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Feasibility of Real-Time Angiographic Perfusion Imaging in the Treatment of Cerebral Vasospasm

Background: Objective assessment and quantification of the severity of cerebral vasospasm following aneurysmal subarachnoid hemorrhage is not routinely utilized. We investigated the feasibility of angiographic perfusion imaging derived from digital subtraction angiography (DSA) following endovascular vasospasm treatment procedures. Methodology: Real-time blood flow analysis was performed using parametric color coding on pre- and postintervention DSA. Semiquantitative parenchymal perfusion parameters (arrival time [AT] of contrast, time to peak [TTP] opacification, and mean transit time [MTT] of contrast) were calculated across 3 vascular territories (anterior cerebral artery [ACA], middle cerebral artery [MCA], and lenticulostriate arteries) using standard 2-D angiographic perfusion software. The pre- and postintervention arterial vessel diameters were compared. Results: Twelve endovascular vasospasm treatments in 6 patients were performed. All patients received intra-arterial vasodilator therapy with either nimodipine, milrinone, or both. Following intra-arterial intervention, parenchymal flow analysis showed improvement in TTP and MTT across all vascular territories (p < 0.002) and improvement in AT in the ACA and MCA territories (p < 0.03). Improvement in parenchymal perfusion parameters was associated with improvement in vessel diameters in all territories following treatment (p < 0.05). Conclusion: Real-time parenchymal perfusion imaging during endovascular vasospasm treatment procedures is feasible and provides reliable semiquantitative measurement of angiographic treatment response.