Does pneumonia always show up on chest x-ray?

Pneumonia does not always show up on chest x-ray. In the early stages of pneumonia, there may be only minor changes in the lungs that are not visible on a chest x-ray. Additionally, certain types of pneumonia, such as walking pneumonia, may not cause any visible changes on a chest x-ray. In these cases, other imaging tests, such as a CT scan or ultrasound, may be necessary to diagnose pneumonia.