<prompt> A patient presented with a history of blunt trauma to the chest and abdomen. On USG examination in M mode the following finding is seen. What could be the likely diagnosis?Pleural effusionBronchial obstructionLung abscessPneumothorax  <response>: Pneumothoraxis a serious potential consequence of blunt thoracic trauma and, if misdiagnosed, it may quickly become life-threatening. On M mode of USG, classical signs for the gray scale imaging are seen: seashore sign: normal lung sliding barcodestratosphere sign: pneumothorax 