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. Author manuscript; available in PMC: 2009 Sep 11.
Published in final edited form as: Med Phys. 2006 Aug;33(8):3006–3017. doi: 10.1118/1.2219332

Table VI.

Mean CT numbers (HU) of the 16 mm diameter reference nodules for three scans at each technique and the standard deviations of the mean CT numbers.

High resolution
NLST
LTRC
Nodule no. Mean Standard deviation Mean Standard deviation Mean Standard deviation
100 mg/cc 1 81.1 0.6 82.2 1.6 83.0 1.5
2 79.4 0.4 79.9 1.5 82.6 2.3
3 79.1 0.3 78.4 1.9 82.5 1.3
4 68.4 0.3 69.2 0.4 75.0 0.9
5 78.9 0.5 81.9 0.7 83.4 1.5
Overall mean 77.4±5.1 78.3±5.3 81.3±3.5
6 25.1 0.4 25.6 3.0 33.9 1.9
7 20.3 0.2 22.4 2.0 29.1 0.9
50 mg/cc 8 19.3 0.2 19.6 3.7 27.9 0.5
9 25.2 0.2 25.5 1.5 33.5 1.3
10 25.5 0.6 26.3 0.3 33.4 0.4
Overall mean 23.1±3.0 23.1±2.8 31.6±2.8