Heart size and pumping function
Measures right- and left-ventricular volumes, ejection fraction, muscle thickness and regional wall motion with high reproducibility.
Advanced Non-Invasive Heart Imaging
Cardiac MRI
Detailed magnetic resonance imaging of the heart to assess cardiac structure, pumping function, blood flow, inflammation, scar tissue and complex heart conditions—without ionising radiation.
Heart structure and function
Tissue and scar assessment
No ionising radiation
Imaging methodMagnetic field and radio waves
RadiationNo ionising radiation
Typical durationAbout 30–60 minutes
ContrastUsed only when clinically required
Understanding the scan
What is Cardiac MRI?
Cardiac Magnetic Resonance Imaging, also called Cardiac MRI or cardiovascular magnetic resonance (CMR), is a non-invasive scan that creates detailed moving and still images of the heart and nearby blood vessels. It uses a strong magnetic field, radiofrequency waves and specialised computer processing rather than X-rays.
The scan can measure the size of the heart chambers, pumping function, wall motion and blood flow. It can also characterise the heart muscle itself—helping doctors look for inflammation, swelling, scar tissue, previous heart-attack damage, infiltration or abnormal thickening that may not be fully explained by an ECG or routine echocardiogram.
01
Detailed anatomy
Shows the heart chambers, muscle, valves, pericardium and major vessels in multiple planes.
02
Functional assessment
Measures ventricular volumes, ejection fraction, regional wall motion and selected blood-flow patterns.
03
Tissue characterisation
Selected sequences can identify oedema, fibrosis, scar and other changes within the heart muscle.
Cardiac MRI is not the same as CT coronary angiography. It is excellent for heart-muscle structure, function, scar and many complex conditions, but it is not usually the first test used to show the detailed inside of small coronary arteries.
Clinical information
What can a Cardiac MRI evaluate?
Cardiac MRI combines anatomy, motion, blood-flow measurements and tissue characterisation. The findings are interpreted together with symptoms, ECG, Echo, laboratory tests and previous imaging.
Cardiomyopathy
Helps assess hypertrophic, dilated, arrhythmogenic, restrictive and other heart-muscle disorders, including patterns of scar or infiltration.
Myocarditis and inflammation
Can identify tissue changes consistent with inflammation, oedema or injury when myocarditis or another inflammatory condition is suspected.
Previous heart-attack damage
Contrast-enhanced imaging may show the location and extent of myocardial scar and whether damaged muscle may still be viable.
Congenital and structural conditions
Defines complex anatomy, shunts, repaired congenital defects, right-heart function and major-vessel relationships when Echo is incomplete.
Valves, pericardium and major vessels
May quantify selected valve leakage, assess pericardial disease and examine the aorta or pulmonary arteries as part of a tailored protocol.
When it may be advised
Why might a cardiologist recommend Cardiac MRI?
The test is often requested when another investigation has raised a question that needs more detailed structural, functional or tissue assessment.
Unexplained reduced heart-pumping function
Suspected myocarditis or myocardial inflammation
Hypertrophic or dilated cardiomyopathy
Possible cardiac sarcoidosis or infiltrative disease
Scar assessment after a heart attack
Myocardial viability before selected treatment
Complex congenital heart disease
Right-ventricular size and function
Cardiac mass, tumour or thrombus evaluation
Pericarditis or constrictive pericardial disease
Aortic and major-vessel assessment
Selected stress perfusion assessment
Urgent chest pain should not be delayed for an outpatient MRI appointment. New severe chest pressure, breathlessness, fainting or other emergency symptoms require immediate medical assessment.
Tailored protocols
Does every Cardiac MRI use the same protocol?
No. The radiologist and cardiologist select sequences according to the diagnostic question, previous results and patient safety.
Non-contrast functional imaging
Moving cine images can assess chamber size, wall motion, ejection fraction and anatomy without an injection of contrast.
Contrast-enhanced tissue imaging
Gadolinium may be used to evaluate perfusion, scar, fibrosis, inflammation or masses when the expected benefit justifies contrast.
Stress perfusion Cardiac MRI
Selected patients may receive a medicine that temporarily increases coronary blood flow while MRI looks for areas receiving less blood. This requires specific screening and monitoring.
Before your appointment
How to prepare for Cardiac MRI
Preparation varies according to whether contrast, sedation or stress medicine is planned. Follow the imaging centre’s instructions rather than making medication changes yourself.
MRI safety and device information
- Tell the team about pacemakers, defibrillators, loop recorders, cochlear implants, pumps, clips, stimulators, surgical metal or retained metal fragments.
- Bring the implant card, model number or operative record whenever available.
- Remove jewellery, watches, hearing aids, mobile phones, cards and other metal or electronic items before entering the MRI area.
- Report previous metal work, welding injuries or possible metal fragments in the eyes.
Health, medicines and contrast
- Tell the centre about kidney disease, dialysis, pregnancy, breastfeeding, allergies, recent surgery and previous reactions to MRI contrast.
- A kidney-function blood test may be requested before gadolinium contrast.
- Take usual medicines unless the doctor gives different instructions.
- Food, drink and caffeine restrictions vary—especially for stress MRI or sedation—so confirm the exact protocol in advance.
- Discuss claustrophobia early. If sedation is prescribed, arrange an adult escort and do not drive afterward.
Step-by-step
What happens during a Cardiac MRI?
The exact sequence varies, but most examinations follow the general process below.
1
Safety screening
The team confirms implants, metal exposure, kidney history, pregnancy status, allergies and whether contrast, sedation or stress medicine is planned.
2
Preparation and monitoring
You change into MRI-safe clothing. ECG stickers are placed on the chest to synchronise images with the heartbeat, and a blood-pressure cuff may be used. An IV line is inserted when contrast or stress medicine is required.
3
Positioning in the scanner
You lie on a padded table with a special receiver coil over the chest. The table moves into the scanner, and ear protection is provided for the loud tapping sounds.
4
Breath-hold image sequences
The technologist communicates by intercom and asks you to hold your breath for short periods. Remaining still is important because movement can blur the images.
5
Contrast or stress sequences, when ordered
Gadolinium may be injected to assess tissue or scar. In a stress study, medication is given under monitoring and stopped according to the protocol and your response.
6
Image check and completion
The team reviews the images for completeness before removing the IV. Most patients can leave after the routine scan; additional observation may be needed after stress medication or sedation.
During the scan
What might you feel?
Cardiac MRI is usually painless, although lying still, repeated breath-holds and the enclosed scanner can be uncomfortable for some people.
Loud scanner sounds
Rhythmic tapping and thumping are normal. Earplugs or headphones reduce the noise, and you remain in contact with the technologist.
Short breath-holds
You may be asked to hold your breath repeatedly for several seconds. Tell the team if you cannot follow a breath-hold instruction.
Contrast sensations
Some people notice temporary warmth, coolness at the IV site or a metallic taste. Report pain, swelling, rash, wheeze or unusual symptoms immediately.
Safety information
Is Cardiac MRI safe?
For most appropriately screened patients, Cardiac MRI is a safe test. The main precautions relate to the magnetic field, implanted devices, contrast, kidney function, pregnancy, sedation and stress medicines.
MRI magnetic-field precautions
- The scan does not use ionising radiation.
- Some implants are MRI-conditional and can be scanned only under specified device settings and monitoring protocols.
- Unknown or unsafe metal may move, heat, malfunction or distort the images.
- Never enter the MRI room with unapproved metal or electronic equipment.
Contrast, sedation and stress risks
- Gadolinium reactions are uncommon, but allergic reactions can occur.
- Serious kidney disease requires careful contrast selection and may lead to a non-contrast protocol.
- Sedation can affect alertness and breathing, so monitoring and an escort may be required.
- Stress medicines may cause flushing, breathlessness, chest discomfort, headache or rhythm changes and are given only with appropriate supervision.
Do not assume an implant is safe simply because it is modern. MRI compatibility must be confirmed using the exact device information and the imaging centre’s safety protocol.
Understanding the report
What may a Cardiac MRI report include?
The report is tailored to the clinical question and may include quantitative measurements as well as a description of tissue patterns.
Left- and right-ventricular volumes
Ejection fraction and wall motion
Heart-muscle thickness and mass
Oedema or active inflammation patterns
Late gadolinium enhancement or scar
Ischemic versus non-ischemic scar pattern
Valve flow and regurgitation measurements
Shunt or congenital-flow calculations
Pericardial thickness, fluid or inflammation
Aortic and pulmonary-vessel findings
Mass, thrombus or tumour characterisation
Recommended correlation or follow-up
One result does not stand alone. Ejection fraction, scar, oedema and other findings must be interpreted with symptoms, ECG, blood tests, Echo, family history and the reason the scan was requested.
Limitations and follow-up
When might another test be needed?
Cardiac MRI answers many complex questions, but image quality and diagnostic value depend on the clinical problem and the patient’s ability to complete the scan.
Motion or rhythm limitations
Severe breathlessness, inability to lie still, frequent irregular beats or difficulty with breath-holds can reduce image quality.
Coronary-lumen assessment
Small coronary arteries are usually assessed more directly with CT coronary angiography or invasive coronary angiography when clinically indicated.
Additional functional testing
Stress Echo, nuclear perfusion imaging, Holter monitoring or catheter-based tests may be needed depending on symptoms and the MRI findings.
2D Echocardiography
CT Coronary Angiography
Treadmill Stress Test
Dobutamine Stress Echo
Holter Monitoring
Coronary Angiography
Cardiologist-led evaluation
Dr. Kiran Lakkireddy
MBBS, MD, DM (Cardiology – JIPMER), FSCAI, FAPSIC
Senior Interventional Cardiologist
Senior Interventional Cardiologist
Dr. Kiran Lakkireddy provides evidence-based cardiac evaluation with a focus on accurate diagnosis, clear explanation and individualised treatment planning. Cardiac MRI findings are most useful when they are correlated with the patient’s symptoms, ECG, Echo, laboratory results and previous cardiac procedures.
Apollo Hospitals, Jubilee Hills
CANES Cardio & Neuro Clinic, Kondapur
Patient questions
Frequently asked questions
Clear answers to common questions about Cardiac MRI.
What is the difference between Cardiac MRI and 2D Echo?
Echo uses ultrasound and is usually the first-line test for heart structure and function. Cardiac MRI provides more detailed tissue characterisation, highly reproducible chamber measurements and additional information in complex cardiomyopathy, inflammation, scar and congenital-heart cases.
Does Cardiac MRI use radiation?
No. It uses a magnetic field and radiofrequency waves rather than X-rays. MRI safety screening is still essential because the magnetic field can interact with some implants and metal objects.
How long does a Cardiac MRI take?
Many examinations take about 30 to 60 minutes. Complex congenital, stress or tissue-characterisation protocols may take longer, while focused protocols can be shorter.
Will I need an injection?
Not every study requires contrast. Gadolinium may be advised when the clinical question involves scar, inflammation, perfusion, viability, a mass or another tissue abnormality. An IV is also needed for stress medication when stress MRI is planned.
Is gadolinium the same as CT contrast?
No. MRI commonly uses gadolinium-based contrast, while CT usually uses iodine-based contrast. A previous iodine reaction does not automatically mean you will react to gadolinium, but all allergies and previous reactions should be reported.
Can I have Cardiac MRI with a pacemaker or defibrillator?
Some modern devices are MRI-conditional and can be scanned under a specialised protocol. Others may be unsuitable. The exact manufacturer, model, leads and implantation details must be checked before scheduling.
What if I am claustrophobic?
Tell the centre before the appointment. Explanation, positioning support, a wider-bore scanner or prescribed sedation may help. If sedation is used, arrange an escort and do not drive afterward.
Do I need to fast?
Instructions vary. Routine scans may allow normal food and medicines, while stress MRI or sedation may require fasting and caffeine restrictions. Follow the specific instructions from the imaging centre.
Can Cardiac MRI detect a heart blockage?
Stress perfusion MRI may identify areas of heart muscle receiving insufficient blood, but routine Cardiac MRI does not directly show every coronary narrowing. CT coronary angiography or catheter angiography may be needed for detailed coronary anatomy.
Can Cardiac MRI show a previous heart attack?
Yes. Contrast-enhanced sequences can often identify the location, pattern and extent of myocardial scar and help assess whether affected muscle is likely to be viable.
Can I return to normal activities afterward?
Most patients resume routine activities immediately after a standard scan. If you receive sedation, follow driving and supervision restrictions. After stress medication, the team may observe you briefly before discharge.
When will the result be available?
Cardiac MRI includes many image sequences and measurements, so specialist interpretation takes time. Report timing varies by hospital and study complexity. Your cardiologist should review the report in the context of your complete clinical history.
Appointments in Hyderabad
Has your doctor advised a Cardiac MRI?
Book a cardiac consultation to review the reason for the scan, previous reports, implant information, kidney function and the most appropriate imaging protocol.
This page provides general patient education and does not replace medical consultation. The indication, preparation, implant screening, use of contrast or stress medicine, scan protocol, risks and interpretation of Cardiac MRI depend on individual clinical assessment and the imaging centre’s safety policy.