How is chronic thromboembolic pulmonary hypertension (CTEPH) diagnosed?
If your healthcare provider suspects CTEPH, they will examine you and then may order one or more of the following tests:
- Lung ventilation-perfusion scan (also called lung V/Q scan): This type of test uses X-ray scanning equipment to take pictures of what is happening in your lungs. The ventilation portion calls for you to breathe in a little bit of a radioisotope gas-oxygen mixture. The perfusion portion calls for an injection of the radioisotope (basically contrast material) into your veins. The special X-rays can then determine if there is blockage due to a clot and how well blood and air moves in your lungs. A chest X-ray is usually done before or after a lung V/Q scan.
- Echocardiogram (sonogram of the heart; also called transthoracic echocardiogram or TTE): Sonography uses sound waves to make pictures of your heart and can estimate the pressure in the lung arteries. This painless test is often done early in the diagnosis process.
- Computed tomography (CT) scan: Contrast material is injected into your vein and X-ray pictures are taken. The pictures will show blood clots.
- Right-heart catheterization: This test, which uses a catheter placed in the neck or groin, measures blood pressure in the right side of the heart and lungs. This is the most accurate test for pulmonary hypertension.
- Angiography of lung (pulmonary angiogram): In tests of these kind, dye is injected into the arteries via a catheter put into a vein in the neck or groin. Pictures are taken. The dye highlights blockages in arteries of the lungs.
- Pulmonary function tests: These tests measure how well the lungs are working and the extent of damage to tissues.