Table 2.

Tumour/surrogate and bronchi score categories

Score	1	2	3	4
Edge detection	Edge clearly defined	Structure edge slightly blurred, not impairing definition of boundary	Considerable blurring of structure edge impacting on accurate definition of boundary	Significant blurring of boundary edge, definition of structure boundary not achievable
Artefacts	No artefacts	Minimal artefact not impairing image quality	Considerable artefacts impacting evaluation of anatomical structures	Extreme artefacts obscuring delineation of structures
Image noise	Minimal noise	Minimal noise not impairing image quality	Considerable noise impacting evaluation of anatomical structures	Extreme noise obscuring definition of structures
Overall image quality	Very good image quality	Fair image quality not impairing delineation of structures	Impaired image quality that may lead to incorrect delineation	Anatomical structure not definable