Abstract
ObjectivesTo investigate the accuracy of bone mineral density (BMD) quantification using dual-layer spectral detector CT (SDCT) at various scan protocols.MethodsTwo validated anthropomorphic phantoms containing inserts of 50–200 mg/cm3 calcium hydroxyapatite (HA) were scanned using a 64-slice SDCT scanner at various acquisition protocols (120 and 140 kVp, and 50, 100 and 200 mAs). Regions of interest (ROIs) were placed in each insert and mean attenuation profiles at monochromatic energy levels (90–200 keV) were constructed. These profiles were fitted to attenuation profiles of pure HA and water to calculate HA concentrations. For comparison, one phantom was scanned using dual energy X-ray absorptiometry (DXA).ResultsAt both 120 and 140 kVp, excellent correlations (R = 0.97, P < 0.001) were found between true and measured HA concentrations. Mean error for all measurements at 120 kVp was -5.6 ± 5.7 mg/cm3 (-3.6 ± 3.2%) and at 140 kVp -2.4 ± 3.7 mg/cm3 (-0.8 ± 2.8%). Mean measurement errors were smaller than 6% for all acquisition protocols. Strong linear correlations (R2 ≥ 0.970, P < 0.001) with DXA were found.ConclusionsSDCT allows for accurate BMD quantification and potentially opens up the possibility for osteoporosis evaluation and opportunistic screening in patients undergoing SDCT for other clinical indications. However, patient studies are needed to extend and translate our findings.Key points• Dual-layer spectral detector CT allows for accurate bone mineral density quantification.• BMD measurements on SDCT are strongly linearly correlated to DXA.• SDCT, acquired for several indications, may allow for evaluation of osteoporosis.• This potentially opens up the possibility for opportunistic osteoporosis screening.
Highlights
Osteoporosis is a disease associated with low bone mineral density (BMD), increasing the risk for fractures, and thereby contributes substantially to morbidity and mortality and carries social and economic burdens [1]
spectral detector CT (SDCT) allows for accurate BMD quantification and potentially opens up the possibility for osteoporosis evaluation and opportunistic screening in patients undergoing SDCT for other clinical indications
BMD measurements on SDCT are strongly linearly correlated to dual energy X-ray absorptiometry (DXA)
Summary
Osteoporosis is a disease associated with low bone mineral density (BMD), increasing the risk for fractures, and thereby contributes substantially to morbidity and mortality and carries social and economic burdens [1]. There is the size dependency of an areal BMD measurement; artefacts which cause inaccuracies (overlying soft tissue, aortic calcifications, vertebral fractures and spinal degenerative changes); and integral bone measurements as DXA measures the whole vertebra including the neural arch, thereby including the cortical bone [5], whereas the inner trabecular bone is found to be more metabolically active and more influenced by changes in bone mineral density [6]. QCT is subject to higher radiation exposure and typically requires an in-scan calibration phantom, eliminating the option for routine BMD measurements in CT acquired for any indication. Bone density measurements on conventional single-energy CT can be substantially affected by scanner instability, X-ray tube voltages, intravenous contrast medium injection, presence of fat within bone marrow, beam hardening artefacts, patient scatter and metal artefacts [5, 10,11,12,13,14]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
