Quantifying Intracranial Aneurysm Wall Permeability for Risk Assessment Using Dynamic Contrast-Enhanced MRI: A Pilot...

Area of Science:

• Neuroradiology
• Medical Imaging
• Vascular Biology

Background:

• Pathological changes in intracranial aneurysm walls can increase permeability.
• The clinical significance of aneurysm wall permeability for rupture risk is not well understood.
• This pilot study explores aneurysm wall permeability as a novel marker for rupture risk.

Purpose of the Study:

• To quantify intracranial aneurysm wall permeability (Ktrans, VL) to contrast agent.
• To assess aneurysm wall permeability as a measure of aneurysm rupture risk.
• To compare permeability parameters with established clinical and anatomic risk factors.

Main Methods:

• Dynamic contrast-enhanced MR imaging was used in 27 unruptured intracranial aneurysms from 23 patients.
• Wall permeability parameters (Ktrans, VL) were measured and compared to control MCA.
• Parameters were evaluated against clinical (symptomatic lesions) and anatomic (size, location, morphology) risk metrics.

Main Results:

• High interobserver agreement for Ktrans measurements (ICC > 0.92).
• Significantly increased wall permeability in aneurysms compared to healthy MCA (P < .001).
• Ktrans correlated with aneurysm size (P < .001) and predicted risk independent of size in anatomic and combined risk groups.

Conclusions:

• This is the first study to model contrast permeability in intracranial aneurysms using DCE-MRI.
• Aneurysm wall permeability significantly correlates with aneurysm size and size-independent anatomic risk factors.
• Ktrans is a significant, size-independent predictor of high-risk aneurysms based on morphology and clinical factors.