Table 1.

Comparison of non-invasive coronary imaging modalities

Imaging parameters	CT calcium scan	CT coronary angiography	MRCA	PET
Image acquisition
Scan duration	0.5–10 s	0.5–10 s	10–20 min	60–90 min (tracer uptake)15–30 min/PET bed
Spatial resolution	1.5–3.0 mm	0.5–1.0 mm	1.0–2.0 mm	4.0–10.0 mm (tracer dependent)
Temporal resolution	240–420 ms	240–420 ms (65 ms with dual-source CT)	<60 ms	Minutes
Radiation exposure	<1 mSv	1–10 mSv (protocol dependent)	Nil	6–15 mSv (less in PET-MR)
Advantages	Wide availability Low cost Low radiation exposure Large evidence base to support prognostic implications	Short scan time Wide availability Best spatial resolution Robust evidence to support use	Radiation free imaging Allows concurrent assessment of cardiac function Not limited by coronary calcification Soft tissue characterization	Tracers can be developed to target almost any structural or pathophysiological process of interest
Limitations	Limited spatial resolution Non-calcified (potentially high-risk) plaque not detectable	Requires adequate heart rate control Risk of contrast reaction/nephropathy Imaging limited by dense coronary calcification and stents Radiation exposure	Limited spatial resolution Prolonged scan duration High cost Limited availability Claustrophobia Metallic implants	Poor spatial resolution Prolonged tracer uptake time and long scan duration Relatively high radiation exposure (PET-CT) although this can be substantially reduced with PET-MR High cost Very limited availability
Indications	Risk stratification in primary prevention for individuals at low-intermediate risk of cardiovascular events	Non-invasive assessment of suspected stable angina in patients with intermediate pre-test probability of coronary artery disease	Anomalous coronary arteries Follow-up of Kawasaki disease (coronary aneurysms) Assessment of coronary bypass grafts	Research purposes only at present

CT, computed tomography; MRCA, magnetic resonance coronary angiography; PET, positron-emission tomography.