Final answer:
In an AP Chest X-ray, the x-ray machine emits x-rays that pass first through the patient's front (anterior) side and are then captured after passing through the body. Energy levels of x-ray photons, typically around 50.0 kV for chest x-rays, are essential for obtaining clear images. CT scans provide more detailed images using multiple x-ray angles and computer processing.
Step-by-step explanation:
When obtaining an Anteroposterior (AP) Chest X-ray (CXR), the x-ray machine sends x-rays first through the patient's anterior body before reaching the posterior where the image is captured on a film or digital detector. The energy of the emitted x-rays from the x-ray photon is crucial as it determines the penetration level through different materials. A higher energy photon will penetrate more material, which means the x-ray tube may be operated at a higher kilovoltage (kV) depending on the density of the tissue. Typically, a chest x-ray may be operated at around 50.0 kV, while denser body parts could require a higher kV setting.
X-rays are slightly impeded by soft tissues which appear gray on the x-ray plate, whereas hard tissues like bones block the rays more completely, creating a light-toned "shadow" image. This difference in absorption helps to visualize the various structures within the body. However, an x-ray provides only a two-dimensional image which may not fully capture the complex three-dimensional structure of the body's internal organs and tissues. Computed Tomography (CT) scans advance this by providing a more detailed cross-sectional view through computer processing of x-ray measurements taken from multiple angles.