Anorexia is an eating disorder characterised by emaciation, distorted body image and intense fear of gaining weight. People with the disorder perceive themselves as overweight, even when they are dangerously thin. The disorder affects one in 100 adolescent girls, according to the National Women's Health Information Center.
Among the health problems associated with anorexia is bone loss. "Impairment of bone development may permanently alter bone structure and increase the risk of fractures and osteoporosis in adult life," said Miriam A. Bredella, musculoskeletal radiologist at Massachusetts General Hospital.
Typically, dual energy x-ray absorptiometry (DXA) is used to test bone mineral density in adolescents with anorexia. Bredella and colleagues set out to determine if alterations in bone structure occur before significant decreases in bone mineral density become evident.
The researchers used high-resolution, flat-panel volume CT and DXA to study ten adolescent girls, age 13 to 18, with mild anorexia and ten age-matched girls without the disorder. The new, high-resolution 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.
The results showed 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 analysed 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."
MEDICA.de; Source: Radiological Society of North America