Abstract: Apparatus and methods are described including a processor (20) configured to receive first and second sets of extraluminal images of a lumen, the second set being acquired while an endoluminal device is being moved through the lumen. The processor designates at least one of the first set of images as a roadmap image, and designates, within the lumen in the roadmap image, a roadmap pathway (42). A plurality of features (44, 46, 48, 50) that are visible within at least some of the second set of extraluminal images are identified, and an arrangement of three or more of the features within the image are compared to a shape of at least a portion of the roadmap pathway. Based upon the comparing, the identified features are mapped to locations along the roadmap pathway within the roadmap image. Other applications are also described.

Abstract: Apparatus and methods are described including an endoluminal device configured to move along a portion of a lumen of a subject's body, an extraluminal imaging device, and at least one computer processor. While the endoluminal device moves along the portion of the lumen, a display displays an extraluminal image of the lumen in which a first indication of a location of the lumen is shown. The extraluminal imaging device acquires a sequence of extraluminal images of the endoluminal device moving along the portion of the lumen. The indication of the location of the lumen that is displayed is updated based upon the acquired sequence of extraluminal images, and the acquired sequence of images is displayed with the updated indication of the location of the lumen overlaid upon the images. Other applications are also described.

Abstract: Apparatus and methods are described including receiving, via a computer processor, at least one image of a portion of a subject's body. One or more features that are present within the image of the portion of the subject's body, and that were artificially added to the image subsequent to acquisition of the image, are identified. In response thereto, an output is generated on an output device.

Abstract: Apparatus and methods are described including, using a computer processor, automatically identifying whether a given pixel within an image corresponds to a portion of an object. A set of concentric circles that are disposed around the pixel are sampled, and a first function is applied to each of the circles such that the circles are defined by a first set of rotationally invariant descriptors. A second function is applied to the set of circles to generate a second set of descriptors, each of which represents a difference between respective pairs of the circles. A third function is applied such that the second set of descriptors becomes rotationally invariant. The processor identifies whether the given pixel corresponds to the portion of the object, based upon the first and second sets of rotationally invariant descriptors. Other applications are also described.

Abstract: Apparatus and methods are described for use with an endoluminal device that includes one or more radiopaque portions and that moves through a lumen of a subject. A sequence of radiographic images of a portion of the subject's body, in which the lumen is disposed, is acquired, during movement of the endoluminal device through the lumen. Locations at which the one or more radiopaque portions of the endoluminal device were imaged during the movement of the endoluminal device through the lumen are identified, by analyzing the sequence of radiographic images. A set of locations at which the one or more radiopaque portions were disposed during the movement of the endoluminal device through the lumen is defined, and an endoluminal path of the device through the lumen is estimated based upon the set of locations. Other applications are also described.

Abstract: Apparatus and methods are described for use with a tool that is inserted into a portion of a body of a subject that undergoes cyclic motion. The apparatus and methods include using an imaging device, acquiring a plurality of images of the tool inside the portion of the body, at respective phases of the cyclic motion. Using at least one computer processor, an extent of movement of the tool with respect to the portion of the body that is due to the cyclic motion of the portion of the body is determined. In response thereto, an output is generated that is indicative of the determined extent of the movement of the tool with respect to the portion of the body. Other applications are also described.

Abstract: Apparatus and methods are described for imaging a tool inside a portion of a subject's body that undergoes motion. A plurality of image frames are acquired of the portion of the subject's body. The image frames are image tracked by (a) automatically identifying at least a feature of the tool in at least a portion of the image frames, and (b) aligning the tool in image frames of the portion of the image frames, based on the automatic identifying. The image-tracked image frames of the portion of the subject's body are displayed as an image stream. Other embodiments are also described.

Abstract: Apparatus and methods are described including an endoluminal device configured to move along a portion of a lumen of a subject's body, an extraluminal imaging device, and at least one computer processor. While the endoluminal device moves along the portion of the lumen, a display displays an extraluminal image of the lumen in which a first indication of a location of the lumen is shown. The extraluminal imaging device acquires a sequence of extraluminal images of the endoluminal device moving along the portion of the lumen. The indication of the location of the lumen that is displayed is updated based upon the acquired sequence of extraluminal images, and the acquired sequence of images is displayed with the updated indication of the location of the lumen overlaid upon the images. 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 are described including a processor (20) configured to receive first and second sets of extraluminal images of a lumen, the second set being acquired while an endoluminal device is being moved through the lumen. The processor designates at least one of the first set of images as a roadmap image, and designates, within the lumen in the roadmap image, a roadmap pathway (42). A plurality of features (44, 46, 48, 50) that are visible within at least some of the second set of extraluminal images are identified, and an arrangement of three or more of the features within the image are compared to a shape of at least a portion of the roadmap pathway. Based upon the comparing, the identified features are mapped to locations along the roadmap pathway within the roadmap image. 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 including receiving, via a computer processor, at least one image of a portion of a subject's body. One or more features that are present within the image of the portion of the subject's body, and that were artificially added to the image subsequent to acquisition of the image, are identified. In response thereto, an output is generated on an output device.

Abstract: Apparatus and methods are described including, using a computer processor (28), automatically identifying whether a given pixel (111) within an image corresponds to a portion of an object. A set of concentric circles (132a-c) that are disposed around the pixel are sampled, and a first function is applied to each of the circles such that the circles are defined by a first set of rotationally invariant descriptors. A second function is applied to the set of circles to generate a second set of descriptors, each of which represents a difference between respective pairs of the circles. A third function is applied such that the second set of descriptors becomes rotationally invariant. The processor identifies whether the given pixel corresponds to the portion of the object, based upon the first and second sets of rotationally invariant descriptors. 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 provided for use with an endoluminal data-acquisition device that acquires a set of endoluminal data-points of a lumen of a subject's body at respective locations inside the lumen, a second endoluminal device, and a display configured to display images. At least one processor includes location-association functionality that associates a given data point acquired by the endoluminal data-acquisition device with a given location within the lumen. Location-determination functionality determines, by means of image processing, in an extraluminal image of the second endoluminal device, a current location of at least a portion of the second endoluminal device. Display-driving functionality drives the display to display an indication of the endoluminal data point associated with the location, in response to determining that the portion of the second device is currently at the location. Other applications are also described.

Abstract: Apparatus and methods are described for receiving into at least one processor a set of images of blood vessels of a subject. A road map of the subject's blood vessels is generated, by automatically (a) deriving at least one image from the set of images of the blood vessels, based upon visibility of at least a portion of the blood vessels in the set of images, and (b) in the derived image, determining a location of edge lines of at least some of the portion of the blood vessels in the image. An output is generated by the processor, based on the road map. Other embodiments are also described.

Abstract: Apparatus and methods are described including generating a road map of a blood vessel in a portion of a subject's body. A given feature that is within the portion of the subject's body is identified in the road map, the given feature being visible even in images of the portion the generation of which does not include use of a contrast agent. A tool is inserted into the blood vessel, and a current location of a portion of the tool is determined with respect to the given feature, by imaging the tool and the feature. In response to the determined current location, a current position of the tool within the road map is determined. In response to determining the current position of the tool within the road map, the current position of the tool with respect to the road map is displayed. Other embodiments are also described.

Abstract: Apparatus and methods are described, including, using an imaging device, acquiring a plurality of images of a portion of a body of a subject. Using a processor, a first feature within each of the images is aligned. At least one enhanced image that is enhanced with respect to the first feature is generated, using the aligned images. Visibility of a second feature is reduced in the enhanced image, and the at least one image that is enhanced with respect to the first feature is displayed upon a display. Other applications are also described.

Abstract: Apparatus and methods are described including, using a computer processor (28), automatically identifying whether a given pixel (111) within an image corresponds to a portion of an object. A set of concentric circles (132a-c) that are disposed around the pixel are sampled, and a first function is applied to each of the circles such that the circles are defined by a first set of rotationally invariant descriptors. A second function is applied to the set of circles to generate a second set of descriptors, each of which represents a difference between respective pairs of the circles. A third function is applied such that the second set of descriptors becomes rotationally invariant. The processor identifies whether the given pixel corresponds to the portion of the object, based upon the first and second sets of rotationally invariant descriptors. Other applications are also described.

Abstract: Apparatus and methods are provided for imaging a tool inside a portion of a subject's body that undergoes motion. A plurality of image frames of the portion are acquired. An image frame in which the tool is enhanced is generated by (a) identifying radiopaque markers in the image frames, (b) identifying edge lines in a vicinity of the markers within the image frames, the edge lines corresponding to contours of the tool, (c) in response to the identifying of the edge lines, selecting a subset of the image frames that are based upon the acquired image frames, based upon a level of similarity between the edge lines in the selected image frames to one another, (d) aligning the contours in a plurality of the selected image frames, and (e) averaging the plurality of aligned frames to generate an averaged image frame. Other applications are also described.