Lung ultrasound is a diagnostic technique used to capture real-time tomographic images, either artefactual or anatomical, that serve to dynamically evaluate a patient’s pulmonary status. It is frequently clinician-operated and applied at the bedside (or more generally, “point-of-care” ultrasound; POCUS) to obtain vital patient information instantaneously. It may be used across a wide-variety of settings, but is particularly well-suited for the evaluation of critically ill patients who frequently suffer respiratory or circulatory failure. The objective of this thesis is to investigate the utility of lung ultrasound for critically ill patients through four crucial contemporary challenges: • Lung ultrasound and clinical management • Lung ultrasound and discrimination of interstitial syndromes • Lung ultrasound and pandemic considerations • Lung ultrasound and methodological refinement