Then and Now | Chest X-Ray

Central Ray | perpendicular to the midsagittal plane entering the level of T7

Evaluation Criteria

• Apices and costophrenic angles
• Both lungs and 10 ribs visible above the diaphragm
• Heart on the left side
• Spinous process centered demonstrating no rotation of the body
• Adequate air filling the lungs demonstrated by the dark contrast of the lung field.

Shielding: gonads

IR: 14x17in (35x43cm) Crosswise

SID: 72 inches (183cm)

Breathing: Suspended

The history of the PA view x-ray projection of the chest is a long and fascinating one. The first chest x-rays were taken in the early 1890s, shortly after the discovery of X-rays by Wilhelm Roentgen in 1895. These early x-rays were of poor quality and did not provide much information about the internal structures of the chest.

In the early 1900s, a number of improvements were made to x-ray technology, including the development of the grid, which helped to reduce the amount of scattered radiation that reached the film. These improvements made it possible to take clearer and more detailed chest x-rays.

In the 1920s, a new technique for taking chest x-rays was developed called the posteroanterior (PA) view. In a PA view, the patient stands or sits facing the x-ray machine, with their back to the film. The x-ray beam passes through the front of the chest and onto the film.

The PA view quickly became the standard way of taking chest x-rays. It provides a clear view of the lungs, heart, and other structures in the chest. The PA view is also less likely to be affected by rotation of the patient than other views, such as the anterior-posterior (AP) view.

Today, the PA view is still the most common way of taking chest x-rays. It is used to diagnose a wide range of conditions, including pneumonia, heart disease, and cancer. The PA view is also used to monitor the progress of treatment for these conditions.