Emergency Department Radiograph Interpretation: You Need a System!

There are a few times in emergency medicine you need a system: a standard approach. This is with chest XRAYS, as well as EKGs/ECGs. This must be easy and consistent. My approach, that I have taught to thousands of people, is called the "RIP'T, ROARing ABCs" approach. Use this system every time you evaluate a CXR, and you will become extremely confident and competent in your evaluation skills.

Then we come to the main portion of CXR interpretation. We use "RIP'T" for the evaluation of the quality of the CXR. 'R' is rotation. 'I' is inspiration. 'P' is penetration. 'T' is technique.

Let's talk about that in more detail. With the 'R' for rotation, we want to see if the clavicles line up like the site on a gun behind the spinous process. There should be equal distance between the spinous process and the end of the clavicle, the medial aspect of the clavicle. If a patient is twisted and their right shoulder is closer to the x-ray beams and further away from the film than the left shoulder, there will be distortion in anatomy. I am not saying you disqualify a film if it is moderately rotated, but you need to weigh that in when you review the film. If you are evaluated and elderly lady with very severe kyphosis, they will be rotated to some degree and you just have to weigh that in when reviewing the films. Inspiration is where we actually count the ribs to make sure we see between 9 and 11 ribs. The deeper of a breath they take, the more of the lungs you will be able to see. In someone who does not take a deep breath, again someone who is demented and cannot follow instructions, you will maybe only see six ribs and will really have to weigh in your thought process that they may have pathology lying in the posteroinferior aspects of the lungs that we would not be able to see on a PA radiograph, and a lateral x-ray would be much more helpful. P is penetration where we want to see the vertebral bodies behind the heart. If the heart is so white or under-penetrated that we cannot see the vertebral bodies, we call this film under-penetrated and is going to be more difficult to interpret the radiograph as opposed to a film that is over-penetrated which means that the film is excessively black. Those films are easier to read. When working as a house officer, five years in, I really thought I was becoming good at what I did. I had a consistent problem of not telling if the radiograph was under-penetrated versus congestive heart failure. So, I turned to my senior colleagues, people who were house officer PAs for 20 years, and asked that question. 'How can you tell if it is really congestive heart failure versus under-penetrated?' I was really expecting these great words of wisdom to help me differentiate between them. Both of them looked at me and said, 'You know, John, I had a tough time with that too.' So, with that said, an under-penetrated film can fool you into thinking it is congestive heart failure. But, you really need to weigh in whether you can see the vertebral bodies or not and use pretest probability. How does the patient look? T is for technique which is a PA film versus an AP film. PA means posterior-anterior, and AP means anterior-posterior. If you hold your hand in front of a flashlight that is shining against a wall, you will understand the concept of posterior and anterior. The flashlight beams are the x-ray beams, and the wall is the film. Your hand shadow is going to be what appears on the radiograph. Now, if you take your hand and put it very close to the wall, your shadow is going to be quite crisp and the shadow is going to be almost the exact size of your hand. If you take your hand and move it back towards the flashlight, the shadow will become bigger and will become blurred. This concept applies the say when interpretation a PA film as compared to a PA film. Now, the heart lies anterior in the chest, so if you are doing and AP film which means the beam of the x-ray is going from the anterior to the posterior. WIth a portable CXR the heart is more posterior in the chest wall, therefore the heart will be more enlarged and more hazy. A posterior-anterior film is when the patient actually turns their back, puts their back up to the film, and the x-ray beams go posterior-anterior. That is a more perfect film, and you get a better view of the heart, a crisper heart shadow, and therefore a PA film is a much better film than the AP film. YOU NEED TO TAKE YOUR TIME! You walk up to a film and take 2 minutes to apply the RIP'T, ROARing ABCs. RIPT is rotation, inspiration, penetration and technique.

We are going to discuss ROAR. This is the easy one. ROAR stands for right patient, old x-rays, alignment and right date. This is where you are going to spend just a 10-20 seconds validating the data, making sure that you do indeed have the right patient, are there old x-rays to compare it with, if the film is hung correctly, and that you have the right date. I am used to working in smaller hospitals, where there are only 2 or 3 radiographs done per hour. At a bigger hospital, you do an x-ray, go down to look at it, and one is hanging. If you are assuming this is your patient's film, you are going to get burned sooner or later. So, take the time to ensure that you have the right dated, the right patient and if there are old films to compare with, you just want them handy and if any abnormalities, you can compare and contrast them. Here is a pearl for you. If you are evaluating a radiograph, and in the review of the old films, you see multiple different films of multiple different body systems (and there is not a good explaniation, such that the patient is a stunt bike rider) it implies to me the patient derives secondary gain from the medical system (in other words, they are crazy.)


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You need a reproducible system of evaluation. It has to be easy to remember and recall to evaluate a CXR. I call this system John's "RIP'T, ROARing ABC's" Just as the interpretation of a chest radiograph is critical in the assessment of a pulmonary patient, so is the electrocardiogram to the assessment of a patient with chest pain.