Is Virtual Bronchoscopy Effective for Identifying the Pathways to Peripheral Lung Lesions on CT Images? An Experiment to Determine the Accuracy of CT-based Readings

Abstract

Background. In recent years, it has been reported that virtual bronchoscopy simulation is effective for the trans-bronchial biopsy of peripheral pulmonary lesions. However, because the three-dimensional bronchial structure is generated from two-dimensional computed tomography (CT) images, the accuracy of virtual bronchoscopy is questionable. Purpose. To determine whether or not virtual bronchoscopy is superior to a two-dimensional interpretation, even that obtained by skilled bronchoscopists, CT image readings were used to determine the bronchial pathway to the target lesion. Methods. Pulmonologists with 5 to 31 years of bronchoscopy experience were asked to determine the bronchial pathway to the target lesion on CT images. The study included two model cases that had been diagnosed with peripheral lung cancer using a trans-bronchial lung biopsy with virtual bronchoscopy. In Case 1, a non-target bronchus was occluded by sputum. In Case 2, the normal bronchial structure was substantially altered by large bullae. The bronchoscopists were directed to interpret the chest CT images without any time restriction. They were then asked to identify the next route at each bronchial bifurcation on the virtual bronchoscopy images from the trachea to the target bronchus. The criterion for test completion was the selection of an incorrect route. Results. The correct answer rate at the third- and fourth-order bronchi was 88% and 50%, respectively, in Case 1, and 38% and 6%, respectively, in Case 2. The correct answer rate was not related to the years of bronchoscopy experience. Conclusions. This study showed that the degree of experience of bronchoscopists was independent of their ability to identify the pathway to peripheral lung lesions on CT images. The lack of inter-individual differences in the interpretation ability may support the usefulness of virtual bronchoscopy.