Method and device for acquiring tomographic image data by oversampling, and control program

A tomographic image data acquisition device comprising:

• a detection device having N detection elements arranged in at least one row where N is an integer greater than or equal to 1;
• and
• a control device that controls the detection device so that the detection device detects waves or particles after the waves or particles are transmitted each part of an object disposed in a detection range of the detection device by each of the detection elements in a detection direction, wherein the detection direction is changed with respect to the object while irradiation of the waves or particles toward the detection device by an emission device is performed, or while the waves or particles not generated by the emission device are transmitted through each part of the object and wherein the waves or particles are detectable by the detection device,
• wherein the tomographic image data acquisition device further comprises:
• a decimation sequence storage unit that stores sequence data representing a decimation order;
• and
• a discrete inverse Radon transform matrix storage unit for storing a discrete inverse Radon transform matrix, and
• wherein the control device comprises:
• a discrete Radon transform processing unit for changing the detection direction over (N+n) directions that are not overlapped with each other in a relative detection direction for the waves or particles viewed from the object and for making the detection device output a detection signal for an oversampled sinogram with (N+n) rows and N columns, each row and each column of which are associated with each detection direction and each detection element, respectively;
• a vectorization processing unit for obtaining from the detection signal a first vector having N×(N+n) elements corresponding to those obtained by vectorizing the oversampled sinogram;
• a vector decimation processing unit for removing n×N elements according to a sequence data representing the decimation order from the first vector and for obtaining a second vector having the remaining N×N elements;
• a discrete inverse Radon transform processing unit for obtaining a third vector having N×N elements by operating the discrete inverse Radon transform matrix to the second vector;
• and
• an image data generation unit for de-vectorizing the third vector and for obtaining image data for a two-dimensional tomographic image with N pixels×N pixels having a pixel arrangement that is stationary with respect to the object.

A control program for an acquisition device of the tomographic image data, the acquisition device having:

• a detection device having N detection elements arranged in at least one row where N is a positive integer;
• and
• a control device that controls the detection device so that the detection device detects waves or particles after the waves or particles are transmitted each part of an object disposed in a detection range of the detection device for the waves or particles by each of the detection elements in a detection direction, wherein relative detection direction for the waves or particles is changed with respect to the object while irradiation of the waves or particles toward the detection device by an emission device is performed, or while the waves or particles not generated by the emission device are transmitted through each part of the object and wherein the waves or particles are detectable by the detection device,
• wherein the control program makes the control device to perform:
• processing a discrete Radon transform in which the detection device is made to output a detection signal for an oversampled sinogram with (N+n) rows and N columns (n is an integer greater than or equal to 1), each row and each column of which are associated with each detection direction and each detection element, respectively, while changing the detection direction over (N+n) directions that are not overlapped with each other in a relative detection direction for the waves or particles viewed from the object;
• obtaining from the detection signal a first vector with N×(N+n) elements corresponding to those obtained by vectorizing oversampled sinogram;
• retrieving a sequence data representing a decimation order from a decimation sequence storage unit and obtaining a second vector having the remaining N×N elements by removing n×N elements from the first vector according to the sequence data;
• retrieving a discrete inverse Radon transform matrix from a discrete inverse Radon transform matrix storage unit and obtaining a third vector having N×N elements by operating the discrete inverse Radon transform matrix to the second vector;
• and
• obtaining image data for a two-dimensional tomographic image of N pixels×N pixels having a pixel arrangement stationary with respect to the object by de-vectorizing the third vector.