Patent ID: 9629557
Date: 2017-04-25
CPC Classifications: A61B

Claim:
1. A photoacoustic image generation apparatus comprising: an acoustic wave detector that includes a plurality of detector elements arranged in a line, and detects, after light has been output to a subject to be examined, a photoacoustic wave induced in the subject by the output light; a dummy data adder that adds dummy data corresponding to the at least one virtual detector element to photoacoustic data in which pieces of data of the photoacoustic wave detected by the plurality of detector elements in the acoustic wave detector, respectively; and an image generator that generates a photoacoustic image by reconstructing the photoacoustic data to which the dummy data have been added by using a two-dimensional Fourier transform method, wherein the reconstruction by using the Fourier transform method includes performing two-dimensional Fourier transform on the photoacoustic data to which the dummy data have been added and performing two-dimensional inverse Fourier transform on the photoacoustic data on which the two-dimensional Fourier transform has been performed, wherein the at least one of virtual detector element is arranged by a channel pitch, which is the same as a channel pitch of the detector elements in the acoustic wave detector, outside of an arrangement of the plurality of detector elements in a direction of arrangement of the detector elements along with the line of the detector elements, and wherein the photoacoustic data to which the dummy data have been added in which pieces of data detected by each the detector elements and pieces of data added for the at least one of virtual detector element are arranged in accordance with the positions of the detector elements and the positions of the at least one of the virtual detector element in the line, respectively where an angle from a straight line perpendicular to an acoustic wave detection surface of the acoustic wave detector is α and the center frequency is f, and a depth determined based on the center frequency f is D(f), the angle α is determined based on a value obtained by dividing the sound velocity of an acoustic wave traveling in the subject to be examined by the product of the channel pitch of the detector elements and the center frequency of the detector elements, the number of the at least one virtual detector element is determined such that the at least one virtual detector elements is arranged at the channel pitch within a length represented by a product of D(f) and tan α; an image masker that masks a mask area in the generated photoacoustic image, wherein the mask area is an area from a mask line, which includes a pixel corresponding the detector element of the end of the detector elements arranged in the line, toward opposite to an area including pixels corresponding the detector elements arranged in the line, the mask line is a straight line extending at the angle a from a straight line in the photoacoustic image corresponding to a straight line perpendicular to an acoustic wave detection surface of the acoustic wave detector and extending outside an real data area in the photoacoustic image, wherein the real data area is an area generated from the photoacoustic data obtained by the detector elements.