Chest X Ray- The Diaphragm is unique and provides clue to your diagnosis!!!

Pulmonary Medicine Blog By Dr Deepu

There are a few things which beginners often miss in a chest x ray, one among those is failure to comment on the diaphragms.
Today I am going to discuss importance of tracing diaphragm in a chest X ray with an example.
          Normal diaphragm in a chest X ray has the following characteristics
1.     Trace the diaphragm on right and left
2.     The right diaphragm is usually placed between the fifth and the sixth Rib in the mid clavicular line, It can be seen upto middle of sixth and seventh rib.
3.     The Diaphragms are usually not at the same level on the frontal , erect , inspiratory chest X rays, but they are usually within one rib intercostals space height ( roughly 2 cm) of each other.
4.     The left diaphragm is usually lower than right.
5.     The costophrenic angles should be sharp, making an acute angle.
6.      If the left hemidiaphragm is equal to Right or higher than Right or Right diaphragm is higher than left by more than 3 cms, Causes of diaphragmatic elevation should be considered.
The causes of elevated hemidiaphragm are
1.            Causes above the diaphragm- decreased lung volume due to Lung Collapse, lobectomy, pneumonectomy , fibrosis and pulmonary Hypoplasia
2.            Causes in the diaphragm- Phrenic nerve palsy , diaphragmatic evantration
3.            Causes below the diaphragm- abdominal malignancy, subphrenic abscess, distended   hollow viscus.
After knowing the cause I want to discuss with you a chest x ray where the subtle change in the diaphragm was missed.
Before we proceed Read the chest X ray

 The Chest X ray showed a subtle change in Diaphragm
1. Both the diaphragms are at the same levels.
2. The air shadow underneath the left diaphragm is more prominent.
3. The patient was not evaluated further because chest X Ray appeared normal and sent home with conservative treatment for COPD. 
He came back to our center with hemoptysis one month later referred from the center which treated him initially, a second Radiograph was performed. study the Chest X Ray before proceeding further.  

The chest X ray  now shows features of full blown disease, the hilum is prominent with CORONA RADIATA SIGN suggestive of bronchogenic carcinoma, The left Diaphragm is now placed higher compared to right. Further HR and CECT revealed a tumor in the Left Main bronchus with lymph node metastasis. With Bronchoscopy the diagnosis of squamous cell carcinoma was made.

With this I will end this post, requesting everyone to look at any subtle changes in diaphragm which if ignored may cause some grave diagnosis at a later date.


  1. Sir, congrats for staring such a blog.. Its informative..!:). I have a question over here.. In the first film, the L higher diaphragm is due to visceral distension.?!. So wat is the clue for us to think of thorax for further investigation.. ?.

  2. Dear Vinay, thanks for your appreciation. In the first x ray, there is a prominent hilum and there is a small patch in the left lower zone just above the diaphragm, That should have prompted for a lateral chest x ray and further CT thorax.


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