Synopsis
Choose cardiac magnetic resonance or radionuclide perfusion for the clinical question, interpret perfusion together with function and tissue pattern, recognise artefact and balanced ischaemia, and translate the result into a safe coronary or non-ischaemic disease pathway.
- CMR combines cine ventricular function, anatomy, oedema and parametric mapping, first-pass perfusion and late gadolinium enhancement in one examination.
- Cine imaging quantifies volumes and ejection fraction without geometric assumptions, while regional wall motion may reveal ischaemia, infarction or cardiomyopathy.
- After uncertain or non-diagnostic CT coronary angiography in stable chest pain, first-pass contrast-enhanced MR perfusion and myocardial perfusion scintigraphy with SPECT are alternative functional tests selected by patient factors and local expertise; they are not routinely sequential.
Key red flags
Current chest pain with instability, dynamic ECG change or rising troponin: manage as possible acute coronary syndrome before elective stress imaging.
Decompensated heart failure, uncontrolled important arrhythmia, severe hypotension or another contraindication to the proposed stress agent: postpone stress and stabilise or choose another route.
A non-MR-conditional implant, retained ferromagnetic foreign body or uncertain device status: stop and complete formal MRI-safety assessment rather than relying on patient recollection alone.
A new severe perfusion abnormality, stress-induced wall-motion abnormality or high-risk ventricular arrhythmia during testing: terminate stress, treat clinically and communicate urgently.
A fixed defect with acute symptoms or a new regional wall-motion abnormality is not automatically old scar; reconcile timing, ECG, biomarkers and artefact before closing the diagnosis.
Pregnancy or possible pregnancy requires an explicit justification and radiation-safety pathway before radionuclide imaging.
Because SPECT displays relative uptake, homogeneous global flow reduction can look uniform. Transient ischaemic dilation, stress-induced left-ventricular dysfunction, extensive coronary calcification on hybrid imaging, symptoms or ECG change and a high-risk clinical profile should lower confidence in an apparently normal perfusion distribution.
Investigation priorities
Serve as a NICE-listed functional imaging option after uncertain or non-diagnostic CT coronary angiography; it may be preferred when myocardial tissue and scar information plus avoidance of ionising radiation are valuable.
Serve as a NICE-listed functional imaging option after uncertain or non-diagnostic CT coronary angiography; it may be preferred when local expertise, availability or MRI-related patient factors favour radionuclide imaging, with gated function where acquisition permits.
Management branches
A stable patient has symptoms compatible with angina and CT coronary angiography is uncertain or non-diagnostic for the functional significance of disease.
- Recheck symptom pattern, CT image quality, lesion location and the probability that the uncertain segment could explain the presentation.
- Choose one non-invasive functional test according to local expertise and patient factors. NICE options are myocardial perfusion scintigraphy with SPECT, stress echocardiography, first-pass contrast-enhanced MR perfusion, or MR imaging for stress-induced wall-motion abnormalities.