Interventional cardiologists incorporate a variety of diagnostic tools during catheterization procedures in order to plan, guide, and assess therapies. Fluoroscopy is generally used to perform angiographic imaging of blood vessels. In turn, such blood vessel imaging is used by physicians to diagnose, locate and treat blood vessel disease during interventions such as bypass surgery or stent placement. Intravascular imaging technologies such as optical coherence tomography (OCT) are also valuable tools that can be used in lieu of or in combination with fluoroscopy to obtain high-resolution data regarding the condition of the blood vessels for a given subject.
Intravascular optical coherence tomography is a catheter-based imaging modality that uses light to peer into coronary artery walls and generate images for study. Utilizing coherent light, interferometry, and micro-optics, OCT can provide video-rate in-vivo tomography within a diseased vessel with micrometer level resolution. Viewing subsurface structures with high resolution using fiber-optic probes makes OCT especially useful for minimally invasive imaging of internal tissues and organs, as well as implanted medical devices such as stents.
Stents are a common intervention for treating vascular stenoses. It is critical for a clinician to develop a personalized stent plan that is customized to the patient's vascular anatomy to ensure optimal outcomes in intravascular procedures. Stent planning encompasses selecting the length, diameter, and landing zone for the stent with an intention to restore normal blood flow to the downstream tissues. However, flow-limiting stenoses are often present in the vicinity of vascular side branches. Side branches can be partially occluded or “jailed” during deployment of a stent intended to address a stenosis in the main vessel. Since side branches are vital for carrying blood to downstream tissues, jailing can have an undesired ischemic impact and also can lead to thrombosis. The ischemic effects of jailing are compounded when multiple side branches are impacted or when the occluded surface area of a single branch is increased.
Metal stent detection methods typically detect individual stent struts by detecting shadows cast by the struts onto the blood vessel wall, followed by detecting the location of the struts within the detected shadows. However, struts over jailed side branches are difficult to detect via this method. Side branches appear as large shadows in images because the scan line can be perpendicular to the side branch opening. As a result, it is difficult or impossible to detect strut shadows overlying side branches. Consequently, jailing struts are easily missed by the shadow based detection methods.
The present disclosure addresses the need for enhanced detection of jailing stent struts.