A gantry includes two X-ray source rings and a detector ring. Each X-ray source ring includes a plurality of X-ray sources arrayed circumferentially. The detector ring is provided next to the X-ray source ring and includes a plurality of X-ray detectors arrayed circumferentially. Each of the plurality of X-ray detectors detects X-rays from the X-ray source ring. A data collection circuit collects raw data corresponding to the intensity of the detected X-rays. A reconstruction unit reconstructs the collected raw data into a CT image based on digital data.
