Current medical imaging technologies allow visualization of tissue anatomy in the human body at resolutions ranging from 100 micrometers to 1 millimeter. These technologies are generally not sensitive enough to detect early-stage tissue abnormalities associated with diseases such as cancer and atherosclerosis, which require micrometer-scale resolution. Here, optical coherence tomography was adapted to allow high-speed visualization of tissue in a living animal with a catheter-endoscope 1 millimeter in diameter. This method, referred to as "optical biopsy," was used to obtain cross-sectional images of the rabbit gastrointestinal and respiratory tracts at 10-micrometer resolution.

In Vivo Endoscopic Optical Biopsy with Optical Coherence Tomography

Embodiments include a system for determining cardiovascular information for a patient. The system may include at least one computer system configured to receive patient-specific data regarding a geometry of the patient's heart, and create a three-dimensional model representing at least a portion of the patient's heart based on the patient-specific data. The at least one computer system may be further configured to create a physics-based model relating to a blood flow characteristic of the patient's heart and determine a fractional flow reserve within the patient's heart based on the three-dimensional model and the physics-based model.

Method and system for patient-specific modeling of blood flow

Optical coherence tomography patterns of stent restenosis

Devices and methods for implantation at a native mitral valve having a non-circular annulus and leaflets. One embodiment of the device includes a valve support having a first region configured to be attached to a prosthetic valve with a plurality of prosthetic leaflets and a second region. The device can further include an anchoring member having a longitudinal dimension and including a first portion configured to contact tissue at the non-circular annulus, a second portion configured to be attached to the valve support, and a lateral portion between the first portion and the second portion. The second portion of the anchoring member is attached to the second region of the valve support while in a low-profile configuration in which the anchoring member and the valve support are configured to pass through vasculature of a human. The lateral portion is transverse to the longitudinal dimension. The anchoring member and the valve support are configured to move from the low-profile configuration to an expanded configuration in which the first portion of the anchoring member at least partially adapts to the non-circular annulus of the native mitral valve and the first region of the valve support is spaced inwardly from the first portion of the anchoring member relative to the longitudinal dimension of the anchoring member such that a shape of the first region of the valve support is at least partially independent of a shape of the first portion of the anchoring member.

Prosthetic heart valve devices, prosthetic mitral valves and associated systems and methods

Diagnostic Accuracy of Angiography-Based Quantitative Flow Ratio Measurements for Online Assessment of Coronary Stenosis

Haemodynamic factors, in particular wall shear stresses (WSSs) may have significant impact on growth and rupture of cerebral aneurysms. Without a means to measure WSS reliably in vivo, computational fluid dynamic (CFD) simulations are frequently employed to visualise and quantify blood flow from patient-specific computational models. With increasing interest in integrating these CFD simulations into pretreatment planning, a better understanding of the validity of the calculations in respect to computation parameters such as volume element type, mesh size and mesh composition is needed. In this study, CFD results for the two most common aneurysm types (saccular and terminal) are compared for polyhedral- vs. tetrahedral-based meshes and discussed regarding future clinical applications. For this purpose, a set of models were constructed for each aneurysm with spatially varying surface and volume mesh configurations (mesh size range: 5119-258, 481 volume elements). WSS distribution on the model wall and point-based velocity measurements were compared for each configuration model. Our results indicate a benefit of polyhedral meshes in respect to convergence speed and more homogeneous WSS patterns. Computational variations of WSS values and blood velocities are between 0.84 and 6.3% from the most simple mesh (tetrahedral elements only) and the most advanced mesh design investigated (polyhedral mesh with boundary layer).

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Tetrahedral vs. polyhedral mesh size evaluation on flow velocity and wall shear stress for cerebral hemodynamic simulation.

The invention relates to a method for acquiring and evaluating vascular examination data, comprising: acquisition of IVUS images of a vessel to be examined using an IVUS catheter; simultaneous acquisition of angiography data of the IVUS catheter having at least one angiography marker; acquisition of OCT images of the same point of the vessel to be examined using an OCT catheter; simultaneous acquisition of angiography data of the OCT catheter having at least one angiography marker; registering the IVUS and OCT images; determination of contours of the structures of the vessel under examination based on the OCT images; arithmetic histological analysis of the co-registered IVUS and OCT images using the information about the contours; and display the results.

Method for acquiring and evaluating vascular examination data

The invention relates to a method for tomographically displaying a cavity by optical coherence tomography (OCT) and to an OCT device, wherein the path length of a measuring light beam in the catheter can change as a result of a movement of the catheter and brings about a change in the display scale, wherein a possible change in the path length of the measuring light beam in the event of a movement of the catheter is electronically determined and automatically compensated.

Method for tomographically displaying a cavity by optical coherence tomography (OCT) and an OCT device for carrying out the method

A method and appertaining system permit a co-registration between points in a three-dimensional model of a vessel and vascular images obtained by an imaging catheter within the vessel at the respective points. The three-dimensional model is created by utilizing information from at least two external two-dimensional images produced by, e.g., one or more x-ray devices. The three-dimensional model is displayed on an analysis workstation, and a user may view the vascular images at particular points by selecting the appertaining points on the three-dimensional model.

Three-dimensional co-registration between intravascular and angiographic data

In hemodynamic determination in medical imaging, the classifier is trained from synthetic data rather than relying on training data from other patients. A computer model (in silico) may be perturbed in many different ways to generate many different examples. The flow is calculated for each resulting example. A bench model (in vitro) may similarly be altered in many different ways. The flow is measured for each resulting example. The machine-learnt classifier uses features from medical scan data for a particular patient to estimate the blood flow based on mapping of features to flow learned from the synthetic data. Perturbations or alterations may account for therapy so that the machine-trained classifier may estimate the results of therapeutically altering a patient-specific input feature. Uncertainty may be handled by training the classifier to predict a distribution of possibilities given uncertain input distribution. Combinations of one or more of uncertainty, use of synthetic training data, and therapy prediction may be provided.

Thomas Redel

Papers

Tetrahedral vs. polyhedral mesh size evaluation on flow velocity and wall shear stress for cerebral hemodynamic simulation.

Method for acquiring and evaluating vascular examination data

Method for tomographically displaying a cavity by optical coherence tomography (OCT) and an OCT device for carrying out the method

Three-dimensional co-registration between intravascular and angiographic data

Synthetic data-driven hemodynamic determination in medical imaging