Accelerated Medical Imaging Workshop in Madison WI on June 17th – 18th

The 2nd annual accelerated imaging workshop at UW Madison is next week, and should be a great event. There are scheduled speakers from Mayo Clinic, Northwestern, UIUC, Berkeley, Harvard, the NIH, and GE Healthcare (among others). If you think you might be able to attend, the free registration deadline is Saturday June 12th, otherwise you can register on-site for a nominal fee. Here’s the registration form, which you can fax or email in.

Imaging Workshop - Madison/Freiburg

The International Center for Accelerated Medical Imaging at the University of Wisconsin, Madison, USA and the Dept. of Diagnostic Radiology, Medical Physics, at the University of Freiburg, Germany are co-hosting the 2nd Workshop on Accelerated Medical Imaging ‘Rapid MR Imaging – Beyond the Nyquist Limit’.

Objectives of this workshop are to discuss the current state of the art accelerated imaging concepts and applications, roadblocks to clinical applications and strategies to effectively address these limitations.

  • Fundamentals of the Constrained Reconstruction Rainbow
  • State-of-the-Art Concepts and Applications in MRI and other modalities
  • Rapid Quantitative Imaging
  • Performance Metrics – Connecting Imaging Science with Radiology
  • New Hardware Developments

Invited speakers will present keynote lectures on pertinent topics with further presentations by contributed papers. The workshop in Madison will also be tailored towards students’ education.
Extended poster viewing and discussion sessions are an integral part of the scientific program and will allow discussions about new concepts.

The workshop will take place in Madison, WI at the Health Science Learning Center (HSLC), which is located on the University of Wisconsin-Madison campus adjacent to the UW Hospital & Clinics.

The workshop announcement in pdf format can be found here.

If you don’t want to download the PDF of the program, I’ve embedded it below the fold. Also check out the official workshop website on the UW Madison website for more details.

[click to continue…]


Global and local fMRI signals driven by neurons defined optogenetically by type and wiring

Ars Technica has a nice writeup about a paper in Nature which isolates the BOLD signal from a specific type of neuron:

With everything in place, the researchers confirmed that firing an impulse in excitatory neurons produced a signal that matched nicely with the ones observed during regular experiments. Putting the channelrhodopsin into inhibitory neurons produced a small BOLD signal in the area where the light triggered an impulse, but it was surrounded by a halo of depressed activity, consistent with the neurons’ inhibitory role.

But the BOLD signals weren’t limited to the area where the light triggered activity. With a slight delay, signals started showing up in other areas of the brain, with the precise locations changing based on where exactly the activity was triggered. The authors indicate that these additional signals provide an indication of the brain’s wiring—the nerves at the site of the initial activity were simply doing what they normally did, and communicating with other areas of the brain. With enough time, they suggest, their technique could be used to map functional connections throughout the brain.

It’s impressive work that really takes aim at the foundation of fMRI and signal origin rather than most of the empirical neurologic applications that we usually see in the literature. I’m sure there must have been some work at this years’ ISMRM that went in a similar direction…

Here’s the full paper in Nature. Abstract:

Global and local fMRI signals driven by neurons defined optogenetically by type and wiring

Despite a rapidly-growing scientific and clinical brain imaging literature based on functional magnetic resonance imaging (fMRI) using blood oxygenation level-dependent (BOLD)1 signals, it remains controversial whether BOLD signals in a particular region can be caused by activation of local excitatory neurons2. This difficult question is central to the interpretation and utility of BOLD, with major significance for fMRI studies in basic research and clinical applications3. Using a novel integrated technology unifying optogenetic4, 5, 6, 7, 8, 9, 10, 11, 12, 13 control of inputs with high-field fMRI signal readouts, we show here that specific stimulation of local CaMKIIα-expressing excitatory neurons, either in the neocortex or thalamus, elicits positive BOLD signals at the stimulus location with classical kinetics. We also show that optogenetic fMRI (ofMRI) allows visualization of the causal effects of specific cell types defined not only by genetic identity and cell body location, but also by axonal projection target. Finally, we show that ofMRI within the living and intact mammalian brain reveals BOLD signals in downstream targets distant from the stimulus, indicating that this approach can be used to map the global effects of controlling a local cell population. In this respect, unlike both conventional fMRI studies based on correlations14 and fMRI with electrical stimulation that will also directly drive afferent and nearby axons, this ofMRI approach provides causal information about the global circuits recruited by defined local neuronal activity patterns. Together these findings provide an empirical foundation for the widely-used fMRI BOLD signal, and the features of ofMRI define a potent tool that may be suitable for functional circuit analysis as well as global phenotyping of dysfunctional circuitry.


Self-Assembled Plasmonic Nanoparticle Clusters

(In addition to MRI and medical physics, it’s worth keeping an open mind and keeping tabs on various other branches of physics and science. To that end, I’ll highlight interesting papers or research that strikes my fancy from time to time.)

Eric Berger aka SciGuy, a science columnist at the Houston Chronicle, points to a new paper in Science that introduces new “metamaterials” which can manipulate light, which are easy to fabricate (in principle). Eric makes the analogy to this being as much a game-changer as lasers were when they were invented almost exactly 50 years ago.

Here’s the abstract of the paper:

Self-Assembled Plasmonic Nanoparticle Clusters

The self-assembly of colloids is an alternative to top-down processing that enables the fabrication of nanostructures. We show that self-assembled clusters of metal-dielectric spheres are the basis for nanophotonic structures. By tailoring the number and position of spheres in close-packed clusters, plasmon modes exhibiting strong magnetic and Fano-like resonances emerge. The use of identical spheres simplifies cluster assembly and facilitates the fabrication of highly symmetric structures. Dielectric spacers are used to tailor the interparticle spacing in these clusters to be approximately 2 nanometers. These types of chemically synthesized nanoparticle clusters can be generalized to other two- and three-dimensional structures and can serve as building blocks for new metamaterials.

and here’s a link to the full text of the article. As with lasers when they were first introduced, it’s a challenge to the imagination to envision how this might be used or applied. What possible medical imaging applications could this be exploited for? That’s the billion dollar question :)


ISMRM 2010 follow up: posters, CME, and video

If you attended the ISMRM meeting and were chased out of the poster session by angry Swedes for trying to take photos of the posters, then know that I’ll be uploading my own shots to Flickr later on. However, ISMRM is asking that everyone send their final PPT/PDF files of their posters as printed to, so they can post those online as well. Hopefully they will ask for these ahead of the meeting, and encourage people during the meeting to do so, next year. I suspect compliance will still be pretty low unless they market this more. Of course, they already have the e-posters, this is just regarding the traditional posters.

Also, TODAY is the last day for submitting your CME online at:

Finally, they expect to have video of the oral sessions uploaded to the official site ( within a month. So be patient! An incredible resource, well worth waiting for.


welcome back to Reference Scan – the MRI blog

Does this thing still work?

Well, as far as hiatuses go, this one probably set some kind of record. Real life of course intrudes to varying degrees, but I am hopeful that I can start anew here and we can regain some of the lost ground.

My aim is to make this a genuinely interesting resource for MRI scientists and also a means of enhancing our knowledge and career skills. So, let’s try again!

welcome back :)


MRI of acute Wiiitis

Magnetic resonance imaging of acute “wiiitis” of the upper extremity.

We present the first reported case of acute “wiiitis”, documented clinically and by imaging, of the upper extremity, caused by prolonged participation in a physically interactive virtual video-game. Unenhanced magnetic resonance imaging (MRI) demonstrated marked T2-weighted signal abnormality within several muscles of the shoulder and upper arm, without evidence of macroscopic partial- or full-thickness tearing of the muscle or of intramuscular hematoma.

Nett MP, Collins MS, Sperling JW. Skeletal Radiol. 2008 May;37(5):481-3. PMID 18259743.

It was really just a matter of time… the floodgates are now open. I expect that the musculoskeletal specialists are eagerly anticipating the release of the Wii Fit


stay tuned

RefScan has been pretty moribund of late, mainly because I have been preparing for a cross country move and tying up loose ends at my postdoc. Please rest assured that there will be new content regularly appearing again in the near future. For a few weeks though, the dry spell will continue.

Also, incidentally, upgrading to WordPress 2.2 kind of hosed our K2 theme install, so we are looking a bit retro until I can fix that.

1 comment

Paul Lauterbur dies at age 77

The father of Magnetic Resonance Imaging passed away on Tuesday:

Physicist Paul C. Lauterbur, who received a 2003 Nobel Prize in Physiology or Medicine for giving physicians the ability to look inside the human body without using harmful radiation, died Tuesday at his home in Urbana, Ill.

He was 77 and had been suffering from kidney disease.

1 comment

NIH funding running dry

This isn’t exactly a surprise, but worth mentioning anyway:

Before the ink was dry on the government’s 2007 budget (or even completed for that matter), the Bush administration’s proposal for the 2008 budget was submitted on February 5th, and the news for biomedical researchers was not very good. According to sources the NIH is slated to receive a $500 million budget cut, before inflation is factored in—assuming a bill inflating their budget for 2007 passes through congress.

Making this even more dire for biomed researchers is the fact that over 10,000 NIH extramural grants are up for renewal in 2008. Those contending for extensions or renewals of such grants are now faced with double difficulty: less money to go around and more people vying for the same number of spaces. Constraints such as these have driven the average age of first-time grant recipients to over 40 years old, barely a young researcher anymore.

The simple truth is that the NIH is probably the single greatest investment of public funds apart from NASA in terms of knowledge generation for the benefit of society that the world has ever seen. Less funds mean less research; less Ph.D.s choosing an academic career; less innovation and less risk-taking. That means more orthodoxy, entrenched and defensive peer-review, and ultimately more echo-chambering.

Even with new funding programs aimed at transitioning postdocs to faculty, it’s hard to justify doing a post-doc to people in the field nowadays – if they have the flexibility, they can make more than double the salary working for industry. What does the future of our field, medical physics and MRI in particular, look like?


Video of MRI explosion

An MRI unit exploded last year at Peninsula Regional Medical Center in Maryland. This was actually caught on film by a local TV crew!


Just for fun, here’s a bonus video of a chair stuck in a magnet. That looks like a lot of work.

1 comment