牙科用X光斷層影像儀之CT值的差異 分析研究

Analysis of CT value variation of dental cone-beam X-ray tomography

陳聰銘(Tsung-Ming Chen)

指導教授 ： 婁世亮

中原大學/工學院/生物醫學工程研究所/碩士(2012年)

https://doi.org/10.6840/cycu201200800

摘要

摘 要
人工植牙已成為牙齒短缺上主要治療方式，齒槽骨本身條件，即齒槽骨本身的骨質和密度，也成為人工植牙的成功與否之關鍵。電腦斷層掃瞄儀(Computer Tomography, CT)是牙科外科手術常用工具之一，CT提供了口腔顎面骨架三維影像診斷醫療用途外，其CT值(Housfield unit， 縮寫為Hu，或稱CT number)可以評估齒槽骨本身的骨質和密度。牙科用電腦斷層掃瞄儀(Dental Cone Beam Computer Tomography, Dental CBCT)已成為牙科使用電腦斷層掃瞄儀之主流；因此，Dental CBCT在CT值的表現，有值得探討的必要。本研究以Dental CBCT和新式之多切CT(Multi-Detector CT, MDCT)在CT值上的表現做為研究，並設計數種假體，以台灣現有使用Dental CBCT和MDCT分別進行模擬攝影，攝影後影像分別以標準DICOM格式儲存，再由第三者以外軟體ImplantMax，進行CT值的讀取和描述，再經由Excel的XY散佈圖進行分析與討論。分析內容包括空氣、水、鋁金屬等物質，鋁金屬的衰減系數接近人體骨頭，可以做為骨的代替分析。研究結果顯示，Dental CBCT的CT值分布範圍比MDCT廣，而且與正常值偏移離很多，因此，目前現有使用的Dental CBCT，不建議針對齒槽骨骨質，以CT值做定量分析，而現有MDCT方面， CT值之定量分析方面，則有一定之價值。

關鍵字

CT ； 人工植牙 ； 牙科用CBCT ； CT值 ； ImplantMax

並列摘要

Abstract

Dental Implant has become the major treatment for the toothless patient. The alveolar bone conditions, bone quality and density, are the key points for the implant as success or not. Computer Tomography (CT) is one of the methods for diagnostic tools of dental surgery. The CT value, (Housfield unit, Hu, or CT number) is useful for clinical assessment at the quality and density of alveolar bone. Dental Cone Beam CT (Dental CBCT) has become the mainstream of the dental fields to use CT. Thus, the CT value of Dental CBCT is worth exploring in the performance of the CT value. In this study, to design some of phantoms is necessary. The phantoms will be scanned by the current machines of Dental CBCT and Multi-Detector CT (MDCT) in Taiwan. MDCT is the current CT now. The images of phantoms will be stored by DICOM format after scanned. After importing the DICOM images, the third party software, ImplantMax will read and describe the data of the CT value. The data will be analyzed and discussed via Excel X/Y Scattergram. The data of the CT numbers include air, water and aluminum material. Aluminum material is often used at radiographic analysis as bone, because the attenuation coefficient of the aluminum material for x-ray is close to the attenuation coefficient of human bone. The results show that the distribution of CT value range of Dental CBCT is wider than MDCT. The CT number of Dental CBCT is far away the real CT number of phantom material. The current Dental CBCT is not recommended to make the quantitative analysis of the CT value for alveolar bone by this study, but there is a certain value on MDCT.

並列關鍵字

ImplantMax ； CT value ； Dental CBCT ； Implant ； CT

參考文獻

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