Fleiter T, Merkle EM, Aschoff AJ, Lang G, Stein M, Gorich J, Liewald F,
Rilinger N, Sokiranski R
Department of Diagnostic Imaging, University of Ulm, Germany.
Title
Comparison of real-time virtual and fiberoptic bronchoscopy in
patients with bronchial carcinoma: opportunities and limitations.
Source
AJR Am J Roentgenol 1997 Dec;169(6):1591-5
Abstract
OBJECTIVE: Both helical CT and fiberoptic bronchoscopy are used in the staging of
pulmonary tumors for therapeutic decision making. The improved resolution offered by
helical CT has led to the clinical use of three-dimensional reconstruction techniques such
as virtual bronchoscopy. We tested this new simulated endoscopic view of inner organ
surfaces and compared it with corresponding fiberoptic examinations of the
tracheobronchial system. SUBJECTS AND METHODS: Twenty patients with
malignancies of the lung and mediastinum were examined with both virtual bronchoscopy
and fiberoptic bronchoscopy. Both examinations were reviewed by radiologists and
surgeons familiar with fiberoptic bronchoscopy. Virtual bronchoscopy was calculated and
reconstructed from the cross-sectional images on a separate workstation. Stenoses and
tumor infiltration were classified from the fiberoptic examination. These results were
compared with the virtual bronchoscopy findings. RESULTS: Virtual bronchoscopy of
diagnostic quality was achieved in 19 of 20 patients. High-grade stenoses were revealed
equally well with virtual and fiberoptic techniques. Virtual bronchoscopy offered the
advantage of being able to visualize areas beyond even high-grade stenoses. However, on
virtual bronchoscopy discrete infiltration or extraluminal impression was not visible in five
patients. In another patient, strong heart pulsation produced motion artifacts that
prevented evaluation of the reconstruction. CONCLUSION: Virtual bronchoscopy
represents a new noninvasive method for evaluating helical CT findings. In comparison
with fiberoptic bronchoscopy, virtual bronchoscopy offers the advantage of being able to
visualize areas beyond even high-grade stenoses. In addition to the limited view of
fiberoptic bronchoscopy, extraluminal causes of lumen compressions can be analyzed in
the cross-sectional images and evaluated together with the virtual representation.
However, it was not possible to detect small infiltrations with virtual bronchoscopy. This
new representation of helical CT data might be helpful for postoperative follow-up
examinations, such as after stent implantation, and can be carried out without additional
risk to the patient. Radiologists do need special fiberoptic bronchoscopy knowledge and
experience with three-dimensional-reconstructions to differentiate between real stenoses
and artificial stenoses that might be caused by pulsation artifacts.