Apparatus and method for CT data reconstruction based on motion compensation

An apparatus for computed tomography (CT) data reconstruction based on motion compensation, the apparatus comprising:

• a storage configured to store N CT projection radiographs, wherein N is a total number of the stored CT projection radiographs, which is equal to or greater than 2;
• and
• an image processor configured to obtain pairs of opposite projection radiographs from the N CT projection radiographs, and to determine whether or not a radiography subject has moved based on a correlation between the projection radiographs of each pair of opposite projection radiographs,
• wherein each of the N/2 pairs of opposite projection radiographs includes a first projection radiograph and a second projection radiograph, and for each of the N/2 pairs of opposite projection radiographs, the image processor is further configured to determine both a first motion vector for the second projection radiograph based on the first projection radiograph and a second motion vector for the first projection radiograph based on the second projection radiograph,
• wherein the image processor is further configured to perform smoothing filtering on determined N/2 first motion vectors, and to perform the smoothing filtering on determined N/2 second motion vectors, and
• wherein for each of the N/2 pairs of opposite projection radiographs, the image processor is further configured to
• (i) perform the motion compensation on the second projection radiograph using the first motion vector so as to generate motion-compensated second projection radiographs,
• (ii) reconstruct a first sectional image from the motion-compensated second projection radiograph and remaining CT projection radiographs except for second projection radiographs of the N CT projection radiographs,
• (iii) perform the motion compensation on the first projection radiograph using the second motion vector so as to generate motion-compensated first projection radiographs,
• (iv) reconstruct a second sectional image using the motion-compensated first projection radiographs and remaining CT projection radiographs except for first projection radiographs of the N CT projection radiographs,
• (v) identify which image of the first sectional image and the second sectional image has higher resolution, and
• (vi) determine the motion-compensated second projection radiograph as the motion-compensated projection radiograph when identifying resolution of the first sectional image is higher than resolution of the second sectional image,
• or determine the motion-compensated first projection radiographs as the motion-compensated projection radiographs when identifying the resolution of the second sectional image is higher than the resolution of the first sectional image.

An apparatus for computed tomography (CT) data reconstruction based on motion compensation, the apparatus comprising:

• a storage configured to store N CT projection radiographs, wherein N is a total number of the stored CT projection radiographs, which is equal to or greater than 2;
• and
• an image processor configured to:
• obtain pairs of opposite projection radiographs from the N CT projection radiographs, wherein each pair includes a first projection radiograph and a second projection radiograph;
• for each pair, determine whether a radiography subject has moved based on a correlation between the first projection radiograph and the second projection radiograph;
• for each pair, when the radiography subject is determined as moved, generate a first motion-compensated projection radiograph using the second projection radiograph, generate a second motion-compensated projection radiograph using the first projection radiograph;
• for each pair, select one of the first motion-compensated projection radiograph and the second motion-compensated projection radiograph;
• when the first motion-compensated projection radiograph is selected, reconstruct CT data using the first motion-compensated projection radiographs of the N/2 pairs and the second projection radiographs of the N/2 pairs;
• and
• when the second motion-compensated projection radiograph is selected, reconstruct CT data using the second motion-compensated projection radiographs of the N/2 pairs and the first projection radiographs of the N/2 pairs.