In October 2010 pediatric radiologist Melissa Spevak, citing some 7 million CT scans performed in children each year, urged fellow physicians, nurses and radiology technicians to consider ways to reduce radiation exposure in children. “CT scans save lives and have revolutionized medical diagnostics, but as physicians we should remind ourselves that every CT scan we order now stays with a child for a lifetime,” said Spevak. 

Fast forward to mid-February 2011 and pediatrician Jeannie Limpert sends a similar message to pediatric residents at a Hopkins Children’s grand rounds: “The largest increase in imaging is in children, who are uniquely more susceptible to radiation and its long-term effects than adults.” 

Though the risk to each individual per CT scan is low, Limpert explained, tissues and organs that are developing – as they are in children – are more sensitive than those in adults to the effects of radiation. Also, children have longer life spans, making them more vulnerable to radiation-related cancers because such cancers take a long time to develop. Radiation from a fixed dose, Limpert added, is higher in children than in adults. So, what can pediatricians do? 

Both Limpert and Spevak recommend that pediatricians –  

• Determine whether CT is indicated 
• Consider alternate modalities like MRI and ultrasound 
• Discuss theoretical radiation risks with the family 
• Review the child’s imaging history, and 
• Communicate with the pediatric radiologist to determine the optimal study. 

For pediatric radiologists, Limpert and Spevak recommend they follow the ALARA (As Low as Reasonably Achievable) principle, adjust settings based on the weight and size of the child, minimize the use of multiple scans for each exam, limit imaging coverage to answer the clinical questions, and consult with the referring pediatrician. 

“Most of us pediatric radiologists really enjoy the challenge of deciding what is the best test for a patient,” Spevak said. “We do defer to some extent to what pediatricians request, but we want them to be aware of the risks and, when appropriate, discuss them with the patient and family.” 

Are physicians talking to patients about possible radiation risks? In a study of 76 adult emergency department patients who underwent CT scan, Limpert noted that only 7 percent reported receiving information on risks and benefits. Also, only 2 percent of the patients were informed about the CT radiation dose (Radiology 2004;231:393-398).  

In another study of 100 parents designed to determine their understanding of and willingness to allow their children to undergo CT after receiving a handout on radiation dose and risk, 66 percent said they believed CT uses radiation before reading the handout, versus 99 percent afterward. Before reading the handout, 13 percent believed CT increases the lifetime risk of cancer, versus 86 percent afterward. Interestingly, after reading the handout parents’ willingness to have their child undergo CT recommended by their doctor did not significantly change, and no parent refused or requested to defer CT after reading the handout (AJR 2007; 189:271-275). 

“CT has become widely available, it’s extremely fast and easy, it’s informative, and in many cases it may not be necessary,” Spevak said. “There is a general interest in knowing what a CT may show, though knowing doesn’t necessarily change the management of the suspected illness or condition.”