This medical comparison chart displays axial CT scans, 3D lung reconstructions, and voxel distribution histograms comparing two mechanical ventilation strategies in Acute Respiratory Distress Syndrome (ARDS): ARDSnet-24h and Open Lung Concept (OLC)-24h. The top panel (ARDSnet) shows significant bilateral dorsal atelectasis, represented in the 3D model by large black regions (non-aerated tissue) and poorly aerated white areas. Its corresponding histogram shows a bimodal distribution with a prominent peak in the non-aerated range (> -100 Hounsfield Units). The bottom panel (OLC) demonstrates improved alveolar recruitment, evidenced by a shift in the 3D model to predominantly blue (normally aerated) tissue and a reduction in black dorsal collapse. The OLC histogram shows a unimodal distribution with a primary peak in the normally-aerated range (-900 to -500 HU) and a higher PaO2/FiO2 ratio (195 vs 114 mmHg). This clinical imaging study illustrates the efficacy of recruitment maneuvers and PEEP titration in achieving more homogeneous lung aeration and reducing intrapulmonary shunt in critically ill patients.

This diagnostic image matrix displays Lung Ultrasound (LUS) frames arranged by anatomical region (Anterior, Lateral, and Posterior zones) and positive end-expiratory pressure (PEEP) levels (10, 30, and 14 cmH2O) to demonstrate recruitment maneuver outcomes. At baseline (PEEP 10 cmH2O), the images show a 'C-pattern' characterized by severe loss of aeration with dynamic air bronchograms in anterior/posterior zones and an irregular thickened pleural line with multiple coalescent B-lines laterally. During recruitment (PEEP 30 cmH2O), there is visible reaeration characterized by a transition to a 'B1-pattern' with horizontal A-lines and well-defined, discrete B-lines. At the final titrated PEEP (14 cmH2O), the 'B2-pattern' is evident, showing some recruitment maintenance via A-lines but recurring multiple coalescent B-lines and persistent dynamic air bronchograms posteriorly. This comparison illustrates the dynamic nature of lung aeration, pleural line morphology, and ultrasound artifacts (A-lines vs. B-lines) in response to mechanical ventilation adjustments in patients with respiratory distress.

A series of axial thoracic CT scans illustrating lung recruitment in an animal model, likely used for studying Acute Respiratory Distress Syndrome (ARDS) or mechanical ventilation. The image is divided into two main panels: (a) Expiratory occlusion and (b) Inspiratory occlusion. Each panel contains a 2x3 grid comparing 'pre-recruitment maneuver' (top row) and 'post-recruitment maneuver' (bottom row) states at three anatomical levels: apical, middle, and basal. In the 'pre-recruitment' images, there are significant bilateral areas of high density (ground-glass opacities and consolidation) predominately in the dependent (posterior) lung regions, indicating atelectasis and non-aerated lung tissue. Post-recruitment, there is a visible reduction in these dense areas and a concomitant increase in radiolucency (darker regions), signifying improved alveolar aeration and lung volume (Vgas). The changes are most pronounced in the basal levels during both expiratory and inspiratory occlusions, demonstrating the effectiveness of the maneuver in opening collapsed alveoli and homogenizing lung parenchyma density.