scholarly journals Spatial Distribution of Perfusion Abnormality in Acute MCA Occlusion is Associated with Likelihood of Later Recanalization

2014 ◽  
Vol 34 (5) ◽  
pp. 813-819 ◽  
Author(s):  
Susanne Siemonsen ◽  
Nils Daniel Forkert ◽  
Anne Hansen ◽  
Andre Kemmling ◽  
Götz Thomalla ◽  
...  
Keyword(s):  
Acute Stroke ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Three Dimensional ◽  
Area Under The Curve ◽  
Fibrinolytic Therapy ◽  
Data Sets ◽  
Infarct Core ◽  
Compensatory Mechanisms ◽  
Time To Peak

The aim of this study is to investigate whether different spatial perfusion-deficit patterns, which indicate differing compensatory mechanisms, can be recognized and used to predict recanalization success of intravenous fibrinolytic therapy in acute stroke patients. Twenty-seven acute stroke data sets acquired within 6 hours from symptom onset including diffusion- (DWI) and perfusion-weighted magnetic resonance (MR) imaging (PWI) were analyzed and dichotomized regarding recanalization outcome using time-of-flight follow-up data sets. The DWI data sets were used for calculation of apparent diffusion coefficient (ADC) maps and subsequent infarct core segmentation. A patient-individual three-dimensional (3D) shell model was generated based on the segmentation and used for spatial analysis of the ADC as well as cerebral blood volume (CBV), cerebral blood flow, time to peak (TTP), and mean transit time (MTT) parameters derived from PWI. Skewness, kurtosis, area under the curve, and slope were calculated for each parameter curve and used for classification (recanalized/nonrecanalized) using a LogitBoost Alternating Decision Tree (LAD Tree). The LAD tree optimization revealed that only ADC skewness, CBV kurtosis, and MTT kurtosis are required for best possible prediction of recanalization success with a precision of 85%. Our results suggest that the propensity for macrovascular recanalization after intravenous fibrinolytic therapy depends not only on clot properties but also on distal microvascular bed perfusion. The 3D approach for characterization of perfusion parameters seems promising for further research.

scholarly journals Clinically Meaningful MRI Perfusion Abnormalities in Acute Stroke: Comparison of Analytic Techniques

Stroke ◽  
2001 ◽  
Vol 32 (suppl_1) ◽  
pp. 339-339
Author(s):  
Chen-Sen Wu ◽  
Lawrence L Latour ◽  
Steven Warach
Keyword(s):  
At Risk ◽  
Acute Stroke ◽  
Moment Method ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Clinical Severity ◽  
Perfusion Parameter ◽  
Time Curve ◽  
Time To Peak ◽  
First Moment

P2 Background: MRI perfusion imaging (PWI) can demonstrate hemodynamic abnormalities in acute stroke. The volume of hypoperfusion derived from calculated perfusion parameter maps has been used to predict tissue at risk for infarction and to identify presumptive ischemic penumbra. It is unclear how best to distinguish true tissue at risk from benign hypoperfusion. A first step toward this goal is identifying clinically significant PWI abnormalities in stroke patients. Our purpose was to evaluate four different perfusion parameter maps to determine which algorithm best correlates with clinical severity. Methods: Twenty patients were retrospectively selected from our database. Selection criteria included 1) acute hemispheric lesion, 2) MRI within 24 hours of symptom onset, and 3) no history of prior stroke. Perfusion maps were derived using four different algorithms to estimate relative mean transit time (rMTT): 1) cerebral blood volume (CBV) / cerebral blood flow (CBF), 2) CBV / peak of the concentration-time curve, 3) time to peak (TTP), and 4) ratio of the 1 st / 0 th moment of the transfer function (first moment method). Abnormal perfusion volumes were derived from ever-increasing thresholds of rMTT delay relative to normal contralateral tissue. The volumes at each delay threshold were correlated with National Institutes of Health Stroke Scale (NIHSS) for each algorithm. Results: Significant correlations between hypoperfusion volumes and NIHSS were found for all algorithms. The first moment method had the highest correlation (r = 0.76) and the correlations for this method were independent of the delay threshold used to derive the volumes. For the other algorithms, the best correlations were observed for volumes including only voxels with delays of 4 seconds or greater. Conclusions: This analysis suggests that the first moment method may have advantages over the others in determining the correlation of hypoperfusion volume to NIHSS. Further analyses correlating acute hypoperfusion volumes to final infarct volumes may help refine the choice of best analytic method for determining clinically relevant PWI abnormalities.

Is Perfusion MRI without Deconvolution Reliable for Mismatch Detection in Acute Stroke? Validation with 15O-Positron Emission Tomography

2018 ◽  
Vol 46 (1-2) ◽  
pp. 16-23 ◽  
Author(s):  
Johanna Reimer ◽  
Cornelia Montag ◽  
Alexander Schuster ◽  
Walter Moeller-Hartmann ◽  
Jan Sobesky ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
At Risk ◽  
Acute Stroke ◽  
Characteristic Curve ◽  
Area Under The Curve ◽  
Treatment Decisions ◽  
Emission Tomography ◽  
Time To Peak ◽  
Positron Emission ◽  
First Moment

Background: In acute stroke, the magnetic resonance (MR) imaging-based mismatch concept is used to select patients with tissue at risk of infarction for reperfusion therapies. There is however a controversy if non-deconvolved or deconvolved perfusion weighted (PW) parameter maps perform better in tissue at risk prediction and which parameters and thresholds should be used to guide treatment decisions. Methods: In a group of 22 acute stroke patients with consecutive MR and quantitative positron emission tomography (PET) imaging, non-deconvolved parameters were validated with the gold standard for penumbral-flow (PF) detection 15O-water PET. Performance of PW parameters was assessed by a receiver operating characteristic curve analysis to identify the accuracy of each PWI map to detect the ­upper PF threshold as defined by PET cerebral blood flow <20 mL/100 g/min. Results: Among normalized non-deconvolved parameters, PW-first moment without delay correction (FM without DC) > 3.6 s (area under the curve [AUC] = 0.89, interquartile range [IQR] 0.85–0.94), PW-maximum of the concentration curve (Cmax) < 0.66 (AUC = 0.92, IQR 0.84–0.96) and PW-time to peak (TTP) > 4.0 s (AUC = 0.92, IQR 0.87–0.94) perform significantly better than other non-deconvolved parameters to detect the PF threshold as defined by PET. Conclusions: Non-deconvolved parameters FM without DC, Cmax and TTP are an observer-independent alternative to established deconvolved parameters (e.g., Tmax) to guide treatment decisions in acute stroke.

Optimal thresholds for ischemic penumbra predicted by computed tomography perfusion in patients with acute ischemic stroke treated with mechanical thrombectomy

2017 ◽  
Vol 10 (3) ◽  
pp. 279-284 ◽  
Author(s):  
Katsuharu Kameda ◽  
Junji Uno ◽  
Ryosuke Otsuji ◽  
Nice Ren ◽  
Shintaro Nagaoka ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Cerebral Blood Volume ◽  
Mechanical Thrombectomy ◽  
Ct Perfusion ◽  
Characteristic Curve ◽  
Mean Transit Time ◽  
Area Under The Curve ◽  
Ischemic Penumbra ◽  
Optimal Thresholds

Background and purposeOptimal thresholds for ischemic penumbra detected by CT perfusion (CTP) in patients with acute ischemic stroke (AIS) have not been elucidated. In this study we investigated optimal thresholds for salvageable ischemic penumbra and the risk of hemorrhagic transformation (HT).MethodsA total of 156 consecutive patients with AIS treated with mechanical thrombectomy (MT) at our hospital were enrolled. Absolute (a) and relative (r) CTP parameters including cerebral blood flow (aCBF and rCBF), cerebral blood volume (aCBV and rCBV), and mean transit time (aMTT and rMTT) were evaluated for their value in detecting ischemic penumbra in each of seven arbitrary regions of interest defined by the major supplying blood vessel. Optimal thresholds were calculated by performing receiver operating characteristic curve analysis in 47 patients who achieved Thrombolysis In Cerebral Infarction (TICI) grade 3 recanalization. The risk of HT after MT was evaluated in 101 patients who achieved TICI grade 2b–3 recanalization.ResultsAbsolute CTP parameters for distinguishing ischemic penumbra from ischemic core were as follows: aCBF, 27.8 mL/100 g/min (area under the curve 0.82); aCBV, 2.1 mL/100 g (0.75); and aMTT, 7.30 s (0.70). Relative CTP parameters were as follows: rCBF, 0.62 (0.81); rCBV, 0.83 (0.87); and rMTT, 1.61 (0.73). CBF was significantly lower in areas of HT than in areas of infarction (aCBF, p<0.01; rCBF, p<0.001).ConclusionsCTP may be able to predict treatable ischemic penumbra and the risk of HT after MT in patients with AIS.

Abstract T P20: Correlation Between Whole Brain Ct Perfusion Maps And Non-contrast Ct Alberta Stroke Program Early Ct Score (aspects) In Patients Undergoing Acute Endovascular Stroke Interventions

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Simon Morr ◽  
Maxim Mokin ◽  
Ashish Sonig ◽  
Kenneth Snyder ◽  
Adnan Siddiqui ◽  
...  
Keyword(s):  
Acute Stroke ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Pearson Correlation ◽  
Volume Data ◽  
Post Intervention ◽  
Whole Brain ◽  
Brain Ct ◽  
Time To Peak

Introduction: Tools for evaluating risk of post-intervention risk hemorrhage in the setting of acute stroke include a noncontrast head CT based Alberta Stroke Program Early CT score (ASPECTS) and contrasted CT based perfusion plots. The correlation between these parameters is unknown. Methods: We performed a retrospective analysis of a prospectively collected endovascular stroke database of patients with M1 middle cerebral artery occlusion who underwent endovascular recanalization. We reviewed admission preintervention noncontrast CT for Alberta Stroke Program Early CT score (ASPECTS) and 320-detector row whole brain CT perfusion parameters (Cerebral blood volume and time to peak). Pearson correlation was determined between cerebral blood volume on the side of the stroke and ASPECTS. Results: ASPECTS and CT perfusion map were identified in 45 and 43 patients respectively. Statistically significant correlation was found between ASPECTS and cerebral blood volume data on CT perfusion MAP. (p=0.034, r=-0.28). The correlation coefficient is very weak. No correlation could be found between time to peak and ASPECTS. Conclusion: A statistically significant, but weak correlation exists between ASPECTS and CBV. Further research is needed to assess the physiological meaning of diverse imaging modalities utilized in the acute stroke setting.

Abstract TP63: Detection of Perfusion Deficits Using FLAIR and GRE Based Vessel Signs

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Dennys Reyes ◽  
Emi Hitomi ◽  
Alexis Simpkins ◽  
John Lynch ◽  
Amie Hsia ◽  
...  
Keyword(s):  
Acute Stroke ◽  
Roc Analysis ◽  
Area Under The Curve ◽  
Arterial Blood Flow ◽  
Lesion Volume ◽  
Perfusion Deficit ◽  
Stroke Patients ◽  
Time To Peak ◽  
Arterial Blood ◽  
Perfusion Deficits

Background: The presence of a perfusion deficit in an acute stroke patient can play an important role in their clinical management. However, many patients are unable to have perfusion-weighted imaging (PWI) due to renal disease. Perfusion deficits are often accompanied by FLAIR hyperintense vessels (FHV), presumably due to slow arterial blood flow, and GRE hypointense vessels (GHV), presumably due to venous congestion. Purpose: To determine how well FHV and GHV perform at identifying PWI lesions. Methods: One rater, blinded to the PWI MR sequences, retrospectively reviewed the DWI, FLAIR and GRE scans of acute stroke patients enrolled in the NIH Natural History of Stroke study during 2013-2014 who had an MRI with PWI prior to being treated with IV tPA. DWI images were used to guide evaluation of the FLAIR and GRE images for FHV and GHV and in each case were classified as definitively present, possibly present or absent. PWI lesion volumes were calculated by thresholding the time-to-peak (TTP) maps at 4 seconds beyond normal tissue. ROC analysis was used to assess the performance of FHV and GHV at various PWI lesion volume thresholds. Results: 102 patients were included in the analysis; their mean PWI lesion volume was 52 mL with a standard deviation of +/- 66 mL. 22% of patients had no perfusion deficit. The ROC analysis found the presence of any FHV performed the best with an area under the curve (AUC) of 0.925 displayed in the figure. Any GHV performed modestly with an AUC of 0.776. Combining FHV with GHV did not improve the performance over FHV alone (AUC=0.876). The sensitivity and specificity for identifying any perfusion deficit with FHV was 95% and 67% respectively with 87% being correctly classified. For detecting a PWI lesion greater than 10 mL, FHV had an 80% sensitivity and 93% specificity classifying 83% correctly. Conclusions: FHV is highly sensitive for identifying a perfusion deficit in stroke patients, and for patients with a lesion volume greater than 10 mL it is highly specific.

scholarly journals Predictive Value of the Velocity of Collateral Filling in Patients with Acute Ischemic Stroke

2014 ◽  
Vol 35 (2) ◽  
pp. 206-212 ◽  
Author(s):  
Sebastian E Beyer ◽  
Louisa von Baumgarten ◽  
Kolja M Thierfelder ◽  
Marietta Rottenkolber ◽  
Hendrik Janssen ◽  
...  
Keyword(s):  
Cerebral Blood Volume ◽  
Ct Perfusion ◽  
Mean Transit Time ◽  
Intravenous Thrombolysis ◽  
Lesion Size ◽  
Small Lesion ◽  
Time Resolved ◽  
Time To Peak ◽  
Magnetic Resonance Imaging Mri

The velocity of collateral filling can be assessed in dynamic time-resolved computed tomography (CT) angiographies and may predict initial CT perfusion (CTP) and follow-up lesion size. We included all patients with an M1± internal carotid artery (ICA) occlusion and follow-up imaging from an existing cohort of 1791 consecutive patients who underwent multimodal CT for suspected stroke. The velocity of collateral filling was quantified using the delay of time-to-peak (TTP) enhancement of the M2 segment distal to the occlusion. Cerebral blood volume (CBV) and mean transit time (MTT)-CBV mismatch were assessed in initial CTP. Follow-up lesion size was assessed by magnetic resonance imaging (MRI) or non-enhanced CT (NECT). Multivariate analyses were performed to adjust for extent of collateralization and type of treatment. Our study comprised 116 patients. Multivariate analysis showed a short collateral blood flow delay to be an independent predictor of a small CBV lesion ( P<0.001) and a large relative mismatch ( P<0.001) on initial CTP, of a small follow-up lesion ( P<0.001), and of a small difference between initial CBV and follow-up lesion size ( P=0.024). Other independent predictors of a small lesion on follow-up were a high morphologic collateral grade ( P=0.001), lack of an additional ICA occlusion ( P=0.009), and intravenous thrombolysis ( P=0.022). Fast filling of collaterals predicts initial CTP and follow-up lesion size and is independent of extent of collateralization.

scholarly journals Observer Agreement on Computed Tomography Perfusion Imaging in Acute Ischemic Stroke

Stroke ◽  
2019 ◽  
Vol 50 (11) ◽  
pp. 3108-3114 ◽  
Author(s):  
Salwa El-Tawil ◽  
Grant Mair ◽  
Xuya Huang ◽  
Eleni Sakka ◽  
Jeb Palmer ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Time Delay ◽  
Acute Stroke ◽  
Transit Time ◽  
Delay Time ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Observer Agreement ◽  
Intraobserver Agreement ◽  
Noncontrast Ct

Background and Purpose— Computed tomography (CT) perfusion (CTP) provides potentially valuable information to guide treatment decisions in acute stroke. Assessment of interobserver reliability of CTP has, however, been limited to small, mostly single center studies. We performed a large, internet-based study to assess observer reliability of CTP interpretation in acute stroke. Methods— We selected 24 cases from the IST-3 (Third International Stroke Trial), ATTEST (Alteplase Versus Tenecteplase for Thrombolysis After Ischaemic Stroke), and POSH (Post Stroke Hyperglycaemia) studies to illustrate various perfusion abnormalities. For each case, observers were presented with noncontrast CT, maps of cerebral blood volume, cerebral blood flow, mean transit time, delay time, and thresholded penumbra maps (dichotomized into penumbra and core), together with a short clinical vignette. Observers used a structured questionnaire to record presence of perfusion deficit, its extent compared with ischemic changes on noncontrast CT, and an Alberta Stroke Program Early CT Score for noncontrast CT and CTP. All images were viewed, and responses were collected online. We assessed observer agreement with Krippendorff-α. Intraobserver agreement was assessed by inviting observers who reviewed all scans for a repeat review of 6 scans. Results— Fifty seven observers contributed to the study, with 27 observers reviewing all 24 scans and 17 observers contributing repeat readings. Interobserver agreement was good to excellent for all CTP. Agreement was higher for perfusion maps compared with noncontrast CT and was higher for mean transit time, delay time, and penumbra map (Krippendorff-α =0.77, 0.79, and 0.81, respectively) compared with cerebral blood volume and cerebral blood flow (Krippendorff-α =0.69 and 0.62, respectively). Intraobserver agreement was fair to substantial in the majority of readers (Krippendorff-α ranged from 0.29 to 0.80). Conclusions— There are high levels of interobserver and intraobserver agreement for the interpretation of CTP in acute stroke, particularly of mean transit time, delay time, and penumbra maps.

scholarly journals Perfusion Changes in Acute Stroke Treated with Theophylline as an Add-on to Thrombolysis

2021 ◽  
Author(s):  
Boris Modrau ◽  
Anthony Winder ◽  
Niels Hjort ◽  
Martin Nygård Johansen ◽  
Grethe Andersen ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Cerebral Blood Volume ◽  
Neuroprotective Effect ◽  
Mean Transit Time ◽  
Control Group ◽  
Infarct Core ◽  
Treatment Groups ◽  
Stroke Models ◽  
Magnetic Resonance Imaging Mri

Abstract Purpose Theophylline has been suggested to have a neuroprotective effect in ischemic stroke; however, results from animal stroke models and clinical trials in humans are controversial. The aim of this study was to assess the effect of theophylline on the cerebral perfusion with multiparametric magnetic resonance imaging (MRI). Methods The relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and relative mean transit time (rMTT) in the infarct core, penumbra, and unaffected tissue were measured using multi-parametric MRI at baseline and 3‑h follow-up in patients treated with theophylline or placebo as an add-on to thrombolytic therapy. Results No significant differences in mean rCBF, rCBV, and rMTT was found in the penumbra and unaffected tissue between the theophylline group and the control group between baseline and 3‑h follow-up. In the infarct core, mean rCBV increased on average by 0.05 in the theophylline group and decreased by 0.14 in the control group (p < 0.04). Mean rCBF and mean rMTT in the infarct core were similar between the two treatment groups. Conclusion The results indicate that theophylline does not change the perfusion in potentially salvageable penumbral tissue but only affects the rCBV in the infarct core. In contrast to the penumbra, the infarct core is unlikely to be salvageable, which might explain why theophylline failed in clinical trials.

The influence of decompressive craniectomy for major stroke on early cerebral perfusion

2015 ◽  
Vol 123 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Philipp Jörg Slotty ◽  
Marcel Alexander Kamp ◽  
Thomas Beez ◽  
Henrieke Beenen ◽  
Hans-Jakob Steiger ◽  
...  
Keyword(s):  
Decompressive Craniectomy ◽  
Cerebral Perfusion ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Residue Function ◽  
Perfusion Ct ◽  
Local Pressure ◽  
Partial Restoration ◽  
Time To Peak ◽  
Major Stroke

OBJECT Multiple trials have shown improved survival and functional outcome in patients treated with decompressive craniectomy (DC) for brain swelling following major stroke. It has been assumed that decompression induces an improvement in cerebral perfusion. This observational study directly measured cerebral perfusion before and after decompression. METHODS Sixteen patients were prospectively examined with perfusion CT within 6 hours prior to surgery and 12 hours after surgery. Preoperative and postoperative perfusion measurements were compared and correlated. RESULTS Following DC there was a significant increase in cerebral blood flow in all measured territories and additionally an increase in cerebral blood volume in the penumbra (p = 0.03). These changes spread as far as the contralateral hemisphere. No significant changes in mean transit time or Tmax (time-to-peak residue function) were observed. CONCLUSIONS The presurgical perfusion abnormalities likely reflected local pressure-induced hypoperfusion with impaired autoregulation. The improvement in perfusion after decompression implied an increase in perfusion pressure, likely linked to partial restoration of autoregulation. The increase in perfusion that was observed might partially be responsible for improved clinical outcome following decompressive surgery for major stroke. The predictive value of perfusion CT on outcome needs to be evaluated in larger trials.

Below-the-Ankle Arrival Time as a Novel Limb Tissue Perfusion Index: Two-dimensional Perfusion Angiography Evaluation

2020 ◽  
Vol 27 (2) ◽  
pp. 198-204
Author(s):  
Kuniyasu Ikeoka ◽  
Tetsuya Watanabe ◽  
Yukinori Shinoda ◽  
Tomoko Minamisaka ◽  
Hidetada Fukuoka ◽  
...  
Keyword(s):  
Lower Limb ◽  
Arrival Time ◽  
Characteristic Curve ◽  
Mean Transit Time ◽  
Area Under The Curve ◽  
Tissue Perfusion ◽  
Time To Peak ◽  
Below The Knee ◽  
Pearson Coefficient ◽  
Before And After

Purpose: To identify lower limb 2-dimensional (2D) perfusion angiographic parameters that are related to skin perfusion pressure (SPP), a predictor of wound healing in patients with chronic limb-threatening ischemia (CLTI) undergoing below-the-knee (BTK) endovascular treatment (EVT). Materials and Methods: Thirty-three consecutive patients (mean age 74.5 years; 18 men) with 47 isolated BTK lesions in 33 limbs (Rutherford category 3–5) underwent EVT. Dorsal and plantar SPPs were measured before EVT and the day after. The indexed blood flow below the ankle was measured using 2D perfusion angiography before and after EVT to determine changes in perfusion parameters [arrival time (AT), time to peak, wash-in rate, mean transit time, and width and area under the time-density curve] at rest vs during hyperemia induced with a 20-mg intra-arterial papaverine infusion. Correlations between the 2D perfusion parameters and SPPs were assessed using the Pearson coefficient. The cutoff points to predict mean SPPs >40 mm Hg were analyzed using a receiver operating characteristic curve; outcomes are reported as the area under the curve (AUC) with 95% confidence interval (CI). Results: After EVT at rest and during hyperemia, only AT was significantly changed, although hyperemia produced significant changes in all the pre-/post-EVT 2D perfusion parameters except the wash-in rate. Dorsal and plantar SPPs after EVT were significantly increased and correlated with hyperemic AT and the AT ratio (hyperemia/at rest values) below the ankle. Hyperemic ATs <6.3 seconds and AT ratios <0.78 were predictive factors for a mean SPP >40 mm Hg, with AUCs of 0.83 (95% CI 0.67 to 0.99) and 0.78 (95% CI 0.61 to 0.95), respectively. Conclusion: Hyperemic ATs <6.3 seconds or AT ratios <0.78 below the ankle may be essential to obtain sufficient SPPs for limb salvage in BTK lesions. Thus, the use of 2D perfusion angiography enabled the monitoring of lower limb tissue perfusion throughout EVT and may thereby optimize treatment of CLTI.

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