An ultrasound computed tomography diagnostic system comprising: a plurality of elements configured to perform at least one of emission of ultrasound to a test object and reception of reflected ultrasound that is ultrasound reflected from the test object; a data collection unit configured to collect measurement data of the reflected ultrasound through at least one of the plurality of elements while switching an element that emits ultrasound; an image acquisition unit configured to perform steps of extracting, from the collected measurement data, partial measurement data corresponding to a point of interest, inputting the partial measurement data to a first learner, and acquiring pixel values of a partially reconstructed image output from the first learner, wherein the image acquisition unit is configured to repeatedly perform the steps for a plurality of points of interest included in a region of interest in order to reconstruct a tomographic image corresponding to the region of interest of the test object; an image display device configured to display said reconstructed tomographic image corresponding to the region of interest of the test object; and the first learner using a neural network, the first learner being configured to learn using training data including a test-object model and simulation measurement data and to output the partially reconstructed image from the partial measurement data which is input to the first learner, the test-object model being expressed by a distribution of acoustic features, the simulation measurement data being obtained by emitting ultrasound while switching an element that emits ultrasound and receiving reflected ultrasound from the test-object model using at least one of the plurality of elements in a simulation space in which a size and an arrangement of the plurality of elements are simulated. a plurality of elements configured to perform at least one of emission of ultrasound to a test object and reception of reflected ultrasound that is ultrasound reflected from the test object; a data collection unit configured to collect measurement data of the reflected ultrasound through at least one of the plurality of elements while switching an element that emits ultrasound; an image acquisition unit configured to perform steps of extracting, from the collected measurement data, partial measurement data corresponding to a point of interest, inputting the partial measurement data to a first learner, and acquiring pixel values of a partially reconstructed image output from the first learner, wherein the image acquisition unit is configured to repeatedly perform the steps for a plurality of points of interest included in a region of interest in order to reconstruct a tomographic image corresponding to the region of interest of the test object; an image display device configured to display said reconstructed tomographic image corresponding to the region of interest of the test object; and the first learner using a neural network, the first learner being configured to learn using training data including a test-object model and simulation measurement data and to output the partially reconstructed image from the partial measurement data which is input to the first learner, the test-object model being expressed by a distribution of acoustic features, the simulation measurement data being obtained by emitting ultrasound while switching an element that emits ultrasound and receiving reflected ultrasound from the test-object model using at least one of the plurality of elements in a simulation space in which a size and an arrangement of the plurality of elements are simulated.