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Hello and welcome to the second video in my series on respiratory medicine. This video is going to be covering chest X ray interpretation and how we can use a chest X ray in os but also in er clinical practice uh as a common investigation for evaluating patients with respiratory complaints. So a chest x-ray involves firing a beam of x rays at a person, you fire it at the chest and uh depending upon whether or not the patient is facing the detector or facing away from the detector, you will achieve a slightly different view um known as either anterior posterior or a posterior anterior view. It's a very common investigation because it's easy to perform and uh it doesn't take a lot, doesn't take long to perform patients typically exposed to about a 0.2 miniver dose of radiation per radiograph, which is roughly around 2 to 3 days of background radiation. So it isn't a significant amount of radiation exposure. And therefore a good investigation is an invaluable and easy investigation in the assessment of patients with respiratory problems. So there are various indications for a chest X ray. One common indication is using usually, like I said earlier in patients with respiratory complaints. So a patient complaining of chest pain, shortness of breath hemoptysis, uh somebody with a chronic cough or even acute cough, um and other associated symptoms such as fever, they provide images that essentially look at the pleura, the parenchyma and uh also the media sign of structures and bones. They can also be used for evaluation of lines in tubes. So after placing an NG tube, for example, um a method of checking that the tube is in the right place can be by performing a chest X ray to make sure that the NG tube is going into the stomach. This is performed by a registrar and cannot be performed by a foundation of your doctor. Another indication for a chest X ray also includes looking at evaluation of treatment, for example, post uh complicated pneumonia. You can use a chest X ray to look for resolution of any complications such as an empyema or opal effusion in the os. There is a specific etiquette and approach to a chest x-ray that should be performed and is expected. So initially, you wanna comment on the basic features of the chest X ray ie patient ID name number and orientation. Is it anterior, posterior or posterior, anterior or rarely laural decubitus? Although I don't expect the la decubitus as a chest X ray to appear in our exams. You'd also want to comment on the quality of the film So making sure that you're looking at the exposure. So do they have enough ribs? Uh So usually between uh 5 to 7 ribs, um should be enough for a good inspiration. You wanna make sure that you can see the diaphragms. You can also see the AP CS of the lung. You wanna make sure that you also have good penetration. So can you see the lung markings behind the heart retrocardiac or can you see the lung markings behind the diaphragm? So retro diaphragmatically and do you have visibility of the vertebral bodies or the spinal cirrhosis of the vertebrae through the heart or through the media sinus structures? You also wanna comment on the most obvious sign of pathology first and then take a systematic approach to the rest of the chest X ray. The approach I use is a very common one and is the A two F er schemer. Other people can use other schemers use whatever schemer you you find useful and reliable and that helps you assess the chest X ray in a systematic fashion. So this is uh just one slide where I'm just gonna briefly talk through the basic approach to a chest X ray. You've undoubtedly heard of this before and have your own schema. But this is just a basic review of the process before we move on to some case questions. So the first thing you wanna do is assess the airways. So making sure that you can check and see if the trachea is central, looking at where it been bifurcates into the right bronchus and the left bronchus is important. You want to make sure that the trachea isn't deviated excessively towards one side. A sign of media standard deviation associated with pathologies which either cause volume loss. For example, a patient who may have had low bar collapse, um or um an increase in volume on one side, ie potentially somebody with a massive tension pneumothorax. So you need to consider the position of the trachea and whether it's central, this is also obviously going to be affected by the quality of the film. So making sure that you've adequately this rotation by looking at the medial lens of the clavicles and comparing that distance from the medial end of the clavicle to the spinus processes of the thoracic vertebrae. After you've looked at the airways, um you want to check the bones. So making sure that you just briefly have a look through. So the the posterior ribs are more horizontal and the anterior ribs which are more angulated and then sort of disappear as you grow closer to the midline. Because obviously at that point, that's where the ribs then form and attached using costal cartilage to the sternum. The cartilage is going to be less dense than bone. So it's going to be less visible than the bone, um which is seen more horizontally posteriorly and then more angulated anteriorly. You wanna have about 5 to 7 bones um on inspiration for adequate uh exposure, you then wanna look at the soft tissue surrounding, making sure you don't have any excessive air within the soft tissue. So this is a normal line of uh subcutaneous fat, but any excess of air suggestive of potentially subcutaneous emphysema is uh a sign of potentially a massive trauma to the thoracic cavity. You wanna make sure and you want to check the cardiac contours. So making sure you look at the left heart border and the right heart border, the right heart border being formed by the right atrium and the left heart border being the left ventricle. Um You wanna make sure that there's a nice clean crisp demarcation there and that the cardiophrenic angle itself is quite clear. You wanna be able to see the lung markings posteriorly or behind the cardiac shadow and you then wanna also assess uh the mediastinum. So the mediastinum, the key structures to look at in the hilum include here, which is your aortic knuckle. Um Then you have the descending aorta down here. You have the left and the right hila, which are important to assess and they form a sort of concave angle as you can see on both sides. And you also have the pulmonary artery here. So the gap between the aortic knuckle and the pulmonary artery would form the aortic pulmonary window, which if obscured. It's a potential sign of uh a higher pathology like a lymphadenopathy, potentially associated with some form of lymphoma or even uh lung cancer. And on the right side, you can see this stripe here known as the paratracheal stripe, which is also obscured in any form of higher pathology, which is also important to assess the superior and inferior vena cava may potentially also be seen here and here. And you wanna then look at the diaphragm. So making sure that the diaphragm itself is nice and clean and crisp. The right hemidiaphragm is going to be elevated. Um normally above the left hemi diaphragm because of the presence of the liver. And you would normally have an area of gas underneath the left hemi diaphragm, which is the gastric air bubble, just make sure you don't have any gas under the diaphragm here, which is a potential sign of pneumo media, uh pneumoperitoneum and a potential sign of perforation of the abdominal cavity. Finally, you want to look for any effusion. So normally on a chest X ray, the pleura are not visible but in pleural pathologies like a pleural effusion secondary to potentially chest infection or a drug reaction, you would have accumulation of fluid within the pleura which should be visible as uh initially and early on. Um looking at the costophrenic angles which become obscured or blunted with a massive accumulation leading to this classical meniscus sign and a white, completely white denser fusion. And then you want to just compare the long fields and look at your review areas such as your AP CS behind the heart behind the diaphragm. Um just to check and make sure if there's any lines and tubes that you've assessed those as well. So this is the first case in our video. We have a 55 year old woman with shortness of breath and a chronic cough for the last five months. She's an ex smoker of 25 years on examination. She has clubbed fingers and at the bedside, you can see that she has uh blood in her sputum pore. She also com er complains of a bloody cough over the last few months as well. Look at the chest X ray, describe the findings and your top differential. So the first thing you would comment on is the details of the film. So the date of the film, the orientation of the film, you'd also comment that you'd like to look at any further previous imaging to provide a good comparison. And then you'd look at the quality of the film. So this is a posterior anterior chest X ray, which is important because an anterior posterior chest X ray would affect cardiac size as the heart is further away from the detector and would become magnified by the X ray beam. Meaning that any assessment of cardiac size would become inaccurate on this particular chest X ray. There's minimal rotation. It's good inspiration as you can see about seven ribs bilaterally on both sides and there's adequate penetration as the lung markings can be seen behind the heart and behind the diaphragm. You'd comment on the most obvious pathology first and that's a left sided, well circumscribed, solitary mass in the left middle zone adjacent to the left is you would then take a systematic approach to the rest of the chest x-ray, commenting on tracheal positioning for the airways, commenting on the bones, the pleura, whether there is any evidence of any costophrenic. Um um a few, any evidence of any pleural effusions in the costophrenic angles of which there are down here. The costophrenic angles are clear, look at the diaphragm and the heart borders and look at the hilum as well. So this chest X ray would suggest a possible diagnosis of lung cancer. This is because when you tie together the image findings of a well circumscribed solitary mass with the clinical features of a patient who has a chronic cough, hemoptysis and clubbed fingers. The most likely diagnosis in this patient with a strong history of smoking is lung cancer. And this is ultimately an exercise that's repeated with a with throughout any osk, but also clinically in in in the clinical setting where you're looking to tie together the radiological imaging findings with the other diagnostic tests and blood tests and other tests as well as the history and examination to make your most likely diagnosis to help guide your overall management with lung cancer specifically, you look at potentially further imaging biopsy. So you can get a histological sample of the tumor. And you then consider a referral to an MDT where they could discuss further management in the form of chemotherapy surgery, radiotherapy, depending upon the grade, the stage performance status and the patient wishes. This is our second case where we have a 36 year old man presenting with sudden onset right sided chest pain and shortness of breath. What is the most likely diagnosis in looking at this chest X ray? What is the initial recommended management for this condition? So, as you can see clearly, there's a right sided pneumothorax with the collapsed lung located near the right uh heart border. You can see clearly that lung markings do not extend towards the periphery as mentioned earlier when assessing the pleura and because the lung markers do not extend towards the periphery and there's an area of darkened or uh hyperlucency throughout the majority of the right side of the thoracic cavity. We can clearly say that this patient has a right sided pneumothorax. To say with this tension would depend upon uh looking at any evidence of mediastinal deviation alongside evidence of hemodynamic compromise, such as uh BP changes, such as hypertension secondary to a sable obstruction. So in this patient who potentially um does not have attention in the orx, the most likely recommended management would be conservative management in the form of monitoring oxygen saturations. And therefore considering this patient potentially for discharge, if they potentially worsen and develop a degree of hemodynamic compromise, the needle thoracocentesis would also be an appropriate management as well. So this is our last case where you have a 40 year old male patient who has a fever and an acute cough for the last four days. He has a cough, productive of yellow sputum and has reduced breath, sounds over the middle of his left chest with increased vocal resonance. So the most likely diagnosis in this case would be a lobar pneumonia affecting the left upper lobe. You can see this because when you look at the red arrows, they're pointing at the oblique fissure which separates the upper lobe from the lower lobe and the um shadowing and the opacification is limited to the upper lobe of the lung with pneumonia. You would want to assess the severity using CB 65 and this would help guide whether or not you want to keep the patient as an outpatient, given oral antibiotics or whether you want to admit them for more intensive intravenous antibiotics therapy. You would need a chest X ray at six weeks if it's complicated. Um after symptoms resolve to see if there's any resolution of symptoms, which is one of the common indications for a chest X ray. So as usual, uh thanks to Doctor Ammon Verma for helping review these slides and helping me make the presentation, the Leicester medical school has an amazing radiology resource looking at the L MS radiology site, not only for chest x rays, but for other forms of imaging and interpretation, which would help you as a doctor, but also for your OSC as well. Thank you for now.