Baseline Diffusion-weighted Imaging Lesion Volume Research Articles

Collateral estimation by susceptibility-weighted imaging and prediction of functional outcomes after acute anterior circulation ischemic stroke

To determine the value of susceptibility-weighted imaging (SWI) for collateral estimation and for predicting functional outcomes after acute ischemic stroke. To identify independent predictors of favorable functional outcomes, age, sex, risk factors, baseline National Institutes of Health Stroke Scale (NIHSS) score, baseline diffusion-weighted imaging (DWI) lesion volume, site of steno-occlusion, SWI collateral grade, mode of treatment, and successful reperfusion were evaluated by multiple logistic regression analyses. A total of 152 participants were evaluated. A younger age (adjusted odds ratio (aOR), 0.42; 95% confidence interval (CI) 0.34 to 0.77; P < 0.001), a lower baseline NIHSS score (aOR 0.90; 95% CI 0.82 to 0.98; P = 0.02), a smaller baseline DWI lesion volume (aOR 0.83; 95% CI 0.73 to 0.96; P = 0.01), an intermediate collateral grade (aOR 9.49; 95% CI 1.36 to 66.38; P = 0.02), a good collateral grade (aOR 6.22; 95% CI 1.16 to 33.24; P = 0.03), and successful reperfusion (aOR 5.84; 95% CI 2.08 to 16.42; P = 0.001) were independently associated with a favorable functional outcome. There was a linear association between the SWI collateral grades and functional outcome (P = 0.008). Collateral estimation using the prominent vessel sign on SWI is clinically reliable, as it has prognostic value.

Early successful reperfusion after endovascular therapy reduces malignant middle cerebral artery infarction occurrence in young patients with large diffusion-weighted imaging lesions.

Malignant middle cerebral artery infarction (MMI) is a severe complication of acute ischaemic stroke (AIS). The aim of our study was to assess whether successful reperfusion after endovascular therapy (EVT) in AIS with clinical and imaging predictors of MMI decreased its occurrence. Data were collected between January 2014 and July 2018 in a monocentric prospective AIS registry of patients treated with EVT. Patients selected were <65years old with severe anterior circulation AIS with a National Institutes of Health Stroke Scale score >15, baseline Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Score≤6 and baseline diffusion-weighted imaging lesion volume >82mL within 6h of symptom onset. Successful reperfusion was defined as a Thrombolysis in Cerebral Ischemia score≥2b. Occurrence of MMI was the primary endpoint. A total of 66 EVT-treated patients were included in our study. MMI occurred in 27 patients (41%). In unadjusted analysis, successful reperfusion was associated with fewer MMIs (31.8% vs. 65.0%; P=0.015) and with more favorable outcome at 3months (50% vs. 20%; P=0.023). In multivariate analysis, successful reperfusion was associated with an adjusted odds ratio (95% confidence intervals) of 0.35 (0.10-1.12) for MMI and 2.77 (0.84-10.43) for 3-month favorable outcome occurrence. Early successful reperfusion performed in patients with AIS with clinical and imaging predictors of MMI was associated with decreased MMI occurrence. Reperfusion status might be considered in evaluating the need for craniectomy in patients with early predictors of MMI.

Dynamic Evolution of Diffusion-Weighted Imaging Lesions in Patients With Minor Ischemic Stroke.

Diffusion-weighted imaging (DWI) lesion volume on magnetic resonance imaging is increasingly being used as a surrogate outcome measure in clinical trials. We aimed to characterize the evolution of DWI lesion volumes within 30 days of symptom onset after minor stroke. Minor stroke patients with DWI lesions on magnetic resonance imaging within 48 hours of symptom onset were prospectively followed with magnetic resonance imaging brain scan at 7 and 30 days. Change in the lesion volume was defined as the difference between day 30 Fluid-Attenuated Inversion Recovery and baseline DWI lesion volumes. Three patterns of infarct evolution were observed: reduction (72 [63%]), no change (26 [23%]), and growth (16 [14%]). Patients with infarct reduction at 30 days had larger baseline DWI lesion volumes (2.5 [0.9-8.5] mL) than those with stable infarcts (0.5 [0.3-0.9] mL; P=0.01). Complete DWI reversal at day 30, was seen in only 6 (5.3%) patients. The most common pattern of infarct evolution in patients with minor stroke is a reduction in volume, but complete resolution is uncommon.

Pilot Study of Intravenous Glyburide in Patients With a Large Ischemic Stroke

Preclinical and retrospective clinical data indicate that glyburide, a selective inhibitor of sulfonylurea receptor 1-transient receptor potential melastatin 4, is effective in preventing edema and improving outcome after focal ischemia. We assessed the feasibility of recruiting and treating patients with severe stroke while obtaining preliminary information on the safety and tolerability of RP-1127 (glyburide for injection). We studied 10 patients with acute ischemic stroke, with baseline diffusion-weighted imaging lesion volumes of 82 to 210 cm3, whether treated with intravenous recombinant tissue-type plasminogen activator, age 18 to 80 years, and time to RP-1127≤10 hours. Recruitment was completed within 10 months. The mean age was 50.5 years, and baseline diffusion-weighted image lesion volume was 102±23 cm3. There were no serious adverse events related to drug and no symptomatic hypoglycemia. The increase in ipsilateral hemisphere volume was 50±33 cm3. The proportion of 90-day modified Rankin Scale≤4 was 90% (40% modified Rankin Scale, ≤3). RP-1127 at a dose of 3 mg/d was well tolerated and did not require any dose reductions. A clinical trial of RP-1127 is feasible. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01268683.

Acute Perfusion and Diffusion Abnormalities Predict Early New MRI Lesions 1 Week After Minor Stroke and Transient Ischemic Attack

Transient ischemic attack and minor stroke are associated with high ischemic recurrence in the first week. We prospectively studied the correlation between baseline diffusion/perfusion deficits and development of new ischemic lesions. Patients with transient ischemic attack and those with minor stroke (n=50) underwent MRI at admission. Acute perfusion-weighted imaging deficit (Tmax+2-second delay) and diffusion-weighted imaging (DWI) lesion volumes were measured planimetrically. Follow-up scans were examined for new DWI/fluid-attenuated inversion recovery lesions at Days 7 and 30. Twenty-eight patients (56%) had acute DWI lesions. New DWI lesions developed in 9 of 50 patients (18%) at 1 week and 11 of 50 (cumulative 22%) at 4 weeks. Patients with new infarcts were more likely to have baseline DWI lesions (χ²=8.264, P=0.003). Baseline DWI lesion volume was significantly larger in those who developed new lesions at Day 7 (median, 13.2 mL; interquartile range, 12 versus median 0.1 mL; interquartile range, 2 mL; P<0.001) and Day 30 (11.1 mL; interquartile range, 13 mL versus 0.1 mL; interquartile range, 13 mL; P<0.001). Thirty-eight patients had baseline perfusion-weighted imaging. Patients with recurrent lesions were more likely to have baseline perfusion deficits (χ²=19.5, P<0.0001). All new lesions developed within the baseline hypoperfused regions. Baseline DWI lesion volume predicted new lesion development at day 7 (OR, 1.17 per mL; CI, 1.05 to 1.30; P=0.005) and Day 30 (OR, 1.39 per mL; CI, 1.03 to 1.26; P=0.009) by regression analysis. Early recurrence of stroke is much more likely in patients with larger baseline DWI and perfusion-weighted imaging lesions. MRI lesion "recurrence" appears to be related to completion of the natural history of the original cerebrovascular syndrome rather than de novo events in most patients.

Evidence-based guideline: The role of diffusion and perfusion MRI for the diagnosis of acute ischemic stroke: Report of the Therapeutics and Technology Subcommittee of the American Academy of Neurology

Objective: To assess the evidence for the use of diffusion-weighted imaging (DWI) and perfusionweighted imaging (PWI) in the diagnosis of patients with acute ischemic stroke. Methods: We systematically analyzed the literature from 1966 to January 2008 to address the diagnostic and prognostic value of DWI and PWI. Results and Recommendations: DWI is established as useful and should be considered more useful than noncontrast CT for the diagnosis of acute ischemic stroke within 12 hours of symptom onset. DWI should be performed for the most accurate diagnosis of acute ischemic stroke (Level A); however, the sensitivity of DWI for the diagnosis of ischemic stroke in a general sample of patients with possible acute stroke is not perfect. The diagnostic accuracy of DWI in evaluating cerebral hemorrhage is outside the scope of this guideline. On the basis of Class II and III evidence, baseline DWI volumes probably predict baseline stroke severity in anterior territory stroke (Level B) but possibly do not in vertebrobasilar artery territory stroke (Level C). Baseline DWI lesion volumes probably predict (final) infarct volumes (Level B) and possibly predict early and late clinical outcome measures (Level C). Baseline PWI volumes predict to a lesser degree the baseline stroke severity compared with DWI (Level C). There is insufficient evidence to support or refute the value of PWI in diagnosing acute ischemic stroke (Level U). Neurology ® 2010;75:177–185

Stromal-Derived Factor-1α Correlates With Circulating Endothelial Progenitor Cells and With Acute Lesion Volume in Stroke Patients

Endothelial progenitor cells (EPC) are important participants of neovascularization and are mobilized through signaling with stromal-derived factor (SDF-1α), vascular endothelial growth factor (VEGF), granulocyte colony-stimulating factor, and stem cell factor. The association between EPC levels and these growth factors (GF) in acute stroke has not been previously established. We aimed to determine the association between EPC and these GF, and to elucidate a relationship between these GF and stroke severity in acute stroke patients. Seventeen patients were selected from 175 patients with imaging-confirmed acute ischemic stroke. EPC were quantified using CD34, CD133, and VEGF-R2 markers. Plasma VEGF, SDF-1α, granulocyte colony-stimulating factor, and stem cell factor were determined by enzyme-linked immunosorbent assay on days 1 and 3, and brain MRI was performed at baseline and on days 1 and 5 after the stroke onset. Levels of SDF-1α strongly (r=0.6) correlated with the numbers of EPC subsets CD133(+)VEFG-R2(+) (P<0.004), CD34(+)VEGF-R2(+) (P<0.01), and CD34(+)CD133(+)VEGF-R2(+) (P<0.01) on day 1. Stem cell factor strongly (r=0.5) correlated with CD133(+)VEGF-R2(+) (P<0.05). SDF-1α moderately inversely (r=-0.49) correlated with baseline diffusion-weighted imaging lesion volumes (P<0.04). Median levels of SDF-1α (1561 pg/mL) increased (P<0.04) on day 3 compared to day 1 (1379 pg/mL). Similarly, VEGF at day 3 (95 pg/mL) increased (P<0.03) compared to day 1 (64 pg/mL). These results indicate that SDF-1α and stem cell factor correlate with an increase in EPC early in ischemic stroke patients.

Evidence-based guideline: The role of diffusion and perfusion MRI for the diagnosis of acute ischemic stroke [RETIRED

To assess the evidence for the use of diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) in the diagnosis of patients with acute ischemic stroke. We systematically analyzed the literature from 1966 to January 2008 to address the diagnostic and prognostic value of DWI and PWI. DWI is established as useful and should be considered more useful than noncontrast CT for the diagnosis of acute ischemic stroke within 12 hours of symptom onset. DWI should be performed for the most accurate diagnosis of acute ischemic stroke (Level A); however, the sensitivity of DWI for the diagnosis of ischemic stroke in a general sample of patients with possible acute stroke is not perfect. The diagnostic accuracy of DWI in evaluating cerebral hemorrhage is outside the scope of this guideline. On the basis of Class II and III evidence, baseline DWI volumes probably predict baseline stroke severity in anterior territory stroke (Level B) but possibly do not in vertebrobasilar artery territory stroke (Level C). Baseline DWI lesion volumes probably predict (final) infarct volumes (Level B) and possibly predict early and late clinical outcome measures (Level C). Baseline PWI volumes predict to a lesser degree the baseline stroke severity compared with DWI (Level C). There is insufficient evidence to support or refute the value of PWI in diagnosing acute ischemic stroke (Level U).

Relative Energy Index of Microembolic Signal Can Predict Malignant Microemboli

Microembolic signals (MES) found on transcranial Doppler range from harmless air bubbles to large, solid, particulate emboli from the heart and large vessels. The presence of MES is not always associated with poor clinical outcome. The purpose of our study was to determine whether the relative energy index of MES measured by power M-mode Doppler can distinguish malignant from benign MES and to identify patients with worse prognosis. We prospectively collected transcranial Doppler emboli monitoring data from patients with symptomatic carotid stenosis presenting with TIA or ischemic stroke. For each patient, we calculated the relative energy index of MES and categorized those >1.0 as malignant MES. We compared the clinical characteristics, number, and volume of diffusion-weighted imaging lesions, and degree of stenosis and plaque characteristics on CT angiogram of patients with malignant and benign MES. We enrolled 92 patients, 29 with TIA and 63 with stroke, within 48 hours of symptom onset. Twenty-six patients had a total of 319 MES; of these, 82.4% were benign and were 17.6% malignant. Malignant MES traveled further within intracranial vessels than benign MES. The 9 patients with >1 malignant MES had significantly larger baseline diffusion-weighted imaging lesion volume, had a higher prevalence of intraluminal thrombus on CT angiogram of the neck and plaque ulceration, and were more likely to have a poor clinical outcome (modified Rankin Score > or = 2) than those with benign MES (OR, 6.5; 95% CI, 1.47-28.68). The presence of malignant MES led to the institution of more aggressive secondary prevention measures. Power M-mode transcranial Doppler identifies a subgroup of patients with malignant MES. These signals are more frequent in longer arterial trajectory. Patients with malignant MES have larger baseline infarcts, a higher prevalence of intraluminal thrombus or ulcerated plaque in the carotid artery, and worse clinical outcome.

Reliability of Measuring Lesion Volumes in Transient Ischemic Attack and Minor Stroke

Lesion volume measurements in disabling ischemic stroke have excellent reliability, but it is not clear whether this is also true for small lesions. We assessed the reliability of measuring baseline and follow-up lesion volumes in transient ischemic attack and minor stroke. Patients who presented with a transient ischemic attack or minor stroke (NIHSS < or = 3) who had brain MRI within 24 hours from symptom onset and at 30-day follow-up and had an acute lesion on baseline MRI were included. Using semiautomated software, 4 stroke fellows independently assessed ischemic lesions twice on acute diffusion-weighted imaging and follow-up fluid-attenuated inversion recovery. Eighty patients were included, with a median baseline NIHSS of 1. Mean baseline diffusion-weighted imaging lesion volume was 3.4+/-7.4 mL (87.5% had <5 mL). There was excellent inter-rater/intrarater reliability, with intraclass correlation coefficients of 0.94/0.96 for acute diffusion-weighted imaging, 0.74/0.92 for follow-up fluid-attenuated inversion recovery, and 0.81/0.93 for growth. We found excellent concordance between and within raters for acute diffusion-weighted imaging and 30-day follow-up fluid-attenuated inversion recovery lesion volume measurements in patients with transient ischemic attack and minor stroke.