1. A method for reducing mis-registration during multiple energy scanning on computed tomographic (CT) imaging systems or multiple energy electron beam tomography (EBT) systems, said method comprising: scanning a portion of a patient including a cyclically moving body part using a multiple energy computed tomographic (CT) imaging system or multiple energy electron beam tomography (EBT) system having at least two different energies; monitoring characteristics of the cyclically moving body part; gating the multiple energy CT imaging system or multiple energy EBT system in accordance with the monitored characteristics of the cyclically moving body part so that acquisitions are acquired at at least two different kvps; and utilizing data acquired at the different kVps to generate material decomposition images of the cyclically moving body part.