Longitudinal Multimodal Assessment in Severe Pneumonia: A Narrative Review of Chest Computed Tomography, Electrical Impedance Tomography, and Digital Lung Sounds

Severe pneumonia requires repeated assessment, but anatomical abnormalities, oxygenation, and regional ventilation may follow different recovery trajectories. This narrative review examines chest computed tomography (CT), electrical impedance tomography (EIT), and digital lung sounds as complementary sources of structural, ventilation, and acoustic information, with lung ultrasound (LUS) considered as an important bedside comparator. Focused searches and source verification were conducted in October 2026, with an evidence publication cutoff of 15 July 2026. CT characterizes whole-lung anatomy and complications when clinically indicated; EIT tracks regional ventilation-related changes; and digital auscultation provides stored recordings for serial and remote review. LUS supports bedside assessment of accessible peripheral lesions, pleural abnormalities, and reaeration. Small pneumonia studies support the measurement of regional ventilation trends, and selected controlled studies report favorable short-term findings. Acoustic evidence is concentrated in pediatric populations, with limited adult severe-pneumonia validation. Findings from ARDS and ventilator-weaning studies provide additional physiological context. The proposed longitudinal framework brings these complementary signals together across early assessment, treatment response, ICU transitions, and recovery. Prospective studies should establish its reproducibility, incremental clinical value, resource requirements, and effects on patient-important outcomes before routine implementation.