Principles Behind 4D Time-Resolved MRA/Dynamic MRA in Neurovascular Imaging

Abstract

The abstract summarizes the evolution and role of dynamic magnetic resonance angiography (MRA) in neurovascular imaging. It highlights the historical context of neuroimaging, including the development of non-invasive techniques such as MRA. Different sequences of MRA, including time of flight (TOF), phase-contrast, contrast-enhanced, time-resolved, and dynamic MRA, are discussed, emphasizing their unique capabilities and clinical applications. Dynamic MRA, a four-dimensional imaging technique, offers high temporal and spatial resolution without ionizing radiation exposure, making it valuable for diagnosing cerebrovascular conditions like aneurysms, arteriovenous malformations (AVMs), dural arteriovenous fistulas (DAVF), steno-occlusive extracranial vascular disease, spinal vascular disease, neurovascular conflict, head and neck tumors, and cerebral venous sinus thrombosis (CVT). Comparative analyses with other imaging modalities, such as digital subtraction angiography (DSA), computed tomographic venography (CTV), and MR-based images, are presented, highlighting the diagnostic strengths and limitations of each technique. While DSA remains the gold standard, dynamic MRA shows promise as a non-invasive alternative with broad clinical utility. However, further large-scale prospective studies are needed to validate its diagnostic accuracy and establish its role in clinical practice.