11.7T in Korea in superconductor science & technology journal

Well, so it was published, finally, last month (SUST article, Feb 2025). A few facts according to the paper: The magnet warm bore is 70 cm in diameter, the magnet runs in persistent mode and has been stable in the last 2+ years. In comparison with the Iseult magnet in France, passive shielding (requiring massive shielding walls) and persistent mode (as opposed to driven mode) appear to be the main differences in addition to the magnet bore size (90 cm for Iseult). I could not find gradient coil specification, but from my visit to Gachon a few years ago, the coil's small thickness is unlikely to allow windings with high gradient amplitudes. The paper included a 3D gradient-echo image of an ex-vivo monkey brain with 12.8 cm FOV and 0.5 mm isotropic resolution. This shows the imaging system is operational but the authors certainly would want more images to meet the magnet's high expectation. So, congratulations to the team, and let's hope more is coming.

Compact 3T service visit to Mayo Clinic

February 2025 marks the 9th anniversary of the delivery of Compact 3T scanner to Mayo Clinic. This year, the week of February 17th was a frigid one, not best for air travel, but a service visit to Rochester, Minnesota was made to replace and renew the magnet's cooling system. Thanks to the hard work of the GE HealthCare colleagues and help from the Mayo Clinic support team, the week's task was completed in time. The work will continue until the end of March, with more service visits to ramp the magnet and calibrate the scanner. Hopefully the refreshed 3T system, still the world's only high-performance compact 3T MRI scanner for humans, will serve the research community for many years to come. 

ISMRM 2025 Abstract Announcement

In my counting, 35 x 151 + 23 = 5308 abstracts are accepted, of which 851 (16%) are oral, and 549 are power pitches. Two submissions of mine were both accepted as an oral presentation, which is not a common event based on the probability (0.16^2 = 2.6%). In addition, Lydia's implanted lead heating work, from Mayo Clinic and where I am the second author, was also accepted as an oral. So apparently you don't have to do low-field or machine learning to get invited to speak in the conference. Now whether I will actually fly to the conference and present in person is another question. I wish remote presentation option was still available after the pandemic. 

Duke university visit

Early this month, an informal research meeting was held at Prof. Allen Song's laboratory at Duke University in North Carolina. Three people from GE Healthcare met with Allen, Prof. Dean Darnell, and a graduate student Devon Overson, to talk about MRI systems engineering to realize wireless receiver coils. This was a second visit in about two years. In 2022, when we were still wearing masks (picture on the left), we had a meeting on the "iPRES" coil, an RF receiver coil that doubles as a multi-channel shim array. The meeting this month, as before, was very productive. The Duke team has worked on wireless signal transmission for peripheral devices control for a number of years. It remains to be seen whether wire-free, battery-powered MRI RF coil can be realized without sacrificing the sensitivity to replace the traditional signal reception architecture.

ISMRM Abstracts, 2025

The meeting next year will be in Hawaii, a popular place, and the ISMRM organizers are sifting through more than 8000 abstracts submitted for presentation there. I have been critical to the abstract's HTML format, and a recently introduced sectioned Synopsis (in fact the presence of Synopsis at all). However, from an abstract reviewer's point of view, I must say these changes are helpful, to quickly get to know the work, and inspect details of selected figures. The organizers also did a good job in summarizing the review progress graphically in real time. This allows a reviewer to stay "normalized", by observing how the score distribution changes from start to finish as more than 50 assigned abstracts are scored. Certainly a lot of change has happened in ISMRM abstract processing since the early 2010s. I still hold up two things as suggestions to the Society: (1) The scores should be made available to the authors, and (2) All rejected abstracts should be given a chance to be archived, if not presented, on-line. That is democratization, not giving out low-performance MRI to those who deserve better.

MRI as a patient

I guess a web log dedicated to Magnetic Resonance Life is not complete without MR images of the author as a patient. For that purpose, I had an opportunity, albeit painful, to collect exactly such data in early November. The 1.5 T GE Signa Artist images shown above display "unremarkable" brain anatomical images with multiple contrasts following a standard protocol in Albany Medical Center. The total exam lasted for 21 minutes, and I must say the image qualities are pretty good for 1.5 T. The Center used apparent diffusion coefficient (ADC) to look for brain vessel blockage (infarct), and susceptibility-weighted imaging (SWI) for brain blood leakage (hemorrhage).

Three patent applications of summer of 2024

Three patent applications were published in July, that are all related to what is called concomitant gradient correction. This refers to magnetic field vector components that are unwanted but occurring as a byproduct of the desired magnetic fields in MRI. The three patents each address measurement, hardware-based correction, and software correction. The problem of concomitant field first came to me in early 2000s when I was a graduate student working on microTesla MRI with superconducting sensors. That work was reported here in a JMR article: https://pubmed.ncbi.nlm.nih.gov/19664947/. At that time the issue was too weak a main magnetic field; now the problem is due to too strong a gradient field. Different regime, but the same physics.