Role of Vessel Wall MRI in Differentiaition Between Intracranial Atherosclerotic Disease and Vasculitis as Causes of Ischemic Stroke

Intracranial arterial diseases, such as intracranial atherosclerotic disease (ICAD) and vasculitis, are major contributors to ischemic stroke globally. Differentiating these conditions, which is critical for effective clinical management given their distinct pathogenic mechanisms and therapeutic requirements. Traditional imaging modalities, including magnetic resonance angiography (MRA), computed tomography angiography (CTA), and digital subtraction angiography (DSA), predominantly assess the arterial lumen, detecting stenosis or occlusion. While valuable for identifying luminal abnormalities, these techniques often fail to characterize the vessel wall pathology, a key limitation in distinguishing between ICAD and vasculitis. Both conditions can manifest with similar clinical presentations of ischemic stroke, rendering diagnosis challenging with conventional methods.

Vessel wall magnetic MRI has emerged as an effective diagnostic tool. This non-invasive technique directly visualizes and characterizes the intracranial arterial wall, providing detailed information on wall thickening patterns, contrast enhancement characteristics, and plaque morphology. Current strategies show ability of vessel wall MRI to differentiate Intracranial atherosclerotic disease, typically presenting with eccentric wall thickening and eccentric enhancement if the atherosclerotic plaque is active and no enhancement if the atherosclerotic plaque is inactive, from vasculitis, which often exhibits circumferential wall thickening and enhancement.

The rationale for utilizing vessel wall magnetic resonance imaging stems from the need to move beyond mere luminal assessment to a more granular, tissue-level understanding of cerebrovascular disease. This advanced characterization facilitates precise diagnosis, guides appropriate treatment decisions-such as antiplatelet therapy for intracranial atherosclerotic disease versus immunosuppression for vasculitis-and ultimately aims to improve patient outcomes following ischemic stroke.

Inclusion criteria

• Patients with ischemic stroke within 2 weeks from onset detected by magnetic resonance imaging (MRI) and have intracranial artery stenosis seen in magnetic resonance angiography (MRA).

Exclusion criteria

• Contraindications for MRI such as claustrophobia, heart pacemaker and ferromagnetic implants.

• Contraindications for contrast as patients with renal impairment.
• Patients in which the misaligned images or distortions due to motion artifacts made the interpretation of the MRI unreliable.