Is sea shore sign a presentation of normal lung or pneumothorax in "m" mode?

Is sea shore sign a presentation of normal lung or pneumothorax in “m” mode ?

Sea shore sign is indicative of normal lung on a M mode USG.

Basically the waves of sea represents the skin, subcutaneous layers and parietal pleura.

Distal to it, there is granular appearance due to lung parenchyma; forming the shore.

In pneumothorax, there is air in pleural cavity. Air is a poor conductor of sound waves and reflects almost all of it, leading to a ‘Barcode’ or ‘Stratosphere’ sign.

The most specific sign of pneumothorax is seen by sudden absence of lung sliding - the ‘Lung point’ sign.

Yea thats y I had that doubt when Rohan sir said its a feature of pneumothorax thanks for confirming

He Said That It’d Be Discussed By Dr MAK Sir In Radiology…I remember

Sea Shore is Normal, Barcode/Stratosphere is Abnormal

sea shore is normal lung in m mode

It’s seen in normal. Absent in pneumothorax