MPRAGE/3D FGRE/3D FAST SPGR/3D TFE/3D FAST FE
Magnetization Prepared Rapid Gradient Echo Imaging (MPRAGE) is a modified TurboFLASH technique that incorporates magnetization-prepared inversion pulses. The image acquisition process involves an initial 180-degree inversion pulse, followed by a GRE imaging sequence in a steady state that utilizes rewinder gradients. To generate 3D images, a secondary phase encoding step occurs in the slice-select direction. Only one segment or partition of a 3D data record is obtained per preparatory pulse. After signal acquisition, all the rows within a 3D partition use a delay time denoted as TD. This delay time is necessary to prevent saturation effects. MPRAGE sequences are commonly employed for high-resolution 3D isotropic brain imaging. When compared with T1-weighted SE sequences, MPRAGE offers superior image quality and better contrast between gray matter and white matter.
MPRAGE MRI image appearance
T1 SE and MPRANGE sequences appear similar. The only noticeable difference is that MPRANGE sequences exhibit better contrast between gray and white matter. MPRANGE sequences produce high-resolution 3D isotropic images, enabling multiplanar reconstruction after image acquisition.
Tissues and their MPRANGE appearance
Bone marrow : – equal to or higher than that of muscle (fatty marrow is usually bright)
Moving blood : – gray ( bright after contrast administration)
White matter : – whiter (brighter than the white matter in T1 SE)
Gray matter : – gray
Fluids : – dark
Muscles :- gray
Bone : – dark
Fat : – bright
Air : – dark
Pathological appearance on MPRAGE
Pathological processes typically lead to an increase in the water content of tissues. This additional water component results in a signal loss on MPRAGE-weighted images, causing pathological processes to generally appear dark in such weighted images. Vascular lesions, on the other hand, will appear bright in Post-Gadolinium DTPA MPRAGE scans.