Radiological Investigation III: Pulmonary Angiogram and PET Scan

A pulmonary angiogram is an invasive procedure where a catheter is inserted through a femoral vein and threaded through the right side of the heart into the pulmonary artery. A contrast medium is injected to highlight lung blood vessels, followed by fluoroscopy X-rays to visualize the pulmonary arteries and detect blockages or narrowing.

The primary purpose of a pulmonary angiogram is to locate obstructions or pathological conditions such as a pulmonary embolus. It provides a detailed view of the pulmonary vessels, aiding in diagnosis and treatment planning of pulmonary diseases when less invasive tests yield inconclusive results, particularly for detecting congenital abnormalities.

A PET scan uses radioactive glucose injected into the bloodstream. The patient rests for 30 to 60 minutes to allow the tracer to spread throughout the body. The scanner detects gamma rays emitted by the tracer as it accumulates in areas of high metabolic activity, such as cancer cells, infection sites, or inflammation.

A PET scan distinguishes between benign and malignant pulmonary nodules by demonstrating increased glucose uptake in malignant cells. Malignant lung cells have higher glucose metabolism than normal tissue, allowing the PET scan to accurately differentiate between normal and diseased tissue for cancer staging and management.

Pre-procedure nursing responsibilities include checking for allergies to radiopaque agents like iodine and shellfish, assessing anticoagulation status and renal function, and ensuring nothing by mouth status for 4 hours before the procedure. The nurse must also verify informed consent has been obtained.

Post-procedure care includes encouraging fluid intake to facilitate elimination of radioactive substances and monitoring vital signs and oxygen saturation. The nurse should ensure the patient understands the importance of hydration for eliminating the radioactive tracer and provide education about recovery expectations.

Computed tomography scans have largely replaced pulmonary angiograms due to their less invasive nature. However, pulmonary angiograms remain valuable when less invasive tests yield inconclusive results, particularly for detecting congenital abnormalities of the pulmonary vascular tree and confirming suspected pulmonary emboli with endoscopic studies bronchoscopy and thoracoscopy.