[Retracted] Different Grades of Collateral Circulation for Evaluating Cerebral Hemodynamic Status in Carotid Artery Stenosis

Figure 1

DSA in patients with ipsilateral sided carotid stenosis showing collateral circulation from contralateral carotid artery injection. (a) Grade 1 indicates no or slight collateral distribution, often with dilution; (b) Grade 2 indicates small but definite collateral supply; (c) Grade 3 indicates near complete collateral with cross-filling of the ipsilateral middle cerebral artery after contralateral carotid injection; (d) illustrated the image of carotid NO: as grey arrow points, significant stenosis of ICA bifurcation with poor antegrade blood flow; (E) the grey arrows show the reduced diameter of the ICA without full collapse and delayed cranial arrival of ICA.

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