Wisconsin Alumni Research Foundation

Erick Oberstar

Charles Anthony Mistretta

Michael Speidel

Ethan K Brodsky

Justin Mertes-Mistretta

Martin Wagner

Mariya Pravdivtseva

Aspects of the disclosure are directed to methods and/or apparatuses involving modifying flow and/or concentration of an agent being injected for characterizing a vascular system. As may be implemented in accordance with one or more embodiments, a liquid including an agent is injected into a vascular system, by dynamically modulating a flow rate of the agent being injected over a range of flow rates. The vascular system is characterized based on a response of the vascular system to the dynamic modulation. In some implementations, such an approach involves using an injector that operates to separately control the rate at which an agent and other liquid such as saline are injected. These approaches can be implemented with modulation schemes using one or more of a variety of functions.

Dynamic agent injection for cardiovascular characterization

A system and method is provided for imaging a contrast agent. The system includes a power injector that delivers a contrast agent as a series of boluses using a known period, flow rate, or duration and with a rate of at least one or more separate boluses per cardiac cycle. An x-ray imaging system acquires a reference dataset of the subject before the contrast agent is delivered and acquires an imaging dataset as the series of boluses are delivered to the subject, wherein multiple images are acquired of the subject per bolus. A computer system receives the reference dataset and the imaging dataset from the x-ray imaging system and reconstructs the reference dataset and the imaging dataset using a reconstruction process that removes the subject from the images to generate time-resolved volumetric images of the contrast agent moving within a volume of the subject without the subject.

System and method for flow-resolved three-dimensional imaging

A night vision device and method for filtering a series of image frames that depict a moving subject, which thereby improves the signal-to-noise ratio of each image frame, is provided. A composite image is formed for each image frame by combining pixel values in a current image frame with pixel values in composite images corresponding to image frames acquired before the current image frame. Additionally, pixels values in image frames acquired subsequent to the acquisition of the current image frame are included when forming the composite image. A bi-directional recursive filter is used to weight the contributions from the previous composite images and subsequent image frames with a decay constant. Motion of the imaging system is optionally compensated for by establishing a moving reference frame and shifting the image frames to account for this motion; thus, registering the image frames before filtering the current image frame.

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Madison, WI, United States of America

Erick Oberstar