Evaluation and Development of Advanced Imaging Modalities for Intracranial Aneurysms

The clinical management of intracranial aneurysms is undergoing a transformative shift from traditional luminal evaluation to advanced vessel wall characterization. Conventional "lumenography," including DSA, CTA, and MRA, provides essential morphological data but fails to capture the biological processes, such as inflammation and wall remodeling, that drive aneurysm instability and rupture. This review evaluates the development of high-resolution vessel wall MRI (VW-MRI) and emerging modalities like photon-counting detector CT (PCD-CT) and 4D-Flow MRI. VW-MRI, particularly at 3T and 7T field strengths, utilizing "black-blood" sequences, has introduced Aneurysm Wall Enhancement (AWE) as a promising adjunctive imaging biomarker. AWE correlates with macrophage infiltration and neovascularization, offering a non-invasive means to identify "vulnerable" lesions that may be more prone to rupture. Furthermore, PCD-CT provides unprecedented spatial resolution and metal artifact reduction, while 4D-Flow MRI enables the quantification of hemodynamic stressors like wall shear stress. The integration of artificial intelligence and radiomics further enhances diagnostic precision through automated detection and quantitative risk scoring. By synthesizing technical principles with clinical applications, this review illustrates how these advanced modalities are moving neurovascular care toward a more personalized, biology-based approach to stroke prevention and aneurysm management.