[Diagnostic value of the airway post-processing technique of multi-slice spiral CT in Accessory cardiac bronchus]

Objective: This study aimed to assess the diagnostic value of the airway post-processing technique of multi-slice spiral CT(MSCT) in Accessory cardiac bronchus(ACB)and to improve the understanding of this disease. Methods: The original MSCT axial images and various post-processing reconstructed images of 9 ACB cases were retrospectively analyzed.Airway post-processing techniques, including multi-planar reformation(MPR), minimum intensity projection (MinIP), volume rendering technique(VRT), CT virtual endoscopy(CTVE) and tissue transition projection (TTP), were employed. Three-dimensional recombination images of bronchial trees were obtained and classified according to the Mangiulea classification. Results: Among the 9 cases with ACB, there were 6 cases of accessory-lobed type, 3 cases of long diverticular type, and no cases of short diverticular type. The lateral axial images, MPR, MinIP, VRT, CTVE, and TTP all clearly displayed ACB. Among the 6 cases of accessory-lobed type, there were 5 cases with accessory lobe dysplasia and one case with pneumonia in an accessory lobe;One case was complicated with accessory lobe emphysema. Among the 3 cases with long diverticular type ACB, one had pneumonia. Among the 9 cases, there was 1 case with old tuberculous focus, 1 case with pulmonary fibrous focus, 1 case with pleural thickening and adhesion, and 1 case with tracheal diverticulum. Conclusion: The airway post-processing technique of MSCT can not only clarify the diagnosis, origin and classification of ACB, but also measure the opening diameter, length and distance to the tracheal carina of ACB.It guides clinical treatment and tracheoscopy, etc, and can be used as the preferred examination method for ACB.