EPI Outside the Brain
Jana Hutter1
1King's College London, United Kingdom

Synopsis

Keywords: Physics & Engineering: Pulse design, Body: Body, Contrast mechanisms: Diffusion

Echo Planar Imaging is a key tool for a range of imaging techniques such as diffusion MRI, elastography and functional MRI outside of the brain. Its efficiency and ability to freeze motion within the slice but also challenges such as vulnerability to susceptibility artifacts, T2* blurring and limits in possible resolution are all emphasized outside of the brain and trigger exciting novel technical developments. EPI is a standard part of the diagnostic pathway in eg breast and prostate cancer. Novel insights into the fiber architecture of the beating heart and the transfer of oxygen across the placenta are enabled.

Motivation

Echo Planar Imaging is a key tool for functional imaging and used as the working horse in diffusion MRI, functional MRI, MR elastography among many others. Its high signal to noise ratio, speed of the acquisition and ability to effectively freeze motion for each slice are key benefits - especially outside of the brain! Challenges such as vulnerability to susceptibility artifacts, chemical shift artifacts, eddy currency artifacts, T2* blurring associated with the length of the readout and limits regarding the achievable resolution are (unfortunately) also emphasized outside of the brain due a in general larger required FOV, an environment characterized by more complex air-tissue interfaces as well as dynamic motion patterns from respiratory, cardiac, breathing to in the extreme case involuntary fetal motion. The resulting exciting opportunities and interesting engineering challenges have triggered and continue to trigger a never ending stream of novel developments, technical advances and novel ideas in this area. Clinically, EPI outside of the brain, and more specifically often employed as the acquisition technique for diffusion MRI, is a standard in a range of organs, particularly in cancer, for example in the breast, prostate and liver. Furthermore, fetal MR (including the non-adult brain) has been a prime application for EPI since the very early days of fetal MRI, where it enables the full range of contrasts in-utero.

Content and objectives

The objectives of this talk are hence to
  • understand the challenges of EPI outside of the adult brain
  • learn about strategies to deal with these challenges
  • discover exciting applications of EPI outside of the brain - from the heart to breast, liver, kidney, fetus to prostate
  • hear about novel developments from hardware to pulse sequence and analysis.

Acknowledgements

No acknowledgement found.

References

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Proc. Intl. Soc. Mag. Reson. Med. 32 (2024)