CT Scan for Pulmonary Embolism: Fast Diagnosis Saves Lives

A pulmonary embolism (PE) is a blood clot that travels to the lungs and blocks blood flow. It is a medical emergency — and one of the leading causes of preventable death in hospitalized patients. According to the Centers for Disease Control and Prevention, PE and deep vein thrombosis (DVT) together cause up to 100,000 deaths per year in the United States.

The key to survival is rapid diagnosis, and CT scan is the gold standard for detecting pulmonary embolism.

What Is a Pulmonary Embolism

A PE typically begins as a blood clot in the deep veins of the legs — a condition called deep vein thrombosis. If part of that clot breaks off, it travels through the bloodstream to the heart and then into the pulmonary arteries, where it can block blood flow to the lungs.

Symptoms of PE include:

• Sudden shortness of breath
• Sharp chest pain, especially when breathing deeply
• Rapid heart rate
• Coughing (sometimes with blood)
• Dizziness or fainting
• Leg pain or swelling (if DVT is present)

These symptoms can overlap with other conditions like heart attack or pneumonia, which is why imaging is essential for accurate diagnosis.

How CT Pulmonary Angiography Works

CT pulmonary angiography (CTPA) is the primary imaging test used to diagnose PE. It is a specialized CT scan that uses intravenous contrast dye to visualize the pulmonary arteries.

During the scan, contrast is injected into a vein in your arm. The CT scanner takes rapid images as the contrast flows through your heart and into your lungs. Clots appear as dark filling defects within the bright contrast-enhanced arteries.

The American College of Radiology considers CTPA the first-line imaging test for suspected PE because of its high sensitivity (detecting over 90 percent of PEs), specificity (accurately ruling out PE when absent), speed (scan takes only seconds), and ability to show alternative diagnoses (pneumonia, aortic dissection, etc.).

What to Expect During the Exam

1. IV placement — A technologist will place a small IV in your arm for contrast injection
2. Lie on the table — You will lie flat on the CT scanner table
3. Breath hold — You will be asked to hold your breath for a few seconds during the scan
4. Contrast injection — You may feel a warm sensation or metallic taste as the contrast is injected
5. Scan — The actual imaging takes about 10 to 15 seconds
6. Total time — The entire process takes 15 to 20 minutes

Results are typically available within hours — or even faster in emergency situations.

Risk Factors for Pulmonary Embolism

Certain factors increase your risk of developing blood clots that can lead to PE:

• Recent surgery, especially hip or knee replacement
• Prolonged immobility (long flights, bed rest, hospitalization)
• Cancer and cancer treatment
• Pregnancy and postpartum period
• Hormone therapy or birth control pills
• Obesity
• Smoking
• Personal or family history of blood clots
• Certain genetic clotting disorders

The National Heart, Lung, and Blood Institute emphasizes that anyone can develop a PE, but risk increases with multiple factors.

Treatment and Outcomes

When PE is diagnosed quickly, treatment with blood thinners (anticoagulants) is highly effective. In severe cases, clot-busting medications (thrombolytics) or surgical intervention may be needed.

Without treatment, large pulmonary embolisms can be fatal within hours. With prompt diagnosis and treatment, most patients recover fully.

Prevention After Diagnosis

If you have had a PE or DVT, your doctor may recommend long-term blood thinners, compression stockings, an inferior vena cava (IVC) filter in certain cases, and lifestyle changes including regular movement, hydration, and avoiding prolonged sitting.

Follow-up imaging with CT scan or vascular ultrasound may be ordered to monitor clot resolution.

Fast Diagnosis When It Matters

At Advanced Medical Imaging, we offer CT pulmonary angiography with rapid turnaround. If your doctor suspects a pulmonary embolism, call (727) 398-5999 or schedule online. In a potential emergency, go to the nearest emergency room immediately.