OBJECTIVE: Unruptured intracranial aneurysms and arteriovenous malformations (AVMs) are commonly detected with noninvasive imaging techniques. This article examines the various diagnostic imaging modalities used to characterize these vascular lesions, outlines their classification, and discusses the treatment options and decision-making processes involved in their management. LATEST DEVELOPMENTS: Refined imaging techniques such as CT angiography (CTA) and magnetic resonance angiography (MRA) enable noninvasive characterization of both unruptured intracranial aneurysms and AVMs. In parallel, new artificial intelligence tools now assist radiologists in automated detection of unruptured intracranial aneurysms and intracerebral hemorrhages, potentially increasing the overall detection rate as these tools become routinely integrated into clinical workflows. The decision to manage unruptured intracranial aneurysms and AVMs with either periodic surveillance or treatment is increasingly personalized, guided by high-resolution CTA and MRI protocols that provide precise anatomic characterization. These imaging advances, combined with clinical information, help determine the necessity for intervention. Meanwhile, endovascular treatment for unruptured intracranial aneurysms continues to improve with the development of novel technologies that enhance clinical outcomes. ESSENTIAL POINTS: Although CTA and MRA are essential for characterizing unruptured intracranial aneurysms and AVMs, digital subtraction angiography remains the definitive modality for vascular lesion assessment. The decision to observe or treat an unruptured intracranial aneurysm or AVM should be made by a multidisciplinary team.
Edgar A. Samaniego (2026) studied this question.