EndoView: A Phantom Study of a tracked virtual bronchoscopy

Project Duration: 2000 - 2001

Abstract

Virtual endoscopy can be used for preoperative planning, for training and intraoperatively. Surface rendering displays the inner lumen very well. Volume rendering has to be used if the external structures are of interest. For certain applications, e.g. endoluminal biopsy, it is of great advantage to be able to use both techniques at once. In this work we describe an approach that allows to use these two methods in combination on a low-end standard personal computer. Since image generation is done in a preprocessing step, any high quality volume or polygonal rendering technique can be used and mixed together without any loss in performance at run-time. This work extends a previous image based rendering system for virtual bronchoscopy to include tracking of a rigid or flexible endoscope and finding one's way in the tracheal tree by displaying the endoscope's position in a top-view map of the trachea. Natural landmarks, i.e. bifurcations in the bronchial tree, are used for registration. Properties of the technique are explored on a phantom data set.

Download the paper (.ps.gz, 2.4MB)

Download the paper (.pdf, 2.4MB)

Figures in the paper (JPEG)

	Figure 1: Screenshot of a typical working session
	Figure 2: Trachea with transparent walls and tumor shining through
	Figure 3: Colorcoded trachea guiding the distance to the tumor
	Figure 4, Figure 5: Real endoscopic image and corresponding image in EndoView
	Figure 6: The phantom device.
	Figure 7: The wooden endoscope

Animation Sequences

All animations were recorded in real time during the usage of EndoView on a standard PC and converted to MPEG2 files later.

	Movie 1: A flight through the phantom device in navigation mode. Filesize: 3038 KB Length: 20 secs
	Movie 2: Moving through the phantom device in online mode by tracking a flexible endoscope. Filesize: 4285 KB Length: 42 secs
	Movie 3: A flight through a patient's data set. Includes: blending front/back, back shines through mode, changing field of view, showing/hiding the aorta. Filesize: 4758 KB Length: 31 secs

Phantom Device

The dataset of the phantom device referenced in the paper can be downloaded from here. The data format is 6 byte header plus raw data. The header consists of three 16-bit values with x-,y- and z-resolution. In the raw data the x-coordinate runs fastest, the z-coordinate runs slowest, each voxel taking 2 bytes. The resolution of the data set is 456 x 222 x 402 voxels, where each voxel is 0,759766mm x 0,759766mm x 0.997901mm.

This page assembles some results of work that is part of our visualization research. The figures are provided in JPEG format.

A part of the work presented in this publication has been done in the VRVis research center Vienna/Austria, which is partly funded by the Austrian government research program Kplus.

Daniel Wagner, last update on April 4, 2001.