Musical Mod Lets MRI Scanner Soothe the Frazzled Patient

Hackers love to make music with things that aren’t normally considered musical instruments. We’ve all seen floppy drive orchestras, and the musical abilities of a Tesla coil can be ear-shatteringly impressive. Those are all just for fun, though. It would be nice if there were practical applications for making music from normally non-musical devices.

Thanks to a group of engineers at Case Western Reserve University in Cleveland, there is now: a magnetic resonance imaging machine that plays soothing music. And we don’t mean music piped into the MRI suite to distract patients from the notoriously noisy exam. The music is actually being played through the gradient coils of the MRI scanner. We covered the inner working of MRI scanners before and discussed why they’re so darn noisy. The noise basically amounts to Lorenz forces mechanically vibrating the gradient coils in the audio frequency range as the machine shapes the powerful magnetic field around the patient’s body. To turn these ear-hammering noises into music, the researchers converted an MP3 of [Yo Yo Ma] playing [Bach]’s “Cello Suite No. 1” into encoding data for the gradient coils. A low-pass filter keeps anything past 4 kHz from getting to the gradient coils, but that works fine for the cello. The video below shows the remarkable fidelity that the coils are capable of reproducing, but the most amazing fact is that the musical modification actually produces diagnostically useful scans.

Our tastes don’t generally run to classical music, but having suffered through more than one head-banging scan, a half-hour of cello music would be a more than welcome change. Here’s hoping the technique gets further refined.

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Walking Through MRIs With A Vive

If you were to make a list of the most important technological achievements of the last 100 years, advanced medical imaging would probably have to rank right up near the top. The ability to see inside the body in exquisite detail is nearly miraculous, and in some cases life-saving.

Navigating through the virtual bodies generated by the torrents of data streaming out of something like a magnetic resonance imager (MRI) can be a challenge, though. This intuitive MRI slicer aims to change that and makes 3D walkthroughs of the human body trivially easy. [Shachar “Vice” Weis] doesn’t provide a great deal of detail about the system, but from what we can glean, the controller is based on a tablet and Vive tracker. The Vive is attached to the back of the tablet and detects its position in space. The plane of the tablet is then interpreted as the slicing plane for the 3D reconstruction of the structure undergoing study. The video below shows it exploring a human head scan; the update speed is incredible, with no visible lag. [Vice] says this is version 0.1, so we expect more to come from this. Obvious features would be the ability to zoom in and out with tablet gestures, and a way to spin the 3D model in space to look at the model from other angles.

Interested in how the machine that made those images works? We’ve covered the basics of MRI scanners before. And if you want to go further, you could always build your own.

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MRIs: Why Are They So Loud?

My dad was scheduled for his first MRI scan the other day, and as the designated family technical expert, Pop had plenty of questions for me about what to expect. I told him everything I knew about the process, having had a few myself, but after the exam he asked the first question that everyone seems to ask: “Why is that thing so damn loud?”

Sadly, I didn’t have an answer for him. I’ve asked the same question myself after my MRIs, hoping for a tech with a little more time and lot more interest in the technology he or she uses to answer me with more than the “it’s the machine that makes the noise” brush-off. Well, duh.

MRI is one of those technologies that I don’t feel I have a firm enough grasp on, and it seems like something I should really be better versed in. So I decided to delve into the innards of these modern medical marvels to see if I can answer this basic question, plus see if I can address a few more complicated questions.

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Hackaday Prize Entry: An MRI Machine

Magnetic resonance imaging devices are one of the most fantastically incredible machines humans have ever built. They’re capable of producing three-dimensional images of living tissue by flipping protons around with a magnetic field. Ninety percent of the population doesn’t know what that sentence means, yet you can find an MRI machine inside nearly any reasonably equipped hospital in America.

For his Hackaday Prize entry, [Peter Jansen] is building a magnetic resonance imager, capable of producing the same type of images you’d get from the radiology department at a hospital. It’s going to be a desktop unit, capable of scanning fruit and other similarly sized objects, and can be built using tools no more advanced than a hot air gun and a laser cutter.

This project is a continuation of what should have been [Peter]’s Hackaday Prize entry last year. Things got busy for him last summer, he dropped out of the Hackaday Prize, which means he’s welcome to continue his build this year.

Last year, [Peter] developed the plywood mechanism that would rotate a magnetic sensor across the diameter of the scanning volume, rotate the object to be scanned, and lift the object through the volume. It’s a weird 3-axis CNC machine, basically, but the parts near the magnetic sensor can’t be made out of metal. Dental floss worked okay, but we have a few hundred feet of Spectra fishing line if we ever bump into [Peter]. Magnetic resonance imaging means big coils of wire, too, which means the tedious task of winding coils around a cylinder is part of the build. [Peter] built a machine to do the work for him.

This is not [Peter]’s first attempt at building an imaging device. He built a desktop CT scanner that is exceptionally slow, but does shoot radiation through fruit to produce an image. His first project on Hackaday.io was the Open Source Science Tricorder, one of the top five finalists in the first year of the Hackaday Prize.

Already, [Peter] has some amazing work under his belt that produces real data that could not be otherwise obtained. An Open Source MRI is the perfect project for the Hackaday Prize’s Citizen Science phase, and we’re very happy to see him enter this project.

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Full-size MRI Machine Replica

Foam MRI machine

It’s been a bit dusty lately in Seattle’s Metrix Create:Space. That’s because they’ve taken on their biggest project yet — a full scale replica of an MRI machine for university research.

[Tom Grabowski], a professor of Radiology & Neurology at the University of Washington, needed a replica MRI machine. This is because time on real MRI machines is very expensive, and when performing research on Autism, it is important to get the test subjects used to the process before using the real deal. He originally turned to the Center for Human Development and Disability, also at the University of Washington, but the project was just simply too big for their facilities. He did however get to meet a fellow researcher named [Fritz] who then contacted Metrix to see if it was possible, and like any good hackers, the members of the space were more than up for the challenge.

The replica MRI machine is made out 2″ thick, 4′ by 8′ foam insulation sheets, which is the maximum size their router can handle. Not having made use of the 3D z-cutting capabilities before, they had a bit of learning to do, but as you can see from the pictures, it worked out quite well. Over a few weeks they were able to construct the general shape of the MRI machine, and finish the surface nicely — it’s far from complete though, as they might even be adding lights and other features to make it one heck of a replica. It’s a great project, and those who have helped are happy to do so as the replica will benefit not only [Tom] but many other researchers at UW — for science, yeah!