Fig 2.

Antegrade flow for a case with left M1 occlusion was detected from time-resolved MIP images (A), which may reflect partial recanalization of the vessel. The extent of collateral flow can be accurately detected from the tMIP images for a case with a right M1 occlusion (B). Collateral flow can be evaluated by using any of the 4 commonly used scoring systems based on these images. Time-density curves for bilateral symmetric measuring points can be generated from early-phase (C, left and middle) and late-phase (D, left and middle) time-resolved MIP images, respectively. Compared with the normal side (C, right), the lesion side (D, right) has delayed vessel filling (34/17, 8.5 seconds) and reduced vessel enhancement (396/676, 58.6%).