Fig. 7
From: Lung ultrasound—a primary survey of the acutely dyspneic patient
M-mode studies of lung sliding. a A proper M-mode study begins with the cursor (vertical line) centred over the SLF. The pleural line (thick arrow) separates the extra-pulmonary soft tissues (ST) and the SLF. b The M-mode showing “seashore” sign, where the quiet ST tracing (“sea”) is separated by the pleura line (thick arrow) from the noisy SLF tracing (“sandy shore”), caused by lung sliding. At regular intervals, the lung pulse (thin arrows) is seen. c M-mode showing “stratosphere” sign. The SLF tracing is “quiet” as there is no activity (lung sliding) at pleural line. There is also no lung pulse in this image