| Condition | Cardiac MRI Findings |
|---|---|
| Myocardial Infarction | Late gadolinium enhancement (LGE) in a subendocardial or transmural pattern, wall thinning, hypokinesia |
| Hypertrophic Cardiomyopathy | Asymmetric septal hypertrophy, LGE in areas of fibrosis, left ventricular outflow tract obstruction |
| Dilated Cardiomyopathy | Dilated ventricles, reduced ejection fraction, global hypokinesia, LGE in a mid-wall pattern |
| Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) | Right ventricular dilation, fatty infiltration, wall motion abnormalities, LGE in right ventricle |
| Cardiac Amyloidosis | Diffuse subendocardial LGE, thickened ventricular walls, atrial enlargement, reduced ventricular function |
| Myocarditis | LGE in a patchy or subepicardial pattern, increased myocardial T2 signal, pericardial effusion |
| Constrictive Pericarditis | Thickened pericardium, pericardial effusion, septal bounce, abnormal ventricular interdependence |
| Ischaemic Heart Disease | LGE in regions corresponding to coronary artery distribution, wall motion abnormalities |
| Non-Compaction Cardiomyopathy | Prominent trabeculations with a non-compacted to compacted myocardium ratio >2.3:1, LGE in non-compacted segments |
| Cardiac Sarcoidosis | LGE in a patchy or nodular pattern, particularly in the basal and mid-ventricular segments, wall motion abnormalities |
| Aortic Stenosis | Left ventricular hypertrophy, post-stenotic dilation of the aorta, LGE in areas of fibrosis |
| Mitral Regurgitation | Left atrial and ventricular dilation, flow jets visible on cine MRI, LGE in areas of fibrosis |
Notes
- Late Gadolinium Enhancement (LGE) is a critical MRI technique for identifying myocardial fibrosis and scarring. Post-administration of a gadolinium-based contrast agent, delayed imaging (typically 10-20 minutes) is performed. Pathologic myocardium, such as areas of infarction or fibrosis, retains the contrast longer than normal myocardium, resulting in hyperintense regions on T1-weighted images. This differential enhancement allows for precise characterisation of myocardial viability, aiding in the diagnosis and management of various cardiomyopathies, myocarditis, and ischemic heart disease. LGE is particularly useful for distinguishing between ischaemic and non-ischaemic patterns of injury.
- Subendocardial:
- Refers to the innermost layer of the heart wall, just beneath the endocardium (the lining of the heart chambers).
- Typically affected in ischemia or infarctions that do not extend through the full thickness of the myocardium.
- Mid-wall:
- Refers to the middle layer of the heart wall, within the myocardium.
- Often used to describe fibrosis or scarring that occurs within the central portion of the myocardium.
- Subepicardial:
- Refers to the outermost layer of the heart wall, just beneath the epicardium (the outer layer of the heart).
- Commonly involved in conditions like myocarditis or epicardial fat deposits.
- Transmural:
- Refers to the entire thickness of the heart wall, from the endocardium through the myocardium to the epicardium.
- Typically used to describe myocardial infarctions that affect the full thickness of the heart muscle.
Coronary Artery Distributions and Corresponding Myocardium
- Left Anterior Descending (LAD) Artery:
- Supplies the anterior wall of the left ventricle.
- Supplies the anterior two-thirds of the interventricular septum.
- Supplies the apex of the heart.
- Left Circumflex (LCx) Artery:
- Supplies the lateral wall of the left ventricle.
- Supplies part of the posterior wall of the left ventricle.
- Supplies the left atrium.
- Right Coronary Artery (RCA):
- Supplies the right atrium.
- Supplies the right ventricle.
- Supplies the inferior wall of the left ventricle.
- Supplies the posterior one-third of the interventricular septum.
- Supplies the sinoatrial (SA) node (in about 60% of people).
- Supplies the atrioventricular (AV) node (in about 80-90% of people).