Method for three-dimensional localization of an object from a two-dimensional medical image

摘要

A method for determining the three-dimensional location of an object in real-time from a two-dimensional medical image obtained with a medical imaging system is provided. For example, the three-dimensional location of an interventional medical device or a marker positioned on such a device may be determined from a two-dimensional x-ray image obtained with an interventional x-ray imaging system. Template images corresponding to the object under different imaging geometries and orientations are produced and are compared to images acquired with the medical imaging system. Similarity measures, such as normalized cross correlation and normalized similarity integral, are used to determine the similarity between a selected template image and the medical images in different stages of refining the position information for the object.

主权项

1. A method for determining a three-dimensional location of an interventional medical device using a two-dimensional x-ray image obtained with an x-ray imaging system, the steps of the method comprising:
a) obtaining x-ray images with the x-ray imaging system; b) producing an initial image by down-sampling one of the obtained x-ray images by a down-sampling factor; c) determining an initial position estimate of the medical device using the initial image produced in step b); d) updating the initial position estimate by iteratively calculating a shift-invariant similarity measure between the initial image and a template image, the template image depicting a synthesized x-ray projection of the medical device positioned at the initial position estimate, in which the initial position estimate and template image are updated in successive iterations and the shift-invariant similarity measure is iteratively calculated until the shift-invariant similarity measure exceeds a threshold value; e) refining the updated position estimate by iteratively calculating a shift-variant similarity measure between the image and a template image, the template image depicting a synthesized x-ray projection of the medical device positioned at the updated position estimate, in which the updated position estimate and template image are updated in successive iterations and the shift-variant similarity measure is iteratively calculated until the shift-variant similarity measure exceeds a threshold value; and f) determining from the refined position estimate, at least one of the three-dimensional location and orientation of the medical device.