When performing nuclear (e.g., SPECT or PET) and CT scans on a patient, an imaging system (10) includes three or more carbon nanotube x-ray sources (20) are circumferentially spaced along an arc of a rotatable gantry (16) that spans a distance larger than a maximum cross-sectional dimension of a section of a patient (14) to be imaged. The x-ray sources are sequentially pulsed to emit x-rays for scanning a section of a patient (14) including a volume of interest (VOI) (13). Only one source (20) is in an ON state at a time to create a duty cycle, which reduces cooling time for the respective sources as well as radiation dose to the subject. X-rays traversing the patient (14) are received at a flat panel x-ray detector (22) that has a width smaller than the maximum cross-sectional dimension, which further reduces the weight and size of the system (10).
