’Considerable disagreement’ between quantitative sonography and DXA for diagnosing osteoporosis

A lack of correlation between quantitative sonography and dual-energy X-ray absorptiometry (DXA) in detecting osteoporosis makes quantitative sonography impractical for routine diagnostic use, despite it being able to evaluate bone fracture risk without the use of ionizing radiation, say researchers from the University of Vienna in Austria.

Both quantitative sonography and DXA are imaging methods used to measure bone density and quality, with the former using sound waves and the latter X-rays. Currently, DXA is the gold standard for detecting osteoporosis. For the study, the researchers took DXA measurements of the lower spine and thigh and quantitative sonography measurements of the forearm in 121 patients. Thirty-one percent of the patients were diagnosed as osteoporotic after DXA of the spine and 43% after DXA of the thigh, whereas 34% were diagnosed as osteoporotic after quantitative sonography of the forearm. According to the study, the correlation between the two methods is categorized as only “fair to moderate” and lower than the threshold level needed for practical diagnostic use.

“If the correlation between quantitative sonography and DXA measurements were better, quantitative sonography would have the advantage to replace DXA measurements in individuals suspected of having osteoporosis,” said Christian R. Krestan, MD, lead author of the study. “Our study demonstrates only limited correlation. However, for practical reasons further studies should be carried out with quantitative ultrasound devices,” he added.

The article appears in the September 2004 issue of the American Journal of Roentgenology.