Table 1. Description of the five-point likert scale used in qualitative analysis of CTA.

Score	Diagnostic value	Description	Clinical value
1	Uninterpretable examination	Absent opacification, extremely severe artifacts	Non-diagnostic
2	Poor image quality	Insufficient opacification, major artifacts
3	Acceptable image quality	Sufficient opacification, minor artifacts	Diagnostic
4	Good image quality	Excellent arterial opacification, negligible artifacts
5	Excellent image quality	Excellent arterial opacification, no artifacts