A 99mTc linear source was made with a plastic cover

and SPECT/CT imaging was performed with a GE Hawkeye hybrid system and patient’s beds under load or nothing.The two kinds of data acquired were reconstructed and fused

and the deviation was quantitatively analyzed by the profiling method.Without load on the patient’s bed

the SPECT and CT images matched perfectly

with the SPECT image center being deviated from that of the CT image at only(1.37±0.96) mm.Under 25-kg load

the deviation of SPECT and CT image centers was(2.21±1.32) and(3.26±1.52) mm for new and old beds

respectively

with the statistical difference of the deviations being P<0.05 between the new and old beds.For the new and old beds under the load or nothing

the deviation of SPECT and CT image centers was significant

P<0.05

with the largest deviation being 6.0 mm.These indicate that the position change of the patient’s bed under load could result in deviation of the SPECT and CT image match

and affect the quality of image fusion.