CT pulmonary angiogram
Overview
A CT pulmonary angiogram (CTPA) is a special type of CT scan that takes detailed pictures of the blood vessels in your lungs. It uses a contrast dye (a special liquid) injected into a vein to make the vessels show up clearly. Doctors usually order this test to check for blood clots in the lungs, a condition called pulmonary embolism (PE).
Key facts
- CTPA is a quick, non-invasive scan that takes only a few minutes.
- The contrast dye helps highlight any blockages or clots in the lung arteries.
- It is the most common and accurate imaging test for diagnosing pulmonary embolism.
- The scan uses a small amount of radiation, similar to other CT scans.
Yes, CTPA is a common test performed in hospitals and radiology departments when a doctor suspects a blood clot in the lungs.
CTPA is used for people of any age who have symptoms that might be caused by a pulmonary embolism, such as sudden shortness of breath or chest pain. It is especially important for those with risk factors like recent surgery, prolonged bed rest, or a history of blood clots.
Symptoms
- Sudden severe difficulty breathing
- Chest pain that feels like a heavy pressure or squeezing
- Fainting or feeling like you might pass out
- Coughing up a significant amount of blood
- ⚠Swelling, pain, or warmth in one leg (which could be a deep vein thrombosis, a clot in the leg that can travel to the lungs)
- ⚠Unexplained shortness of breath that is getting worse over hours or days
Common symptoms
- Sudden shortness of breath
- Sharp chest pain that gets worse when you cough or take a deep breath
- Coughing up blood
- Rapid or irregular heartbeat
Symptoms in children
- Children with pulmonary embolism may have similar symptoms to adults, but they might also show signs like irritability, not wanting to move, or fast breathing.
Symptoms in older adults
- In older adults, symptoms of a blood clot in the lungs can be less obvious, such as feeling lightheaded, having a low blood pressure, or just feeling unusually tired.
Causes
Main causes
- The main reason for having a CTPA is to check for a pulmonary embolism, which is usually caused by a blood clot that travels from another part of the body, often the legs (deep vein thrombosis).
- Less commonly, other conditions like a tumor or air bubble can block a lung artery.
Risk factors
- Recent major surgery, especially on the legs, hips, or abdomen
- Prolonged immobilization, such as long car or plane trips or bed rest
- Cancer and its treatments
- Pregnancy and the postpartum period
- Use of hormone therapy or birth control pills
- Obesity
- Smoking
- Family history of blood clots
When to see a doctor
See a doctor urgently if:
- If you have sudden shortness of breath, sharp chest pain, or coughing up blood – call your local emergency number right away.
- If you have signs of a deep vein thrombosis (swollen, painful leg) along with breathing problems, seek emergency care.
Book a routine appointment if:
- If you have mild symptoms like a persistent cough or slight breathlessness that is not improving, make an appointment with your GP to discuss your risk factors.
- If you have had a blood clot before and are worried about a recurrence, see your doctor for a check-up.
Diagnosis
A CT pulmonary angiogram is done in a hospital radiology department. A doctor or radiologist will review your symptoms and medical history first. The test itself takes about 10 to 15 minutes. You will lie on a table that slides through the CT scanner. A small tube (IV) will be placed in your arm to inject the contrast dye. The machine will take several X-ray images while you hold your breath for a few seconds.
Tests that may be done
- CT pulmonary angiogram (CTPA) – the main test to look for lung artery clots
- Blood tests like D-dimer (a clot breakdown product) may be done first to see if a CTPA is needed
- Chest X-ray or electrocardiogram (ECG) might be done to rule out other causes
- Ultrasound of the legs can find a deep vein thrombosis
What to expect at your appointment
Before the test, you may be asked not to eat or drink for a few hours. Let the team know if you have any allergies to contrast dye or kidney problems. You will lie still while the table moves through the scanner. You might feel a warm sensation or a metallic taste when the dye is injected, but this is normal. After the test, you can usually go back to your normal activities. Drink plenty of water to help flush the dye out of your system.
Treatment
Treatment for a pulmonary embolism (if found) focuses on preventing the clot from getting bigger and stopping new clots from forming. The most common treatment involves medicines that thin the blood (anticoagulants). Your doctor will decide the best approach based on the size of the clot and your overall health.
Self-care at home
- If you are on blood thinners, take them exactly as prescribed and attend all follow-up appointments
- Wear compression stockings if your doctor recommends them to prevent leg swelling after a deep vein thrombosis
- Stay active as advised – gentle walking may help circulation
- Avoid alcohol if on blood thinners, as it can increase bleeding risk
Medical treatments
The main medical treatment is anticoagulant medication (blood thinners) that you take by mouth or as an injection. These medicines reduce the blood's ability to clot. Treatment usually lasts at least 3 to 6 months, sometimes longer. In severe cases, doctors may use a medicine that dissolves clots directly (thrombolytics) or place a filter in a large vein to catch future clots.
When is surgery considered?
Surgery is rarely needed. In very rare cases where a massive pulmonary embolism causes severe instability, a surgeon may remove the clot through a procedure called embolectomy.
Living with this condition
If you have had a pulmonary embolism, your daily life may change a bit while you are on blood thinners. You will need to be careful to avoid cuts and bruises, and let all healthcare providers know you are on this medication. Most people return to normal activities within a few weeks, but it is important to follow your doctor's advice about activity levels.
Lifestyle tips
- Wear a medical alert bracelet or carry a card that says you are on a blood thinner
- Avoid activities with a high risk of falls or injury (like contact sports)
- Tell your dentist about your blood thinner before any procedures
- If you smoke, consider quitting – smoking increases clot risk
Diet and exercise
You can eat a normal healthy diet, but if you are on blood thinners, keep the amount of vitamin K-rich foods (like spinach, kale, broccoli) consistent week to week, as large changes can affect how well the medicine works. Light to moderate exercise like walking or swimming is usually safe, but check with your doctor first.
Mental health and emotional wellbeing
Having a blood clot can be scary. Many people feel anxious or worried about another clot happening. These feelings are normal. Talk to your healthcare team about your concerns – they can help you understand your risk and recovery.
Prevention
Some pulmonary embolisms can be prevented. If you are at high risk (after surgery or during long travel), your doctor may recommend blood thinners, compression stockings, or frequent movement. Staying active, maintaining a healthy weight, and not smoking also reduce your risk.
Complications
If left untreated
- A pulmonary embolism that is not treated can be life-threatening – the clot can block blood flow to the lungs and cause the heart to fail.
- Long-term damage to the lungs (pulmonary hypertension) can develop, making it hard to breathe even after the clot is gone.
- The clot may travel to other parts of the body or cause a heart attack or stroke in rare cases.
Long-term outlook
The outlook for pulmonary embolism is very good with prompt diagnosis and treatment. Most people recover fully and can return to their normal lives. The risk of another clot decreases over time, especially if you follow your treatment plan and manage risk factors.
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Health guidance differs by country and region. This page is general education and may not match the guidelines, medicines, or practice where you live. Discuss your concerns with your own doctor or healthcare provider, and follow local guidance where it exists.
Important notice This information is for educational purposes only. It does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about your specific situation. If you are experiencing a medical emergency, call your local emergency services immediately.
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Sources and guidance
No guideline names this topic
No health guideline or clinical chapter that names this exact topic is cited here. This page is for general education and information only. It is not a diagnosis, a treatment plan, or personal medical advice. Check with your own doctor and follow their advice. If symptoms are severe, sudden, or worrying, get medical care promptly, and call your local emergency number in an emergency. Ruqelo LLC is not responsible for medical or legal outcomes from decisions based on this information.
Last updated: July 16, 2026
Educational note: This information is for education only and is not a diagnosis.
Use it to support, not replace, advice from a licensed clinician.
If symptoms are severe, worsening, or urgent, call your local emergency number or seek emergency care.
Guidance may differ by country or region. Confirm local recommendations with a qualified healthcare provider.