A syringe for use with a powered injector to inject a fluid into a patient inclides an encoder. The encoder includes at least a first indicator positioned on the encoder. The first indicator is adapted to interact with at least a portion of energy being propagated through or adjacent the encoder in a manner that is detectable. The presence (or absence) of the first indicator provides or corresponds to information about the syringe configuration. The indicator(s) of the present invention can, for example, provide information about syringe configuration by the number and/or position thereof. A plurality or set of such syringes can be provided, with the configuration of each such syringe being represented by the presence or absence of indicator(s) of that syringe.