Improved dynamic CT angiography visualization by flow territory masking

This review summarizes the current state of knowledge regarding the use of imaging to guide stroke treatment. Brain imaging plays a central role in the diagnosis of stroke and identification of the mechanism of stroke, which is relevant to acute treatment, prognosis, and secondary prevention. The chief potential modalities are computed tomography (CT) and magnetic resonance imaging (MRI). Currently, most imaging occurs in hospital but mobile stroke units have expanded CT brain imaging into the prehospital field. The proven therapies for ischemic stroke are based on achieving reperfusion and the DAWN and DEFUSE 3 trials have now firmly established a need for imaging selection based on estimated ischemic core volume to guide reperfusion decisions in patients beyond 6 h of stroke onset. However, data also indicate that estimated ischemic core volume, in conjunction with patient factors and expected time delay to reperfusion, forms one of the most useful prognostic assessments that could alter decision-making for patients within 6 h. Current trials are also investigating agents that aim to achieve neuroprotection, reduction in edema or prevention of hemorrhagic transformation. Imaging may play a role in identifying patients likely to benefit from this next generation of interventions for stroke patients.

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“…11 CTP acquisitions may even allow segmentation of collateral territories, similar to those produced using arterial spin labeling MRI. 69…”

Section: Imaging Collateralsmentioning

confidence: 99%

Imaging selection for acute stroke intervention

Campbell

Parsons

2018

International Journal of Stroke

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“…Territorial segmentation using BAT based region-growing. The territorial segmentation is performed within the angiography mask by a multiple seed region-growing algorithm based on the estimated BAT (similar to Christensen et al 9 ). First, the reference time (t 0 ) is defined, in a similar way to the calculation in step one, but in higher temporal resolution.…”

Section: Territorial Segmentationmentioning

confidence: 99%

“…A recently reported study suggested a post-processing method for territorial segmentation based on computer tomography (CT) data using multiple-seed, iterative region-growing algorithm in which the territories are gradually segmented according to the bolus-arrival-time (BAT). 9 However, this method did not include arteries upstream of the circle of Willis, and was not applied to MRI data. Based on four-dimensional (4D) phase contrast, flow tracking cartography was suggested, yet this method enables segmentation of only the large blood vessels and is limited by the velocity encoding used.…”

Section: Introductionmentioning

confidence: 99%

Vascular territorial segmentation and volumetric blood flow measurement using dynamic contrast enhanced magnetic resonance angiography of the brain

Geri

Shiran

Roth

et al. 2017

J Cereb Blood Flow Metab

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This study proposes a method for territorial segmentation and volumetric flow rate (VFR) distribution measurement of cerebral territories based on time-resolved contrast enhanced magnetic-resonance-angiography (MRA). The method uses an iterative region-growing algorithm based on bolus-arrival-time with increased temporal resolution. Eight territories were segmented: (1) right and (2) left internal carotid arteries, including the middle cerebral artery (ICA+MCA), excluding the anterior cerebral arteries (ACA); (3) right and left ACA (R+L-ACA); (4) right and (5) left external carotid arteries (ECA); (6) right and (7) left posterior cerebral arteries (PCA); and (8) vertebrobasilar territory. VFR percentage, relative to the entire brain (rVFR), was measured based on territorial volume as a function of time. Mean rVFR values of fifteen healthy subjects were: ICA+MCA = 23 ± 2%, R + L-ACA = 17 ± 3%, ECA = 4 ± 2%, PCA = 12 ± 2%, and vertebrobasilar territory = 31 ± 4%. Excluding the ECA-rVFR, which is underestimated, these values are comparable to previously reported values. Six subjects were scanned twice, demonstrating comparable and even higher reproducibility than previously reported using phase-contrast, yet with faster scan time (∼1 min). This method was implemented in one patient with MCA occlusion and one with Moyamoya syndrome scanned before and after bypass surgery, demonstrating its clinical potential for quantitative assessment of the degree of occlusion and the effect of surgery.

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CT vascular territory mapping: a novel method to identify large vessel occlusion collateral

et al. 2022

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Introduction This descriptive study explores typical patterns of vascular territory mapping (VTM) in ischaemic stroke patients with proximal vessel occlusion. VTM is a novel process using CT perfusion that can identify the source and extent of collateral blood flow in patients with vessel occlusion. It functions by determining which vessel provides dominant blood flow to a brain voxel. Methods A total of 167 consecutive patients were analysed from INSPIRE (International Stroke Perfusion Imaging Registry) with their CT perfusion reprocessed through VTM software. We explored the typical territory maps generated by this software relating to common large vessel occlusion location sites (ACA/MCA/PCA). Results/Conclusion In the presence of occlusion, VTM demonstrated a reciprocal increase in collateral vessel territories.

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Improved dynamic CT angiography visualization by flow territory masking

Cited by 5 publications

References 8 publications

Imaging selection for acute stroke intervention

Imaging selection for acute stroke intervention

Vascular territorial segmentation and volumetric blood flow measurement using dynamic contrast enhanced magnetic resonance angiography of the brain

CT vascular territory mapping: a novel method to identify large vessel occlusion collateral

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