Q&A with Philipp Ehses and Tony Stöcker

October 11, 2019

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In today’s interview, we highlight the latest paper by first author Philipp Ehses and last author Tony Stöcker, from the German Center for Neurodegenerative Diseases in Bonn, Germany. The paper is entitled “Whole-brain B1-mapping using three-dimensional DREAM” (DREAM: Dual Refocusing Echo Acquisition Mode) and below are their thoughts on B1 mapping and the importance of transparency in research.

For those who would like to get a quick overview of our discussion, below is an annotation of the interview. Clicking on the timestamp will take you to the exact video location where the topic is discussed.

00:00 Introduction: The authors briefly catch up with Nikola, who has interviewed Philipp previously for MRM Highlights, and provide an overview of their background and how they became involved in this work.

03:12 Audio slides: A new fast B1-mapping technique has been developed using three-dimensional DREAM. A blurring compensated reconstruction technique was developed to reduce artifacts, and the technique was evaluated using simulations and in vivo measurements.

11:04 The path from the original DREAM sequence to the current 3DREAM B1 mapping implementation is discussed. Philipp has been working on this project since his arrival at Bonn.

13:24 Philipp and Tony discuss why post-processing blurring was needed to correct artifacts initially caused by acquisition-induced blurring, and other potential alternative solutions.

14:55 Blurring compensation parameters were determined from pulse sequence and physical parameters.

16:21 The authors made their code available online (https://gitlab.com/pehses/3dream-example), and even included an example Jupyter Notebook. They choose to share their code as they had benefited from open-source code from others in the past, and because it supports reproducibility in the MRI field.

18:02 Although implementing this pulse sequence from scratch would not be an easy task, the authors have already started to share their pulse sequence files with centers that have the same vendor platform.

19:26 Currently, many studies have started to include their 3DREAM sequence in their protocols to acquire B1 maps. Moving forward, they hope to use this technique with parallel transmit and B1 shimming. Many other quantitative MRI techniques could benefit from using this rapid B1 mapping technique.

21:58 To finish off, Philipp and Tony give us a sneak peek on the rest of their work week, and what they enjoy doing after-hours in Bonn.