Table 1.

Comparison of endoscopic and 3D CT cross-sectional measurements displayed as individual area measurements for each level and as ratio of endoscopic measurement divided by 3D CT measurement (E/3D).

Level of Interest	Area Endoscopic (mm2)	Area 3D-CT (mm2)	E/3D ratio	Area Absolute Difference (mm2)	Horizontal Midline (E/3D))	Vertical Midline (E/3D)	Horizontal Max Distance (E/3D)	Vertical Max Distance (E/3D)	Fields of View Used
3rd Stricture	177.0	191.2	0.93	−14.1	1.01	0.90	n/a	n/a	1
2nd Stricture	205.7	204.9	1.00	0.8	1.00	1.04	n/a	n/a	1
1st Stricture	127.8	129.6	0.99	−1.8	0.95	1.01	0.93	1.06	1
Vocal cords	82.0	89.8	0.91	−7.8	1.05	0.89	1.06	n/a	2
Width of Epiglottis	n/a		n/a	n/a	n/a	n/a	n/a	0.90	2
Tip of Epiglottis	51.2	69.9	0.73	−18.7	n/a	1.05	n/a	n/a	1
Base of Tongue	489.00	387.7	1.26	101.4	n/a	1.00	n/a	n/a	4
Minimal Pharyngeal Cross-Sectional Area	414.10	291.4	1.42	122.7	n/a	0.73	2.28	n/a	7
Left Choana	100.90	137.6	0.73	−36.7	0.88	0.85	n/a	n/a	6

n/a = clinically irrelevant or too difficult to assess

AP = Anterior-Posterior