An x-ray imaging apparatus and associated methods are provided to execute multi-pass imaging scans for improved quality and workflow. An imaging scan can be segmented into multiple passes that are faster than the full imaging scan. Data received by an initial scan pass can be utilized early in the workflow and of sufficient quality for treatment setup, including while the another scan pass is executed to generate data needed for higher quality images, which may be needed for treatment planning. In one embodiment, a data acquisition and reconstruction technique is used when the detector is offset in the channel and/or axial direction for a large FOV during multiple passes.

A method for reconstructing target cardiac images is provided. The method may include: obtaining projection data, the projection data including a plurality of sub-sets of projection data, each sub-set of projection data corresponding to a cardiac motion phase; obtaining a plurality of sampled cardiac motion phases; generating a plurality of cardiac images of the plurality of sampled cardiac motion phases by reconstructing, based on the one or more sub-sets of projection data corresponding to the each sampled cardiac motion phase, one or more cardiac images of the each sampled cardiac motion phase; determining a plurality of cardiac motion parameters corresponding to the plurality of sampled cardiac motion phases based on the plurality of cardiac images; determining a mean phase based on the plurality of cardiac motion parameters corresponding to the plurality of sampled cardiac motion phases; and reconstructing the one or more target cardiac images of the mean phase.

A computer-implemented method includes, in an embodiment, receiving first X-ray projections of an examination volume in respect of a first X-ray energy and second X-ray projections in respect of a second X-ray energy, the first and second X-ray energies differing. The method further includes determination of a multienergetic real image data record of the examination volume based upon the first and second X-ray projections; selection of first voxels of the multienergetic real image data record based upon the multienergetic real image data record; selection of second voxels of the multienergetic real image data record based upon the first X-ray projections and the second X-ray projections, the first voxels including the second voxels and the second voxels mapping contrast medium in the examination volume. The method further includes provision of a constraint image data record and/or a difference image data record based upon the second voxels.

Disclosed herein are methods for simulating the results of a visual field (VF) test using an optical coherence tomography (OCT) system. The disclosed methods may utilize structural information extracted from OCT image datasets, such as thickness measurements, or may utilize functional information, such as blood perfusion measurements, extracted from OCT angiography (OCTA) image datasets. Other embodiments may be described and claimed.

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.

A method for evaluating image quality is provided. The method may include: obtaining an image, the image including a plurality of elements, each element of the plurality of elements being a pixel or voxel, each element having a gray level; determining, based on a maximum gray level of the plurality of elements, one or more thresholds for segmenting the image; determining one or more sub-images of a region of interest by segmenting, based on the one or more thresholds, the image; and determining, based on the one or more sub-images of the region of interest, a quality index for the image.

The invention provides for a medical imaging system (100, 300) comprising a processor (106) for controlling the medical imaging system. Execution of machine executable instructions (112) causes the processor to receive (200) a static angiographic image (114) of a region of interest (322), receive (202) a time series of angiographic images (116, 116′) of the region of interest, construct (204) an image mask (118) using the static angiographic image, determine (206) a time dependent signal (120) for each voxel within the image mask using the time series of angiographic images, construct (208) a composite angiographic image by: assigning (210) a fill time (126) to each voxel within the image mask using an extremum (124) of the time dependent signal if the extremum deviates from an average of the time dependent signal more than a predetermined threshold, and identifying (212) voxels within the image mask as being unfilled voxels.

Multimodal imaging apparatus and methods include a rotatable gantry system with multiple sources of radiation comprising different energy levels (for example, kV and MV). Fast slip-ring technology and helical scans allow data from multiple sources of radiation to be combined or utilized to generate improved images and workflows, including for IGRT. Features include large field-of-view (LFOV) MV imaging, kV region-of-interest (ROI) imaging, and scalable field-of-view (SFOV) dual energy imaging.

A radiotherapy delivery device is provided. The device includes a source of therapeutic radiation and a first detector positioned to receive radiation from the source of therapeutic radiation. The device also includes a source of imaging radiation and a second detector positioned to receive radiation from the source of imaging radiation. A collimator assembly is positioned relative to the second source of radiation to selectively control a shape of a radiation beam emitted by the second radiation source to selectively expose part or the whole of the second radiation detector. A reconstruction processor can be operatively coupled to the detector and configured to generate patient images based on radiation received by the second detector from the second source of radiation. The device is configured to move from one imaging geometry to another using all or part of the second detector.

A system and method are provided for determining vascular velocity using non-invasively acquired medical images. The method includes reconstructing CT angiography (CTA) data into a plurality of images of the subject by producing a composite image using the CTA data corresponding to a set of the plurality of view angles, backprojecting each view angle in the CTA data and weighting a value backprojected into at image pixel by an attenuation value of a corresponding pixel in the composite image, and summing backprojected values for each image pixel to produce a CT image of the subject. The method also includes determining a flow direction or a velocity of flow within a vessel, calculating, using the flow direction or velocity, a pressure in the vessel, and generating a quantitative map of the subject indicating the flow direction, velocity, or pressure in the vessel against an image of the subject including the vessel.