Patent ID: 7688935

Claim:
A CT system comprising: a rotatable gantry having an opening for receiving a subject to be scanned; an HF electromagnetic energy source configured to project a number of HF electromagnetic energy beams toward the subject; a generator configured to energize the HF electromagnetic energy source to at least a first energy state and a second energy state; a first filtering apparatus comprising: a hub; and a number of HF electromagnetic energy filters attached to the hub and positional between the HF electromagnetic energy source and the subject, the number of HF electromagnetic energy filters including at least a first filter and a second filter wherein at least the first filter is positioned between the HF electromagnetic energy source and the subject by rotation of the hub to a first filter position in synchronization with the HF electromagnetic energy source being energized to the first energy state, and at least the second filter is positioned between the HF electromagnetic energy source and the subject by rotation of the hub to a second filter position in synchronization with the HF electromagnetic energy source being energized to the second energy state; and wherein rotation of the hub between the first filter position and the second filter position is about an axis of rotation that is substantially parallel to an axis of rotation of the rotatable gantry of the CT system.