Nobutaka Doba1, Hiroyuki Fukuda2, Kazushi Numata2, Yoshiteru Hao2, Kouji Hara2, Akito Nozaki2, Masaaki Kondo3, Makoto Chuma2, Katsuaki Tanaka2, Shigeo Takebayashi2, Norihiro Koizumi4, Akira Kobayashi5, Junichi Tokuda6, Shin Maeda3. 1. Gastroenterological Center, Yokohama City University Medical Center, 4-57 Urafune-cho, Minami-ku, Yokohama, Kanagawa, 232-0024, Japan. douba1176@yahoo.co.jp. 2. Gastroenterological Center, Yokohama City University Medical Center, 4-57 Urafune-cho, Minami-ku, Yokohama, Kanagawa, 232-0024, Japan. 3. Department of Gastroenterology, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-0004, Japan. 4. Department of Mechanical and Intelligent Systems Engineering, Graduate School of Informatics and Engineering, School of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Choufugaoka, Choufu City, Tokyo, Japan. 5. National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, Chiba, 263-8555, Japan. 6. Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA, 02115, USA.
Abstract
PURPOSE: Radiofrequency ablation for liver tumors (liver RFA) is widely performed under ultrasound guidance. However, discriminating between the tumor and the needle is often difficult because of cavitation caused by RFA-induced coagulation. An unclear ultrasound image can lead to complications and tumor residue. Therefore, image-guided navigation systems based on fiducial registration have been developed. Fiducial points are usually set on a patient's skin. But the use of internal fiducial points can improve the accuracy of navigation. In this study, a new device is introduced to use internal fiducial points using 2D US. METHODS: 3D Slicer as the navigation software, Polaris Vicra as the position sensor, and two target tumors in a 3D abdominal phantom as puncture targets were used. Also, a new device that makes it possible to obtain tracking coordinates in the body was invented. First, two-dimensional reslice images from the CT images using 3D Slicer were built. A virtual needle was displayed on the two-dimensional reslice image, reflecting the movement of the actual needle after fiducial registration. A phantom experiment using three sets of fiducial point configurations: one conventional case using only surface points, and two cases in which the center of the target tumor was selected as a fiducial point was performed. For each configuration, one surgeon punctured each target tumor ten times under guidance from the 3D Slicer display. Finally, a statistical analysis examining the puncture error was performed. RESULTS: The puncture error for each target tumor decreased significantly when the center of the target tumor was included as one of the fiducial points, compared with when only surface points were used. CONCLUSION: This study introduces a new device to use internal fiducial points and suggests that the accuracy of image-guided navigation systems for liver RFA can be improved by using the new device.
PURPOSE: Radiofrequency ablation for liver tumors (liver RFA) is widely performed under ultrasound guidance. However, discriminating between the tumor and the needle is often difficult because of cavitation caused by RFA-induced coagulation. An unclear ultrasound image can lead to complications and tumor residue. Therefore, image-guided navigation systems based on fiducial registration have been developed. Fiducial points are usually set on a patient's skin. But the use of internal fiducial points can improve the accuracy of navigation. In this study, a new device is introduced to use internal fiducial points using 2D US. METHODS: 3D Slicer as the navigation software, Polaris Vicra as the position sensor, and two target tumors in a 3D abdominal phantom as puncture targets were used. Also, a new device that makes it possible to obtain tracking coordinates in the body was invented. First, two-dimensional reslice images from the CT images using 3D Slicer were built. A virtual needle was displayed on the two-dimensional reslice image, reflecting the movement of the actual needle after fiducial registration. A phantom experiment using three sets of fiducial point configurations: one conventional case using only surface points, and two cases in which the center of the target tumor was selected as a fiducial point was performed. For each configuration, one surgeon punctured each target tumor ten times under guidance from the 3D Slicer display. Finally, a statistical analysis examining the puncture error was performed. RESULTS: The puncture error for each target tumor decreased significantly when the center of the target tumor was included as one of the fiducial points, compared with when only surface points were used. CONCLUSION: This study introduces a new device to use internal fiducial points and suggests that the accuracy of image-guided navigation systems for liver RFA can be improved by using the new device.
Authors: Tito Livraghi; Luigi Solbiati; M Franca Meloni; G Scott Gazelle; Elkan F Halpern; S Nahum Goldberg Journal: Radiology Date: 2003-02 Impact factor: 11.105
Authors: Thomas Lange; Nils Papenberg; Stefan Heldmann; Jan Modersitzki; Bernd Fischer; Hans Lamecker; Peter M Schlag Journal: Int J Comput Assist Radiol Surg Date: 2008-10-19 Impact factor: 2.924