design-implementation-bespoke-robotic-manipulator-for-extra-corporeal

Design and Implementation of a Bespoke Robotic Manipulator for Extra-corporeal Ultrasound

With the potential for high precision, dexterity, and repeatability, a self-tracked robotic system can be employed to assist the acquisition of real-time ...

King's College London

This study demonstrates magnetization transfer (MT) effects directly affect relaxometry measurements and develops a framework that allows single-pool models to be valid in 2-pool MT systems.

Fast quantitative MRI using controlled saturation magnetization transfer.

Simultaneous multi-slice techniques are reliant on multiband RF pulses, for which conventional design strategies result in long pulse durations, lengthening echo-times so lowering SNR for spin-echo imaging, and lengthening repetition times for gradient echo sequences. Pulse durations can be reduced with advanced RF pulse design methods that use time-variable selection gradients. However, the ability of gradient systems to reproduce fast switching pulses is often limited and can lead to image artifacts when ignored. We propose a time-efficient pulse design method that inherently produces gradient waveforms with lower temporal bandwidth.

Multiband RF pulse design for realistic gradient performance.

The emergence of multiparametric diffusion models combining diffusion and relaxometry measurements provides powerful new ways to explore tissue microstructure, with the potential to provide new insights into tissue structure and function. However, their ability to provide rich analyses and the potential for clinical translation critically depends on the availability of efficient, integrated, multi-dimensional acquisitions. We propose a fully integrated sequence simultaneously sampling the acquisition parameter spaces required for T1 and T2* relaxometry and diffusion MRI. Slice-level interleaved diffusion encoding, multiple spin/gradient echoes and slice-shuffling are combined for higher efficiency, sampling flexibility and enhanced internal consistency. In-vivo data was successfully acquired on healthy adult brains. Obtained parametric maps as well as clustering results demonstrate the potential of the technique to provide eloquent data with an acceleration of roughly 20 compared to conventionally used approaches. The proposed integrated acquisition, which we call ZEBRA, offers significant acceleration and flexibility compared to existing diffusion-relaxometry studies, and thus facilitates wider use of these techniques both for research-driven and clinical applications.

Article	Year
Fast quantitative MRI using controlled saturation magnetization transfer. Magnetic resonance in medicine\| PubMed ID: 30257044	2019
Multiband RF pulse design for realistic gradient performance. Magnetic resonance in medicine\| PubMed ID: 30277267	2019
Integrated and efficient diffusion-relaxometry using ZEBRA. Scientific reports\| PubMed ID: 30310108	2018

Joseph Hajnal

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