Feasibility of exercise treadmill 13N-ammonia positron emission tomography myocardial perfusion imaging using an off-site cyclotron

J Nucl Cardiol. 2022 Jun;29(3):938-945. doi: 10.1007/s12350-020-02366-z. Epub 2020 Oct 18.


Background: Myocardial perfusion imaging with treadmill exercise nitrogen-13 (13N)-ammonia positron emission tomography (PET) presents a logistical challenge. We investigated the feasibility of exercise treadmill (GXT) 13N-ammonia PET MPI using an off-site cyclotron for production of 13N-ammonia.

Methods: Thirty-three patients underwent GXT 13N-ammonia PET MPI over 23 months. 13N-ammonia doses were prepared at an off-site cyclotron. Patients underwent 13N-ammonia resting and 13N-ammonia GXT emission and transmission scans at our facility. Image quality, perfusion data, and clinical variables were evaluated.

Results: We analyzed 33 patients (7/26 female/male). Mean age was 63 ± 12 years and mean BMI was 33.7 ± 6.9. GXT PET was feasible in all patients. Image quality was good in 29 patients, adequate in 3, and severely compromised in 1 patient. Summed stress score was 4.5 ± 5.7. Resting and GXT left ventricular ejection fractions were 63.7 ± 10.9% and 66.3 ± 13.1%. TID ratio was 1.0 ± 0.1.

Conclusions: Treadmill exercise 13N-ammonia PET is feasible in a large medical center without access to an on-site cyclotron. This technique requires close coordination with an off-site cyclotron but expands the role of PET to patients for whom exercise is more appropriate than pharmacologic stress imaging.

Keywords: 13N-ammonia; PET; cyclotron; exercise.

MeSH terms

  • Aged
  • Ammonia*
  • Cyclotrons
  • Feasibility Studies
  • Female
  • Humans
  • Male
  • Middle Aged
  • Myocardial Perfusion Imaging* / methods
  • Nitrogen Radioisotopes
  • Positron-Emission Tomography / methods
  • Tomography, X-Ray Computed


  • Nitrogen Radioisotopes
  • Nitrogen-13
  • Ammonia