MPRAGE

MPRAGE, or Magnetization Prepared Rapid Acquisition Gradient Echo, is a 3D T1-weighted magnetic resonance imaging sequence used to obtain high-resolution structural images of the brain in a single scan. It combines an inversion-prepared magnetization approach with a rapid spoiled gradient-echo readout to produce isotropic voxels suitable for detailed morphometric analysis.

In operation, an inversion pulse creates contrast based on T1 relaxation. After the inversion, successive gradient-echo reads sample the recovering magnetization. The inversion time (TI) controls the T1 weighting, while the repetition time (TR) and echo time (TE) are chosen to balance image quality and scan time. Typical 3D acquisitions yield voxel sizes around 0.8–1.0 mm, though higher or lower resolutions are possible depending on the protocol and scanner.

MPRAGE is widely used for structural brain imaging, enabling accurate volumetric measurements, cortical thickness estimation, and atlas-based analyses. It is preferred when high-resolution anatomical detail is required for clinical assessment of neurodegenerative disease, neuroanatomical studies, and pre-surgical planning. The technique provides strong gray–white matter contrast and robust whole-brain coverage, making it a standard in both clinical and research settings.

Parameters vary by scanner and field strength. At 1.5 Tesla TI is commonly around 600–900 ms, and at 3 Tesla around 900–1100 ms, with TR typically 2–3 seconds and TE around 2–4 ms. The method originated in the 1990s, with development led by Mugler and Brookeman, and has since become a standard 3D T1-weighted sequence.