So let?s review some normal anatomy before we go on to pathology.
Again, with all of radiology, it?s important to be able to recognize what normal anatomy looks like
so that if you do have an abnormality, you can help differentiate what?s normal and what?s not.
So let?s start first with heart and mediastinal anatomy.
We take a look at the trachea which again should be midline,
and it?s the air-filled structure within the mediastinum.
We then take a look at the shadow of the SVC or the superior vena cava
and that?s seen just to the right of the mediastinum.
You can see it pointed out here and you can see the shadow coming down this way.
We wanna take a look at the hilum to look for any kind of hilar abnormality.
It?s a very common place to have a mass or lymphadenopathy
and each of those green circles represents the hilum on each side.
The pulmonary artery is also located in this region.
You wanna take a look at the right atrium which is the right heart border
so the entire right heart border on a frontal film represents right atrium.
You can see the aorta.
You can see a portion of the ascending aorta as well as a portion of the descending aorta
on a chest radiograph.
Again, this is the left hilum and a portion of the pulmonary artery
is also present there; and here you can see behind the heart, a shadow of the descending aorta.
The entire left heart border represents the left ventricle.
So how about on a lateral view?
Again, it?s important to have both a frontal and a lateral view whenever possible.
However, it?s almost never, a lateral view is almost never performed alone.
It?s still important to recognize the anatomy on this view so let?s take a look.
We should have a retrosternal clear space.
So right here, we have the bony sternum and then just behind it,
you should have an air-filled space between the sternum and the heart and mediastinum.
The anterior aspect of the heart on a lateral view represents the right ventricle.
You can see two different diaphragmatic shadows here
and usually the one that?s higher up is the right hemidiaphragm
and that?s a little bit higher than the left because of the liver that?s right underneath it.
You can see the descending aorta shadow coming all the way down
so you can see a portion of the arch here and then the shadow comes all the way down here.
You can see the hilum and again, you can only see one hilum.
They both overlap each other on the lateral view
and here you can see a portion of the right atrium as forming the posterior heart border.
So the superior aspect of the posterior heart border is the right atrium
while the inferior aspect of the posterior heart border is the left ventricle.
And posteriorly here, slightly lower than the right hemidiaphragm,
is the shadow of the left hemidiaphragm.