Efficient Multimodal MRI Evaluation for Endovascular Thrombectomy of Anterior Circulation Large Vessel Occlusion

https://doi.org/10.1016/j.jstrokecerebrovasdis.2020.105271Get rights and content

Abstract

Background

MRI and CT modalities are both current standard-of-care options for initial imaging in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). MR provides greater lesion conspicuity and spatial resolution, but few series have demonstrated multimodal MR may be performed efficiently.

Methods

In a prospective comprehensive stroke center registry, we analyzed all anterior circulation LVO thrombectomy patients between 2012–2017 who: (1) arrived directly by EMS from the field, and (2) had initial NIHSS ≥6. Center imaging policy was multimodal MRI (including DWI/GRE/MRA w/wo PWI) as the initial evaluation in all patients without contraindications, and multimodal CT (including CT with CTA, w/wo CTP) in the remainder.

Results

Among 106 EMS-arriving endovascular thrombectomy patients, initial imaging was MRI 62.3%, CT in 37.7%. MRI and CT patients were similar in age (72.5 vs 71.3), severity (NIHSS 16.4 v 18.2), and medical history, though MRI patients had longer onset-to-door times. Overall, door-to-needle (DTN) and door-to-puncture (DTP) times did not differ among MR and CT patients, and were faster for both modalities in 2015–2017 versus 2012–2014. In the 2015–2017 period, for MR-imaged patients, the median DTN 42m (IQR 34-55) surpassed standard (60m) and advanced (45m) national targets and the median DTP 86m (IQR 71-106) surpassed the standard national target (90m).

Conclusions

AIS-LVO patients can be evaluated by multimodal MR imaging with care speeds faster than national recommendations for door-to-needle and door-to-puncture times. With its more sensitive lesion identification and spatial resolution, MRI remains a highly viable primary imaging strategy in acute ischemic stroke patients, though further workflow efficiency improvements are desirable.

Section snippets

Methods

In a prospectively maintained comprehensive stroke center registry, we analyzed all anterior circulation AIS-LVO thrombectomy patients: (1) arriving directly by EMS transport from the field, (2) with initial NIHSS ≥6, between 2012–2017. This study received approval from our institutional review board with waiver of the need for patient consent. Throughout this period, the Center's policy was to obtain multimodal MRI as the initial imaging modality in all patients meeting the criteria for

Results

From 2012–2017, 1831 AIS was evaluated, of which 200 consecutive AIS-LVO underwent mechanical thrombectomy. Among those, 106 patients were EMS-arriving and anterior circulation. The initial imaging modality was MRI in 62.3% and CT in 37.7%. Demographics and clinical characteristics of MRI and CT patients are shown separately for the periods 2012–2014 and 2015–2017 in Table I and combined across years 2012–2017 in Supplemental Table I. MR and CT patients were similar in age, vascular risk

Discussion

The leading finding of this study is that magnetic resonance imaging can serve as the first and only imaging modality in EMS-arriving patients presenting with acute ischemic stroke due to large vessel occlusion in a time efficient manner. Among patients imaged with the MR strategy, median door-to-needle times greatly and median door-to-puncture times moderately surpassed national guideline targets. These findings indicate that the greater insights into patient-specific pathophysiology and

Conclusion

AIS-LVO patients can be evaluated by multimodal MR imaging with care speeds faster than national recommendations for door-to-needle and door-to-puncture times. With its greater pathophysiologic insight, MRI remains a highly viable primary imaging strategy in acute ischemic stroke patients, though further workflow efficiency improvements are desirable.

Disclosures:

None reported for all authors.

Conflict of Interest

No conflict of interest for all authors.

References (21)

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  • Impact of Coronavirus Disease 2019 on Time Delay and Functional Outcome of Mechanical Thrombectomy in Tokyo, Japan

    2021, Journal of Stroke and Cerebrovascular Diseases
    Citation Excerpt :

    In addition, medical staff suddenly had to wear unfamiliar personal protective equipment, which could help explain the delay in door (H1) to door (H2) time. The difference in D2P time in the subgroup analysis from October to December 2020, during the peak of the third wave, cannot fully be explained by other predictors (e.g., transfer, iv-rtPA, diagnostic modality for occluded vessels, anesthesia) since these factors did not indicate any imbalances; and although CTA may require less time than MRA, the diagnostic modality for occluded vessels (MRA or CTA) was not found to be a predictor of D2P time in a previous study16; thus, it could be explained by the different protocols and systems in each hospital, information on which was not collected in the present study. However, D2P time was not significantly different for the entire study period, so we may conclude that the COVID-19 pandemic did not affect the initial management in each hospital.

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