Fig. 1

a ‘Bedside Lung Ultrasound in Emergency’ (BLUE) and 12-zone lung ultrasound protocol. The blue points represent BLUE-points of the lung ultrasound protocol, they are identified as follows: two hands are placed consecutively just below the clavicle, excluding the thumbs. The upper BLUE-point is at the middle of the upper hand, whereas the Lower BLUE-point is at the middle of the lower palm. The posterolateral alveolar and/or pleural syndrome (PLAPS)-point is just below the posterior axillary line at the height of the diaphragm. At the PLAPS-point the probe was moved posteriorly in order to obtain as much information as possible about the posterior lung region. The green points are scanned additionally in the 12-zone lung ultrasound protocol. AAL: anterior axillary line; PAL: posterior axillary line; B1: BLUE-1; B2: BLUE-2; LS: lateral superior; LI: lateral inferior; PS: posterior superior; PLAPS: posterolateral alveolar and/or pleural syndrome. b A schematic image of how thoracic CT was divided into two hemithoraces and an anterior and posterior region. Two lines were drawn tangent to the anterior and posterior border of both lungs and at the height of the sternum anteriorly and spinous process posteriorly a line perpendicular to the tangent lines was drawn to divide the thoracic cavity into a right and left side. Both lungs were then divided into an anterior and posterior half by drawing a line perpendicular from the middle of the line between the sternum and spinous process to the lateral border of the lung. Each hemithorax was evaluated for anterior consolidations, posterior consolidations, interstitial syndrome, pneumothorax or pleural effusion