Triphasic Perfusion Computed Tomography in Acute Middle Cerebral Artery Stroke

Lee, Kwang Ho; Cho, Soo-Jin; Byun, Hong Sik; Na, Dong Gyu; Choi, Nak-Cheon; Lee, Soo Joo; Jin, In-Seon; Lee, Te Gyu; Chung, Chin‐Sang

doi:10.1001/archneur.57.7.990

Cited by 61 publications

(24 citation statements)

References 33 publications

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“…4, Reliability assessments were available for 2 of these methods, demonstrating good and very good inter-/intraobserver agreement (n ϭ 172). 6,14,40 Arterial injection sites, when described, included unilateral carotid/MCA (n ϭ 3), 34,54,56 bilateral carotid (n ϭ 3), 24,52,63 a minimum of ipsilateral carotid and vertebral (n ϭ 10), 9,31,36,38,39,45,51,53,55,58 and other combinations (n ϭ 5). 10,11,28,49,50 Seven grading scales by using CTA were identified, with LMF assessments performed on 593 patients with suspected acute stroke (Table 3).…”

Section: Medline Andmentioning

confidence: 99%

“…10,11,28,49,50 Seven grading scales by using CTA were identified, with LMF assessments performed on 593 patients with suspected acute stroke (Table 3). 5,34,[64][65][66][67][68][69][70][71][72][73] Interobserver agreement was assessed for 5 CTA methods, ranging from moderate to excellent (n ϭ 247). One grading scale used a combination of CTP in addition to CTA to confirm the retrograde direction of true LMF.…”

Section: Medline Andmentioning

confidence: 99%

“…2,13,19,27,31,35,51,[74][75][76][77][78][79][80][81][82][83][84][85][86] A total of 8 publications compared noninvasive LMF assessments with MR imaging (n ϭ 5), CT (n ϭ 2), or TCD (n ϭ 1) with a reference standard by using DSA; in each, a different grading scale for the criterion standard was used. 13,19,27,31,[34][35][36]51 …”

Section: Medline Andmentioning

confidence: 99%

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Systematic Review of Methods for Assessing Leptomeningeal Collateral Flow

McVerry¹,

Liebeskind²,

Muir³

2011

AJNR Am J Neuroradiol

194

162

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Section: Medline Andmentioning

confidence: 99%

Section: Medline Andmentioning

confidence: 99%

See 1 more Smart Citation

Systematic Review of Methods for Assessing Leptomeningeal Collateral Flow

McVerry¹,

Liebeskind²,

Muir³

2011

AJNR Am J Neuroradiol

194

162

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“…[48][49][50][51] Receiver operating characteristic curve analysis in 130 patients suspected of having acute ischemic stroke suggested that relative MTT was the CTP parameter most accurately characterizing salvageable penumbra, and absolute CBV, the parameter most accurately characterizing infarct core at admission, again with an optimal threshold of 2.0 mL/100 g. 47 An additional alternative approach for determining threshold values for penumbra and core in gray matter 52 differs from that in previous work because it incorporates the interaction between CBF and CBV. Logistic regression was applied to data points from patients who underwent recanalization of occluded vessels to define thresholds for separating core from penumbra.…”

Section: Ctp Map Image Interpretation: Challenges and Limitationsmentioning

confidence: 99%

Theoretic Basis and Technical Implementations of CT Perfusion in Acute Ischemic Stroke, Part 2: Technical Implementations

Konstas¹,

Goldmakher²,

Lee³

et al. 2009

AJNR Am J Neuroradiol

204

141

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SUMMARY:CT perfusion (CTP) is a functional imaging technique that provides important information about capillary-level hemodynamics of the brain parenchyma and is a natural complement to the strengths of unenhanced CT and CT angiography in the evaluation of acute stroke, vasospasm, and other neurovascular disorders. CTP is critical in determining the extent of irreversibly infarcted brain tissue (infarct "core") and the severely ischemic but potentially salvageable tissue ("penumbra"). This is achieved by generating parametric maps of cerebral blood flow, cerebral blood volume, and mean transit time. Part 1 of this review established the clinical context of CT perfusion (CTP).1 Next, a discussion followed on CTP map construction using the maximum slope method and the 2 main deconvolution techniques, Fourier transformation and singular value decomposition (SVD) (the latter being the most commonly used numeric method in CTP). Part 2 discusses the "pearls and pitfalls" of CTP map 1) acquisition, 2) postprocessing, and 3) image interpretation. Issues including radiation dose-reduction strategies, methods of correcting arterial input function (AIF) delay, the effect of the laterality of AIF choice, vascular pixel elimination, the importance of correct cerebral blood flow (CBF) and cerebral blood volume (CBV) threshold selection, and the selection of appropriate perfusion parameters for correct estimation of penumbra are addressed. The review highlights the need for validation and standardization of important CTP parameters to improve patient outcomes and design future randomized clinical trials that will provide evidence for the importance of the core/ penumbra "mismatch" in patient triage for recanalization therapies beyond the current 3-hour therapeutic window for intravenous thrombolysis. Technical Implementations CTP AcquisitionAt a recent meeting of stroke radiologists, neurologists, emergency physicians, National Institutes of Health (NIH) administrators, and industry leaders in Washington, DC, sponsored by the NIH and the American Society of Neuroradiology, both technical and clinical issues regarding advanced acute stroke imaging were discussed. Expert consensus regarding standardized CTP and MR perfusion (MRP) acquisition was achieved, published simultaneously as a position paper in American Journal of Neuroradiology and Stroke.2,3 The baseline CT study should have 3 components: unenhanced CT, vertexto-arch CT angiography (CTA), and dynamic first-pass CTP. 4 Addition of cardiac multidetector row CT (MDCT) for the detection of possible left atrial appendage thrombus is optional but may gain in popularity because cardioembolic strokes comprise about one third of all ischemic strokes (and their incidence appears to be increasing as stent placement/ endarterectomy for primary stroke prevention of carotid embolic stroke becomes more common place).5 Ruling out a cardiac source may have important consequences for patient management. A recent study reported 80% specificity, 73% sensitivity, and 92% negative predicti...

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“…19 This relationship between good early collaterals on pretreatment imaging and smaller infarct volume with better outcomes has been described in several studies. [20][21][22] Despite this positive relationship, its role in therapeutic decision-making for AIS patients Stratification by the Miteff system, the Maas system, and the ASPECTS collateral system remains poorly established. We recognize that good initial collaterals are beneficial but how does the change in collaterals affect our clinical management?…”

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confidence: 99%

How temporal evolution of intracranial collaterals in acute stroke affects clinical outcomes

et al. 2016

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Objective: We compared intracranial collaterals on pretreatment and day 2 brain CT angiograms (CTA) to assess their evolution and relationship with functional outcomes in acute ischemic stroke (AIS) patients treated with IV tissue plasminogen activator (tPA).Methods: Consecutive AIS patients who underwent pretreatment and day 2 CTA and received IV tPA during 2010-2013 were included. Collaterals were evaluated by 2 independent neuroradiologists using 3 predefined criteria: the Miteff system, the Maas system, and 20-point collateral scale by the Alberta Stroke Program Early CT Score methodology. We stratified our cohort by baseline pre-tPA state of their collaterals and by recanalization status of the primary vessel for analysis. Good outcomes at 3 months were defined by a modified Rankin Scale score of 0-1.Results: This study included 209 patients. Delayed collateral recruitment by any grading system was not associated with good outcomes. All 3 scoring systems showed that collateral recruitment on the follow-up CTA from a baseline poor collateral state was significantly associated with poor outcome and increased bleeding risk. When the primary vessel remained persistently occluded, collateral recruitment was significantly associated with worse outcomes. Interestingly, collateral recruitment was significantly associated with increased mortality in 2 of the 3 grading systems.Conclusions: Not all collateral recruitment is beneficial; delayed collateral recruitment may be different from early recruitment and can result in worse outcomes and higher mortality. Prethrombolysis collateral status and recanalization are determinants of how intracranial collateral evolution affects functional outcomes. Neurology ® 2016;86:434-441 GLOSSARY AF 5 atrial fibrillation; AIS 5 acute ischemic stroke; ASPECTS 5 Alberta Stroke Program Early CT Score; CI 5 confidence interval; CTA 5 CT angiography; IRB 5 institutional review board; mRS 5 modified Rankin Scale; NIHSS 5 NIH Stroke Scale; OR 5 odds ratio; ROC 5 receiver operating characteristic; SICH 5 symptomatic intracranial hemorrhage; tPA 5 tissue plasminogen activator.Ischemic stroke is the largest contributor to disability in most developed countries. In clinical practice, infarct growth does not always progress to involve the full extent of the vascular territory, even if the affected intracranial artery fails to recanalize. The presence and recruitment of various collateral channels are believed to be responsible for this phenomenon in acute ischemic stroke (AIS).1 These collaterals may also play an important role in influencing the safety and efficacy of acute revascularization approaches. 2Although blood supply from the leptomeningeal collaterals may temporarily maintain the ischemic penumbra, the persistence and effectiveness of this alternative circulatory supply is erratic and unpredictable. Some collaterals may disappear over time (collateral failure); this is one of the mechanisms responsible for clinical deterioration following initial improvement. Conversely, dra...

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Triphasic Perfusion Computed Tomography in Acute Middle Cerebral Artery Stroke

Cited by 61 publications

References 33 publications

Systematic Review of Methods for Assessing Leptomeningeal Collateral Flow

Systematic Review of Methods for Assessing Leptomeningeal Collateral Flow

Theoretic Basis and Technical Implementations of CT Perfusion in Acute Ischemic Stroke, Part 2: Technical Implementations

How temporal evolution of intracranial collaterals in acute stroke affects clinical outcomes

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