Abstract: This discussion extends that review to a description of dual-heads coincidence (DHC).On the imaging reconstruction of DHC, new algorithms using iterative reconstruction that based on the ordered subsets estimation maximization (COSEM) has been developed for coincidence imaging that improved the effect of imaging.The attenuation correction (AC) for the body DHC imaging was performed by the using CT or ¹³⁷Cs.On the comparison of the effect of imaging between AC and no AC, the image quantity of AC imaging is superior to that no AC's.The numerous studies have shown the fusion imaging from coregistered the function imaging of DHC and anatomy imaging of CT or MRI can apply more accurately imaging than DHC only.This paper also compare the efficiency of diagnosis for tumor patients with PET and FDG-DHC.The efficiency of DHC detecting to the mass of >1.5cm was higher, but the mass of <1.5cm was lower.