Imaging professionals are urged to “child size,” or use the lowest radiation dose needed, in medical imaging exams on pediatric patients, according to new guidance issued on x-rays by the US Food & Drug Administration (FDA).

Though the pediatric population is defined by the FDA as birth to 21 years old, the announcement said a patient’s size, rather than their age, is a determinant for dosage.

“While the level of risk from the radiation associated with x-rays is small, especially when compared with the benefits of an accurate diagnosis, health care professionals must be especially sensitive to their appropriate use in children,” said the FDA in the statement. “Pediatric patients generally require less radiation than adults to obtain a quality image from an x-ray exam, so doctors must take extra care to ‘child size’ the radiation dose.”

Healthcare professionals are urged to ensure justification of pediatric x-ray imaging. Additionally, the FDA recommends healthcare professionals explore imaging modalities that do not expose the patient to ionizing radiation, which can obtain the same result.