New automatic software for virtual colonoscopy: technical aspects.
OBJECTIVE
To evaluate a new virtual endoscopy software package capable of automatically plotting the path along which to perform endoscopic exploration.


METHODS
We reviewed the examinations of 50 patients with colonic neoplasms studied by CT colonoscopy by using a single-detector CT scanner (Philips Tomoscan AVE1). The technical parameters used were: slice thickness 3 mm, pitch 1.4, reconstruction interval 2-2.5, 120 kV, 150-200 mA. The images were processed on a separate workstation (Philips Easy Vision 5.1) running an experimental virtual endoscopy software package capable of automatically drawing a line along which to move the virtual endoscope to explore the colon. Reconstruction of the endoscopic images along the path obtained was set at an interval of 15-20 mm between one endoscopic view and the next, to a total of 70 to 120 images. The endoscopic animated image sequence was then saved and evaluated by comparing the starting axial images and the three-dimensional images obtained.


RESULTS
The programme plotted the endoscopic path correctly in a single pass in 40 of the 50 cases studied. The overall time spent by the radiologist on image-processing did not exceed 5 minutes.


CONCLUSIONS
The need to reduce the time spent by audiologists on post-processing has led to a gradual improvement in image-processing hardware and software. In the context of virtual endoscopy, one of the main goals is to obtain the path for endoscopic exploration in as short a time as possible. The programme we evaluated successfully fulfils this requirement as, once the image-processing technical parameters have been defined, it plots a path along the entire colon and performs the reconstruction procedures automatically. The time spent by the operator on post-processing does not exceed 5 minutes.


CONCLUSIONS
The new programme evaluated in this study facilitates the processing of endoscopic images, reduces radiologist time and may contribute to the widespread use of virtual colonoscopy.
Morra
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A
Dipartimento di Scienze Cliniche e Morfologiche, Unità Clinica Operativa di Radiologia, Università degli Studi, Trieste, Italy.
Rimondini
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A
Pozzi-Mucelli
R
R
D003110:Colonic Neoplasms / Q000000981:diagnostic imaging*; D023881:Colonography, Computed Tomographic; D006801:Humans; D021621:Imaging, Three-Dimensional; D012984:Software