Purpose: To show the feasibility of calculating the bone mineral density (BMD) from computed tomographic colonography (CTC) scans using fully automated software.
Materials and Methods: Automated BMD measurement software was developed that measures the BMD of the first and second lumbar vertebrae on computed tomography and calculates the mean of the 2 values to provide a per patient BMD estimate. The software was validated in a reference population of 17 consecutive women who underwent quantitative computed tomography and in a population of 475 women from a consecutive series of asymptomatic patients enrolled in a CTC screening trial conducted at 3 medical centers.
Results: The mean (SD) BMD was 133.6 (34.6) mg/mL (95% confidence interval, 130.5-136.7; n = 475). In women aged 42 to 60 years (n = 316) and 61 to 79 years (n = 159), the mean (SD) BMDs were 143.1 (33.5) and 114.7 (28.3) mg/mL, respectively (P < 0.0001). Fully automated BMD measurements were reproducible for a given patient with 95% limits of agreement of −9.79 to 8.46 mg/mL for the mean difference between paired assessments on supine and prone CTC.
Conclusions: Osteoporosis screening can be performed simultaneously with screening for colorectal polyps.
From the *Imaging Biomarkers and Computer-Aided Diagnosis Laboratory, Radiology and Imaging Sciences Department, National Institutes of Health Clinical Center, Bethesda, MD; †Department of Radiology, University of Wisconsin School of Medicine & Public Health, Madison, WI; and ‡Walter Reed Army Medical Center, Washington, DC.
Received for publication August 2, 2010; accepted September 21, 2010.
Reprints: Ronald M. Summers, MD, PhD, Imaging Biomarkers and Computer-Aided Diagnosis Laboratory, Radiology and Imaging Sciences Department, National Institutes of Health Clinical Center, Bldg 10, Room 1C224D MSC 1182, Bethesda, MD 20892-1182 (e-mail: email@example.com, Web: http://www.cc.nih.gov/drd/summers.html).
This article was supported in part by the Intramural Research Program of the National Institutes of Health Clinical Center.
This article was presented in part at the 2009 American Society for Bone and Mineral Research and Radiological Society of North America Annual Meetings.
Authors Summers and Yao have pending and/or awarded patents for the subject matter described in the article and receive royalty income for a patent license from iCAD. Author Summers is a Johnson & Johnson stockholder. His laboratory is supported in part by a cooperative research and development agreement with iCAD. Viatronix supplied the V3D Colon software to National Institutes of Health free of charge. Author Pickhardt is on the medical advisory boards of Viatronix, Inc and Medicsight, Inc, a consultant to Philips, and cofounder of VirtuoCTC. Author Choi is on the medical advisory boards of Viatronix, Inc and QI and has received research support from E-Z-EM. All other authors have no conflicts of interest.