This study will evaluate a new technique for examining the air passages of the lungs called
"virtual bronchoscopy." It involves using computed tomography (CT) images of the chest to
generate a 3-dimensional model of the walls of the trachea and bronchi (airway passages).
This non-invasive method lets doctors see small masses and areas of narrowing in the
passages without having to do surgery or pass a tube through them.
Patients with diseases of the air passages who are enrolled in an NIH clinical trial may
participate in this study, which requires having a CT scan. The patient lies on a table
that slowly slides into a hole in a donut-shaped X-ray machine (the scanner). Patients may
have to hold their breath several times during the procedure. Some patients may be given an
injection of a contrast agent through a catheter (thin tube) placed in an arm vein to
improve visibility of abnormalities. Patients may also be asked to breathe oxygen through
nasal prongs to allow them to hold their breath longer. The procedure usually takes 15 to
This project is a test of the efficacy of a new diagnostic method for imaging the airways
known as virtual bronchoscopy. Virtual bronchoscopy is performed by acquiring thin section
computed tomography (CT) images of the chest. These images are used to generate a three
dimensional model of the tracheal and bronchial walls on a graphics workstation in 3-D. The
model can be manipulated to allow the viewer to "fly through" the tracheobronchial tree
providing views similar to those obtained during bronchoscopy. The technique produces a
display of the human bronchial system in a readily understood format. Moreover, it allows
investigation of post-stenotic portions of the bronchial tree that are beyond the reach of
fiberoptic bronchoscopy. Further, virtual bronchoscopy may be used to guide interventional
procedures. The patients that will be studied in this protocol will be those having
inflammatory, infectious, or neoplastic pulmonary processes who would have had a chest CT
for clinical reasons. These patients will be recruited from current NIH protocols. The
study design consists of scanning of the thorax using thin section helical CT, followed by
three dimensional surface rendering of the airways and transfer of the digital data to
videotape. In one of four parts of the protocol, the virtual bronchoscopy will be compared
with results from fiberoptic bronchoscopy in a blinded study. In a second part of the
protocol, the virtual bronchoscopy will be used to perform a descriptive analysis of
cavitary lung lesions. In the third part, the utility of virtual bronchoscopy in diagnosis
of neoplastic lesions of the chest will be studied. In the fourth part, certain technical
problems in the virtual bronchoscopy procedure will be investigated. The patients will only
have fiberoptic bronchoscopy for clinically indicated purposes. We anticipate that virtual
bronchoscopy will be diagnostically efficacious for disorders which produce a morphologic
alteration in bronchial anatomy.
Patients with Wegener's granulomatosis who are scheduled for fiberoptic bronchoscopy.
Patients with cavitary lung diseases who are enrolled in protocols studying patients with
Wegener's granulomatosis, chronic granulomatosis disease, host immune defects,
mycobacterial infections, and Job's syndrome.
Patients with bronchogenic carcinoma, other thoracic malignancies, or metastatic disease
to the thorax.
Patients will be selected from Clinical Center inpatient and outpatient population based
on a clinical suspicion of pulmonary, mediastinal or bronchial disease, and are to have
medically indicated chest CT.
Written informed consent will be obtained from all patients and studies will only be done
with the permission of the patient's attending physician.
Patients will be drawn from the following protocols:
Subjects must not be pregnant and be able to hold their breath for required periods of