1. A method for producing a time-resolved three-dimensional image of a subject, the method comprising: acquiring image projection data from the subject using a medical imaging system during a single contrast injection, the medical imaging system including a single source/single detector system; generating a time-series of two-dimensional images from at least a portion of the acquired image projection data; reconstructing a three-dimensional image substantially without temporal resolution from at least a portion of the acquired image projection data; selecting, for each two-dimensional image in the time-series, a current image and a paired image; multiplying, for each two-dimensional image in the time-series, the current image into the three-dimensional image substantially without temporal resolution to determine a first product value; multiplying, for each two-dimensional image in the time-series, the paired image into the three-dimensional image substantially without temporal resolution to determine a second product value; taking the square root of the multiplication of the first and second product values to produce a frame of a time-resolved three-dimensional image having a signal-to-noise ratio substantially higher than a signal-noise-ratio of the acquired image projection data, wherein one or more voxels in the frame is nullified based on the current image or the paired image; and combining frames of the time-resolved three-dimensional image to form the time-resolved three-dimensional image.