A Hybrid Emission CT - HEADTOME II

HEADTOME II for a hybrid emission computed tomography for brain has been developed. The system includes multislice capability of both positron emission tomography (PET) and single photon emission tomography (SET) in one system. It consists of three detector rings of 42cm in diameter on which 64 NaI crystals are arranged per ring, 192 as a total. Four kinds of collimators are prepared: high resolution (HR) collimator and high sensitivity (HS) collimator for both SET and PET. The tangential spatial resolution is 6.5mm-11mm for SET with the HR collimator and 10.5mm-20mm with the HS collimator measured with 99mTc line source. System sensitivity with the single photon HS collimator is 58.5 kcps/μCi/ml for a 20cm diameter uniform solution of 99mTc. System sensitivity with the positron HS collimator is 25 kcps/μCi/ml for 68Ga solution.