Chest x-ray - mnemonics - Pulmonary edema

Alveolar edema (bat's wing or butterfly)

These are pulmonary opacities seen in bilateral perihilar areas. Outer third of the lung usually spared in pulmonary edema.

Kerley B lines

Kerley B lines are short (1-2 cm) horizontal linear shadows, perpendicular to the pleura, seen close to costo pherenic angles caused by thickened interlobular septae, due to accumulation of fluid (transudate). Other than pulmonary edema rare causes of kerley B lines are lymphangitis carsinomatosis, sarcoidosis, viral and mycoplasmal pneumonia.

 Cardiomegaly

In normal individuals cardio thoracic ratio(CTR) is less than 50%. CTR is the maximum transevers diameter of the heart divided by the greatest internal diameter of the thoracic cage. In cardiomegaly CTR is more than 50%.

Dilated prominent upper lobe vessels

In a patient with congestive heart failure, the pulmonary capillary wedge pressure rises  and the upper zone veins dilate and are equal in size or larger than lower zone pulmonary veins, also termed as cephalization.In normal individuals, the lower zone pulmonary veins are larger than the upper zone veins due to gravity.

Pleural effusion

Thia is due to increase hydrostatic pressure in pulmonary vasculature so it is a transudate.

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Medicine OSCE 2

Write the answers your self and compare......

1.What is the abnormality seen in this chest radiograph

2. Give two likely causes for this condition


Answer

1) Air- fliud level in the left hemithorax (6)

2) Hemopneumothorax(2), pyopneumothorax (2)  

Discusion

            

Collection of fluid in the pleural space with an air- fluid level is seen with lung abscess, hemopneumothorax and pyopneumothorax.

 Lung abscess is characterized by a such collection with a well demarcated capsule and when the air fluid level is seen across the hemi thorax without a capsule it is due to hemopneumothorax and pyopneumothorax. These can arise as a rupture of lung abscess (pyopneumothorax) or following trauma ( hemopneumothorax)

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Medicine OSCE 1

52 year old patient presented with cough and several bouts of haemoptysis of four month duration.  

1. Describe two abnormalities on chest Xray

2.  Give a likely diagnosis     

Answer

1. a) Two opacities in the upper zones of the left lung

   b) cavitations with thick walls in the left upper zone 

2. malignant lesions with central cavitations

 
Discusion

Lung opacities with irregular margins are features of either primary or secondary malignancy. Cavitations within the lesion also favor this. Cavitations with thick irregular walls are more in favor of a malignant lesions. Always look for erosion of ribs, hilar lymph node enlargement, calcifications and plural effusion(which are not present in this case) when there is suspicious malignant lesions in the lung.

Squamous cell carcinoma commonly present as a large peripheral mass with central cavitation.

primary sites of pulmonary metastasis

female- breast, tthyroid

male- testis, colon

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