Introduction Diffusion weighted imaging (DWI) has its limitations, as evidenced in the literature by reports of variable sensitivity and accuracy. Increasingly, reports of the utility of CT perfusion (CTP) are being made in predicting acceptable thrombolysis candidates. This is being done by evaluating infarct core and discriminating ischemic territory from penumbra in the acute setting.

Methods A single institution, retrospective review of 21 patients who underwent multimodal endovascular intervention for stroke from January 2010 to 2011 was conducted after institutional review board approval. Immediate CTP of the head and neck was obtained in all cases upon admission. Posterior circulation stroke, lacunar infarcts, and those unable to undergo MRI post-operatively were excluded. Calculated volumes of the penumbra from CTP data were compared to post-operative MRI volumetric calculations of the completed infarct. This data was contrasted to 21 control patients that were excluded from intervention, but had CTP and MRI in the acute setting.

Results Eleven patients in the interventional group and 10 patients in the control group received intravenous tissue plasminogen activator. In both the control group and interventional groups, DWI studies obtained after multimodal recanalization in all patients demonstrated diffusion restriction in the infarct core. Varying volumes of diffusion restriction were seen in the penumbra. The mean difference calculated between the mismatch area on CTP and the correlating diffusion restriction on MRI was a decrease of 43.01 cm³ (p<0.05). In the interventional group, the area of restriction was less than the predicted mismatch area calculated. In the control group, 7 of the 21 patients (33%) had a net increase in the stroke territory. The calculated mean difference between the mismatch on CTP and the diffusion restriction on MRI was a decrease of 14.12 cm³ (p<0.05).

Conclusions DWI and CTP are useful tools in the assessment of ischemic stroke patients in the acute interventional setting. By comparing mismatch on CTP to MRI diffusion restriction after endovascular intervention, we show a decreased conversion of penumbra to stroke than in the patients undergoing medical management alone. Larger, prospective studies with quantitative metrics are necessary for further evaluation of stroke patients.

Competing interests None.