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Four-dimensional computed tomography angiography analysis of internal carotid arteries opacification at the skull
Julien Ognard1,2,3, Mourad Cheddad El Aouni4,5, Brieg Dissaux4,5
1Neuroradiology Unit, Department of Radiology, University Hospital of Brest, Brest, France. julien.ognard@chu-brest.fr.
Insights
Analyzing internal carotid artery opacification at the skull base can help detect delayed cerebral ischemia after subarachnoid hemorrhage. A nonlinear opacification pattern strongly indicates this condition, aiding early intervention.
Area of Science:
- Neurology
- Radiology
- Medical Imaging
Background:
- Delayed cerebral ischemia (DCI) is a major complication following subarachnoid hemorrhage (SAH), leading to poor functional outcomes.
- Vasospasm is a common cause of DCI, necessitating accurate and early detection methods.
Purpose of the Study:
- To investigate the feasibility of detecting DCI by analyzing arterial opacification of the internal carotid arteries (ICAs) at the skull base.
- To determine if specific opacification patterns can predict the occurrence of DCI.
Main Methods:
- An exploratory, retrospective diagnostic accuracy study involving patients with suspected vasospasm after SAH.
- Four-dimensional computed tomography angiography (4D CTA) was used to assess ICA opacification at the skull base with high temporal resolution (0.15 s).
- A semi-automated segmentation and wavelet transform analysis, followed by k-means clustering, was applied to opacification curves to identify patterns associated with DCI.
Main Results:
- The analysis of ICA opacification patterns was feasible in the studied cohort.
- Two distinct types of opacification curves were identified through k-means clustering.
- A nonlinear opacification pattern was significantly associated with the presence of DCI (p < 0.001).
Conclusions:
- Analysis of ICA opacification at the skull base using the described processing method is a viable approach for DCI detection.
- The identified opacification patterns, particularly the nonlinear type, may aid in the early detection and prevention of DCI.
- This method shows promise for DCI detection, especially in cases with imaging artifacts from aneurysm treatment materials.
Purpose:
Delayed cerebral ischemia represents a significant cause of poor functional outcome for patients with vasospasm after subarachnoid hemorrhage. We investigated whether delayed cerebral ischemia could be detected by the arterial opacification of internal carotid artery at the level of the skull base.
Methods:
In this exploratory, nested retrospective cohort diagnostic accuracy study, patients with clinical and/or transcranial Doppler suspicion of vasospasm who underwent four-dimensional computed tomography angiography were included. They were split into two groups for the main endpoint analysis, according to the actually adopted morphological (cerebral infarction) and clinical criteria (neurologic deterioration) of delayed cerebral ischemia. Opacification with a temporal resolution of 0.15 s of both internal carotid arteries at the skull base level was obtained through a semi-automated segmentation method based on skeletonization, and analyzed by a wavelet transform (rbio2.2, level 1). The results obtained by k-means clustering were analyzed with regard to the state of delayed cerebral infarction.
Results:
Over ten patients included and analyzed, five patients presented a delayed cerebral ischemia, two of them in both side. The semi-automated processing and analysis clustered two different types of opacification curves. The obtaining of a nonlinear opacification pattern was associated (p < 0.001) with delayed cerebral ischemia.
Conclusions:
The analysis of arterial opacification of internal carotid arteries at skull base by the proposed processing is feasible and leads to cluster two types of opacification that may help to early detect and prevent delayed cerebral ischemia, in particularly when examinations are artifacted by aneurysm treatment materials.
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