One of the ongoing issues with magnetic resonance imaging is that it's often a problematic exam to conduct on pediatric patients.
Such patients have to hold completely still for an extended period of time in a confined space, and must often hold their breath on command--all of which is an impossibility for many children. The result is that many children end up undergoing CT scans on their abdomen, chest or pelvis.
Shreyas Vasanawala, an associate professor of radiology at Stanford University, and a team of collaborators are looking to break down barriers that prevent children from getting MRIs with research support from the National Institute of Biomedical Imaging and Bioengineering.
One of Vasanawala's first objectives has been to design and build MRI signal-receiving coils tailored to children's bodies. These coils surround the part of the body that are being imaged and capture the radiofrequency signals produced during the scan. Standard coils are larger than what is needed for children and therefore pick up extra noise or interference.
To that end, Vasanawala and his colleagues at Stanford have constructed parallel arrays of child-size receiver coils for imaging the abdomen, which allow for increased image clarity and faster scan times because the individual coils pick up the signal from different parts of the body simultaneously, rather than sequentially.
Vasanawala has also worked on reducing scanning times by working to implement something called compressed sensing. Through this technique, Vasanawala is able to use an algorithm to reconstruct a full MR image using just a small fraction of imaging data.
"In MRI pictures, there is not as much information in those pictures as one would initially think, "Vasanawala said in an announcement from the National Institute of Biomedical Imaging and Bioengineering. "You're able to, in a sense, under-collect information and still reconstruct images."
Vasanawala and his colleagues have also developed better motion correction strategies that allow them to produce sharp images even when a child is breathing, allowing children to be imaged without anesthesia. The result is that more children can be imaged through his pediatric abdominal MRI program at Stanford, therefore reducing the number who undergo CT scans.
Increasingly, hospitals are looking for ways to improve the MRI experience for children. For instance, as FierceMedicalImaging reported earlier this year, Women's and Children's Hospital in Columbia, Missouri, purchased a set of $44,000 MRI-compatible video goggles and noise-cancelling headphones to help put younger patients at ease. By using the goggles on these patients, technologists can reduce the amount of time needed for the scan, which "is much more beneficial to the kids," according to Mark Burton, MRI supervisor at Women's and Children's. More importantly from a health standpoint, helping pediatric patients keep calm during MRI procedures means that some of these youngsters can avoid having to be sedated for the scanning process.
Children who use the goggles see nothing but the video they are watching during an MRI procedure, and the noise cancelling headphones eliminate the noise produced by the machine's magnets.
To learn more:
- read the announcement from the National Institute of Biomedical Imaging and Bioengineering