Abstract: The present disclosure discloses a detector module, a detector, and a medical imaging apparatus. The detector module includes a detection unit, analog-to-digital conversion units, and a signal transmission unit. The detection module is configured to convert an optical signal into an analog signal. The analog-to-digital conversion units each configured to convert an analog signal into a digital signal. The signal transmission unit is disposed at a side of the detection unit in a first direction and includes at least one first circuit board and second circuit boards. Each of the at least one first circuit board is connected to the detection unit and a plurality of the second circuit boards. Each of the second circuit boards is connected to at least one of the analog-to-digital conversion units.