This protocol used Dixon based imaging for fat suppression with both series, where T2-weighted images were acquired using a fast spin echo
(FSE) triple echo Dixon sequence (37) and T1-weighted images were acquired using a dual-echo fast spoiled gradient echo (FSPGR) sequence (38).
A fast spin echo
two-point Dixon technique and its combination with sensitivity encoding for efficient T2-weighted imaging.
The standardized protocols consist of the following scanning sequences: sagittal T1-weighted spin echo, axial T2-weighted fast spin echo
, coronal oblique fast fluid-attenuated inversion recovery, coronal oblique fast multiplanar inversion recovery, axial diffusion (single-shot, spin echo planar), b = 1000, all directions), and axial three-dimensional spoiled gradient recalled echo.
Cranial magnetic resonance imaging (MRI) with sagittal T2 fast spin echo
(FSE), axial T2 FSE, axial T1 fluid-attenuated inversion recovery (FLAIR) and coronal T2 FLAIR sequences were performed.
Commonly used are 3D SSFP (Steady State Free Precession) sequence and FSE (Fast Spin Echo
) sequences like HASTE (Half-Fourier Acquisition Single-Shot Turbo Spin Echo) and RARE (Rapid Acquisition with Rapid Enhancement sequence).
Results: Conventional spin echo and fast spin echo
were equivalent for the tissues of comparable signal intensities and for entities moderate difference between signal intensities.
NEX slices Cor T1 TSE 632 8.5 30 4 30 2 Cor T2 FSE 4500 95 32.5 4 30 2 Axial T1 707 8.9 30 4 25 2 Axial T2 4500 101 30 4 25 2 Sag T1 SE 647 8.5 30 4 40 2 (each side) Sag T2 FSE 4500 95 30 4 40 2 (affected side) Axial FS T1 707 8.9 30 4 25 2 post contrast Sag T1 FS 647 8.5 30 4 40 2 (affected side) post contrast Sequence Time (min:sec) Cor T1 TSE 3:21 Cor T2 FSE 2:35 Axial T1 5:09 Axial T2 3:47 Sag T1 SE 4:38 (each side) Sag T2 FSE 3:24 (affected side) Axial FS T1 4:27 post contrast Sag T1 FS 4:38 (affected side) post contrast FSE = fast spin echo
, FOV = field of view, TSE = turbo spin echo, SE = spin echo, FS = fat sat, TR = time to repeat, NEX = number of excitations, ST = slice thickness Table 2.
The following sequences were performed and reviewed: Proton Density (PD) sequences in coronal, sagittal, and axial cuts, Proton Density (PD) Fast Spin Echo
(FSE) sequence in coronal cuts, and T2-weighted Fast Spin Echo
(FSE) with fat suppression (FS) in sagittal cuts.
(2) [T.sub.2]-weighted, fast spin echo
pulse sequence, repetition time (6100 ms), echo time (125 ms), section thickness (6 mm), field of view (26 cm), number of excitations (2), and matrix size (256 x 256).
The typical MR imaging protocol included axial T1, axial proton density (fat sat), sagittal T1, sagittal T2 fast spin echo
(fat sat), coronal T1, coronal T2 fast spin echo
(fat sat) and coronal proton density (fat sat) sequences.
T1 weighted images were obtained using 2D fast spin echo
MR sequences used were 2D fast spin echo
T2 (FSE T2) for 4 patients, 3D FSE T2 for 2 patients, Spin echo T1 (SE T1) for 2 patients, and magnetization prepared rapid acquisition gradient echo T1 (MPRAGE T1) for all 8 patients.