Tech ID: L-19-007
Magnetic Resonance Imaging (MRI) is the non-invasive gold standard for blood flow assessment in larger blood vessels (arteries and veins), but MRI has limitations in terms of accessibility, patient throughput and operating cost. In contrast, Computed Tomography (CT) is one of the most frequently used diagnostic imaging modalities in hospitals, but CT application is primarily focused on anatomical assessment. We have developed an image processing technique that permits CT assessment of vascular blood flow at near real-time temporal resolution, which will facilitate the application of CT for different vascular diseases.
Two current approaches proposed for flow velocity measurement with CT are either impractical or suboptimal for clinical use. One approach is by measuring the time required for the injected imaging dye (radiopaque material) to travel from one to another location in a large blood vessel. However, the flow velocity in a large artery (e.g. aorta) is usually higher than 50 centimeters per seconds (cm/s), and state-of-the-art clinical CT scanners can cover up to 16 cm of our body per scan only, making this approach for flow measurement impractical. The other approach estimates flow velocity based on the area under the dye concentration time curve sampled in a blood vessel, but the temporal resolution of this method is limited by the sampling time of the time curve, which is usually longer than 20 seconds. Such temporal resolution is insensitive to the pulsatile variation in flow velocity within a cardiac cycle, which is useful for assessing the cardiac pumping function and the stiffness of the blood vessels receiving blood from the heart. We have overcome this limitation by developing an image processing technique that allows absolute flow measurement with CT at near real-time temporal resolution, and the new technique has been tested in simulation, flow phantom and large animal studies with promising results.
- Blood flow assessment in large blood vessels at near real-time temporal resolution;
- Assessment of laminar or turbulent flow pattern in large blood vessels with valvular or stenotic problems;
- Generation of pulsatile flow velocity profile of a single heart beat to assess cardiac function and vascular stiffness, with both metrics closely related to aging and hypertension
Computed tomography (CT), non-invasive, blood flow measurement, near real-time temporal resolution, large blood vessel, artery, vein, vascular diseases
US provisional application filed