. Author manuscript; available in PMC: 2010 Sep 22.

Published in final edited form as: Acad Radiol. 2009 Jun;16(6):689–699. doi: 10.1016/j.acra.2008.12.024

Table 5.

Comparability of lung density measures from cardiac CT scans on EBT vs. MDCT scanners

n=10	Median value from EBT cardiac scan (interquartile range)	Median value from MDCT^* cardiac scan (interquartile range)	Spearman's correlation coefficient	Mean difference^† (95% CI)	95% limits of agreement
%emphysema_{-910 HU}	10.8 (7.35, 16.9)	10.9 (6.94, 18.5)	0.94	-0.87 (-2.20, 0.46)	-5.07, 3.34
Alpha_{-910 HU}	1.38 (1.19, 1.59)	1.45 (1.26, 1.61)	0.83	-0.04 (-0.10, 0.02)	-0.23, 0.14
Apical-basilar difference in %Emphysema_{-910 HU}	0.12 (-4.35, 1.63)	-3.27 (-6.58, -1.00)	0.75	2.04 (0.05, 4.03)	-4.25, 8.33
Apical-basilar difference in alpha_{-910 HU}	0.13 (0.09, 0.35)	0.11 (0.07, 0.13)	0.22	0.09 (-0.03, 0.22)	-0.30, 0.49

Siemens 64-slice multidetector CT scanner

^†

Mean difference calculated as EBT value – MDCT value