Perfusion CT Imaging Follows Clinical Severity in Left Hemispheric Strokes.
ABSTRACT The purpose of this study was to assess how imaging findings on admission perfusion CT (PCT) and follow-up noncontrast CT (NCT), and their changes over time, correlate with clinical scores of stroke severity measured on admission, at discharge and at 6-month follow-up.
Fifty-two patients with suspected hemispheric acute ischemic stroke underwent a PCT within the first 24 h of symptom onset and a follow-up NCT of the brain between 24 h and 3 months after the initial stroke CT study. NIH Stroke Scale (NIHSS) scores were recorded for each patient at admission, discharge and 6 months; modified Rankin scores were determined at discharge and 6 months. Baseline PCT and follow-up NCT were analyzed quantitatively (volume of ischemic/infarcted tissue) and semiquantitatively (anatomical grading score derived from the Alberta Stroke Program Early CT Score). The correlation between imaging volumes/scores and clinical scores was assessed. Analysis was performed for all patients considered together and separately for those with right and left hemispheric strokes.
Significant correlations were found between clinical scores and both quantitative and semiquantitative imaging. The volume of the acute PCT mean transit time lesion showed best correlation with admission NIHSS scores (R2 = 0.61, p < 0.001). This association was significantly better for left hemispheric strokes (R(2) = 0.80, p < 0.001) than for right hemispheric strokes (R2 = 0.39, p = 0.131). Correlation between imaging and NIHSS scores was better than correlation between imaging and modified Rankin scores (p = 0.047). The correlation with discharge clinical scores was better than that with 6-month clinical scores (p = 0.012).
Baseline PCT and follow-up NCT volumes predict stroke severity at baseline, discharge and, to a lesser extent, 6 months. The correlation is stronger for left-sided infarctions. This finding supports the use of PCT as a surrogate stroke outcome measure.
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ABSTRACT: PURPOSE: To identify factors impacting outcome in patients undergoing interventions for acute ischemic stroke (AIS). MATERIALS AND METHODS: This was a retrospective analysis of patients undergoing endovascular therapy for AIS secondary during a 30 month period. Outcome was based on modified Rankin score at 3- to 6-month follow-up. Recanalization was defined as Thrombolysis in myocardial infarction score 2 to 3. Collaterals were graded based on pial circulation from the anterior cerebral artery either from an ipsilateral injection in cases of middle cerebral artery (MCA) occlusion or contralateral injection for internal carotid artery terminus (ICA) occlusion as follows: no collaterals (grade 0), some collaterals with retrograde opacification of the distal MCA territory (grade 1), and good collaterals with filling of the proximal MCA (M2) branches or retrograde opacification up to the occlusion site (grade 2). Occlusion site was divided into group 1 (ICA), group 2 (MCA with or without contiguous M2 involvement), and group 3 (isolated M2 or M3 branch occlusion). RESULTS: A total of 89 patients were studied. Median age and National Institutes of health stroke scale (NIHSS) score was 71 and 15 years, respectively. Favorable outcome was seen in 49.4% of patients and mortality in 25.8% of patients. Younger age (P = 0.006), lower baseline NIHSS score (P = 0.001), successful recanalization (P < 0.0001), collateral support (P = 0.0008), distal occlusion (P = 0.001), and shorter procedure duration (P = 0.01) were associated with a favorable outcome. Factors affecting successful recanalization included younger age (P = 0.01), lower baseline NIHSS score (P = 0.05), collateral support (P = 0.01), and shorter procedure duration (P = 0.03). An ICA terminus occlusion (P < 0.0001), lack of collaterals (P = 0.0003), and unsuccessful recanalization (P = 0.005) were significantly associated with mortality. CONCLUSION: Angiographic findings and preprocedure variables can help prognosticate procedure outcomes in patients undergoing endovascular therapy for AIS.CardioVascular and Interventional Radiology 12/2011; 35(6). DOI:10.1007/s00270-011-0323-7 · 1.97 Impact Factor
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ABSTRACT: OBJECTIVES: Endovascular therapy of acute ischemic stroke is evolving towards thrombectomy devices for vessel recanalization. High rates of revascularization have been reported in stroke device trials. However, the discrepancy between recanalization and outcomes raises the question whether patients with irreversible ischemic injury are being exposed to these interventions. This study evaluated a triage methodology that incorporates perfusion imaging against previous device trials that treated all patients within a certain time frame. METHODS: 99 consecutive patients were identified with anterior circulation strokes who had undergone endovascular therapy. All patients had a baseline NIHSS score ≥8 and had undergone pre-intervention CT perfusion. Rates of recanalization and functional outcomes were compared with the MERCI, Multi-MERCI and Penumbra trials. RESULTS: This study's recanalization rate of 55.6% is not significantly different from the 46% for MERCI (p=0.15) and 68% for Multi-MERCI (p=0.08) but was significantly lower than the 82% for the Penumbra trial (p<0.0001). Successfully recanalized patients had a significantly higher good outcome of 67% in this cohort versus 46% in MERCI, 49% in Multi-MERCI and 29% in Penumbra. The rate of futile recanalization was 33% compared with 54% for MERCI, 51% for Multi-MERCI and 71% for Penumbra. A small cerebral blood volume (CBV) abnormality (p<0.0001) and large mean transit time-CBV mismatch (p<0.0001) were strong predictors of a good outcome. CONCLUSION: Despite similar or lower recanalization rates, there was a significantly higher rate of good outcomes in the recanalized population and thus a significantly lower rate of futile recanalization in this study versus the device trials, suggesting a role for pre-intervention perfusion imaging for patient selection.Journal of Neurointerventional Surgery 02/2012; 5(2). DOI:10.1136/neurintsurg-2011-010189 · 2.77 Impact Factor
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ABSTRACT: BACKGROUND: Pre-intervention perfusion imaging is increasingly becoming part of stroke triage. Small studies supporting imaging based patient selection have been published. The goal of this larger study was to determine if perfusion imaging could impact on functional outcomes in patients undergoing stroke interventions. METHODS: All patients who had undergone endovascular therapy for anterior circulation strokes over a 7 year period were retrospectively analyzed. The pre-intervention perfusion imaging was assessed for size of cerebral blood volume (CBV), cerebral blood flow and mean transit time (MTT) abnormalities. A perfusion mismatch for irreversible versus reversible ischemia was based on CBV and MTT. Clinical outcome and mortality were based on the 90 day modified Rankin Scale. An analysis of the pre-intervention perfusion parameters was then performed to determine any impact on functional outcomes. RESULTS: 110 patients underwent endovascular therapy for anterior circulation strokes. A younger age and lower National Institutes of Health Stroke Scale score were important clinical predictors of favorable outcome (modified Rankin Scale ≤2). The extent of the CBV abnormality and percentage of CBV/MTT mismatch were the strongest imaging predictors of outcome and mortality. A CBV area of 229.5 mm(2) (±290) was seen for favorable outcomes versus 968 mm(2) (±1173) for poor outcomes (p<0.0001). A CBV/MTT mismatch of 91% (±10.7) was seen for favorable outcomes versus 72.5% (±31.6) for poor outcomes (p=0.0001). The CBV area was 273 mm(2) (±392) in patients without mortality versus 1401.1 mm(2) (±1310) in patients with mortality (p<0.0001). Patients who survived had a mean CBV/MTT mismatch of 90.2% (±12.5) versus 61.1% (±35.2) for those who did not (p<0.0001). A CBV lesion approximately greater than one-third of the middle cerebral artery distribution predicted a poor outcome and mortality. CONCLUSION: The extent of pre-intervention CBV abnormality is a strong predictor of functional outcomes following endovascular stroke therapy. This information can aid in patient selection and improve procedure efficacy.Journal of Neurointerventional Surgery 03/2012; 5. DOI:10.1136/neurintsurg-2012-010293 · 2.77 Impact Factor