Yuriko Suzuki is developing a novel, completely non-invasive technique that enables visualising blood vessels and flows in patients with vessel-narrowing diseases in the brain, addressing limitations of Magnetic Resonance Angiography using Arterial Spin Labelling technique. She aims to provide an alternative to X-ray Angiography examination to reduce the burden on patients.
Understanding the dynamics of arterial blood supply to the brain is crucial for diagnosing many cerebrovascular diseases. Currently, X-ray Digital Subtraction Angiography (DSA) is the standard examination that visualises the blood vessels and their flow, in which contrast dye is injected from the tip of a catheter tube inserted into the blood vessel. It provides essential diagnostic information: not only the detailed anatomical vessel structure, but also the dynamics of blood flow, such as flow speed and direction. Additionally, by placing the catheter close to the target vessel, only targeted vessels can be selectively visualised, clearly distinguished from other non-targeted vessels. However, X-ray DSA requires highly invasive procedures, including the use of ionising radiation. Also, the contrast dye could cause severe allergic shock and serious kidney problems in high-risk patients.
Arterial Spin Labelling (ASL) is a Magnetic Resonance Imaging (MRI) technique, in which arterial blood itself is utilised as an endogenous tracer, thereby making ASL technique completely non-invasive. ASL can also visualise only an arterial vessel tree arising from a target artery, similar to X-ray DSA. Such advantageous feature of ASL technique makes ASL-based dynamic MR Angiography (MRA) a completely non-invasive, potential alternative to X-ray DSA, which could reduce the physical burden and risks for patients. However, there is a major difficulty in the clinical application of ASL-based dynamic-MRA in patients with vessel-narrowing, steno-occlusive diseases: it suffers from poorer vessel visualisation when blood flow is very slow, which is common in these patients.
With the support of the Royal Academy of Engineering Research Fellowships, Yuriko aims to address such limitations of the use of ASL-based dynamic-MRA in steno-occlusive diseases by utilising cross-disciplinary approach: MRI physics, image processing and machine learning. In the project, she aims to make the proposed technique even more suitable for patients with cerebrovascular diseases and bring a reliable diagnosis.