Enhanced Virtual Bronchoscopy Using the Pulmonary Artery: Improvement in Route Mapping for Ultraselective Transbronchial Lung Biopsy

We evaluated a new simulation method for ultraselective transbronchial lung biopsy using the pulmonary artery. A new method for enhanced virtual bronchoscopy using the pulmonary artery was developed for ultraselective transbronchial lung biopsy. In a volunteer study of healthy adults, three radiologists with different levels of experience independently reconstructed conventional virtual bronchoscopy and enhanced virtual bronchoscopy using the pulmonary artery until reaching the farthest point of the bronchus and pulmonary artery. The bronchovascular branch order and the minimum luminal diameter (e.g., for bronchus and artery) for reconstruction were compared. In a clinical study, virtual bronchoscopy and enhanced virtual bronchoscopy using the pulmonary artery were compared with regard to accessibility to target lesions in 40 patients with small pulmonary nodules or ground-glass opacities. A comparison between the simulated bronchial route reconstructions and actual bronchoscopic routes on biopsy was made to determine the efficacy of each reconstruction method. In the volunteer study, quality of enhanced virtual bronchoscopy using the pulmonary artery was not significantly affected by the experience levels of the radiologists. In the clinical study, bronchial reconstruction was successful in guiding to a bronchoscopic tumor in 35 (87.5%) of 40 cases. The maximum bronchial order on reconstruction was the sixth for the virtual bronchoscopy group and the eighth for the group with enhanced virtual bronchoscopy using the pulmonary artery (p < 0.001, Wilcoxon's signed rank test). The bronchial route reconstructed on enhanced virtual bronchoscopy using the pulmonary artery agreed with the actual biopsy routes in 30 cases (85.7%), but those reconstructed on virtual bronchoscopy alone agreed in only eight cases (22.9%) (p < 0.001, chi-square test). Enhanced virtual bronchoscopy using the pulmonary artery is feasible and helpful for ultraselective transbronchial lung biopsy of small nodules in the lung.