Meeting Banner
Abstract #3480

Parallel Transmission Three-Dimensional Tailored RF (PTX 3DTRF) Pulse Design for Simultaneously Recovering Multi-Slice Signal Loss at 7T

Hai Zheng1, Tiejun Zhao2, Yongxian Qian3, Claudiu Schirda3, Tamer Ibrahim1, 3, Fernando Boada, 13

1Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States; 2Siemens Medical Solutions USA, Pittsburgh, PA, United States; 3Radiology, University of Pittsburgh, Pittsburgh, PA, United States

T2* weighted fMRI in ultra high field is hampered by susceptibility-induced signal loss near air/tissue interfaces of the brain. We demonstrate a robust RF pulse design, based on parallel transmission (PTX) and 3D tailored RF (3DTRF), that is capable of simultaneously and precisely recovering signal loss at multiple locations. An additional scheme for PTX 3DTRF based on time-interpolation approach, is also presented. All schemes were observed to significantly and reproducibly improve signal recovery across multiple slices in human subjects. Time-interpolation method proved to be more robust at regions with large frequency offsets, albeit at the expense of increased computational demand.

Abstract PDF E-Poster Video

Keywords

abstract activations albeit anatomy applications approaches artifacts assuming bold brain compensation computation computational computing concatenate concatenated conjugate conjunction control core cortices demand depict derivations described design desired differential dimensional distortions effective efficiently employed equations equipped excitation excite excited expense extend extension fared fashioned fast field fine five focus formulate frequency frontal global gradient hinder implemented important improvement indicated indicates induced inferior inhomogeneities inhomogeneous interpolation introduced length lengths lobe location locations loss manifest many maps matrix medical moreover near negative notation novel offset offsets orbital original parallel patterns peak performance physiological precisely previously profile profiles proposed proved proves proving pulse pulses quad recent recover recovered recovering recovers recovery regular repeated required respectively responsible robustness running sampling scanned scanner schemes selective sensitivity several severe shaped shorten simultaneously slice slices solid solved spatial strategy strengths studies subject subjects successfully susceptibility tailored temporal terms trajectory transmission twice ultra unattainable unfortunately uniformly unpractical variation whole words