[Virtual endoscopy of the upper airway with spiral CT].
OBJECTIVE
The technical conditions, the optimized scanning protocols and the facilities of virtual endoscopy (VE) are presented in an overview.


METHODS
Phantom studies showed that, for a single-row-detector helical CT, collimation of 3.0 mm combined with pitch of 1.5 provided an optimal compromise between image quality and the scan duration per breath-hold. A multi-row-detector helical CT requires only a fraction of the scanning time. This is especially important for patients with dyspnea.


RESULTS
The threshold-dependent virtual endoscopic surface rendering is a reliable and rapidly practicable reconstruction algorithm for the imaging of the upper airway.


CONCLUSIONS
The VE technique is suitable for the imaging of space-occupying tumors and restricted stenoses. With VE follow-up examinations can be performed non-invasively and interventional procedures can be prepared in an optimal way. Because of the computed tomographic data acquisition the structure of the mucosa is not assessable and there is no opportunity to obtain a biopsy specimen.
Rodenwaldt
J
J
Abteilung Röntgendiagnostik I, Klinikum, Georg-August-Universität Göttingen.
Schorn
C
C
Grabbe
E
E
D020680:Bronchoscopes; D003937:Diagnosis, Differential; D004867:Equipment Design; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D007822:Laryngeal Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D020704:Laryngoscopes; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D011856:Radiographic Image Enhancement / Q000295:instrumentation; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*; D014584:User-Computer Interface