Bilateral Ortohogonality Generative Acquisitions Method for Transmit Field Inhomogeneity Correction in Magnetic Resonance Imaging

Ultra-high field (>7T) magnetic resonance imaging (MRI) systems result in higher intrinsic signal to noise ratio compared to the lower field systems and have been previously utilized for acquisition of high-resolution images and reducing scan time. However, transmit field inhomogeneity of ultra-high field systems, present an obstacle for widespread clinical utilization. In literature, radiofrequency pulse design and multi-acquisition methods with and without parallel transmission systems have been demonstrated for addressing the transmit field inhomogeneity. While substantial improvements have been demonstrated with these methods, they can be limited to certain contrasts, require a library of pulses for specific radiofrequency coils and regions of interest and contain residual field inhomogeneity effects. Herein, the Bilateral Orthogonality Generative Acquisitions method has been developed as a multi-acquisition transmit field inhomogeneity correction method using parallel transmission system that does not require calibration scans or data libraries. Through the applications demonstrated in this work, it has been shown that this method eliminates the transmit field effects without any residual inhomogeneity in the final images and can be utilized for variety of image contrasts. Performance comparisons of the novel method with the previously introduced methods are presented where applicable. Initially, the Bilateral Orthogonality Generative Acquisitions method was utilized for obtaining homogeneous whole brain T2* weighted MRI contrast using dual-echo gradient echo images, where phase information between echoes is preserved. Moreover, accuracy of the phase information is validated by quantitative susceptibility mapping in brain and Dixon imaging in liver and kidney. The multi-contrast turbo spin echo application of the method is also demonstrated for T1, T2 and proton density weighted MRI contrasts. Lastly, implementations of the developed method in quantitative multi-parametric imaging are investigated using the phase cycled balanced steady state free precession sequence and chemical exchange saturation transfer imaging. In conclusion, it has been shown that Bilateral Orthogonality Generative Acquisitions method is a versatile transmit field inhomogeneity correction method that results in homogeneous images at high and ultra-high field strength. As shown in this work, this novel method can be utilized for any region of interest, parallel transmission system, and radiofrequency coil or field strength for many contrasts.

Author dc:creator

• Boğa, Çelik

Contributors dc:contributor

• Vinogradov, Elena
• Henning, Anke
• Park, Jae Mo
• Zou, Qing

• Algorithms
• Brain
• Brain Mapping
• Image Processing, Computer-Assisted
• Imaging, Three-Dimensional
• Magnetic Resonance Imaging
• Phantoms, Imaging

Language dc:language

en

Identifier

1522122339

OAI identifier oai:identifier

oai:utswmed-ir.tdl.org:2152.5/10605