System and method for high-temporal resolution, time-resolved cone beam ct angiography

A method for reconstructing an image using a cone-beam computed tomography (CT) imaging system, the steps of the method comprising:

• a) acquiring data from a subject with the CT imaging system, the acquired data acquired using a short scan of less than 360 degrees and containing a plurality of data consistency classes;
• b) reconstructing an image of the subject from the data acquired in step a), the image of the subject containing artifacts associated with the data inconsistencies;
• c) forming an image matrix having a first column corresponding to the image reconstructed in step b);
• d) computing a target image matrix by iteratively updating the image matrix formed in step c) by minimizing a matrix rank of the image matrix subject to a data consistency condition such that each column of the computed target image matrix corresponds to a different one of the plurality of data consistency classes;
• and
• e) providing each column of the target image matrix computed in step d) as an image of the subject that is substantially free of artifacts to produce a series of images of the subject at a first temporal resolution;
• f) deconvolving the series of images of the subject at the first temporal resolution using a finite temporal window to generate a series of images of the subject with second temporal resolution that is higher than the first temporal resolution;
• and
• g) subtracting the series of images of the subject with the second temporal resolution and from mask images of the subject to generate a time-resolved CT angiogram of the subject.

A cone-beam computed tomography (CT) system comprising:

• an x-ray source and associated detectors configured to acquire imaging data from a subject over a range of view angles;
• a computer system including a processor configured to:
• a) control operation of the x-ray source and associated detectors to acquire data from a subject with the CT imaging system using a limited scan range that is less than 360 degrees;
• b) initialize an image matrix having columns that each correspond to a different image;
• c) reconstruct at least one image of the subject having a first temporal resolution from the data acquired in step a) by:
• i) minimizing a matrix rank of the image matrix;
• ii) constraining the rank minimization of step c)i) subject to a consistency condition that promotes a forward projection of each column in the image matrix to be consistent with a different subset of the acquired data, each subset of the acquired data containing data that are consistent with each other while being inconsistent with data in other subsets of the acquired data;
• d) perform a temporal deconvolution of the at least one image using a finite temporal window to generate at least one image of the subject with a second temporal resolution that is greater than the first temporal resolution;
• and
• e) subtract the at least one image of the subject with the second temporal resolution and a mask image of the subject to generate a time-resolved CT angiogram of the subject.