Patent Number: 6,310,968

Title: Source-assisted attenuation correction for emission computed tomography

Abstract: A method of ML-EM image reconstruction is provided for use in connection with a diagnostic imaging apparatus (10) that generates projection data. The method includes collecting projection data, including measured emission projection data. An initial emission map and attenuation map are assumed. The emission map and the attenuation map are iteratively updated. With each iteration, the emission map is recalculated by taking a previous emission map and adjusting it based upon: (i) the measured emission projection data; (ii) a reprojection of the previous emission map which is carried out with a multi-dimensional projection model; and, (iii) a reprojection of the attenuation map. As well, with each iteration, the attenuation map is recalculated by taking a previous attenuation map and adjusting it based upon: (i) the measured emission projection data; and, (ii) a reprojection of the previous emission map which is carried out with the multi-dimensional projection model. In a preferred embodiment, with source-assisted reconstruction, the recalculation of the attenuation map is additionally based upon: (iii) measured transmission projection data; and, (iv) a reference or blank data set of measured transmission projection data taken without the subject present in the imaging apparatus (10).

Inventors: Hawkins; William G. (Shaker Heights, OH), Gagnon; Daniel (Twinsburg, OH)

Assignee: Picker International, Inc.

International Classification: G01T 1/00 (20060101); G01T 1/29 (20060101); G06K 009/00 ()

Expiration Date: 10/30/2018