General Diagnoses Practice Test 2026 - Free Diagnostic Practice Questions and Study Guide

In pregnancy, the priority is to diagnose pulmonary embolism while minimizing radiation exposure and avoiding unnecessary invasive tests. Ventilation-perfusion scintigraphy uses small amounts of radiotracer to map air flow and blood flow in the lungs, and a mismatch between ventilation and perfusion strongly suggests an embolism. It typically delivers less radiation to sensitive tissues such as breast tissue and avoids iodinated contrast, which is advantageous in pregnancy. Chest X-ray alone can’t diagnose PE, and CT pulmonary angiography, though very accurate, involves more radiation and contrast; pulmonary angiography is invasive. So, when radiation risk is high, V/Q scintigraphy offers a safer, reliable option for evaluating suspected PE.