Leland Stanford Junior University

Billy W Loo, Jr

Peter G Maxim

Lei Xing

Maximilian Diehn

Paul J Keall

Amit Ramakant Sawant

Yelin Suh

Eric Johnston

Byung Chul Cho

A method and system are disclosed for estimating internal position information of a target in real-time based on a single gantry-mounted x-ray imager and a respiratory signal. The x-ray imaging is done periodically to limit radiation dosage. Initial parameters for the estimation model are determined in a pre-treatment session using four dimensional computed tomography (4D CT) in combination with a respiratory signal acquired from the patient. The model parameters are updated during treatment based on the periodic x-ray image data and the respiratory signal.

Method and apparatus for real-time 3D target position estimation by combining single x-ray imaging and external respiratory signals

Improved 4D imaging reconstruction is provided for a freely breathing patient. 3D patient images from an imaging dataset are binned according to respiratory displacement or phase. The bins are defined by ranges, so every image in the raw 3D data set is included in a bin. Since binning in this manner often results in two or more images per bin, the 4D reconstruction is determined by selecting one 3D image from each bin at each patient position. This selection is performed so as to maximize the anatomical similarity of 3D images at adjacent patient positions. In cases where the 3D images include multiple slices, a 2D comparison of the closest slices can be used to determine anatomical similarity of the 3D images.

4D anatomically based image selection procedure for medical imaging

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Foster City, CA, United States of America

Billy W Loo, Jr