A tomographic imaging system includes a source configured to irradiate an object; a first image sensor including a first semiconductor substrate having a first face upon which a monolithic first pixel array is located; and a gantry configured to hold the first image sensor and rotate the image sensor around the object about a first rotation axis, the first pixel array including a first plurality of pixels configured to receive light that travels through or from the object based on the irradiation, the first plurality of pixels of the first pixel array being arranged in one or more rows and a plurality of columns such that, a total number of the one or more rows is less than a total number of the plurality of columns, and the one or more rows extend in a first direction, the first image sensor being arranged such that an angle between the first direction and a second direction is greater than 45 degrees and equal to or less than 90 degrees, the second direction being a direction parallel to the rotation axis or a direction in which the object moves during analysis of the object by the imaging system.