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K. Manusis, J.P. Garcia Jr., R.B. Rosen, P.M. Garcia, P.T. Finger; A New and Improved Automated Technique of Topographic Mapping for Intraocular Tumors . Invest. Ophthalmol. Vis. Sci. 2003;44(13):3645.
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© ARVO (1962-2015); The Authors (2016-present)
Purpose: We present results from the new automated technique (proprietary software program courtesy of Justin Pedro, OTI) recently incorporated into the 3D B-Scan Ultrasound Tomography System (OTI, Canada). Unlike the previous automated technique, this new program has manual mapping capability to correct errors that may arise from the automated technique. Our purpose is to evaluate the new automated technique of topographic mapping for intraocular tumors. Methods: A retrospective analysis of fifty 3D-image files of intraocular tumors were used to generate volumetric topographic maps. To start measuring, the program automatically chooses an image from the 3D volume block showing a transverse view of the tumor at its peak. The mouse was clicked just beneath the apex of the tumor, and dragged towards the vitreous cavity to define the axis of rotation of the mapping software. This step was performed twice to activate automated mapping. Each of the 36 images that were mapped automatically was then corrected manually. Automated and manual mapping of each file was repeated three times to assess intra-observer variability. Results: Due to patient and/or doctor movements during image acquisition, 33 files produced erroneous and unreliable volumetric measurements. Therefore, topographic volumetric maps could be generated in 17 of the 50 files. The algorithm simultaneously estimated tumor height, width and volume. Automated mapping was achieved consistently under 10 seconds, resulting in fairly representative to grossly inaccurate maps. All automated maps required manual correction, lasting from 15 to 60 minutes. Conclusions: The new automated technique improves topographic mapping due to its manual correction capability. However, patient and probe motion continues to affect volumetric measurements. Faster modes of 3D-ultrasound acquisition should enhance the accuracy of this technique.
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