Abstract: Apparatus and methods are provided including, while an endoluminal data-acquisition device is being moved through a lumen of a subject, acquiring a plurality of endoluminal data points of the lumen using the endoluminal data-acquisition device. At at least one location it is determined that an event occurred, the event causing the endoluminal data-acquisition device not to acquire a single endoluminal data point at the location. The endoluminal data points are displayed in a stack, in which the endoluminal data points are positioned at locations corresponding to relative locations within the lumen at which the endoluminal data points were acquired, and in which the event is accounted for. Other applications are also described.

Abstract: Apparatus and methods are described including acquiring a first set of extraluminal images of a lumen, using an extraluminal imaging device. At least one of the first set of images is designated as a roadmap image. While an endoluminal device is being moved through the lumen, a second set of extraluminal images is acquired. A plurality of features that are visible within images belonging to the second set of extraluminal images are identified. In response to the identified features in the images belonging to the second set of extraluminal images, a plurality of local calibration factors associated with respective portions of the roadmap image are determined. Other applications are also described.

Abstract: Apparatus and methods are described including acquiring a plurality of image frames of a blood vessel of a subject, acquisition of the image frames commencing prior to injection of a contrast agent into the blood vessel. A first image frame is identified as being the image frame in which an angiographic sequence commenced by calculating a vesselness descriptor for each one of the image frames, by determining an extent to which pixels within the image frame are likely to correspond to the blood vessel, and by determining that, in the first image frame, there was an increase in the vesselness descriptor relative to at least one image frame acquired prior to the first image frame. An output is generated at least partially in response to identifying the first image frame. Other applications are also described.

Abstract: Apparatus and methods are described including generating a road map of a blood vessel. Subsequent to the generation of the road map, a tool is inserted into the blood vessel. While the tool is inside the blood vessel, the position of the tool is determined. The road map is modified to account for the determined position of the tool. Other embodiments are also described.

Abstract: Apparatus and methods are described for imaging a portion of a body of a subject that undergoes a motion cycle, including acquiring a plurality of image frames of the portion of the subject's body. A given feature is identified in at least some of the image frames. At least some image frames are image tracked with respect to the feature, and the image frames that have been image tracked with respect to the given feature are displayed as a stream of image frames. Visibility of a periphery of the displayed stream of image frames is at least partially reduced. Other applications are also described.

Abstract: Apparatus and methods are described including, while an endoluminal data-acquisition device is being moved through a subject's lumen, acquiring a plurality of endoluminal data points of the lumen using the endoluminal data-acquisition device. It is determined that respective endoluminal data points correspond to respective locations along the lumen. A display is driven to display at least some of the plurality of endoluminal data points in a stack. While a second endoluminal device is inside the lumen, a current location of at least a portion of the second endoluminal device with respect to the lumen is determined. In response thereto, an image of the second endoluminal device is displayed within the stack, at a location within the stack corresponding to the current location of the second endoluminal device. Other applications are also described.

Abstract: Apparatus and methods are described for use with an image of blood vessels of a subject. In response to a user designating a single point on the image (a) a target portion of a blood vessel is automatically identified in the vicinity of the designated point, and (b) quantitative vessel analysis is performed on the target portion of the blood vessel. An output is generated based upon the quantitative vessel analysis. Other embodiments are also described.

Abstract: Apparatus and methods are described including designating within an image of blood vessels of a subject, a target portion of the blood vessels. In response to a first input from a user that designates a single point on the image, a first location within the blood vessels in a vicinity of the designated point is designated. In response to second and third inputs from the user, proximal and distal locations within the target portion are designated. The target portion is designated such that the target portion passes from the proximal location of the target portion to the distal location of the target portion, and such that the target portion includes the first location. Quantitative vessel analysis is performed on the target portion of the blood vessels, and an output is generated based upon the quantitative vessel analysis. Other applications are also described.

Abstract: Apparatus and methods are described for use with a plurality of angiographic image frames of a moving lumen of a subject, including aligning the image frames with each other. Using the aligned image frames, a time it takes a contrast agent to travel a known distance through the lumen is determined. At least partially in response thereto, a characteristic of the lumen is determined, and, in response to the determined characteristic, an output is generated on a display. Other applications are also described.

Abstract: Apparatus and methods for use with a set of angiographic images of a lumen of a subject's body are described. Temporal changes in a density of a contrast agent at a given location within the lumen are analyzed via image processing. In response to the analysis, a characteristic of the lumen at the location is determined, and, in response thereto, an output is generated. Other applications are also described.

Abstract: Apparatus and methods are described including acquiring a plurality of image frames of a blood vessel of a subject, acquisition of the image frames commencing prior to injection of a contrast agent into the blood vessel. A first image frame is identified as being the image frame in which an angiographic sequence commenced by calculating a vesselness descriptor for each one of the image frames, by determining an extent to which pixels within the image frame are likely to correspond to the blood vessel, and by determining that, in the first image frame, there was an increase in the vesselness descriptor relative to at least one image frame acquired prior to the first image frame. An output is generated at least partially in response to identifying the first image frame. Other applications are also described.

Abstract: Apparatus and methods are described for imaging a portion of a body of a subject that undergoes a motion cycle, including acquiring a plurality of image frames of the portion of the subject's body. A given feature is identified in at least some of the image frames. At least some image frames are image tracked with respect to the feature, and the image frames that have been image tracked with respect to the given feature are displayed as a stream of image frames. Visibility of a periphery of the displayed stream of image frames is at least partially reduced. Other applications are also described.

Abstract: Apparatus and methods are described for use with an imaging device (12) configured to acquire a set of angiographic images of a lumen. At least one processor (10) determines blood velocity within the lumen, via image processing. The processor determines a value of a flow-related parameter at the location based upon the determined blood velocity. The processor additionally receives an indication of a value of a second flow-related parameter of the subject, and determines a value of a luminal-flow-related index of the subject at the location, by determining a relationship between the value of the current flow-related parameter and the value of the second flow-related parameter. Other applications are also described.

Abstract: Apparatus and methods are described for use with a lumen including, without generating a virtual three-dimensional model of the lumen, and by performing image processing on two-dimensional angiographic images, determining blood velocity within the lumen, and determining geometry of the lumen at a given location. A value of a current flow-related parameter at the location is determined based upon the determined blood velocity and the geometry of the lumen at the location. An indication of a value of a second flow-related parameter of the subject is received, and a value of a luminal-flow-related index of the subject at the location is determined, by determining a relationship between the value of the current flow-related parameter and the value of the second flow-related parameter. Other applications are also described.

Abstract: Apparatus and methods are described for use with an endoluminal data-acquisition device configured to be moved through a lumen of a subject's body, and a two-dimensional angiographic image of the lumen. A value of a luminal-flow-related index of the subject is determined non-invasively at a plurality of locations along the lumen, at least partially by performing image processing on the angiographic image. While the endoluminal data-acquisition device is being moved through the lumen, a set of endoluminal data points of the lumen at a plurality of locations within the lumen is acquired, using the endoluminal data-acquisition device. It is determined that respective endoluminal data points correspond to respective locations along the lumen, and, in response thereto, it is determined that respective endoluminal data points correspond to respective values of the luminal flow-related index. Other applications are also described.

Abstract: Apparatus and methods are described for imaging a portion of a body of a subject that undergoes a motion cycle. A plurality of image frames of the portion are acquired. The image frames are enhanced with respect to a first given feature of the image frames, by (a) image tracking the image frames with respect to the first given feature, (b) identifying a second given feature in each of the image frames, and (c) in response to the identifying, reducing visibility of the second given feature in the image frames. The image frames that (a) have been image tracked with respect to the first given feature, and (b) have had reduced therein the visibility of the second given feature, are displayed as a stream of image frames. Other embodiments are also described.

Abstract: Apparatus and methods are described including acquiring a first set of extraluminal images of a lumen, using an extraluminal imaging device. At least one of the first set of images is designated as a roadmap image. While an endoluminal device is being moved through the lumen, a second set of extraluminal images is acquired. A plurality of features that are visible within images belonging to the second set of extraluminal images are identified. In response to the identified features in the images belonging to the second set of extraluminal images, a plurality of local calibration factors associated with respective portions of the roadmap image are determined. Other applications are also described.

Abstract: Apparatus and methods are described including, while an endoluminal data-acquisition device is being moved through a lumen of a subject, acquiring a plurality of endoluminal data points of the lumen using the endoluminal data-acquisition device. It is determined that, at at least one location, no endoluminal data point was acquired. An output is generated using at least a portion of the plurality of endoluminal data points of the lumen acquired using the endoluminal data-acquisition device, the output including an indication that no endoluminal data point was acquired at the location. Other applications are also described.

Abstract: Apparatus and methods are provided including, while an endoluminal data-acquisition device is being moved through a lumen of a subject, acquiring a plurality of endoluminal data points of the lumen using the endoluminal data-acquisition device. At at least one location it is determined that an event occurred, the event causing the endoluminal data-acquisition device not to acquire a single endoluminal data point at the location. The endoluminal data points are displayed in a stack, in which the endoluminal data points are positioned at locations corresponding to relative locations within the lumen at which the endoluminal data points were acquired, and in which the event is accounted for. Other applications are also described.

Abstract: Apparatus and methods are described including, while an endoluminal data-acquisition device is being moved through a lumen, acquiring a plurality of endoluminal data points of the lumen using the endoluminal data-acquisition device. The endoluminal data points are displayed in a stack, and are co-registered to respective locations along the lumen in an extraluminal image of the lumen. Based upon the co-registering of the endoluminal data points to respective locations along the lumen in the extraluminal image of the lumen, a parameter of a portion of the lumen that corresponds to a portion of the stack of endoluminal data points is determined. An output is generated in response thereto. Other applications are also described.