How Doctors Use CT Scans and X-rays to Check Heart Arteries

This patent describes a method for precisely evaluating blockages in heart arteries by combining a single X-ray image with a detailed 3D CT scan, then calculating blood flow.

What it covers

The patent outlines a way to image heart arteries using two types of scans. First, it acquires detailed 3D computed tomography (CT) imaging data depicting the patient's entire coronary tree (Claim 1). After the CT scan, it acquires a single 2D X-ray image, called an angiographic projection, of a specific coronary artery, selecting the view with the least amount of vessel superimposition (Claim 1). The system then "registers" or aligns this single angiographic projection to the 3D CT imaging data. This registration involves segmenting the central paths, or "centerlines," of the coronary tree from the CT data, determining their length and three-dimensional shape, and then using this information to align the 2D X-ray (Claim 1). Finally, it determines the Fractional Flow Reserve (FFR) of the coronary artery from this registered data, which indicates how well blood is flowing through it (Claim 1). For example, if a patient has a narrowed artery, this method could help doctors assess if the blockage is severe enough to require a stent (Claim 4).

What it doesn't cover

• —Does not cover methods that require multiple angiographic projections for 3D reconstruction of the coronary artery.
• —Does not cover registration methods that do not rely on segmenting and matching the 3D shape and length of coronary artery centerlines.
• —Does not cover using other 3D imaging modalities, like MRI, instead of computed tomography (CT) data for the initial 3D model.
• —Does not cover diagnostic methods for vessels other than coronary arteries or metrics other than Fractional Flow Reserve (FFR).
• —Does not cover systems that acquire the single angiographic projection without selecting for the least amount of vessel superimposition.

The clever bit

The clever part is efficiently combining a detailed 3D CT scan with just a single 2D X-ray angiogram. It uses the precise 3D centerline information from the CT scan to accurately align the 2D X-ray, allowing for a reliable calculation of blood flow (FFR) with minimal additional imaging.

Why it matters

This technology matters because it offers a less invasive and potentially faster way to diagnose coronary artery disease. By combining existing 3D CT data with a single 2D angiogram, it can reduce the amount of radiation and contrast dye a patient receives compared to traditional methods that might require multiple angiograms. This helps doctors make more informed decisions about treatments like stent placement, improving patient care and outcomes.

Real-world examples

• 1.Cardiac catheterization labs
• 2.Interventional cardiology suites
• 3.Advanced medical imaging systems for heart diagnostics
• 4.Software for FFR calculation from hybrid imaging data