The effect of arm position on respiratory motion of the heart: Implications for emission imaging

Myocardial perfusion imaging (MPI) in SPECT and PET is procedurally performed with the patient´s arms raised above their heads to reduce the attenuation artifacts, and allow close approach of camera heads. There is no data currently presenting the heart motion with respect to the arm positions during imaging. Using MRI navigator technique. Ten volunteers were imaged by MRI with Navigator tracking of liver and heart superior / inferior motion i to investigate the variations in the respiratory motion of the heart with arms raised above the head as commonly employed in SPECT and PET cardiac imaging versus arms kept beside (parallel to) the body. The navigator data containing the motion information from the heart was statistically compared between the two postures. No significant differences were noted between the two arm positions in the same patients. In conclusion, the arm position does not significantly affect the motion of the heart during imaging.