Simulating B1+ heterogeneity

[JanWP]

Feature Request

I am looking into the possibility of performing Bloch simulations of an object with heterogeneous B1+. For now, the only reference I see to B1 is in the scanner object, defining a global scalar value.

Before I set out to try to implement this, I would like to check if this feature has already been worked on? I have searched in the code, in past issues and in existing branches, and have not seen any reference to this.

What would be the best channel to ask for advice on specific implementation details, as well as questions about the code and the inner workings of KomaMRI? I'm sure there will be a few of those coming up if I try to get this done. My first question would be : Would you recommend I base my work on the master branch or on the new-motion branch? My gut feeling is that there might be quite a few conflicting changes between those I would need to implement and those in the new-motion branch and I might be better off starting from there if it is in a reasonably good working state (tests seem to pass).

[cncastillo]

Hi @JanWP, I would gladly help implement this feature. I was going to implement it myself as part of #454, but I haven't had time lately, so it would be very nice if you could try to do it. I can add you as a contributor, so you don't need to generate a fork.

For questions, feel free to talk to me on the Julia Slack. We can have a meeting as well, and I can explain the overall code structure.

Regarding the branches, the new-motion branch should be merged soon by @pvillacorta. We plan to merge it by the end of the week so that you can work directly on main. We will also tag a new release when that happens.

As this would require modifying one of the data structures (Phantom or Scanner), a dev setup would be required, if not you would be able to experiment with a new simulation method like mentioned in #392 (comment).

An incomplete set of instructions on how to do this can be seen here #382 (https://juliahealth.org/KomaMRI.jl/previews/PR382/how-to/4-develop/). If you or @pvillacorta could check the correctness of the instructions, it would be great. I can help you set it up anyway.

Cheers!

[JanWP]

Thanks @cncastillo for your quick reply and for the pointers! I will definitely read up on the documentation and previous work you linked. Great to hear that the new-motion branch will be merged soon, I'll work from there. And a dev setup was what I had in mind. I'll have a look at the instructions and let you know if I see room for improvement. Kudos on the efforts y'all make on the documentation, it's really appreciated!

[I should point out that I will only be able to work on this for a fraction of my time, so I expect progress to be slow.]