Chest X-ray: lung pathology I

Onward with chest we go! Pathology described for non-medical people is basically anything not “normal” in the body. Sometimes it can be really bad like cancer, it could also be a benign lesion (it’s not normal but it’s not going to kill you either), it could be congenital (a developmental/birth abnormality), and on and on. So the point is that all of my writings should be simplified and are intended to be incomplete. I want to convey what I feel to be relevant clinical information. The common sense of medicine if you will. This is not meant to be a catalog but a general review targeted at the most common things healthcare professionals encounter and patients experience.

We’ve covered lung anatomy and seen how there can be tremendous overlap of the lobes of each lung on chest X-ray. So, how does a radiologist figure out where the pathology is located? The answer can lie in the silhouette sign. This occurs when normal aerated lung, which should appear “black” is filled with gunk and becomes “white.” This may then obscure the normal appearing contour lines of a chest X-ray, most notably the heart and diaghragms/bottom of the chest. Again, let’s keep it real simple. When looking at the lungs first compare left and right. Do they look symmetrically filled with air? If not, is the problem on the left or right? Next, is the white spot/opacity in the upper, middle, or lower lung field (NOT lobe but field, a more vague term)? Guess what, you’re done! That localizes the process enough for chest X-ray. You’ve presumably made the finding, given a general location, and provided pertinent clinical information to the referring healthcare provider.

Let’s do a couple of cases:


First, is it right or left?


Next, is it in the upper, middle, or lower lung field?


Good Job! From the lung anatomy lecture we know there can be tremendous overlap in the lobes of the lungs, which is where the lateral chest X-ray can help.


This is tricky but I hope you can appreciate the wedge/pie shaped opacity overlying the heart. Notice how near the diaphragm of the posterior/inferior heart border (LV) it is less dense at the heart but just above it is  dense with the consolidation. This proves the opacity to be in the middle lobe (anterior on the lateral view) and  not in the lower lobe (posterior on the lateral  view).

CXR - right lat 2

Right middle lobe (RML) with “wedge shape” like a pie, pizza, cheesecake, etc. The PA and lateral chest X-ray series can provide a tremendous amount of information.

Let’s do another one:


First, is it right or left?


Next, is it in the upper, middle, or lower lung field?

Middle, No upper, wait middle…uh, is there a lateral view?


So where is it? You found it? If  not, track your eyes up the spine from the belly towards the head. Do you see where it is blacker, gets white, then gets darker again. You just found the pneumonia. It should never get dark again as you move up. The spine is a very effective tool in looking at lateral chest X-rays.

Two more cases for pathology I:

CXR PA - left effusion

First, is it right or left?


Next, is it in the upper, middle, or lower lung field?


Notice how this opacity has caused a silhouette blocking out the left heart border and diaphragm. It’s easy to see on the right chest, but you can’t see either on the left. Hmmmm… Let’s got  to the lateral.

CXR lat - left effusion

Sorry, this was a trick. It is in the front and back. See how the edges of the opacity curve upwards. This is characteristic of  fluid. This is NOT in the lung, but fluid between the lung and chest wall called an effusion.

Okay, last one and I promise to be fair and reward you.


First, is it right or left?


Next, is it in the upper, middle, or lower lung field?


This is a process that is everywhere in the lungs, so it has to be systemic. Notice how these opacities all appear somewhat round  but of varying sizes. This is metastatic  tumor to the lungs. If this were an infection, the person would likely be horribly sick and intubated with a tube in their airway and hooked up to a ventilator. The CT provides nice confirmation.

CXR CT - mets

Well that covers some of the more basic lung pathology, plus an effusion. We’ll keep going with some chest X-ray pathology before moving onto fluoroscopy.

I hope this is helpful to my colleagues in healthcare. This is probably going off the rails for patients, but hey if you’re a geeky nerd like the rest of us then go crazy please!

I hope you like that CT picture. Thought it would be nice to include something other than X-ray. Let me know if you would like to see some more CT, or any other modality or particular exam. I’ve heard from some X-ray technologists, but how about a patient or referrer. Drop me a comment and let me know your reading and what you think! Oh, and check out my new video in the About site page, please!!!



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I am an American Board of Radiology certified Diagnostic Radiologist with a certificate of additional qualification in Neuroradiology. I absolutely love my job. I have learned a tremendous amount about the human body, including its’ expected complications given our extraordinary complexity, and get to use that knowledge to help people. I personally have experienced emotional devastation and loss, which has made me compassionate and empathetic. I really care about people, and I hope I can use this site to help you. I graduated medical school in 2004 from New York Medical College. My wife and I had our first son in NY where we bought our 900 sf two bedroom one bath starter home. I stayed at Westchester Medical Center for radiology residency, where we had our second son. I obtained a neuroradiology fellowship position at Yale New Haven Medical Center commuting about an hour and a half each way for a year while we had our third boy. Upon graduation I was fortunate to return to Westchester Medical Center to work in Neuroradiology, Body Imaging, and Women’s Imaging departments, a rarity in academic medicine. Almost a decade later and I am living in a larger home in Reno working in a private practice community based outpatient radiology group which contracts with a rural hospital in Elko, Nevada. My wife and I now have four boys and gave up on the girl. We also have a male Bernese mountain Dog named Helmut and female Newfoundland named Lucy. Despite all its hardships and tremendous struggles, I have an absolutely amazing life, which is a gift I cherish. It’s down to my philosophy. I am a firm believer in teamwork. So much comes down to communication. When healthcare providers talk to each other one-on-one, the patient care is always improved, every time! We might not find an answer to your problem, but our collective knowledge sure can help improve your chances. At Yale the best conference I ever regularly attended was a head and neck tumor board. The head and neck surgeon (otolaryngologist = ENT) presented the patient’s clinical history, the radiologist showed the images, the oncologist discussed the tumor and chemotherapy options, and the patient came to the conference and we all did a physical exam looking into their mouth to directly visualize a tumor. It was incredible! Patients came from far and wide to see this highly trained, world-renowned, humble, Japanese, gentleman surgeon. It was also an epiphany. I found that when I see the patient, talk to them, listen to their story, examine them and discuss the patient with my colleagues, the patient felt better and I had a lot of fun. It’s weird but reminds me of seeing a comedy where it is always funnier in a packed theater with everyone laughing. Knowledge and compassion are both infectious and contagious. My greatest days are helping patients deal with some of their most difficult days, and I am good at it.

3 thoughts on “Chest X-ray: lung pathology I

  1. This is so good! I will review these several times until I become comfortable at looking at the different structures. I have a neurological condition that affects my breathing and chest x-rays are the first step in determining management changes. The radiologists always give me the CD of my chest x-rays. They once asked if it was too much information for a patient. I told them absolutely not. I know I have heart failure, but nothing encourages me to keep on the right track as a picture of my heart and the lines of atelectasis. You’re invaluable to helping me continue to learn and improve my quality and quantity of life. You’re also saving health care dollars. Better educated patients manage their health care more efficiently and wiser. The healthier we are the more we stay out of hospitals.

    Liked by 1 person

    1. I must commend you as well. Being so diligent and responsible for your own health care is outstanding. We as a society need to do better about taking personal responsibility for our health. Thank you!


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