Today’s x-ray case was one I read a few days ago at our Invision offices. The patient is a 59-year old man who complained of chest pain after he fell while horseback riding.

(The weather in Colorado has been pretty mild lately, so people are still doing horseback riding despite the fact that it’s January. I went for a 4-mile run outside on New Year’s Day in shorts and a t-shirt.)

Here is the patient’s initial chest x-ray:

As usual, the patient’s left side is on the right side of the image (marked with a “L” in the upper corner) and his right side on on the image left — exactly as if he were facing the viewer in real life. The lungs are black. The heart is the white area in the middle.

So what’s the abnormality? (Hint: The abnormality is on the patient’s left side.) Keep scrolling down for the answer.

Here is a normal chest x-ray on a different 50-year old man for comparison:

Finally, we got a CT scan of the chest to better delineate the problem. Here is a matching reconstructed image lined up to correspond with the chest x-ray:

Based on this (and the other CT images), we made the diagnosis of a ruptured diaphragm on the left side.

The diaphragm normally separates the chest from the abdomen. Because his left hemi-diaphragm was torn, it allowed his stomach and a large part of his colon to slide upward into the chest cavity. This compressed most of his left lung and pushed his heart far out of position to the right side, in turn causing additional partial compression of the normal right lung.

Fortunately, the patient was still breathing well with just his partially functioning right lung. A small portion of his left lung was still inflated. But because the left hemi-diaphragm wasn’t working, very little air was moving in and out of the left lung.

The family practice doctor seeing this patient was just as surprised as we were. But she got him plugged in with a trauma surgeon right away, and the last I heard the patient was doing well.