Upright MDCT evaluation of gravity-induced bronchial collapse and paradoxical lung volume reduction in severe thoracic lordoscoliosis: A case report.

A 21-year-old male with severe thoracic lordoscoliosis presented with progressive dyspnea, which worsened in the upright position. Because standing whole-spine radiographs showed postural exacerbation of lordoscoliosis, upright multidetector computed tomography (MDCT) was performed in addition to conventional supine imaging to assess dynamic anatomical changes under gravitational influence. Preoperative upright MDCT revealed significant dynamic bronchial collapse. The right main bronchus diameter decreased from 3.23 mm in the supine position to 1.15 mm in the upright position, representing a 64.4% reduction. Simultaneously, lung volume paradoxically decreased by 30% upon standing. These findings were consistent with posture-dependent worsening of deformity-induced airway compromise and intrathoracic volume reduction under gravitational loading. Postoperatively, upright lung volume increased by 77.5%, with resolved bronchial compression. Upright MDCT may provide valuable adjunctive diagnostic support by quantifying deformity-induced respiratory dysfunction that may not be fully captured by conventional supine imaging, particularly when symptoms are posture-dependent.