A patient identification method and related system use dynamic medical images of a patient, such as dynamic chest x-ray images, to generate pulsation and/or perfusion signals and use them for patient identification. A first pulsation and/or perfusion signal acquired from a current patient is compared to a previously stored second pulsation and/or perfusion signal associated with a known patient, to determine whether the current patient is the same as the known patient. At least one of the first and second pulsation and/or perfusion signals is generated from dynamic medical images. In some embodiments, one of the first and second pulsation and/or perfusion signals is pulsation-like signal obtained from electrocardiogram (ECG). When the current patient is determined to be different from the known patient, warning signals can be generated, and further steps can be taken to prevent medical procedures being conducted on the wrong patient.