TRANSCRIPT LEARNING OBJECTIVES: • to be familiar with the systematic approach to interpreting chest X-rays • to know the correlation between anatomy and normal shadows on the chest X-ray Before just presenting a systematic approach, we should mention a couple of IMPORTANT PRINCIPLES about it: • it is most important for the clinicians least experienced with reading chest X-rays, since it reduces the chance that important findings will be missed • all aspects of chest X-ray interpretation should be included • the individual elements of the approach should be examined in a sequence that is either logical and/or easy to remember • there is no one "best" system, though all should begin with an assessment of the film's technical quality We could informally call such a systematic approach the ABCDEF SYSTEM (each of the letters refers to a specific anatomic structure, but before the A we need to assess the technical quality): • A=AIRWAYS • B=BONES (and soft tissue) • C=CARDIAC SILHOUETTE (and mediastinum) • D=DIAPHRAGM (and gastric bubble) • E=EFFUSIONS (in other words, assessment of the pleura, which actually includes findings beyond just pleural effusions) • F="FIELDS" (i.e. lung fields) • lastly, although it is not explicitly part of the mnemonic, ASSESSMENT OF LINES, TUBES, DEVICES and PRIOR SURGERIES, such as sternotomies and valve replacements Aside from the fact that it is easy to remember, another nice thing about this mnemonic is that the lungs are examined near the end. This is a good idea because normally the lungs are the area of greatest interest and the most likely to be abnormal, therefore once the clinican find an abnormality there, it is very easy to forget examining the rest of the film (for example, overlooking a rib fracture because of a distraction over acute lung pathology) A is for the AIRWAYS. There are three anatomic airway structures that are typically visible on a normal X-ray: • TRACHEA, which is normally in the midline • RIGHT and LEFT MAIN BRONCHUS ○ the left main bronchus tends to take off from the trachea at a slightly more horizontal angle as compared to the right, which is why aspirated foreign bodies, if small enough, are more likely to end up in the right lung than the left, and it is also why endotracheal tubes, if advanced too far, end up in the right main bronchus, blocking off ventilation to the left rather than viceversa The next set of structures is the BONES. There are four types of bones, easily visualized on a PA and lateral X-ray set: • RIBS ○ there are two radiographic components of the rib on the PA film, the POSTERIOR RIB, which is easier to see and is oriented horizontally, and the ANTERIOR RIB, which is harder to see and oriented at a 45 degree angle • CLAVICLE • STERNUM (sometimes visible on the LATERAL film, but is often obscured by soft tissue in the anterior chest wall) • VERTEBRAL BODIES (more easily visible on the LATERAL film, but usually seen on the PA as well, provided that the technical quality is adequate) Then, there are the CARDIAC SILHOUETTE and the MEDIASTINUM, which should logically be evaluated together. There are a lot of anatomic structures that compose the silhouette (on the left side, AORTIC ARCH, LEFT PULMONARY ARTERY, LEFT ATRIUM, LEFT VENTRICLE, while, on the right side, ASCENDING AORTA, RIGHT PULMONARY ARTERY and RIGHT ATRIUM): • we should usually also be able to see another vertical line running just to the patient's left of the vertebral bodies, which corresponds to the LEFT SIDE OF THE DESCENDING AORTA • the one structure on the patient's left called the AORTOPULMONARY WINDOW may be unfamiliar to some: this is an important space between the aortic arch and the pulmonary artery where one will find the recurrent laryngeal nerve and lymphnodes It makes sense to evaluate the DIAPHRAGM and the PLEURA together: • RIGHT and LEFT DIAPHRAGM ○ they are clearly visible on the PA view ○ it is normal for the right hemidiaphragm to be slightly higher than the left, presumably due to the liver being directly beneath it ○ while looking at the diaphragm, it's important to remember that there aren't any truly flat structures in the body: for example, the hemidiaphragms are curved in three-dimensional space; as we might be able to appreciate from comparing the PA to the LATERAL, the hemidiaphragms seen on the PA really just represent the superior most aspect of the diaphragm • PLEURA ○ it is normally invisible due to its thinness ○ however, knowledge that the pleura is there is essential for diagnosing a pneumothorax, pleural plaques from asbestos exposure and pleural thickening • RIGHT and LEFT COSTOPHRENIC ANGLES (although SULCI would probably be more semantically accurate in most circumstances) ○ spaces on either side where the diaphragm meets the thoracic wall ○ these two spaces are usually seen on the PA • POSTERIOR COSTOPHRENIC ANGLE ○ space in the back on the LATERAL film • GASTRIC AIR BUBBLE ○ small pocket of air, visible under the left hemidiaphragm, usually representing air in the stomach ○ occasionally, it can be unclear whether the gas is in the stomach or in the intestines Next, we need to take into consideration the main anatomic structures of the LUNGS: • FISSURES BETWEEN THE LOBES ○ HORIZONTAL FISSURE § there is only one, and it is located on the right side § it is the only one of the three fissures that is commonly visible in normal X-rays, which is because a significant portion of the plain of the fissure is parallel to the direction of the X-ray beams § however, it is only visible on the PA § the right and left oblique fissures are not visible ○ LOBES § RIGHT UPPER LOBE § RIGHT MIDDLE LOBE § RIGHT LOWER LOBE □ because the oblique fissure runs obliquely, as seen in the lateral view, the lower lobe extends almost all the way to the apex of the lung (this will be true on the left side as well) □ as a consequence, if only the PA or AP views are presented without a lateral, it's almost impossible to tell in what lobe a visualized nodule or mass is located, unless it's seen in the uppermost part above the lower lobe's most superior extent § LEFT UPPER LOBE § LEFT LOWER LOBE
Greetings from Indonesia. This is the first radiolology lesson that's able to make me fully understand a CXR. It is very systematic and doesn't cause confusion
Phenomenal presentation with super imposing anatomy. Genius!!! Thank you for the clarity of explanation and please continue doing these videos. Disregard the haters....
This is the first video of yours I have watched and it seems like I'll be seeing more of your awesome clear, made simple videos... I just need to say thank you! THANK YOU
Dr. Eric I appreciate you taking time out of your busy life in making these very educational videos. I am thankful that there are resources like you because my NP school sucks.
Thank you very much for these videos , right from the start you got my attention. You are clear and concise. Most perfect teaching videos that I have watched on you tube.
Your video series helps me a lot to understand the interpretation of the chest x ray and I am looking forward to the next step ,i am basically a science communicator and science graduate and the power plant experts.
Thanks for posting this video. in this video is very useful for me and all medical students also. hope i am become a good radiographer. Once again thanx Mr. Eric's.
Love the ABCDEF mnemonic, thank you for this high-yield series! I've seen it extended to G = gastric bubble, H = Hilum, I = instruments (lines, tubes, devices, etc.). A question: any plans to create a interpreting CT series? Would be very useful (and if not - any recommended free resources for med students?)
Eric, I'd love to see you do a video on how to systematically approach lung lesions of different appearances, + their common differentials. (I couldn't find one already on your channel, though I could have missed it; you have lots of videos!) Your videos are so systematic and relevant that I would specifically want YOU to do one!
Thanks for the vote of confidence! Sorry I"m taking so long to respond to this, and you may have already discovered this, but lessons 7 and 8 in this series on chest X-rays covers the differential diagnosis of various types of lung lesions. You can find the videos by going to my channel page and scrolling down to the playlist "Interpreting Chest X-rays".
Veey interesting and clear explanation. Thank you so much today i got to lern from you. And i recommend those who want to learn please go for it worth watching and very helpful, Thanks.
Hello sir I am a student of pcl diagnostic radiography in nepal I always watch your video to better understand where I study in my collage 🇳🇵🇳🇵thank you for your information video ❤️❤️❤️❤️always respect and love
many thx for your great work, Eric. It's very very helpful. I'm wondering if you have any plan to interpret CT anatomies of neck, chest, abdomen and pelvics.
I'm very glad you've found them helpful! Unfortunately, I have so many other topics on my to-do list that I don't anticipate covering CT imaging in the near future. Perhaps much further down the road. For now, if you are wanting to study CT imaging on your own, I recommend www.radiopaedia.org - they have many great examples and mini-tutorials covering all radiographic modalities.
nice video... very well described, right diaphragm is higher as left diaphragm is pushed down by heart.. as right diaphragm is lower in patient with dextrocardia with normal situs
this is so worth it and a must watch lecture! thank you so much doc. and may i request for another lectures of radiology such as MRI CT or USG please? :3
you are amazing thank youuuuu!! we start radiology and it was very difficult for me to understand everything especially with the pandemic situation where we have our lessons online!! so really thank you , it made it very clear
