Opportunistic Osteoporosis Screening: Addition of Quantitative CT Bone Mineral Density Evaluation to CT Colonography

For patients undergoing CT colonography (CTC), the screening presents an opportunity for concurrent osteoporosis screening, without increasing radiation exposure or the time involved for the patient, using proximal femur quantitative CT-CT x-ray absorptiometry (QCT-CTXA).

This cohort included 129 women and 112 men (mean age: 60.1 ± 8.2 years; range: 50-95 years) who underwent CTC between March 2013 and September 2014. Areal bone mineral density (BMD; g/cm(2)), and resultant left femoral neck T-score, was prospectively measured on the supine CT series. QCT results were reported with the CTC. Chart review evaluated whether the patients were eligible for BMD screening according to guidelines from the US Preventive Services Task Force and the National Osteoporosis Foundation guidelines; whether they had undergone prior BMD testing; and whether QCT results changed patient management.

Overall, 68.0% (164 of 241) of patients from this cohort had not previously undergone BMD screening. According to the National Osteoporosis Foundation guidelines, 44.0% (106 of 241) of patients were eligible for screening. T-scores within the osteopenic and osteoporotic range were detected in 32.3% (78 of 241) and 5.0% (12 of 241) of patients, respectively. Of these patients with low BMD, 66.7% (60 of 90) either had not previously undergone screening or were eligible for BMD testing. Reporting of QCT-CTXA T-scores altered management in 9 patients (3.7%) who had low BMD.

Maximizing the pre-existing value from imaging studies is crucial in the current era of health care reform. We demonstrate that colorectal and osteoporosis screening can be combined at CT examination, adding clinical and likely economic value.