1. Calcium score of small coronary calcifications on multidetector computed tomography: Results from a static phantom study 
J.M. Groen, K.F. Kofoed, M. Zacho, R. Vliegenthart, T.P. Willems, M.J.W. Greuter 
European Journal of Radiology 
Volume 82, Issue 2, Pages e58-e63 (February 2013)
DOI: /j.ejrad
Copyright © 2012 Elsevier Ireland Ltd Terms and Conditions

2. Fig. 1
(a) Schematic axial view of the phantom at one of the four planes containing 25 calcifications each (left), and schematic side view of the phantom showing the all four planes with calcifications (right). (b) Radiologic axial view of the phantom, the different calcifications are clearly visible. (c) Schematic drawing of the analysis method used. The border between detected and undetected calcification as determined by the reference method EBT is given by the visibility curve (isocurve for HU-peak=130HU). Two calcifications are given as example, one with a size of 1.1mm and density of 250mgHA (triangle) which is not detected and thus below the visibility curve, the other with a size of 1.7mm and a density of 450mgHA (circle) which is detected and thus above the visibility curve.
European Journal of Radiology  , e58-e63DOI: ( /j.ejrad )
Copyright © 2012 Elsevier Ireland Ltd Terms and Conditions

3. Fig. 2
(a–d): Visibility curves on MDCT and EBT of the calcifications (a) at different tube voltages, (b) at different slice thickness, (c) at different reconstruction kernels, (d) at different scoring thresholds. The visibility curves are the 130HU isocurves of the calcifications in the size-density plane. Calcifications above the visibility curve are detected, below the visibility curve are not. The black visibility curves represent the reference standard.
European Journal of Radiology  , e58-e63DOI: ( /j.ejrad )
Copyright © 2012 Elsevier Ireland Ltd Terms and Conditions

4. Fig. 3
(a–c): SSD for ASMDCT, MSMDCT compared to ASref, MSref and MSphysical as a function of tube voltage (a), slice thickness and increment (b) and reconstruction kernel (c). On the left axis the SSD for EBT is shown, on the right axis the SSD for the physical mass. The SSD for MSMDCT–MSphysical was multiplied by 10 for better visibility.
European Journal of Radiology  , e58-e63DOI: ( /j.ejrad )
Copyright © 2012 Elsevier Ireland Ltd Terms and Conditions

5. Fig. 4
Adjustment of the scoring threshold for different kV settings as proposed in the scanning protocol. (a) Visibility curves with a slice thickness of 3.0mm, the different kV/threshold combinations showed similar results. (b) Visibility curves with a slice thickness of 0.5mm, again different kV/threshold combinations showed similar results.
European Journal of Radiology  , e58-e63DOI: ( /j.ejrad )
Copyright © 2012 Elsevier Ireland Ltd Terms and Conditions