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Chest X-Ray Radiograph Interpretation

Chest X-Ray Radiograph Interpretation

ABCZ of Chest X-Ray


The key here is to have a systematic way of looking at the radiograph so you will not miss crucial bits and one that sticks to your mind.

Here is my take on it.

Start general then go to the specifics.


1. First, comment on the demographics (follow the arrows)

I follow my order of: This is a chest radiograph (don't say X-ray) of Mr X, in erect PA position, taken on 01/01/11. 

(PA view, which tends to be the case, is where x-ray beams are projected from the back (posterior) of the patient to the front (anterior), hence, posterior-anterior PA view. The opposite is true for AP view.)



2. Next, comment on PFR

  • Penetration/exposure: Under exposed - Too black! Good? (Just about it... should be just be able to work out the spinous process) Over exposed - Too white!
  • Field: Lung apex up down to costophrenic angles  
  • Rotation: Equidistant clavicles to spinous process? (Is the trachea in the midline)


3. The most obvious abnormality is...


4. Going through it systematically,

A: Airway and artefacts

  • Is the airway central? (If not, think atelectasis/pneumothorax/pleural effusion)
  • Are there any artefacts? (e.g. endotracheal tube)


      B: Breast shadow and bones

      • Is there an absence of a breast shadow? (mastectomy) Is there breast calcification?
      • Are all the bones intact? (Important to indicate if there is rib fracture in the presence of a pneumothorax)


          C: Cardiomegaly, Centre (Hilum) and costophrenic angle (+ hyper-expansion?)

          • Cardiac size and position: Dextrocardia? Cardiomegaly (Diameter of heart greater than half the diameter of diaphragm)
          • Centre: Hilum structures (e.g. lymphadenopathy) Causes of hilar lymphadenopathy include tuberculosis, sarcoidosis, lymphoma, carcinoma
          • Costophrenic angle: Visible? If not, blunted (think pleural effusion)
          • Talking about costophrenic angles, you could mention also whether the lungs are hyper-expanded i.e. more than 6 anterior ribs / 9 posterior ribs (in which case, think of COPD) – see below


            Z: Zig-zag manner across all lung fields – comparing sides looking out for areas of consolidation, fluid levels and other lesions! Don't forget to look at the peripheries (the pleura) so that you do not miss out a pneumothorax.



            5. Summarise:

            • In summary, This is a chest radiograph of Mr X, in erect PA position, taken on 01/01/11. There are signs of _______, in line with the diagnosis of ______.



              Familiarise yourself with the most commonly tested CXRs. Here are their signs.

              • Tuberculosis (focus on hilum and apex)
                • Primary: Consolidation, pleural effusion, calcified nodule/lymph node
                • Secondary: Apical consolidation, cavitation
                • Miliary TB: Haematogenous dissemination – uniform small nodules
              • Heart failure
                • A: Alveolar oedema
                • B: Bat's wings, Kerley B lines
                • C: Cardiomegaly
                • D: Dilated upper lobe vessels
                • E: Pleural effusion
              • Pleural effusion (look at costophrenic angle)
                • Gathers in lower part of chest
                  • Erect: Blunting of costophrenic angle and hemidiaphragm
                    • If large enough, it may even cause mediastinal shift away from the affected lung
                  • Supine: Posterior thorax, making it hard to see
              • Pneumonia (look out for white bits)
                • No mediastinal shift
                • Consolidation (white) (+/- air bronchogram)
              • Pneumothorax (where comparison between lung fields becomes even more important)
                • Simple: Absent lung markings distal to visceral pleura
                • Tension: Mediastinal shift away from the affected lung (Do not delay needle decompression!!!)


              Now have a go at these CXRs. Simply overlay your cursor over the image to find out the diagnosis.

                Miliary tuberculosisTuberculosis

                CHFPleural Effusion

                Pneumonia of Right Middle LobeR sided Pneumothorax

                Now have a go at commenting on this chest X-ray! (See below for my interpretation)


                1. Demographics... This is a chest radiograph of Mr Bean, taken in erect PA position, on 01/01/01.
                2. PFR... Penetration and field, is adequate. The patient does not appear to be rotated.
                3. Most obvious abnormality... The most obvious abnormality here is the hyperlucency and hyperexpansion of both lungs.
                4. Going through it systematically, A... the airway is central and there does not appear to be any artefacts. B... There are two normal breast shadows and all bones appear intact. C... The cardiac size appears to be normal. There is no hilar lymphadenopathy and the costophrenic angles are visible. There seems to be hyperexpanded lungs. Z... Although the lung fields appear normal, there is marked hyperlucency.
                5. Summarise... In summary, this is a chest radiograph of Mr X, in erect PA position, taken on 01/01/11. There are signs of hyperlucency and hyperexpansion of both lungs, in line with a diagnosis of COPD.


                Note that in severe COPD you may also see

                • flattening of the diaphragm
                • narrow heart (hyperexpanded lungs push on either sides of the heart)
                • bullae (especially in emphysema)


                In summary:

                1. Demographics
                2. PFR
                3. Most obvious abnormality
                4. Systematic commentary on A, B, C and Z (lung fields)
                5. Summarise


                My method may not suit all so it is best if you adapt it or find/create one that works for you! Good luck with your interpretation!

                Finally, there is no better recipe for CXR interpretation than to...



                Puddy E and Hill Catherine (2007). Interpretation of the Chest Radiograph. Available: Last Accessed Date:07.12.12.

                Clarke C and Dux A (2011).Chest X-rays for Medical Students. 1st Edition .London: Wiley-Blackwell. 1-15


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