FFR-CT uses a computer to estimate how much a heart artery narrowing limits blood flow, using your CT angiography images. Learn how it helps decide on treatment.
FFR-CT (fractional flow reserve from CT) is a computer analysis of your CT coronary angiography images that estimates how much a narrowing reduces blood flow to the heart muscle. It helps doctors decide whether a moderate blockage needs a stent or can be treated with medicines, without an invasive pressure wire test.
The Problem With Moderate Narrowings
A CT angiography can show how narrow an artery looks, but a 50 to 70 percent narrowing may or may not reduce blood flow. Treating it with a stent when it is not limiting flow brings little benefit, while leaving a flow-limiting narrowing untreated can be risky. See CAD-RADS report explained.
FFR-CT valueUsual meaning0.80 or aboveNarrowing unlikely to limit blood flow0.76 to 0.80Borderline; doctor decides0.75 or belowNarrowing likely limits blood flowHow FFR-CT Works
Specialised software builds a 3D model of the coronary arteries from the CT images and uses fluid dynamics to calculate pressure and flow at each point. No extra scan, radiation or injection is needed. The result is a colour-coded map and values along the arteries. Analysis may be done offsite and takes hours to a day.
Who May Benefit?
- People with chest pain and 40 to 90 percent narrowing on CTCA
- Patients where the decision between medicines and angiography is unclear
- People who want to avoid unneeded invasive angiography
It is not needed when the CTCA is normal or the narrowing is clearly severe. See how accurate CTCA is.
Limits
FFR-CT depends on good image quality. Heavy calcium, stents, motion and a fast heart rate can make analysis impossible. It is not available at every centre, and it adds cost. The cardiologist always combines the result with your symptoms and other tests. Invasive FFR remains the reference test.
A Practical Example
Ravi, 59, has chest tightness, and CTCA shows a 60 percent narrowing in the LAD artery. FFR-CT shows a value of 0.86, meaning the narrowing does not limit flow. His cardiologist treats him with medicines and lifestyle changes and avoids angiography. Another patient with a similar looking narrowing has a value of 0.70 and goes on to a stent.
Key Facts at a Glance
- FFR-CT estimates blood flow from CTCA images
- It helps decide on stent versus medicines
- No extra radiation or injection
- Quality of images decides whether it can be done
After the Scan and Next Steps
Ask your cardiologist whether FFR-CT is available and suitable in your case. Whatever the result, the plan includes medicines such as aspirin and statins, blood pressure and sugar control, exercise and tobacco avoidance. If symptoms worsen, seek earlier review, since the CT picture is only one part of your heart health.
Questions to Ask Your Doctor
- Is my narrowing in the range where FFR-CT helps?
- Is the FFR-CT service available and what does it cost?
- Do I need a stress test or angiography if FFR-CT is normal?
- Which medicines should I take?
Common Mistakes to Avoid
- Expecting FFR-CT to be done on every scan.
- Skipping caffeine and heart-rate rules, which can ruin image quality.
- Stopping medicines after a good value.
Booking, Timing and Report
Book a morning slot if possible, since fasting is easier. Carry your doctor's prescription, previous heart and blood reports, a recent creatinine report and a medicine list. Allow 45 to 90 minutes at the centre. Reports are usually ready within 24 to 48 hours, because vessel images need careful review.
Questions About Cost and Availability
FFR-CT is analysed by special software and may involve an extra charge. Ask the centre in advance whether it is offered, how long the result takes, and whether the cost is covered by insurance. Your cardiologist can tell you whether it is likely to change your treatment before you pay for it.
Frequently Asked Questions
What is FFR-CT?
A computer estimate of blood flow across a narrowing, taken from CTCA images.
Does it need another scan?
No.
Does it use extra radiation?
No.
Is it available everywhere?
No, not all centres offer it.
Is it better than invasive FFR?
Invasive FFR is the reference; FFR-CT is a non-invasive aid.
Can heavy calcium prevent analysis?
Yes.
Does a normal value mean no treatment?
It means medicines and lifestyle, not a stent, in most cases.
How long does analysis take?
Hours to a day.
Who decides?
Your cardiologist.
Book Your Test at Ganesh Diagnostic
Ganesh Diagnostic & Imaging Centre in Rohini, Delhi offers this test with trained radiology staff and clear reports. You can book an appointment online, check our branches across Delhi NCR, contact us for current rates, or explore all our services. Reports can be downloaded online through our patient portal, so you do not need to make a second trip just to collect them.
This article is for general information only. It does not replace advice from your doctor. Always follow your doctor's instructions for your test.
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