From the Guidelines
A PA lateral Chest X-ray is a crucial diagnostic tool that involves taking two views of the chest: a PA view and a lateral view, which together provide a comprehensive assessment of the lungs, heart, mediastinum, ribs, and diaphragm. The PA view is taken with the patient standing facing the detector, while the lateral view is taken with the patient's side against the detector, offering complementary perspectives that help evaluate structures that might be obscured in a single view 1.
Key Components of a PA Lateral Chest X-ray
- The PA projection reduces magnification of the heart and provides more accurate cardiac measurements.
- The lateral view can detect as little as 50 ml of pleural fluid, which is not visible on the PA view, by showing posterior costophrenic angle blunting.
- This examination is essential for assessing conditions like pneumonia, heart failure, lung masses, fractures, or pneumothorax.
Clinical Applications
- In the intensive care setting, patients are often imaged supine, and the PA lateral Chest X-ray helps in identifying free pleural fluid, which layers out posteriorly.
- Subpulmonic effusions, often transudates, can be difficult to diagnose on the PA radiograph and may require a lateral decubitus view or ultrasound.
- The combination of PA and lateral views increases diagnostic accuracy by allowing visualization of abnormalities from different angles, making it a fundamental tool in chest imaging 1.
From the Research
PA Lateral Chest Xray
- A PA lateral chest Xray is a type of chest radiograph that provides a lateral view of the chest cavity, which can be useful in diagnosing various conditions such as pneumothorax and pleural effusion 2, 3, 4, 5.
- The lateral chest Xray can be used to detect pneumothorax, with a study showing that it can be seen on the lateral projection in 89% of examinations 2.
- The lateral decubitus position of chest Xray can be used to estimate pleural effusion volume, with a study showing that the area function model is the most appropriate equation for measurement 3.
- Chest Xrays, including PA lateral views, can be used to detect cardiomegaly, pneumothorax, and pleural effusion, with deep learning models achieving high accuracy for detection and semiquantitative analysis 5.
- Dual-energy, dual-exposure PA and lateral chest radiograph systems have been developed, which can provide improved detection of pulmonary nodules and coronary atherosclerosis 6.