Pulmonary hypertension is a serious medical condition characterised by high blood pressure in the arteries that lead to the lower respiratory tract. It can be caused by a variety of factors including genetic disorders, lung diseases, and other underlying medical conditions. Diagnosing pulmonary hypertension requires a combination of clinical evaluation and various diagnostic tests.

One of the primary diagnostic tests used to diagnose pulmonary hypertension is the nuclear imaging test. The nuclear scan is a type of imaging test that uses tiny amounts of radioactive materials, اسکن قلب known as radiopharmaceuticals, to produce detailed images of the lower respiratory tract and surrounding blood vessels.

The purpose of a nuclear scan in diagnosing pulmonary hypertension is to measure the resistance in the blood vessels leading to the heart. In normal lungs, blood flows through the pulmonary arteries with ease, but in the case of pulmonary hypertension, the blood vessels become constricted and their resistance increases. This resistance can be measured by the nuclear scan.

The procedure typically involves lying down on a table and being covered with a special blanket to take pictures of the chest area. A small amount of radioactive tracer is injected into a vein in the arm where it mixes with the bloodstream and travels to the heart. The tracer accumulates in the pulmonary arteries and emits a signal that creates images on a computer screen.

These images show the function and movement of the lungs and the blood vessels supplying them. A special camera, often referred to as a pet camera, is used to pick up the signals emitted by the tracer. The camera takes pictures from different angles and the images are then reconstructed to form a complete and detailed picture.

Doctors interpreting the results of the nuclear scan will look for signs of increased resistance in the blood vessels, abnormal blood flow, and defects in the structure of the lungs or surrounding blood vessels. A follow-up scan may be required to measure the response to medication or further changes.

The nuclear scan is still considered one of the best tools for diagnosing pulmonary hypertension and can be particularly useful when symptoms are subtle or when lung function tests or electrocardiograms (EKGs) are inconclusive. In some situations, other tests such as a chest X-ray, echocardiogram, or cardiac catheterization procedures may also be required to rule out other conditions.

Overall, a nuclear scan is a minimally invasive diagnostic tool used to identify pulmonary hypertension. It provides valuable images of blood flow and resistance, helping doctors to confirm the diagnosis and determine the severity and progression of the disease.