Patent ID: 7016453

Claim:
A CT system for use in interventional procedures on a patient supported by a support surface, having: a radiation source which moves relative to the patient to irradiate the patient over an irradiation field; a radiation detector which detects radiation from the source; an imager which reconstructs raw data acquired by the detector into images of the patient; at least one presence detector operative to, indicate the presence of a person other than the patient in the irradiation field, the presence detector including an analysis circuitry which analyzes at least one of: the raw data acquired by the detector, the images reconstructed by the imager, projection data, and changes in an output from the detector; a control system which controls the radiation source to irradiate the patient in (1) a normal mode and (2) a reduced angle mode in which the patient is irradiated only from directions at which the other person is not indicated to be present in a radiation path between the radiation source and the patient, the control system switching from the normal mode to the reduced angle mode in response to said detection of the other person in the irradiation field.