Lung Anatomy Syllabus: Virtual Bronchoscopy

Although one of the touted virtues of virtual bronchoscopy was to provide the bronchoscopist with a way of "procedural rehearsal" this has been more of a potential application than a primary imaging study. Several articles found that virtual bronchoscopy was a supplemental study. For example Kauczor et al. found that "when it complements bronchoscopy, 3D helical CT allows visualization beyond stenosis, supports planning of endobronchial procedures, and may even substitute for bronchoscopy after endobronchial procedures. "We have similarly found virtual bronchoscopy to be a problem solving tool for the evaluation of the airway. Virtual bronchoscopy with 3D volume rendering presents the airway as a volume structure which makes it easier to define any complex pathology." Review of the images in a stereo display is ideal in these situations as well.

MDCT is especially valuable in these cases because of the ability to combine narrow collimation and rapid data acquisition. This is especially valuable in the pediatric patient where cooperation is limited. In these patients we have used virtual bronchoscopy with CT angiography for evaluating such complications as airway stenosis due to AVM's as well as possible vascular rings. Unsuspected findings like an anomalous bronchus can be recognized on the 3D image but missed on the axial display.

Virtual bronchoscopy may also be helpful in cases of suspected TE (tracheo-esophageal) fistulae by providing an endoluminal look inside the airway. Although in lung cancer staging, virtual bronchoscopy provides little additional information that would impact on patient care or management although the endoscopic CT renderings are often very impressive.

Virtual bronchoscopy is very useful for evaluation of stent placement as well as to plan stent placement. In select cases, custom design of an implant can be done by creating 3D maps of the axial CT data.

"When it complements bronchoscopy, 3D helical CT allows visualization beyond stenosis, supports planning of endobronchial procedures, and may even substitute for bronchoscopy after endobronchial procedures."

Three Dimensional Helical CT of the Tracheobronchial Tree: Evaluation of Imaging Protocols and Assessment of Suspected Stenosis with Bronchoscopic Correlation

Kauczor HU et al.
AJR 1996; 167:419-422