How is chronic thromboembolic pulmonary hypertension (CTEPH) diagnosed?
If your healthcare provider suspects CTEPH, he or she 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 to tell 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.