New CT technology shows anorexia impairs adolescent bone development
CHICAGO—Children and teenagers with even mild cases of anorexia exhibit abnormal bone structure, according to research presented at the 94th annual meeting of the Radiological Society of North America, and simultaneously published in the December issue of Radiology.

“Adolescence is the most critical period for growth of bone mass, and the onset of anorexia interferes with that process,” reported Miriam A. Bredella, MD, musculoskeletal radiologist at Massachusetts General Hospital in Boston. “Impairment of bone development may permanently alter bone structure and increase the risk of fractures and osteoporosis in adult life.”

Anorexia primarily occurs among young women and affects one in 100 adolescent girls, according to the National Women's Health Information Center. Among the many health problems associated with anorexia is bone loss.

Bredella and colleagues set out to determine if alterations in bone structure occur before significant decreases in bone mineral density become evident. They used a dual energy x-ray absorptiometry (DXA) to test bone mineral density in adolescents with anorexia.

The researchers used high-resolution, flat-panel volume CT and DXA to study 10 adolescent girls, age 13 to 18, with mild anorexia and 10 age-matched girls without the disorder. The new CT exam allowed the researchers to identify differences in bone structure between the patients with anorexia and the healthy controls, whereas bone mineral density measurements obtained using DXA did not.

They found that while there was not a significant difference in bone mineral density between the anorexic patients and the healthy control group, there were significant structural differences, indicating that changes in bone structure begin to occur in anorexic patients well before decreases in bone density.

“Our data suggest that reassuring values of bone mineral density obtained using DXA may not reflect the true status of bone structure in this undernourished population,” Bredella said. “In patients with anorexia, bone structure should be analyzed to detect abnormal bone health. Flat-panel volume CT allows the examination of bone at high resolution with relatively low radiation exposure making it a suitable technique for evaluation of bone structure in adolescent patients.”