Utilizing CT with Maximum Intensity Projection Reconstruction Bypassing CTA Improves Time to Groin Puncture in Large Vessel Occlusion Stroke Thrombectomy

Abstract

Background and Purpose: Prior to thrombectomy for proximal anterior circulation large vessel occlusion (LVO) stroke, recent trials have utilized CT angiography (CTA) for vascular imaging immediately following noncontrast CT (NCCT) for decision-making, but thin-section NCCT with automated maximum intensity projection (MIP) reconstruction also has high accuracy in demonstrating the site of an occluding thrombus. We hypothesized that performing thin-section NCCT with MIP alone prior to thrombectomy improves the time to groin puncture (GP) compared to performing CTA after NCCT. Materials and Methods: We performed a retrospective cohort study of anterior circulation LVO thrombectomy at our tertiary care academic medical center. All stroke patients evaluated with thin-section NCCT (0.625 mm) with automated MIP reconstructions alone and those who had additional CTA were included. We excluded transfer patients, in-hospital strokes, posterior circulation strokes, and patients that were evaluated with stroke imaging other than NCCT or CTA prior to thrombectomy. The study groups were compared for duration from NCCT to GP and total stroke imaging duration. Results: From March 2008 through August 2015, 34 thrombectomy patients met the inclusion/exclusion criteria - 13 in the NCCT and 20 in the NCCT+CTA group. The total stroke imaging duration was shorter in the NCCT group than in the NCCT+CTA group (2 min [1-6] vs. 28 min [23-65]; p < 0.001). The NCCT-only group had a shorter time from NCCT to GP (68 min [32-99] vs. 104 min [79-128]; p = 0.030). Conclusion: Avoiding advanced imaging for patients with anterior circulation LVO in whom thin-section NCCT with MIPs reveals a hyperdense sign significantly shortens the imaging-to-GP time.

Thin Slices and Maximum Intensity Projection Reconstructions Increase Sensitivity to Hyperdense Middle Cerebral Artery Sign in Acute Ischemic Stroke

“…Findings in the present study were consistent with the literature. The previously reported high sensitivity of MIP to HAS [3, 7, 8] was confirmed. As an innovative aspect of this study, HAS on MIP was explicitly not assessed by stroke specialists but observers on a lower experience level on NECT.…”

Imaging as a Selection Tool for Thrombectomy in Acute Ischemic Stroke

“…Studies examining workflow efficiency in intrahospital systems of care have shown that when only a plain CT is utilized in lieu of the standard CTA for the purposes of LVO diagnosis, the time required for imaging decreases by an average of 28 minutes, and the time elapsed from hospital presentation to access site puncture time decreases by 36 minutes. 53 Thus, in situations where there is an a priori high likelihood of LVO, forgoing the CTA after head CT in favor of transport directly to the angiography suite may save substantial time to brain reperfusion. An NIHSS cutoff of 10 or above has been shown to predict the presence of LVO with 80% accuracy in the early time window.…”

A randomized pragmatic care trial on endovascular acute stroke interventions (EASI): criticisms, responses, and ethics of integrating research and clinical care

“…As CTA was mandated in the guidelines for thrombectomy [ 31 , 32 ], transfers are commonly delayed by an hour or more to fulfill this criterion, a constraint that is not in the interest of patients. Even at high-volume thrombectomy centers, addition of CTA delays time to groin puncture when compared with selection by hyperdense vessels on CT [ 33 ]. Worse, some trials have imposed delays on patients that would eventually not be included in the trial: the ESCAPE protocol, for example, required that “Stroke patients who have received i.v.…”