Rapid Geometry-Corrected Echo-Planar Diffusion Imaging at Ultrahigh Field: Fusing View Angle Tilting and Point-Spread Function Mapping.

Purpose: Severe geometric distortions induced by tissue susceptibility, water-fat chemical shift, and eddy currents pose a substantial obstacle in single-shot EPI, especially for high-resolution imaging at ultrahigh field. View angle tilting (VAT)-EPI can mitigate in-plane distortion. However, the accompanied strong image blurring prevented its widespread applications.

Dynamic 2D self-phase-map Nyquist ghost correction for simultaneous multi-slice echo planar imaging.

Purpose: To develop a reconstruction pipeline that intrinsically accounts for both simultaneous multislice echo planar imaging (SMS-EPI) reconstruction and dynamic slice-specific Nyquist ghosting correction in time-series data.

Methods: After 1D slice-group average phase correction, the separate polarity (i.e.

A specific absorption rate reduction method for simultaneous multislice magnetic resonance imaging.

This study proposes a modified Shinnar-Le Roux method to synthesize the excitation radio frequency (RF) pulse for a 2D gradient echo (GRE) based simultaneous multi-slice (SMS) magnetic resonance imaging (MRI) with features of low specific absorption rate (SAR) and small out-of-slice ripple. This synthesis method for SMS RF pulses employs thinner slice bandwidth and lower multislice offset frequencies to reduce SAR values and adopts a weighted Parks-McClellan algorithm to reduce sidelobes. Formulas for estimating relative SAR values of the SMS pulses are also introduced.