Table 1.

Measurements of inner diameter, wall thickness, and outer diameter for the five simulated airways tubes, from A (largest) to E (smallest) from micro‐CT and clinical CT scanning (scanner A). Average variation denotes measured difference from nominal values. Tube E was not well visualized with clinical CT and hence not measured.

Tube	Measurement	Designed Nominal value (mm)	Micro‐CT average ± std. dev. (mm)	Micro‐CT average variation from nominal (mm)	Clinical CT average ± std. dev. (mm)	Clinical CT average variation from nominal (mm)
A	Inner Diameter	5	4.98 ± 0.021	−0.016	4.60 ± 0.013	−0.40
	Wall Thickness	2.3	2.33 ± 0.027	0.028	2.50 ± 0.021	0.20
	Outer Diameter	9.6	9.64 ± 0.034	0.039	9.60 ± 0.035	0.004
B	Inner Diameter	4	3.97 ± 0.021	−0.031	3.45 ± 0.032	−0.55
	Wall Thickness	1.8	1.83 ± 0.026	0.028	2.07 ± 0.042	0.27
	Outer Diameter	7.6	7.63 ± 0.035	0.026	7.60 ± 0.066	−0.002
C	Inner Diameter	3	2.95 ± 0.025	−0.052	2.37 ± 0.042	−0.63
	Wall Thickness	1.3	1.35 ± 0.024	0.046	1.59 ± 0.018	0.29
	Outer Diameter	5.6	5.64 ± 0.038	0.039	5.54 ± 0.049	−0.058
D	Inner Diameter	2	1.91 ± 0.022	−0.086	1.31 ± 0.033	−0.69
	Wall Thickness	0.8	0.85 ± 0.022	0.047	1.01 ± 0.028	0.21
	Outer Diameter	3.6	3.61 ± 0.041	0.008	3.32 ± 0.042	−0.28
E	Inner Diameter	1	0.92 ± 0.023	−0.080	NA	NA
	Wall Thickness	0.4	0.44 ± 0.022	0.035	NA	NA
	Outer Diameter	1.8	1.79 ± 0.029	−0.010	NA	NA