The Magic of MRI
We all know mobile technology is revolutionizing our personal and professional lives. But it’s also transforming the field of medicine in new and exciting ways. Magnetic Resonance Imaging (MRI) is an advanced technology that collects and analyzes detailed images and 3D renderings of the body’s internal organs and structures without exposing patients and doctors to dangerous radiation as X-Rays do. Besides simple images of anatomy, MRI can be used for imaging of brain function (functional MRI), blood flow, or even temperature rises (MR thermometry).
While MRI has existed as a diagnostic tool for decades, it is increasingly being used collaboratively with therapy. This emerging field, called Interventional MRI, often involves a physician or team of physicians that are treating the patient directly in the scanner. One example, MRI guided High Intensity Focused Ultrasound (MR-HIFU), involves focusing ultrasound energy deep inside the body, heating tissue at this focus while sparing other tissue along the way. For MR-HIFU, these procedures proceed entirely within an MRI scanner; as the therapy proceeds and part of the body is heated, MRI and MR thermometry is used to monitor the procedure.
Interventional MRI, as a technological procedure, basically spawned from diagnostic MRI, although the workflow of an interventional scan is quite different from a diagnostic scan. Physicians need to be able to control scanning and various aspects of the procedure. However, MRI has one very distinct operating condition compared to other medical imaging modalities: it exists in a highly magnetic field. Most clinical systems operate today at magnetic fields of either 15000 or 30000 Gauss, or 30000 to 60000 times the Earth’s normal magnetic field strength.
The strongly magnetic field can be a danger to devices: a traditional computer could have its hard disk wiped. Even more risky, a device can be a danger to a patient: a device can contain enough magnetic components in a strong enough magnetic field, actually becoming a projectile and shooting towards the center of the magnet. Finally, the device can be a danger to the images: a traditional computer can cause so much interference with the MRI equipment as to effectively render the scan useless.
Currently the only electronic devices that can be used are bulky, specially-made equipment that are heavy on shielding and light on functionality, or ones that are kept far away from the magnet. Being able to have devices that give physicians access and control of these interventional procedures is a priority for improving them and advancing patient care.
Enter webOS
Andrew B. Holbrook, a Research Associate working with Professor Kim Butts Pauly of the Lucas Center in the Department of Radiology at Stanford University, has been developing a promising solution built around connected HP webOS devices that can help take Interventional MRI to the next level. When it comes to devices that exist in magnetic fields, the more plastic and less metal the better! Even non-magnetic metal devices, such as those with aluminum, can be difficult to use in magnetic fields.
The TouchPad, a device primarily constructed of plastics and minimal glues was an excellent choice to start with. Dr. Holbrook made some warranty-voiding adjustments to his TouchPad, removing metallic components such as the vibration motor and speakers. While we at HP normally don’t encourage this, we were excited by Dr. Holbrook’s work and brought in TouchPad hardware engineers to assist in the modification process. With this, he had a minimally metallic device that could be used almost anywhere within the magnet room.
With the TouchPad functioning in the field, Dr. Holbrook constructed a system consisting of a high-powered PC server in a “MR-safe” location that interfaces both with the MRI scanner and with TouchPads onsite that are running a suite of hybrid-PDK apps written by Holbrook to observe and manipulate data.
In this example, Holbrook built an app to control an InSightec ExAblate Conformal Bone Systen HIFU transducer to run an ultrasound test commonly run in the scan room. “Before this,” says Holbrook, “we'd either have a very clunky in-room display with ten keys to control things, or one person would be in the magnet room holding the transducer in place, and another would run the test and interpret the results from afar. With this, I can connect to the transducer, prescribe the test, run it, and then view the data after it was run—all without leaving the transducer's side.”
Holbrook could also take advantage of the best-in-class multitasking in webOS to simultaneously run this app while getting a view of the activity in the respiratory monitoring (bellows) app next to it. The bellows app, shown below, shows how a patient is breathing as they are lying on the MRI table. Even though respiration information and the HIFU information came from separate parts of the MRI suite, both could now be monitored on Holbrook’s portable webOS device.
Besides these two support applications, Dr. Holbrook also created MRI applications that allow scanning in the magnet scan room. Using a platform called RTHawk, a real time MRI control system for GE scanners, he has created apps for controlling slice positioning in MRI scans, as well as MRI scan parameter adjustment, no matter where the user is: in the magnet room or outside. The interface makes use of various features of the TouchPad for MRI control, including multi-touch gestures and even the volume keys for controlling image positions. Such technology has multiple uses, like controlling scans while tracking an implanted device, for example, or even allowing a radiologist to scan in the room, next to the patient.
Beyond the TouchPad
Besides creating applications for the TouchPad, Dr. Holbrook has even begun porting some of his apps onto webOS phones! By creating smaller form factor MR-safe devices and developing applications, such as respiration monitoring, technologists could have more information at their fingertips when setting up scans.
This is the respiratory monitoring application developed for the HP/Palm Pixi Plus. “The Pixi Plus, while an older device, has been the ‘best’ HP device for use in the magnet space. I could take it into the center of our magnet bore, at 30000G, and still have internet functionality:”
“Furthermore, I was very surprised how backwards-compatible webOS was. Aside from one technical bug in my application, which the Dev Community was very helpful in working around, it was extremely easy to compile my webOS 3.x tablet apps to webOS 2.x and 1.4.5.x phones.”
Why webOS?
Dr. Holbrook had many options for choosing both the hardware and software components before embarking on this project. “From a hardware and software perspective, I started with webOS devices for a few reasons. First, I perceived the TouchPad to be easily modifiable, given its mainly plastic frame, absence of glue, and non-reliance on magnets (ie for charging). Second, the webOS interface seemed the most advanced. The card browsing for example, allows for very easy and intuitive control of the various systems of an interventional procedure. Finally, developing is in JavaScript and C++. Those are languages in which I already had some experience.
“From a developer perspective,” he continues, “[HP] webOS has been extremely helpful both officially and unofficially, from answering questions related to the SDK, questions related to the hardware, and finding other webOS contacts, like with the Preware community for solving issues, beyond those that HP could officially help with.” Of course, Stanford and HP both being located in Silicon Valley helps make collaborations easier, too! Indeed, this is just the latest in a long history of collaborative efforts between the people at Stanford and Hewlett-Packard.
Conclusion: The Future
Dr. Holbrook sees continued opportunity for MRI projects in the webOS platform. For diagnostic imaging, his hope is that mobile devices like webOS phones and the TouchPad can lead to both workflow and patient management improvements. For interventional MRI, Dr. Holbrook wants to continue to develop applications that will aid in the multi-tasking common in these procedures. The webOS Enyo SDK enables developers like him to rapidly create custom and intuitive user interfaces.
He has further plans for incorporating webOS devices into interventional procedures, and hopefully will start integrating webOS devices into Stanford Radiology clinical trials in the very near future. We will be following Dr. Holbrook’s exciting progress and keeping you updated!
