Intraprocedural parenchymal blood volume as a marker of reperfusion status in acute ischemic stroke intervention

Parenchymal blood volume (PBV) mapping with flat panel detectors may provide real-time estimates of tissue perfusion during endovascular ischemic stroke procedures. We present two cases of acute middle cerebral artery (MCA) occlusion to demonstrate how PBV may: (1) be used in acute stroke; (2) influence intraprocedural decision-making; and (3) potentially serve as a predicator of clinical outcome. Both cases were successfully recanalized with endovascular embolectomy. Intraprocedural PBV maps were obtained immediately before and after recanalization. Pre-intervention reductions in PBV were seen throughout the MCA territory in both cases, with significant improvement in PBV in one case with good radiographic and clinical outcome and a lack of improvement in PBV in the second case with a large infarct volume. PBV deficit normalization may occur with recanalization of the parent artery and probably represents successful reperfusion. Baseline PBV maps should therefore be interpreted with caution and not interpreted to represent irreversible core infarct.