Cardiac Imaging: Non-Invasive Techniques Excluding Echocardiography

Key points

• NICE CG95 (2016 update): CT CORONARY ANGIOGRAPHY is first-line for stable chest pain where angina cannot be excluded clinically. The older pre-test-probability pathway — calcium scoring below 30%, functional imaging 30-60%, invasive angiography above 60% — was removed and should not be used.
• Second-line if CTCA is non-diagnostic or shows disease of uncertain significance: non-invasive functional imaging for reversible ischaemia — myocardial perfusion scintigraphy with SPECT, stress echocardiography, first-pass contrast stress perfusion MR, or stress MR wall-motion imaging.
• Third-line: invasive coronary angiography, when functional imaging is inconclusive or revascularisation is being considered.
• Do NOT use exercise ECG to diagnose or exclude stable angina in people without known coronary artery disease.
• Nuclear imaging: thallium · technetium-99m sestamibi (MIBI, used in SPECT) · FDG (PET) · SPECT compares rest and stress images (exercise, or adenosine/dipyridamole) — a reversible defect indicates ischaemia, a fixed defect indicates infarction.
• MUGA (radionuclide angiography, technetium-99m + gamma camera) accurately measures LV ejection fraction, typically before and after cardiotoxic chemotherapy · cardiac MRI is the gold standard for structural imaging, ventricular mass and differentiating cardiomyopathies · CT calcium scoring plus contrast CT gives a very high negative predictive value for coronary disease.

Decision points in this pathway

• CTCA non-diagnostic, or shows disease of uncertain functional significance?
• Functional imaging inconclusive, or revascularisation being considered?

The full step-by-step algorithm, including what to do at each branch, opens in the app for approved members.