Yes. A cardiac MRI can detect changes that may be linked to pulmonary hypertension, such as changes in the size and function of the heart’s right side and blood flow through the pulmonary arteries. However, MRI does not directly confirm high pressure in these arteries. Doctors usually start with an echocardiogram and may use right heart catheterization to measure pressure and confirm the diagnosis.
What can an MRI reveal about pulmonary hypertension?
A cardiac magnetic resonance imaging (MRI) scan uses magnetic fields and radio waves to create detailed pictures of the heart and nearby blood vessels. When pulmonary hypertension is suspected, these images can help clinicians assess how the heart is responding to pressure in the pulmonary arteries, which carry blood from the heart to the lungs.
According to Mayo Clinic, MRI can show blood flow in the pulmonary arteries and help evaluate the function of the heart’s right lower chamber, called the right ventricle. Depending on the examination, the images may also provide information about the size and structure of the heart and its chambers.
Findings that may be relevant to a pulmonary hypertension assessment include changes in right ventricular size, reduced pumping function, and altered blood flow. These findings can help clinicians understand whether the right side of the heart is under strain. However, similar changes can occur with other heart or lung conditions, so MRI findings need to be considered alongside other test results and the person's medical history.
Can an MRI measure pressure in the pulmonary arteries directly?
No. Cardiac MRI provides detailed structural and functional information, but it does not directly measure pulmonary artery pressure in the way that right heart catheterization does. An MRI may show changes that raise suspicion of pulmonary hypertension, but those changes do not establish the exact pressure within the pulmonary arteries.
The European Society of Cardiology and European Respiratory Society guidelines explain that cardiac MRI can accurately assess heart chamber size and function and measure blood flow. However, there is no established MRI method for estimating pulmonary artery pressure directly. MRI therefore complements the diagnostic process rather than replacing the tests needed to establish the diagnosis.
Is an echocardiogram better than an MRI for detecting pulmonary hypertension?
An echocardiogram is usually the first imaging test when pulmonary hypertension is suspected. It uses sound waves to create moving images of the heart and can estimate pressure in the pulmonary arteries indirectly. It also helps clinicians assess the size and function of the right ventricle and identify other heart problems that could explain symptoms or affect the results.
The American Thoracic Society describes echocardiography as one of the first tests commonly used to investigate pulmonary hypertension. MRI may be added when more detailed information about heart structure, pumping function, or blood flow is needed.
Neither test provides every piece of information needed in every case. Echocardiography is generally preferred for initial assessment because it is widely available and can estimate the likelihood of pulmonary hypertension. Cardiac MRI can provide additional detailed measurements, particularly of the right ventricle. The choice and sequence of tests depend on the clinical findings and the questions that remain unanswered.
When might a doctor order a cardiac MRI?
A clinician may recommend cardiac MRI when an echocardiogram or another examination raises concerns that need further assessment. It can also be useful when the quality of ultrasound images is limited or when accurate measurements of the heart’s size, pumping function, or blood flow would help guide further evaluation.
For people who already have a confirmed diagnosis, MRI may provide measurements that help clinicians assess heart function over time. Comparing scans performed at different appointments can help show whether the heart's right ventricle is changing and whether its function is responding to treatment. These findings are interpreted with symptoms, examination results, and other tests rather than being used alone to make care decisions.
What test confirms pulmonary hypertension?
Right heart catheterization is the standard test used to confirm pulmonary hypertension when confirmation is clinically indicated. During this procedure, a clinician guides a thin, flexible tube through a blood vessel into the right side of the heart and the pulmonary artery. This allows direct measurement of pressure and other blood-flow measurements that help characterize the condition.
The NHS guidance on pulmonary hypertension diagnosis explains that right heart catheterization can confirm the diagnosis by accurately measuring blood pressure on the right side of the heart and in the pulmonary arteries. Because the procedure is invasive, the decision to perform it is based on the clinical assessment and the results of earlier investigations.
A normal or inconclusive MRI does not automatically exclude pulmonary hypertension if other findings remain concerning. Likewise, an MRI showing changes in the right side of the heart does not prove that pulmonary hypertension is present. A healthcare professional determines whether further testing is appropriate by reviewing the complete clinical picture.
How is an MRI result interpreted alongside other tests?
MRI findings are only one part of the assessment. Clinicians may consider an echocardiogram, right heart catheterization, blood tests, lung function tests, or other imaging when investigating suspected pulmonary hypertension. The combination depends on the person's symptoms, medical history, examination findings, and whether another condition could explain the results.
The National Heart, Lung, and Blood Institute explains that the evaluation can include heart imaging, lung imaging, and tests that measure heart and lung function. This broader assessment helps clinicians investigate possible causes and decide which additional tests are necessary.
If an MRI report mentions right ventricular enlargement, altered blood flow, or other changes, ask the clinician who ordered the scan what those findings mean in the context of the other results. A written imaging report describes what was seen during the examination; it does not always provide a final diagnosis.