A nuclear medicine (NM) imaging system having attenuation correction (AC) has a stationary portion having an NM rotating portion mounted thereon. At least one gamma camera head is mounted on the NM rotating portion proximate a front side of the stationary portion and is configured to be rotated about a central axis. An AC portion comprises an X-ray source mounted on an AC rotating portion. The AC rotating portion is mounted proximate a back side of the stationary portion. The X-ray source is configured to be rotated about the central axis.