CXR 101

Anatomy of the Chest X-ray

Before we dig into an approach for reading chest x-rays, it’s important to know all the things that we’ll looking at. There are typically two views you’ll be looking at PA and lateral. The PA or posterior to anterior shoots a beam from a standing patient’s back through to their front, where the x-ray plate collects it. The lateral shoots the beam through the standing patient’s size through to the other side where the x-ray plate collects it.

For those of you in the M3 CRASH course, here are some useful resources:

CXR Basics

I really appreciate the DRS ABCDE approach from Life In The Fastlane, a modification of what I was taught many years ago (ABCDE).

Details

Details	Are you looking at the right patient? Are you looking at the right date?
RIPE Image	Make sure that the quality of the picture is good. Rotation: look at the clavicular heads Inspiration: did they take a deep enough breath? can you see at least 9-10 posterior ribs? Position: can you see both costo-phrenic angles on the x-ray? Is the picture capturing everything. Exposure: can you barely see the intra vertebral disk space in the spine especially down toward the bottom?
Soft Tissue and Bones	Look for any lesions in the bones. Look at the vessels (like the aorta). Look at the soft tissues, is there any air (black)?
Airways and Mediastinum	The carina and trachea should be in the midline. And the mediastinum should be less than 8 cm in width.
Breathing	Look at the vascularity. They should start to disappear at the periphery, but you can usually still see a few. If it’s all black, consider a pneumothorax. Look for infiltrates and fluids in the fissures and the costophrenic angles.
Circulation	Look at the heart, ⅔ will be on the left side. The cardiothroacic ratio should be about half the distance of the thorax. Heart should have a non-boot shape and be distinct.
Diaphragm	Right hemidiaphragm is usually higher than the left There should be no air underneath but you will see the gastric bubble on the left side.
Extras	Various tubes have radio-opaque strips in them. Common things you will see include an NG tube, chest tube, pacemaker, endotracheal tube and cardiac monitor wires on top of the chest.