Table 1.

Scoring criteria for cone beam CT image quality assessment

Image quality parameter	Score 1 = comparable to planning CT	Score 2 = fair	Score 3 = bad
Streak artefacts	Absent	Medium degree	High degree
Visualization of primary tumour	Clearly visible/distinguished border between tumour and background	Visible, but border between tumour and background not clearly distinguished	Tumour smeared out/non-distinguished border between tumour and background
Visualization of carina and main bronchi	Clearly visible	Visible, but without clear borders	Not visible
Visualization of larger vessels	Clearly visible	Visible to a certain degree	Not visible
Visualization of lung fissures	Clearly visible	Visible to a certain degree	Not visible