 accuracy in 3D Look-Locker imaging}, url = {http://dx.doi.org/10.1016/j.mri.2007.02.020}, volume = {25}, year = {2007} }

TY - JOUR ID - NK07 L3 - citeulike-article-id:3123765 N2 - The Look-Locker (LL) imaging method provides an accurate and efficient approach for mapping the spin-lattice relaxation time, T1. However, the same recovery of signal during LL image acquisition required to estimate T1 also results in unwanted modulation of k-space. This is particularly problematic with 3D LL imaging as the number of phase-encoding steps during the recovery interval (e.g., 16) increases in an effort to reduce imaging times. This modulation of k-space has the effect of introducing a point spread function (PSF), which can lead to either image blurring (if the earlier tip angles are assigned to the centre of k-space) or edge enhancement (if the earlier tip angles are assigned to the edges of k-space), thus corrupting T1 estimation, particularly for small objects. In this study, the PSF and its effect on the acquired images for four different interleaved phase-encode schemes (centric-in, centric-out, sequential and hybrid-sequential) are simulated for a range of T1, tip angle and 3D LL acquisition parameters expected in practice. It is shown by simulation and confirmed experimentally in phantoms that a hybrid sequential phase-encoding scheme reduces image blurring while maintaining T1 accuracy (~2%) and precision (2%) over a range of object sizes down to 2 pixels (2 mm). IS - 8 JF - Magnetic Resonance Imaging EP - 1214 TI - Phase-encoding strategies for optimal spatial resolution and T1 accuracy in 3D Look-Locker imaging VL - 25 SP - 1203 KW - 3d KW - fastt1 KW - nk07 KW - tomrop AU - Nkongchu, Ken AU - Santyr, Giles PY - 2007/10// UR - http://dx.doi.org/10.1016/j.mri.2007.02.020 ER -