"Pseudostring sign" on carotid computed tomographic angiography: collateralization by vasa vasorum
Manzoor Ahmed1, Preet Kang, Gilles Pinault
1Section of Neuroradiology, Cleveland Clinic Foundation, MRI, Cleveland, OH 44195, USA. Ahmedm2@ccf.org
Journal of Computer Assisted Tomography
|February 4, 2009
Summary
We found a rare collateral pathway in unilateral internal carotid artery (ICA) occlusions using CT angiography. This pathway involves the vasa vasorum, offering new insights into cerebral blood flow compensation.
Area of Science:
- Vascular Neurology
- Radiology
- Cerebrovascular Imaging
Background:
- Unilateral internal carotid artery (ICA) occlusion presents diagnostic challenges.
- Collateral circulation is crucial for maintaining cerebral perfusion in ICA occlusion.
- Vasa vasorum's role in collateralization is not well-established.
Observation:
- Three cases of unilateral ICA occlusion were analyzed using computed tomographic angiography (CTA).
- A prominent, single collateralizing vessel originating from the vasa vasorum was identified in all cases.
- Specific CTA features included a "pseudostring sign," serpigenous vasa vasorum course, and eccentric intimal/medial thickening.
Findings:
- The vasa vasorum can form a significant collateral pathway in chronic ICA occlusion.
- CTA demonstrated characteristic imaging findings of this collateral pathway.
- The collateral vessel terminated in the neck or reconstituted the ICA below the skull base.
Implications:
- This finding expands the understanding of collateral circulation in cerebrovascular disease.
- Recognizing this vasa vasorum collateral pathway on CTA is important for accurate diagnosis and treatment planning.
- Further research may explore the functional significance and therapeutic potential of this collateral pathway.
