Coronal images were obtained using a fat saturation, proton density, spin echo acquisition sequence (repetition time 3,400 milliseconds, echo time 64 milliseconds, flip angle 90°, slice thickness 3 mm, field of view 16 cm, pixel matrix 256 × 256, acquisition time 5 minutes 26 seconds, and 1 acquisition).
Coronal images were obtained using a fat saturation, proton density, spin echo acquisition sequence (repetition time 3,400 msec, echo time 64 msec, flip angle 90°, slice thickness 3 mm, field of view 16 cm, pixel matrix 256 × 256, acquisition time 5 min 26 sec, and 1 acquisition).
Coronal images were obtained using a fat saturation, proton density, spin echo acquisition sequence (repetition time 3,400 msec, echo time 64 msec, flip angle 90°, slice thickness 3 mm, field of view 16 cm, pixel matrix 256 × 256, acquisition time 5 minutes 26 sec, and 1 acquisition).
2) H MRS: A 10-cm, circular, double-resonant surface coil was applied above the right soleus muscle to measure IMCL from localized H spectra using the series stimulated echo acquisition mode sequence within a volume of interest of 1.73 cm (5).
The following parameters have been proposed for a turbo field echo acquisition, including 300 images per scan over a time period of, for example, 5 min, a temporal resolution of 1 image per second, TE = 3.6 ms, TR = 10 ms, field of view 450 mm, rectangular field of view 55%, symmetric reduction 50%, flip angle 25°, 256/128 pixels, slice thickness 10 mm, without breath-hold.
During the whole body PET acquisition, a single breath-hold was performed for the T1-spoiled gradient echo acquisition.
Such acceleration techniques have also enabled the implementation of, clinically feasible, simultaneous multi-echo spin- and gradient echo acquisitions, providing more comprehensive and quantitative interrogation of T1, T2 and T∗2 changes.
The presently most powerful technique, however, appears to be high spatial resolution MR angiography with T1-weighted contrast-enhanced 3D gradient echo acquisitions with k-space centred contrast bolus in a breath-hold [50].
Pseudocontinuous ASL perfusion images were collected using 3D fast spin-echo acquisition with background suppression, with a labeling duration of 1500 ms and post-labeling delay of 1500 ms, as suggested previously [ 28].
Due to limitations in the efficiency of the HF transmission line, the HF irradiation was applied only for the central lines of the k-space, corresponding to half of the total number of echo acquisitions.
Although involvement of midbrain regions should be treated with caution in BOLD fMRI, MR-based perfusion imaging with gradient echo acquisitions has been shown to substantially decrease the risk of susceptibility artefacts and signal drop-outs compared to BOLD images because a minimum time of echo (TE) is used [26] [28], [16].
