Cardiac magnetic resonance imaging (MRI) scans are used to diagnose a variety of heart conditions, including congenital heart disease, coronary heart disease, heart valve disease, cardiac tumors, and inherited heart conditions.
The procedure helps to determine the severity of heart conditions and the future outlook for patients. In this blog, we will explain the purpose of cardiac MRIs in cardiovascular imaging; looking at how the procedure works, its benefits and its accuracy.
What is a cardiac MRI?
A cardiac MRI is an imaging test that can provide high resolution images of the heart. It is proven to be a particularly suitable method of diagnosis in complex cases. Cardiac MRI uses radio waves, a strong magnetic field, and computer technology to produce diagnostic images of the heart, and its surrounding structures. With the detailed diagnostic images, the anatomy of the heart and its function can be evaluated.
There are several types of cardiac MRI, including:
- Cardiac viability MRI
- Stress perfusion MRI
- A right ventricle and left ventricle function MRI
- MRI angiogram
- MRI for structural assessment
How long does a cardiac MRI take?
Because a cardiac MRI involves more advanced technology than other imaging tests such as x-rays, it takes a little longer to complete. The time the procedure takes can vary according to the type of condition under investigation. A cardiac MRI will typically take from 20 to 45 minutes. In the case of more complicated heart conditions, scanning could take an hour or more.
Following a cardiac MRI, your doctor will be given a report on the procedure, which he or she will then discuss with you. How long the report takes to become available can vary according to:
- The complexity of the test
- How quickly the results are required
- Whether there are comparisons to be made with previous imaging tests you have had
- If further information is needed before the radiologist can interpret the images
As such, it can take from a few days to a few weeks to get your results from a cardiac MRI.
What does a cardiac MRI show?
A cardiac MRI can be recommended for people at risk of heart failure, or other types of heart problems. It shows a diagnostic image of the heart, including the organ’s anatomy and function. MRI scans produce cross-sections of the body, offering more detailed images than other imaging tests such as x-rays and cardiac CT scans.
The chambers and valves of the heart can be evaluated, as well as the blood flow through its major vessels and surrounding parts. This allows your doctor to both detect and monitor heart disease.
Among the conditions that can be identified or monitored are:
- Congenital heart disease
- Coronary heart disease
- Heart failure
- Heart valve defects
- Inherited heart conditions like dilated cardiomyopathy or hypertrophic cardiomyopathy
- Cardiac tumors
Benefits of cardiac MRI
The benefits of the cardiac MRI technique include:
- More detailed images for certain conditions than other imaging tests (x-rays and CT scans)
- A non-invasive, safe imaging technique that does not use ionizing radiation
- Able to discover abnormalities obscured by bone
- Can be used in interventional procedures to treat heart conditions
- Able to diagnose a wide variety of conditions
- Contrast material used is less likely to cause allergic reaction than iodine-based materials used for other imaging tests
Accuracy of cardiac MRI
Due to the high resolution diagnostic images produced by a cardiac MRI, highly accurate measurements of the heart can be taken. Cardiac MRI has been described as the “gold standard of cardiac function and anatomy, [providing] unsurpassed image quality in evaluating heart structure and function in 3-D-quality moving images”.
However, in order to achieve some diagnostic objectives, such as identifying blockages in smaller sections of the coronary arteries, other imaging techniques may be more effective.
Cardiac MRI vs echo
Echocardiography is an imaging technique that is used to examine the heart and blood vessels. An echocardiogram is an ultrasound scan that uses high frequency sound waves to create echoes that bounce off the body. A small probe picks up these echoes and uses them to create a moving image.
Due to its ability to produce cross-sectional images of the body, ultimately a cardiac MRI can show more detailed diagnostic images than echocardiography. However, advances in echocardiography have made it one of the best methods of evaluation for the heart muscle and valves.
Cardiac MRI vs nuclear stress test
A nuclear stress test uses a tracer (small volume of radioactive material) with an imaging machine to produce images of blood flow to the heart. It can be conducted during rest or exercise to reveal poor blood flow and heart damage.
As well as being significantly faster than a nuclear stress test (which could take up to four hours), a cardiac MRI is also more accurate, being able to provide more information at a higher resolution.
For more information on how a cardiac MRI scan compares to nuclear stress tests, such as PET or SPECT, in diagnosing patients with known or suspected coronary artery disease, please visit our page on myocardial perfusion imaging.
cvi42 for cardiovascular MRI
cvi42 from Circle CVI is the market leading cardiac magnetic resonance solution that is capable of providing fast and accurate results for a range of CMR conditions, such as:
- Congenital Heart Disease
- Heart Failure
- Ischemic Heart Disease
- Pericardial Disease
- Pulmonary Hypertension
- Thoracic Aortic Disease
- Valvular Heart Disease
When evaluating heart function, cvi42 for cardiac MRI provides easy detection of wall motion abnormality, with autodisplay of stroke volume, ejection fraction, and end-diastolic and end-systolic volumes and masses. The software allows blood flow to be quantified and multiple vessel flows to be compared (i.e. streamlined Systemic over Pulmonary flows ratio, a.k.a. Qp:Qs) and corrected.
Owing to a high level of diagnostic accuracy and rapid, automatic analysis, cvi42 is proven to be a superior performer from qualitative, to fully quantitative techniques. Little as no manual segmentation is needed, thanks to the fully automatic quantification of user-independent cvi42.
Gain the advantages of a seamless post-processing solution. Try cvi42 for 42 days, download today.
For more information about the function, flow and accuracy of cvi42, visit our cardiac MRI page, or contact the Circle CVI team.