According to one embodiment, a data detection system for an X-ray CT apparatus includes a data acquisition circuit and a connection structure. The data acquisition circuit includes at least one row of X-ray detection elements arrayed in a channel direction. The data acquisition circuit is configured to acquire data required for generating X-ray CT image data corresponding to the at least one row of the X-ray detection elements. The connection structure is configured to connect the data acquisition circuit with another data acquisition circuit directly or indirectly in a row direction.
