Grading Airway Stenosis Down to the Segmental Level Using Virtual Bronchoscopy: Conclusion
As demonstrated in our study, virtual bronchoscopy may be used for the evaluation of both central and segmental airway stenosis. This enables the evaluation of the segmental airways distal to a stenosis, which is impassable for flexible bronchoscopy. Other potential clinical uses of virtual bronchoscopy include the planning of flexible bronchoscopy, the identification of abnormal airways and pathologic lymph nodes, and the follow-up of airway stenosis over time, in response to treatment, or in patients too ill to tolerate flexible bronchoscopy. Flexible bronchoscopy and virtual bronchoscopy should not be pitted against each other but, rather, should be used as complementary techniques.
In conclusion, virtual bronchoscopy with multirow detector CT scanning enables high-resolution en-doluminal imaging of both central and segmental bronchi. It is slightly more accurate at assessing central airway stenosis than segmental airway stenosis. Virtual bronchoscopy may be used clinically in individual cases, such as in cases of an impassible stenosis in patients undergoing flexible bronchoscopy. In the near future, improved multirow detector CT scanners with a higher longitudinal resolution and reduced scanning times should further enhance the resolution of virtual bronchoscopy, especially for segmental bronchi of small caliber that lie parallel to the axial scan plane. Furthermore, it remains to be studied whether inhalation and expectoration maneuvers of the patient prior to virtual bronchoscopy may help to evacuate secretions from the lumen of smaller bronchi, which could reduce false-positive findings. This may well improve the virtual broncho-scopic assessment of segmental and subsegmental airways for stenosis, allowing for the visualization of more distal airways and thus enabling the detection of endobronchial lesions distal to the reach of a flexible bronchoscope.