Relative Contraindications and Limitations to Performance of Hybrid PET/CT and SPECT/CT Studies
| Modality and contraindications | Consequences |
| Coronary artery calcium scoring, coronary CTA or MPI | |
| Pregnancy* | Unknown effects of radiation to fetus; consider alternative tests |
| Clinical instability (acute myocardial infarction, decompensated heart failure, severe hypotension)* | Potentially unsafe for patient |
| Patient unable to cooperate with imaging (motion artifacts) | |
| Body habitus too large for scanner | Imaging not possible |
| Suboptimal image quality | |
| Inability to obtain adequate intravenous access | Imaging not possible |
| Coronary artery calcium scoring, coronary CTA | |
| Atrial fibrillation or frequent atrial or ventricular ectopy* | Motion artifacts on images |
| Inability to hold breath or follow breath-hold instructions | Motion artifacts on images |
| Coronary artery calcium scoring | |
| Metallic implants (pacemaker, implantable cardioverter defibrillator) | Calcium score potentially less reliable |
| Known coronary artery disease (prior myocardial infarction, prior revascularization) | Not indicated clinically |
| Coronary CTA | |
| Known severe allergic reaction or anaphylaxis to iodinated contrast material* | Allergic reaction; consider alternative tests |
| Renal insufficiency | Renal insufficiency worsened with iodinated contrast material |
| Contraindications for β-blocker use (active bronchospasm, severe aortic stenosis) | Limited image quality from motion artifacts |
↵* Absolute contraindications.
CTA = CT angiogram; MPI = myocardial perfusion imaging; CTAC = CT for attenuation correction.
Adapted from (1–3,5,15,28,29).