Lung Ultrasound: “Healthy Bat Sign” vs. Sick Chiroptera Patterns

Key learning points:1.When presenting the lung ultrasound image, the first step in interpretation should be to assess whether it shows a healthy bat sign or a pathological one, regardless of the specific characteristics of the pathology 2. The Merlin space is a heterogeneous surface composed of two zones: a hyper-echoic twinkling white area and a hypo-echoic twinkling grey colour within a black area.3. The normal hyper-echoic twinkling area should be considered as "the body of healthy bat sign."4. The healthy bat sign is when: pleural line is thin, and sliding is present.The twinkling white area is homogeneous with length 3.5-6.5 cm, with regular borders and truncated cone shape.The rib's shadow borders are regular and extends to the same length as the normal twinkling white area.5. When performing lung ultrasound (LU), the long and short axes must be combined.6. Whenever we suspect for the presence of obstructive syndrome, inspiration and expiration ultrasound images must be practiced 7. The long axis, while it implies a longitudinal view of the lung, is the axis perpendicular to the space between the ribs.The short axis refers to the probe's position, which is almost parallel to the space between the ribs.