MRI Monitor: Pediatric MRI at Scale
By Keith Loria
Radiology Today
Vol. 24 No. 6 P. 8

MRI does not produce ionizing radiation, making it an attractive modality for pediatric imaging. However, MRI is challenging for children because of the need to hold still for long periods of time, the loud noises, and the intimidating environment of the scanner itself.

Fortunately, ultrasound (also nonionizing) can often provide a diagnosis in children due to their small size, precluding the need for MRI. Still, MRI is the standard of care for most cancer staging in children and is also preferred for assessment of the gastrointestinal tract and urinary tract due to its dynamic capability. As such, innovations in pediatric MRI are largely directed toward making MRI more tolerable for children.

Improving Safety
MRI safety for pediatric patients—and all patients—continues to be a top priority for MRI technologists. In fact, Amanda Garlock, MS, RT (R) (MR), former president of the American Society of Radiologic Technologists (ASRT), made technologist-focused MR safety a priority initiative.

“The ASRT leads the conversation on MR safety for pediatrics and all patients via our practice standards,” says Melissa Culp, MEd, RT (R) (MR), executive vice president of member engagement for ASRT. “MR safety is a top-of-mind issue in the MR profession and more and more organizations are looking at how to improve safety in MR departments.”

As such, the ASRT conducted a nationwide survey of MR technologists and convened the MR Safety Best Practices Committee, consisting of MR technologists and safety officers, to create a report on MR safety issues and technologist-driven best practices. This report, “Radiologic Technologist Best Practices for MR Safety,” summarizes the MR technologist’s roles and responsibilities to prioritize safety of patients, family members, and colleagues within the MR scanning environment.

“The ACR Manual on MR Safety is a valuable resource for MR technologists working with pediatric patients,” Culp says. “It highlights best practices for working with children and adults who might be claustrophobic and have anxiety. In addition, it outlines practices for gathering information from young patients and best practices for entering the MR zones prior to entering the MR suite, where the procedures are performed.”

New Trends
Erin Rowe, MD, division chief for pediatric MRI and CT at Yale New Haven Children’s Hospital, notes some hot topics today are compressed sensing technology and the use of deep learning.

“Compressed sensing technology enables us to scan more rapidly by filling in missing data,” she says. “We no longer need a complete dataset to generate an anatomic image. We can train deep learning frameworks with standard methods of MRI reconstruction and then give them the incomplete dataset. The result is a diagnostic image in much less time.”

Low-field scanners are also generating a lot of interest. Because these scanners have an open design, sedation is less likely to be needed for pediatric patients.

“These scanners are lower cost and more portable, potentially making them more accessible for lower income regions, where children may often wait far too long for a needed scan,” Rowe says. “Low-field scanners are also less prone to metal artifact, making them promising for imaging children with metal hardware who otherwise might require repeated CT scans.”

Shreyas Vasanawala, MD, PhD, chief of pediatric radiology at Stanford Medicine Children’s Health, notes that most radiology diagnostic equipment and procedures were developed for the adult setting, which significantly differs from what is needed when examining children. Among many contrasting physical characteristics, children are smaller and tend to breathe faster, which can make imaging difficult.

“One of the current hot items in imaging for pediatric patients are very lightweight and flexible MRI receiver coils,” he says. “These are more comfortable for children and enable higher quality imaging. We’re seeing this advancement emerge as a viable pediatric solution.”

For radiologists working with children, Vasanawala says tailoring exam protocols to their needs is a must.

“Partnering closely with anesthesiologists and child development specialists also greatly enhances diagnostic accuracy and the patient experience,” he says.

One great example of how things are improving is comprehensive cardiac imaging for congenital heart diseases. This imaging can now be performed in under 15 minutes without any anesthesia or requirements for children to hold their breath.

“Historically, these exams took over an hour and required many breath-holds, which can be a challenge for pediatric patients,” Vasanawala says. “We can now eliminate this challenge and enable a smoother imaging process.”

Prioritizing Comfortability
Today’s pediatric MRI suites are often more child friendly. For example, Yale New Haven Children’s Hospital is painted to resemble a beach.

“Child life specialists are available to prepare the patient and family before the scan,” Rowe says. “Some institutions have video goggles for movie viewing during scans. It is standard practice to allow a parent or other adult support person to sit in the room with the child.”

Additionally, virtual reality software allowing children to interact with comforting characters, who remind them to hold still, is a promising new method of distraction. Breath holds, which were once standard, are often no longer necessary as respiratory motion artifacts can be eliminated with particular sequences.

Monitoring Matters
Pediatric imaging optimally requires a hands-on approach. While CT is often one-size-fits-all, MRI can be tailored much more specifically to answer clinical questions. Between the time an order is placed and the time a child is scanned, a lot can go awry unless the process is properly monitored.

At Yale New Haven Children’s Hospital, no pediatric chest or abdominal/pelvic MRI is performed without review by Rowe or one of her colleagues.

“If the test ordered does not fit the clinical question, we speak to the ordering clinician and recommend a different test,” Rowe says. “If the order fits the clinical question, we next consider the age and developmental level of the patient.”

For example, if a chest, abdomen, and pelvis MRI is ordered on a 3-year-old, sedation would be required.

“Very young babies can be fed and then put in the scanner to sleep,” she says. “Children over the age of 8 can usually tolerate the scan with appropriate child life preparation. My team verifies the need—or not—for sedation and then selects the sequences needed for the scan, which is called ‘protocolling’ the scan. We often ask that scans be performed during standard work hours to ensure our availability to check for diagnostic quality. No one wants to scan a child for no added information, especially if sedation is involved.”

Looking Ahead
Dedicated pediatric MRI systems have the potential to transform the field, as radiology continues to play a critical role in catching potential illnesses and diseases in earlier stages. Imaging is also advancing to provide more information earlier in the diagnostic process to cut additional visits or condense steps between time of discovery and time of diagnosis.

Rowe has high hopes that scanning will continue to become faster, eventually allowing younger children to get through a scan without sedation.

“Free-breathing technology on as many scanners as possible is a huge wish of mine,” she says. “Many of our older and sicker patients would best be scanned with free breathing techniques; the benefit is not just for children. I also think a major investment in child life would more than pay for itself in the long run, given how expensive sedation and anesthesia are. A child life specialist could spend 30 minutes to an hour with each family before a scan and assess the child’s potential to make it through without sedation. I suspect the cost of such a session would be tiny compared to an hour of sedation or anesthesia. In this way, we could scan more children in a timely manner and free up our sedation/ anesthesia resources for other patients.” 

— Keith Loria is a freelance writer based in Oakton, Virginia. He is a frequent contributor to Radiology Today.