This, the basic code, covers the morphological and functional assessment that is essential in any CRM exam. It should use dynamic images from balanced steady-state free precession (bSSFP) or gradient-recalled echo sequences and static images from turbo spin-echo or short-tau inversion recovery sequences. The information obtained includes quantification of ventricular volumes and function, and quantification of left ventricular mass, assessment of wall motion and tissue characterization, all without the need for contrast agents, which is useful in the differential diagnosis of a variety of heart diseases.

One of the main advantages of CRM is non-invasive detection of the presence, extent and pattern of myocardial fibrosis, based on T1-weighted inversion recovery sequences with image acquisition around 10 minutes after the administration of paramagnetic contrast. Late enhancement study is indicated in the investigation of cardiomyopathy and myocarditis, ischemic heart disease (to assess myocardial viability and to detect subclinical infarction), cardiac masses, pericardial disease, and other conditions. The many clinical applications of this technique mean that it is used in most CMR exams.

Blood flow can be assessed by CRM using phase contrast methods, which is particularly useful in the investigation of valve disease and congenital heart defects. Quantitative flow analysis requires special post-processing software.

Myocardial perfusion imaging is usually based on assessment of the dynamics of the first pass of a bolus of paramagnetic contrast using fast T1-weighted sequences. Stress in this context refers to the administration of a coronary vasodilator, normally adenosine or dipyridamole, to induce maximum hyperemia. The presence of obstructive atherosclerotic lesions reduces the vasodilator response, leading to a regional asymmetry in myocardial perfusion. Diagnosis of reduced coronary flow reserve is based on comparison of perfusion in different vascular territories and of images obtained during stress and at rest. In some countries, assessment of myocardial perfusion under pharmacological stress is now one of the main reasons for referral for CMR.3 The indications for this technique are similar to those for myocardial perfusion scintigraphy (MPS), but CMR has better spatial resolution and does not involve ionizing radiation. In a recent study, CMR was superior to MPS in the diagnosis of coronary heart disease4; the use of CMR to detect ischemic disease is expected to increase considerably in the coming years.

Rest myocardial perfusion imaging is used for comparisons with pharmacological stress myocardial perfusion imaging to assess the reversibility of perfusion defects and in the investigation of cardiac masses to determine the extent of vascularization. The same sequences are used as in stress imaging.

This technique assesses dobutamine-induced wall motion abnormalities in a similar way to stress echocardiography. Dobutamine is administered via a peripheral vein in increasing doses up to a maximum of 40 μg/kg/min in four or five stages each of 3-5 min, and can be supplemented by atropine to attain the target heart rate. Wall motion is assessed at each stage using bSSFP cine sequences. The use of dobutamine requires careful monitoring of blood pressure, cardiac rhythm and symptoms; the attending physician must be prepared to deal with any complications, particularly arrhythmias or symptoms of myocardial ischemia. Low-dose dobutamine CMR (up to 10 μg/kg/min) is an alternative to late enhancement CMR to assess myocardial viability and the integrity of the myocardial contractile apparatus, or when the transmurality of one or more segments on late enhancement is intermediate or unclear. Dobutamine stress CMR is logistically complex, time-consuming and not without risk, and is therefore now used less to assess ischemia and myocardial viability than vasodilator stress imaging and late enhancement studies, respectively. It is generally used only in cases in which paramagnetic contrast is contraindicated. Despite these limitations, dobutamine stress CMR has higher diagnostic accuracy than dobutamine stress echocardiography,5 particularly when there is a poor acoustic window.

Angiography of the great vessels is usually performed following administration of a bolus of paramagnetic contrast, acquisition time being set to coincide with the passage of contrast through the area of interest. The technique provides accurate three-dimensional angiographic images of the aorta, pulmonary arteries and their branches, pulmonary veins, and other vessels.

This technique is little used in clinical practice, as limitations of spatial and temporal resolution mean that only the proximal segments of the coronary arteries can be assessed. Its main application is to exclude anomalous coronary artery origin and to assess coronary aneurysms in Kawasaki disease; it is not usually indicated in the study of atherosclerotic coronary disease.

The authors declare that no experiments were performed on humans or animals for this study.

The authors declare that no patient data appear in this article.

The authors have obtained the written informed consent of the patients or subjects mentioned in the article. The corresponding author is in possession of this document.