Infarct core

Fig. 5.6 The admission thresholded CT-CBF maps provide optimal correlation with concurrently acquired admission MR-DWI core infarct lesions...

The nsefulness of the core infarct volnme for treatment selection in PAO is supported by multiple studies demonstrating (1) that patients with large pretreatment... 

In anterior circulation proximal artery occlusions, core infarct size is inversely correlated with the degree of collateral flow to the ischemic bed... 

Studies using various imaging modalities (Xe-enhanced CT, MRI DWI, CTA source images, and CTP) have demonstrated that pretreatment core infarct size predicts the clinical response to reperfusion, and that core infarct volume less than 70-100 mL may be an effective treatment target... 

Diffusion-weighted MRI provides the most accurate and reliable estimate of the core infarct in the hyperacute setting (within 6 h of onset)... 

Core infarct estimation represents an important step in the evaluation of acute ischemic stroke patients and may predict the clinical response to intra-arterial therapy... 

In the clinical setting, diffusion-weighted imaging provides the most accurate and reliable estimate of the core infarct. However, MRI is limited by the lack of widespread availability in the emergent setting. Therefore, CT-based methods have been used to measure the infarct core. Studies utilizing these techniques have provided further evidence for the role of core infarct size in determining treatment response. 

The major challenge in using CTP for the assessment of the core infarct is the questionable reliability of dynamic perfusion imaging. CBV measurements are thought to be more robust than CBF and MTT measurements because the calculation of cerebral blood volume is relatively insensitive to bolus delay and dispersion [85, 86]. However, as a calculated parameter, it remains dependent on postprocessing (e.g., partial volume effects) and patient-specific issues (e.g., hematocrit levels) [87-89]. Additionally, as demonstrated in the DIAS-2 study [90], there is poor interrater agreement in assessing the CBV lesion. 

A simpler approach to identifying a significant penumbra is the combination of a proximal artery occlusion, significant clinical deficit (NIHSS score >10), and small core infarct (<70-100 mL)... 

Until current perfusion methods are refined and standardized, a simpler approach using vessel status, clinical deficit, and core infarct size appears to be sufficient for patient selection for lAT... 

Core infarct size by MRI DWI assessment is strongly associated with the risk of clinically significant reperfusion hemorrhage... 

Large core infarct size (>100 mL) is a marker for high risk of significant reperfusion hemorrhage... 

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