Pediatric Imaging: No Small Consideration
By Keith Loria
Radiology Today
Vol. 26 No. 4 P. 28

Best Practices for Imaging Pediatric Patients in the Emergency Department

Children present unique challenges in medical imaging due to their size, developmental stage, and varying levels of communication, and the need for effective and safe imaging of pediatric patients has never been more critical than it is today. Recent advancements in technology, along with a deeper understanding of pediatric needs, have paved the way for more efficient and compassionate imaging protocols. In addition, health care professionals are increasingly focused on implementing best practices that optimize care while minimizing radiation exposure.

Jennifer R. Marin, MD, a professor of pediatrics at the University of Pittsburgh School of Medicine who specialized in emergency pediatric medicine at UPMC Children’s Hospital of Pittsburgh, notes it’s important to consider all the risks of imaging for all patients, not just pediatric ones; however, radiation exposure from CT imaging poses a larger risk in children than adults.

“The illnesses and injuries that we see in children are often very different than those in adult patients, and this is the first thing to consider when deciding on imaging,” she says. “In pediatric patients, common symptoms for which imaging is typically ordered would be abdominal pain to evaluate for appendicitis, head trauma to evaluate for a brain bleed, and headache to evaluate for a mass. Often, we can use the history and physical examination to rule out these conditions without the need for confirmatory imaging at all.”

In some cases, there are published clinical decision rules or validated scoring rules available that can be used to risk-stratify a patient in order to determine if imaging is even indicated. “For example, there are several appendicitis scores which incorporate symptoms, exam findings, and labs to estimate a patient’s risk of appendicitis, which if low, would obviate the need for imaging altogether,” Marin says. “Another example would be a head trauma clinical decision rule which takes into account patient age, symptoms, and exam findings and can determine which children are at very low risk of significant brain injury and, therefore, don’t need CT imaging of their brain.”

Once the decision is made that imaging is necessary, another important point to consider is what kind of test is optimal. For example, to evaluate for appendicitis in a child, the first-line test is an ultrasound, which does not expose the child to radiation, has lower risks of incidental findings, and is less costly than a CT. In a child with a headache who has an abnormal neurologic examination, Marin notes MRI would be more appropriate, as it does not expose the child to radiation and is also a more accurate test than CT.

Minimizing Radiation Exposure
Geetika Khanna, MD, chief of radiology at Children’s Healthcare of Atlanta, says all imaging for children should be double checked to ensure it’s necessary and appropriate so the patient is exposed to the least possible amount of radiation.

“All of our equipment is optimized to decrease the radiation exposure for the child,” she says. “We also try to avoid multiple scans to keep the radiation exposure in check.”

Once a provider decides it is necessary, the next step is determining what the optimal test is. This is often made with a balance of radiation risk, length of study, and diagnostic accuracy.

“For example, if a child comes to the emergency department [ED] with a severe head injury and the provider determines that neuroimaging of the brain is indicated, a CT would be the appropriate study,” Marin says. “We do have the ability to do MRI imaging of the brain; however, for acute head trauma, the current standard of care is CT imaging. In addition, getting an MRI takes much longer than getting a CT scan both in the duration of the actual study and also in the total time from ordering the study to completion.”

In the case of a patient for whom appendicitis is being evaluated, a CT would be a more accurate test than ultrasound; however, ultrasound may be able to make the diagnosis and, because it does not expose the child to radiation, it is considered firstline for this indication, she adds.

Amit Kalaria, MD, a radiologist at the University of Maryland St Joseph Medical Center, notes modern X-ray and CT equipment have dose reduction algorithms built into their interfaces to help make the dose as low as possible while ensuring a diagnostic image. He advises, when possible, to use ultrasound to further reduce dose and provide similar diagnostic information.

“In pediatric cases, we employ a lower threshold to call and discuss findings with the pediatricians and ED staff,” he says. “This can often enhance our ability to interpret imaging by incorporating more clinical information into the interpretation and can help the pediatricians in determining what the next step is.”

Team Effort
When deciding on the work-up for pediatric patients, physicians should consider the patient’s ability to cooperate with an examination. “Motion can render studies indeterminate and require repeat exam or additional imaging, all of which increases cost and potentially radiation exposure,” Kalaria says. “Pediatric patients are smaller, and as such, the anatomy we are evaluating is smaller. The spatial resolution that imaging is able to define does not change with smaller patients, and so there is consequently a drop in the sensitivity for some imaging findings in the pediatric setting.”

He adds that involving parents to help calm the child and keep them well-positioned is often helpful and necessary when imaging young children. All radiation safety measures for workers are then employed for a parent to keep their exposure to a minimum.

Khanna notes children tend not to stay still and have trouble holding their breath, so child specialists may need to be added to the care team to help them through an imaging session. Anxiety is also a common issue with children, so it’s vital that great care is put into making a child feel comfortable when imaging is done. To alleviate worry, Children’s Healthcare of Atlanta created a hospital environment where the scanners are decorated to make them more child-friendly, and there are therapy animals in the hospital that can be used to calm the child.

Marin feels fortunate to practice at a children’s hospital where every aspect of care is child-centered. However, she definitely experiences situations with children who simply won’t cooperate for a test.

“In these cases, we will give the child a calming medicine either orally, through their nose, or through an IV,” she says. “It’s very rare that we cannot get an adequate study in the ED using these methods.”

Multidisciplinary collaboration is critical to successful imaging protocols. This includes a partnership between the doctor and radiology department, to ensure they have the resources to ensure successful execution of imaging protocols. For example, if a department does not have ultrasound technologists who are adept at pediatric abdominal ultrasound, the ED wouldn’t be able to offer that service to their patients.

“Collaboration with subspecialists is also important,” Marin says. ‘For example, quick or rapid MRI protocols are being adopted by more hospitals to safely and efficiently image children who otherwise would have had CT imaging. As MRI imaging does not expose patients to radiation, it can be an ideal study in many cases.”

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