In-stent restenosis (ISR) and its associated inflammation remains a significant concern for long-term patient outcomes following stent implantation in percutaneous coronary intervention (PCI). The problem is intricately associated with endothelial injury, excessive endothelialization, hyperproliferation of smooth muscle cells, and the infiltration of inflammatory molecules. However, commonly employed imaging techniques encounter challenges in simultaneously acquiring both vascular structural information and functional data related to inflammation. Here, we presented a novel Tri modality intravascular imaging system capable of simultaneous optical coherence tomography (OCT), near-infrared fluorescence (NIRF), ultrasound (US) imaging, and fabricated the OCT-NIRF-US catheter which outer diameter is 0.75 mm, aiming to provide a more comprehensive diagnostic tool for ISR and its associated inflammation. Experiments were conducted on atherosclerotic rabbits implanted with a scaffold, divided into two groups (n=3 each group) for assessment on the first and twenty-eighth day, respectively. Primary results demonstrated that the integrated OCT-NIRF-US intravascular system enables complementary structural imaging and functional imaging of inflammation. The system presents the potential to offer a more accurate assessment, providing with valuable insights into the ISR processing and assisting in the development of more precise clinical strategies.
Optical coherence tomography angiography (OCTA) is a non-invasive, high-resolution imaging technique which visualizes capillary vasculatures. However, up to now, no accurate quantitation of capillary velocity based on OCTA images has been reported. Currently study of capillary velocity was substantially performed based on the empirical correlation curves between OCTA signals and blood flow velocity in respective OCT setups and OCTA algorithms. In this study, we proposed an accurate measurement of the capillary velocity in blood vessels using microbubble localization and tracking imaging. Based on localization and tracking of microbubble, motion of microbubble in the blood vessel was identified and parameters of vasculature such as the direction and velocity of capillary flow were subsequently obtained. In this prediction study, a flow phantom using the polystyrene microsphere and a cellulose tubing with the internal diameter of 300μm was used to simulate the flow in a single blood vessel. The flow velocity was set to be 2-6μL/min. In the experiment, 5% milk solution and microsphere suspension were injected into the cellulose tubing using a precision syringe pump. In OCT performance, B-scan imaging was set at a frame rate of 500 frames per second (fps). In each acquisition, 1000 effective frames were acquired, which corresponded to an ultrafast data acquisition of 2s. Speckle Variance (SV) algorithm was employed to remove background tissue signals and extract the flowing microsphere signals in OCT data. The center points of the microsphere were determined by identifying the local maxima of the cross-correlation coefficient. Additionally, the Kuhn-Munkres (KM) assignment algorithm was employed for the purpose of tracking microsphere. Distances between pairs of consecutive frames were then calculated for all microsphere. Ultimately the velocity magnitude map was generated. preliminary results on blood vessel phantom validated the feasibility of the proposed technique, which will be further performed in quantitation of capillary velocity in living tissues.
In the last decade, there has been a growing interest in dual-modality imaging techniques that combine intravascular ultrasound (IVUS) with optical coherence tomography (OCT) for intravascular imaging. However, accurately quantifying the vulnerability of coronary atherosclerotic plaques solely through structural imaging methods remains challenging. Optical Coherence Elastography (OCE) technology, which assesses tissue elasticity by analyzing tissue displacement and strain distribution, has emerged as a promising approach. In recent years, the field of intravascular optical coherence elastography has shown significant progress, and its potential applications are becoming increasingly evident. In this study, we developed a comprehensive imaging system capable of IVUS-OCT-OCE tri-modality imaging for both phantom and biological tissues. Preliminary results indicate that the system exhibits high-quality imaging capabilities and offers precise identification of plaque tissue. This presents a novel approach for characterizing plaque tissue within blood vessels and holds promise for early diagnosis in coronary atherosclerosis
Endoscopic optical coherence tomography (OCT) has been demonstrated for volumetric imaging of subsurface features with high resolution. However, it is difficult to enable endoscopic OCT angiography (OCTA) due to the low inter-frame stability of endoscopic OCT. Recently, stable distal rotational scanning of micromotor catheter enabled imaging of structural features in the en face plane as well as endoscope OCTA. However, most endoscopic OCT in the lab and almost all commercial ones use proximal scanning catheters for diagnosing endoscopic tissues which should be designed much smaller than micromotor catheters. Here, we presented a proximal scanning endoscopic OCT technology that enabled OCTA. A spatiotemporal singular value decomposition (SVD) process was used to remove the eigen components that represented static tissue signals to generate that of the final moving particles. Primary results revealed that the endoscopic imaging system enabled OCTA in the two-and three-dimensional in vitro flow phantom. As the catheter’s outer diameter is less than 1 mm, the system is of potential for providing a more accurate assessment for pancreatic and bile duct cancers and even cardiovascular disease in clinical applications.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.