CT colonography offers opportunity for osteoporosis screening
MedWire News: Screening for osteoporosis could be carried out at the same time as patients undergo CT colonography (CTC) screening, report researchers in the Journal of Bone and Mineral Research.
"It is estimated that up to 50% of women and 20% of men are at risk of developing an osteoporosis-related fracture during their lifetime," Perry Pickhardt (University of Wisconsin School of Medicine and Public Health, Madison, USA) and colleagues explain.
"Despite these statistics, osteoporosis screening with dual-energy X-ray absorptiometry (DXA) remains underused."
The team's study evaluated the opportunity CTC scans pose for simultaneous bone mineral density (BMD) screening of the lumbar spine.
It is thought that patients undergoing CTC scans could benefit from the improved efficiency of being screened for osteoporosis at the same time, reducing the need for any additional exposure to radiation and increasing osteoporosis screening rates.
The study included 252 asymptomatic adults (240 women and 12 men) over 50 years of age, who had undergone both central DXA and CTC screening within a 2-month period. The mean time period between DXA and CTC was 25 days.
DXA T-scores were examined for World Health Organization definitions of osteoporosis (<-2.5) and ostepenia (<-10 to -2.4) .The prevalence of osteoporosis and osteopenia recorded among the patients was 11.5% and 55.2% respectively.
Both phantomless quantitative CT (QCT) technique and simple nonangled region-of-interest (ROI) multi-detector CT (MDCT) attenuation measurements were taken during the CT scan. By comparing the T scores obtained from the CT methods with those collected from screening using DXA techniques the researchers tested the suitability of CT techniques for osteoporosis testing.
The study found that each of the tested CT techniques could be used to identify whether the patients were at risk for osteoporosis or not. All 29 cases of osteoporosis were successfully identified using a BMD cutoff of 90 mg/ml for the QCT technique and a cutoff of 160 HU for the ROI method, therefore translating to 100% sensitivity for osteoporosis for both techniques. The specificity was 63.8% for the QCT technique and 46.4% using ROI.
The study supports the utilization of data from CTC scans for BMD screening, but the researchers emphasize the importance of seeking validation from similar future investigations at other institutions.
"Our results suggest that valuable information pertaining to vertebral BMD assessment is currently going unused at CTC screening, as well as other non-contrast-enhanced abdominal CT examinations. By applying either phantomless QCT analysis or even single-level ROI measurement to non-contrast-enhanced CT studies, we can identify individuals at risk for osteoporosis, as well as those who are not," the authors conclude.
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By Chloe McIvor