Quantitative Measurements of Relative Fluid-Attenuated Inversion Recovery (FLAIR) Signal Intensities in Acute Stroke for the Prediction of Time from Symptom Onset

In acute stroke magnetic resonance imaging, a ‘mismatch’ between visibility of an ischemic lesion on diffusion-weighted imaging (DWI) and missing corresponding parenchymal hyperintensities on fluid-attenuated inversion recovery (FLAIR) data sets was shown to identify patients with time from symptom onset ≤4.5 hours with high specificity. However, moderate sensitivity and suboptimal interpreter agreement are limitations of a visual rating of FLAIR lesion visibility. We tested refined image analysis methods in patients included in the previously published PREFLAIR study using refined visual analysis and quantitative measurements of relative FLAIR signal intensity (rSI) from a three-dimensional, segmented stroke lesion volume. A total of 399 patients were included. The rSI of FLAIR lesions showed a moderate correlation with time from symptom onset ( r = 0.382, P < 0.001). A FLAIR rSI threshold of <1.0721 predicted symptom onset ≤4.5 hours with slightly increased specificity (0.85 versus 0.78) but also slightly decreased sensitivity (0.47 versus 0.58) as compared with visual analysis. Refined visual analysis differentiating between ‘subtle’ and ‘obvious’ FLAIR hyperintensities and classification and regression tree algorithms combining information from visual and quantitative analysis also did not improve diagnostic accuracy. Our results raise doubts whether the prediction of stroke onset time by visual image judgment can be improved by quantitative rSI measurements.

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Negative Fluid-Attenuated Inversion Recovery- Based Intravenous Thrombolysis Using Recombinant Tissue Plasminogen Activator in Acute Stroke Patients with Unknown Onset Time

Cerebrovascular Diseases Extra ◽

10.1159/000348552 ◽

2013 ◽

Vol 3 (1) ◽

pp. 35-45 ◽

Cited By ~ 11

Author(s):

Junya Aoki ◽

Kazumi Kimura ◽

Kensaku Shibazaki ◽

Yuki Sakamoto

Keyword(s):

Acute Stroke ◽

Plasminogen Activator ◽

Tissue Plasminogen Activator ◽

Onset Time ◽

Intravenous Thrombolysis ◽

Recombinant Tissue Plasminogen Activator ◽

Inversion Recovery ◽

Stroke Patients ◽

Tissue Plasminogen ◽

Fluid Attenuated Inversion Recovery

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Intravenous Thrombolysis Based on Diffusion-Weighted Imaging and Fluid-Attenuated Inversion Recovery Mismatch in Acute Stroke Patients with Unknown Onset Time

Cerebrovascular Diseases ◽

10.1159/000323850 ◽

2011 ◽

Vol 31 (5) ◽

pp. 435-441 ◽

Cited By ~ 50

Author(s):

Junya Aoki ◽

Kazumi Kimura ◽

Yasuyuki Iguchi ◽

Kensaku Shibazaki ◽

Takeshi Iwanaga ◽

...

Keyword(s):

Acute Stroke ◽

Diffusion Weighted Imaging ◽

Onset Time ◽

Intravenous Thrombolysis ◽

Inversion Recovery ◽

Stroke Patients ◽

Diffusion Weighted ◽

Fluid Attenuated Inversion Recovery

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Comparison of stroke volume evolution on diffusion-weighted imaging and fluid-attenuated inversion recovery following endovascular thrombectomy

International Journal of Stroke ◽

10.1177/1747493016677985 ◽

2016 ◽

Vol 12 (5) ◽

pp. 510-518 ◽

Cited By ~ 5

Author(s):

Christian Federau ◽

Soren Christensen ◽

Michael Mlynash ◽

Jenny Tsai ◽

Sun Kim ◽

...

Keyword(s):

Symptom Onset ◽

Diffusion Weighted Imaging ◽

Infarct Volume ◽

Inversion Recovery ◽

Lesion Volume ◽

Endovascular Thrombectomy ◽

Post Procedure ◽

Diffusion Weighted ◽

Fluid Attenuated Inversion Recovery ◽

H 26

Background To compare the evolution of the infarct lesion volume on both diffusion-weighted imaging and fluid-attenuated inversion recovery in the first five days after endovascular thrombectomy. Methods We included 109 patients from the CRISP and DEFUSE 2 studies. Stroke lesion volumes obtained on diffusion-weighted imaging and fluid-attenuated inversion recovery images both early post-procedure (median 18 h after symptom onset) and day 5, were compared using median, interquartile range, and correlation plots. Patients were dichotomized based on the time after symptom onset of their post procedure images (≥18 h vs. <18 h), and the degree of reperfusion (on Tmax>6 s; ≥ 90% vs. < 90%). Results Early post-procedure, median infarct lesion volume was 19 ml [(IQR) 7–43] on fluid-attenuated inversion recovery, and 23 ml [11–64] on diffusion-weighted imaging. On day 5, median infarct lesion volume was 52 ml [20–118] on fluid-attenuated inversion recovery, and 37 ml [16–91] on diffusion-weighted imaging. Infarct lesion volume on early post-procedure diffusion-weighted imaging, compared to fluid-attenuated inversion recovery, correlated better with day 5 diffusion-weighted imaging and fluid-attenuated inversion recovery lesions (r = 0.88 and 0.88 vs. 0.78 and 0.77; p < 0.0001). Median lesion growth was significantly smaller on diffusion-weighted imaging when the early post-procedure scan was obtained ≥18 h post stroke onset (5 ml [−1–13]), compared to <18 h (13 ml [2–47]; p = 0.03), but was not significantly different on fluid-attenuated inversion recovery (≥18 h: 26 ml [12–57]; <18 h: 21 ml [5–57]; p = 0.65). In the <90% reperfused group, the median infarct growth was significantly larger for diffusion-weighted imaging and fluid-attenuated inversion recovery (diffusion-weighted imaging: 23 ml [8–57], fluid-attenuated inversion recovery: 41 ml [13–104]) compared to ≥90% (diffusion-weighted imaging: 6 ml [2–24]; p = 0.003, fluid-attenuated inversion recovery: 19 ml [8–46]; p = 0.001). Conclusions Early post-procedure lesion volume on diffusion-weighted imaging is a better estimate of day 5 infarct volume than fluid-attenuated inversion recovery. However, both early post-procedure diffusion-weighted imaging and fluid-attenuated inversion recovery underestimate day 5 diffusion-weighted imaging and fluid-attenuated inversion recovery lesion volumes, especially in patients who do not reperfuse.

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Intra- and Interrater Reliability of Ischemic Lesion Volume Measurements on Diffusion-Weighted, Mean Transit Time and Fluid-Attenuated Inversion Recovery MRI

Stroke ◽

10.1161/01.str.0000249416.77132.1a ◽

2006 ◽

Vol 37 (12) ◽

pp. 2951-2956 ◽

Cited By ~ 62

Author(s):

Marie Luby ◽

Julie L. Bykowski ◽

Peter D. Schellinger ◽

José G. Merino ◽

Steven Warach

Keyword(s):

Transit Time ◽

Interrater Reliability ◽

Mean Transit Time ◽

Inversion Recovery ◽

Lesion Volume ◽

Weighted Mean ◽

Ischemic Lesion ◽

Diffusion Weighted ◽

Fluid Attenuated Inversion Recovery ◽

Volume Measurements

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Improving acute stroke assessment in non-enhanced CT: Automated tool for early ischemic lesion volume detection

Journal of the Neurological Sciences ◽

10.1016/j.jns.2021.119611 ◽

2021 ◽

Vol 429 ◽

pp. 119611

Author(s):

Giovanni Furlanis ◽

Mara Bernardi ◽

Alex Rodriguez ◽

Paola Caruso ◽

Marcello Naccarato ◽

...

Keyword(s):

Acute Stroke ◽

Lesion Volume ◽

Ischemic Lesion ◽

Enhanced Ct ◽

Automated Tool ◽

Stroke Assessment

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Clinical and Radiological Correlates of Reduced CBF Measured Using MRI

Stroke ◽

10.1161/str.32.suppl_1.317-a ◽

2001 ◽

Vol 32 (suppl_1) ◽

pp. 317-318

Author(s):

Vincent N Thijs ◽

Tobias Neumann-Haefelin ◽

Michael E Moseley ◽

Michael P Marks ◽

Gregory W Albers

Keyword(s):

Symptom Onset ◽

Cerebral Blood Volume ◽

Arterial Input Function ◽

Mean Transit Time ◽

Input Function ◽

Lesion Volume ◽

Time Curve ◽

Measured Concentration ◽

Ischemic Lesion ◽

Adc Values

11 Background and purpose Methods for determining CBF using IV bolus tracking MRI have recently become available. Reduced apparent diffusion coefficient (ADC) values of brain tissue are associated with reductions in regional cerebral blood flow (rCBF). We studied the clinical and radiological features of patients with severe reductions of rCBF on MRI and analysed the relationship between reduced rCBF and ADC. Methods We studied patients with non-lacunar acute ischemic stroke in whom PWI and DWI MRI were performed within 7 hours after symptom onset. A PWI>DWI mismatch of >20% was required. Maps of rCBF, cerebral blood volume (rCBV) and mean transit time (rMTT) were generated after deconvoluting the measured concentration-time curve with the arterial input function using singular value decomposition. The ischemic lesion was outlined on the MTT map and the region of interest (ROI) transferred to the rCBF and rCBV map. ADC-maps were calculated. ADC lesions were defined as regions with ADC values ≤ 550 μm m2/sec. We compared the characteristics of patients with ischemic lesions that had a relative CBF of <50% to the contralateral hemisphere to patients with lesions that had relative CBF of >50%. Characteristics analysed included age, time to MRI, baseline NIHSS, mean ADC, DWI lesion volume, PWI lesion volume and absolute mismatch volume. Results Fifteen patients with an initial PWI>DWI mismatch of >20% were included. Ten had lesions with rCBF of >50% (median 60%) and five patients had rCBF of <50% (median 27.7%). Patients with rCBF <50% had lower ADC values (median 431 μmm2/sec versus 506 μ mm2/sec, p=0.028), larger DWI volumes (median 75.6 cm 3 versus 8.6 cm 3 , p=0.001) and larger PWI lesions as defined by the MTT volume (median 193 cm 3 versus 69 cm 3 , p=0.028) and more severe baseline NIHSS scores (median 18 versus 9, p=0.019). The rMTT and rCBV of the lesions were similar in both groups, as were the age, the absolute mismatch volume and the time from symptom onset to MRI. Conclusion These data indicate that ischemic lesions with severe CBF reductions, measured with new MRI techniques, are associated with a lower mean ADC, larger DWI and PWI lesion volumes and a higher NIHSS score.

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Abstract P153: SARS-CoV-2 (COVID-19) Protection Efforts on Acute Stroke Treatment

Stroke ◽

10.1161/str.52.suppl_1.p153 ◽

2021 ◽

Vol 52 (Suppl_1) ◽

Author(s):

Jessica Greenwood ◽

Starlie Belnap ◽

Rodney Bedgio ◽

Guilherme Dabus ◽

Italo Linfante ◽

...

Keyword(s):

Stroke Volume ◽

Endovascular Treatment ◽

Acute Stroke ◽

Symptom Onset ◽

Onset Time ◽

Fold Increase ◽

Medical Attention ◽

Hospital Treatment ◽

Significant Delay ◽

The Impact

Introduction: It is unclear how the interventions designed to restrict community and in-hospital exposure to the SARS-CoV-2 virus affected the care for stroke patients seeking acute treatment. The objective of the following study was to determine the impact COVID-19 has had on the treatment times for patients evaluated as acute stroke alerts at Baptist Hospital of Miami (BHM). A co-primary objective of the study was to assess the risk of contracting SARS-CoV-2 within 2 weeks from hospital discharge. Methods: This retrospective, two phase study was conducted between December 2019 and April 2020. In phase one, we assessed time from symptom onset to hospital arrival, number of strokes with witnessed onset, and in-hospital treatment times pre & post implementation of Covid-19 preventive exposure measures. In phase two of the study, a telephone survey was conducted on the post implementation group to assess the risk of patients developing symptoms or testing positive for SARS-CoV-2 from hospital admission up to two weeks post discharge. Results: Phase I demonstrated there was a 40% decline in stroke volume, but no significant delay to seek medical attention post implementation of the SARS prevention strategies. On average individuals in the pre-group (n=155) waited approximately 260 minutes (SE=24) to seek medical attention vs. 203 minutes (SE=27) minutes for the post-group (n=87). However, there was nearly a six-fold increase in the percentage of cases with unknown symptom onset post implementation of COVID-19 safety precautions. There was significant delay in administering IV alteplase, increasing from 24 mins (n=16) to 33 mins (n=21) post implementation; delays observed for endovascular treatment were not significant (pre, n=13 mean= 73 mins, post n=12 mean= 82 mins). The volume of patients treated with either IV alteplase and/or endovascular treatment remained similar. Phase II of the study is on-going, results will be available for the ISC. Discussion: The COVID-19 crisis in our community was associated with a six-fold increase in the percentage of cases with unknown stroke onset time. Besides a marked decrease in stroke volume, we did not evidence significant delays to either seek or provide acute stroke care outside a modest increase in door to needle time.

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