ALTERATIVE NOISE MAP ESTIMATION METHODS FOR CT IMAGES

摘要

Noise map for CT images have been estimated by generalizing the prior art even-and-odd views approach. One example is to estimate a noise map from images reconstructed from three sets of independent views. A second example is to estimate a noise map from images reconstructed by using two sets of correlated views. A third example is to estimate a noise map from noise map from two images reconstructed from two sets of independent views while the number of views in each set is unequal. Physical phantom data were employed to validate our proposed noise map estimation methods. In comparison to the existing method, our alternative methods yield reasonably accurate noise map estimation.

主权项

1. A method of estimating a noise map from reconstructed images, comprising:
acquiring data for a predetermined first number of views; grouping the views into two groups with some of the views that are correlated between the two groups, one of the two groups having a predetermined second number of the views, the other one of the two groups having a predetermined third number of the views, either one of the predetermined second number and the predetermined third number being less than the predetermined first number of the views; reconstructing two images from the two groups of the views; and estimating variance based upon the two reconstructed images and a weight.