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Evaluation of the reconstruction of image acquired from CT simulator to reduce metal artifact  

Choi, Ji Hun (Department of Radiation Oncology, Seoul national university bundang hospital)
Park, Jin Hong (Department of Radiation Oncology, Seoul national university bundang hospital)
Choi, Byung Don (Department of Radiation Oncology, Seoul national university bundang hospital)
Won, Hui Su (Department of Radiation Oncology, Seoul national university bundang hospital)
Chang, Nam Jun (Department of Radiation Oncology, Seoul national university bundang hospital)
Goo, Jang Hyun (Department of Radiation Oncology, Seoul national university bundang hospital)
Hong, Joo Wan (Department of Radiation Oncology, Seoul national university bundang hospital)
Publication Information
The Journal of Korean Society for Radiation Therapy / v.26, no.2, 2014 , pp. 191-197 More about this Journal
Abstract
Purpose : This study presents the usefulness assessment of metal artifact reduction for orthopedic implants(O-MAR) to decrease metal artifacts from materials with high density when acquired CT images. Materials and Methods : By CT simulator, original CT images were acquired from Gammex and Rando phantom and those phantoms inserted with high density materials were scanned for other CT images with metal artifacts and then O-MAR was applied to those images, respectively. To evaluate CT images using Gammex phantom, 5 regions of interest(ROIs) were placed at 5 organs and 3 ROIs were set up at points affected by artifacts. The averages of standard deviation(SD) and CT numbers were compared with a plan using original image. For assessment of variations in dose of tissue around materials with high density, the volume of a cylindrical shape was designed at 3 places in images acquired from Rando phantom by Eclipse. With 6 MV, 7-fields, $15{\time}15cm2$ and 100 cGy per fraction, treatment planning was created and the mean dose were compared with a plan using original image. Results : In the test with the Gammex phantom, CT numbers had a few difference at established points and especially 3 points affected by artifacts had most of the same figures. In the case of O-MAR image, the more reduction in SD appeared at all of 8 points than non O-MAR image. In the test using the Rando Phantom, the variations in dose of tissue around high density materials had a few difference between original CT image and CT image with O-MAR. Conclusion : The CT images using O-MAR were acquired clearly at the boundary of tissue around high density materials and applying O-MAR was useful for correcting CT numbers.
Keywords
O-MAR; high density material; metal artifact; CT number;
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1 Joemai RMS, Bruin PW, Veldkamp WJH, Geleijns J: Metal artifact reduction for CT: Development, implementation, and clinical comparison of a generic and a scanner-specific technique. Med Phys 2012;39(2):1125-1132   DOI
2 Lewis M, Toms AP, Reid K, Bugg W: CT metal artefact reduction of total knee prostheses using angled gantry multiplanar reformation. The knee 2010;17:279-282   DOI   ScienceOn
3 Li H, Noel C, Chen H, Li HH: Clinical evaluation of a commercial orthopedic metal artifact reduction tool for CT simulations in radiation therapy. Med Phys 2012;39(12):7507-7517   DOI   ScienceOn
4 Webster GJ, Rowbottom CG, Mackay RI: Evaluation of the impact of dental artefacts on intensity-modulated radiotherapy planning for the head and neck. Radiother Oncol 2009;93:553-558   DOI   ScienceOn
5 Lee CH, Yun IH, Hong D, Back GM, Kwon GT: Evaluation of using Gantry Tilt Scan to Head & Neck Patients during Radiation Therapy for Reduction of Metal Artifact. Korean Soc Ther Radiol Oncol 2010;22(2):85-95
6 Zhao S, Robertson DD, Wang G, Whiting B, Bae KT: X-ray CT Metal Artifact Reduction Using Wavelets: An Application for Imaging Total Hip Prostheses. IEEE 2000;19(12):1238-1247
7 Bal M, Spies L: Metal artifact reduction in CT using tissue-class modeling and adaptive prefiltering. Med Phys 2006;33(8):2852-2859   DOI   ScienceOn
8 Matsufuji N, Tomura H, Futami Y, et al.: Relationship between CT number and electron density, scatter angle and nuclear reaction for hadron-therapy treatment planning. Phys Med Biol 1998;43(11):3261-3275   DOI   ScienceOn
9 Judy PF, et al.: AAPM report NO, 1: Phantoms for performance evaluation and quality assurance of CT scanner. 1977
10 Philips Healthcare System: Metal Artifact Reduction for Orthopedic Implants(O-MAR). 2013
11 전호상, 박달, 남지호 등: MV-CT를 이용한 방사선치료 계획용 kV-CT의 금속 왜곡 보정 시스템 개발. 2012