System and method of iterative image reconstruction for computed tomography

A method comprising:

• acquiring a projection dataset from an object using a medical imaging device, the projection dataset comprising a plurality of projection measurements representing attenuation of x-rays by the object;
• generating a modified statistical weighting matrix comprising a plurality of weights that deviate from an inverse variance in the plurality of projection measurements;
• and
• reconstructing an image of the object based on the modified statistical weighting matrix.

An imaging system comprising:

• a rotatable gantry having an opening for receiving an object to be scanned;
• an x-ray source coupled to the rotatable gantry and configured to project x-rays through the opening;
• a generator configured to energize the x-ray source to an energy level to generate x-rays corresponding to the energy level;
• a detector having pixels therein, the detector attached to the rotatable gantry and positioned to receive x-rays projected from the x-ray source;
• and
• a computer programmed to:
• access a CT projection dataset acquired from the object over a period of data acquisition;
• calculate a set of modified statistical weights for an iterative reconstruction algorithm using a scalar parameter tuned to differentiate projection rays of the CT projection dataset having differing attenuation values;
• and
• iteratively reconstruct the CT projection dataset using the set of modified statistical weights as coefficients in the iterative reconstruction algorithm.