Table 1 Collateral status according to vascular flow dynamics on dynax–CTA

Good

Compared to visualization of the M2 or M3 branches in the asymptomatic contralateral hemisphere, the M2 or M3 branches were visualized almost without delay within the ischemic territory

in the symptomatic hemisphere, and prominence and extent was about 70% or more of those in the contralateral hemisphere

Intermediate

Compared to visualization of the M2 or M3 branches in the asymptomatic contralateral hemisphere, the M2 or M3 branches were visualized with a short delay within the ischemic territory

in the symptomatic hemisphere, and prominence and extent was about 30 to 70% of those in the contralateral hemisphere

Poor

Compared to visualization of the M2 or M3 branches in the asymptomatic contralateral hemisphere, the M2 or M3 branches were visualized with a long delay within the ischemic territory

in the symptomatic hemisphere, and prominence and extent was about less than 30% of those in the contralateral hemisphere