Alexis Laugerette1,2, Benedikt J Schwaiger1, Kevin Brown3, Lena C Frerking4, Felix K Kopp1, Kai Mei1, Thorsten Sellerer2, Jan Kirschke5, Thomas Baum5, Alexandra S Gersing1, Daniela Pfeiffer1, Alexander A Fingerle1, Ernst J Rummeny1, Roland Proksa4, Peter B Noël6,7, Franz Pfeiffer1,2. 1. Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str 22, 81675, Munich, Germany. 2. Biomedical Physics & Munich School of BioEngineering, Technical University of Munich, Garching, Germany. 3. Philips Healthcare, Cleveland, OH, USA. 4. Philips Research Laboratories, Hamburg, Germany. 5. Section of Diagnostic and Interventional Neuroradiology, Technical University of Munich, Munich, Germany. 6. Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str 22, 81675, Munich, Germany. peter.noel@uphs.upenn.edu. 7. Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA. peter.noel@uphs.upenn.edu.
Abstract
OBJECTIVES: To develop and evaluate a method for areal bone mineral density (aBMD) measurement based on dual-layer spectral CT scout scans. METHODS: A post-processing algorithm using a pair of 2D virtual mono-energetic scout images (VMSIs) was established in order to semi-automatically compute the aBMD at the spine similarly to DXA, using manual soft tissue segmentation, semi-automatic segmentation for the vertebrae, and automatic segmentation for the background. The method was assessed based on repetitive measurements of the standardized European Spine Phantom (ESP) using the standard scout scan tube current (30 mA) and other tube currents (10 to 200 mA), as well as using fat-equivalent extension rings simulating different patient habitus, and was compared to dual-energy X-ray absorptiometry (DXA). Moreover, the feasibility of the method was assessed in vivo in female patients. RESULTS: Derived from standard scout scans, aBMD values measured with the proposed method significantly correlated with DXA measurements (r = 0.9925, p < 0.001), and mean accuracy (DXA, 4.12%; scout, 1.60%) and precision (DXA, 2.64%; scout, 2.03%) were comparable between the two methods. Moreover, aBMD values assessed at different tube currents did not differ significantly (p ≥ 0.20 for all), suggesting that the presented method could be applied to scout scans with different settings. Finally, data derived from sample patients were concordant with BMD values from a reference age-matched population. CONCLUSIONS: Based on dual-layer spectral scout scans, aBMD measurements were fast and reliable and significantly correlated with the according DXA measurements in phantoms. Considering the number of CT acquisitions performed worldwide, this method could allow truly opportunistic osteoporosis screening. KEY POINTS: • 2D scout scans (localizer radiographs) from a dual-layer spectral CT scanner, which are mandatory parts of a CT examination, can be used to automatically determine areal bone mineral density (aBMD) at the spine. • The presented method allowed fast (< 25 s/patient), semi-automatic, and reliable DXA-equivalent aBMD measurements for state-of-the-art DXA phantoms at different tube settings and for various patient habitus, as well as for sample patients. • Considering the number of CT scout scan acquisitions performed worldwide on a daily basis, the presented technique could enable truly opportunistic osteoporosis screening with DXA-equivalent metrics, without involving higher radiation exposure since it only processes existing data that is acquired during each CT scan.
OBJECTIVES: To develop and evaluate a method for areal bone mineral density (aBMD) measurement based on dual-layer spectral CT scout scans. METHODS: A post-processing algorithm using a pair of 2D virtual mono-energetic scout images (VMSIs) was established in order to semi-automatically compute the aBMD at the spine similarly to DXA, using manual soft tissue segmentation, semi-automatic segmentation for the vertebrae, and automatic segmentation for the background. The method was assessed based on repetitive measurements of the standardized European Spine Phantom (ESP) using the standard scout scan tube current (30 mA) and other tube currents (10 to 200 mA), as well as using fat-equivalent extension rings simulating different patient habitus, and was compared to dual-energy X-ray absorptiometry (DXA). Moreover, the feasibility of the method was assessed in vivo in female patients. RESULTS: Derived from standard scout scans, aBMD values measured with the proposed method significantly correlated with DXA measurements (r = 0.9925, p < 0.001), and mean accuracy (DXA, 4.12%; scout, 1.60%) and precision (DXA, 2.64%; scout, 2.03%) were comparable between the two methods. Moreover, aBMD values assessed at different tube currents did not differ significantly (p ≥ 0.20 for all), suggesting that the presented method could be applied to scout scans with different settings. Finally, data derived from sample patients were concordant with BMD values from a reference age-matched population. CONCLUSIONS: Based on dual-layer spectral scout scans, aBMD measurements were fast and reliable and significantly correlated with the according DXA measurements in phantoms. Considering the number of CT acquisitions performed worldwide, this method could allow truly opportunistic osteoporosis screening. KEY POINTS: • 2D scout scans (localizer radiographs) from a dual-layer spectral CT scanner, which are mandatory parts of a CT examination, can be used to automatically determine areal bone mineral density (aBMD) at the spine. • The presented method allowed fast (< 25 s/patient), semi-automatic, and reliable DXA-equivalent aBMD measurements for state-of-the-art DXA phantoms at different tube settings and for various patient habitus, as well as for sample patients. • Considering the number of CT scout scan acquisitions performed worldwide on a daily basis, the presented technique could enable truly opportunistic osteoporosis screening with DXA-equivalent metrics, without involving higher radiation exposure since it only processes existing data that is acquired during each CT scan.
Authors: Jeffrey R Curtis; Laura Carbone; Hong Cheng; Burton Hayes; Andrew Laster; Robert Matthews; Kenneth G Saag; Robert Sepanski; Simpson B Tanner; Elizabeth Delzell Journal: J Bone Miner Res Date: 2008-07 Impact factor: 6.741
Authors: E Hernlund; A Svedbom; M Ivergård; J Compston; C Cooper; J Stenmark; E V McCloskey; B Jönsson; J A Kanis Journal: Arch Osteoporos Date: 2013-10-11 Impact factor: 2.617
Authors: David Zopfs; Simon Lennartz; Charlotte Zaeske; Martin Merkt; Kai Roman Laukamp; Robert Peter Reimer; David Maintz; Jan Borggrefe; Nils Grosse Hokamp Journal: Br J Radiol Date: 2020-03-04 Impact factor: 3.039