(44.192.66.171) 您好!臺灣時間:2021/05/18 00:07
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果

詳目顯示:::

: 
twitterline
研究生:楊鶴廷
研究生(外文):Hou Ting Yang
論文名稱:電腦斷層掃描之金屬假影修正及評估其對正子放射斷層掃描定量的影響
論文名稱(外文):Study on CT Metal Artifact Correction and its Effect on PET Quantitation
指導教授:蕭穎聰
指導教授(外文):I. T. Hsiao
學位類別:碩士
校院名稱:長庚大學
系所名稱:醫學物理暨影像科學研究所
學門:醫藥衛生學門
學類:醫學技術及檢驗學類
論文種類:學術論文
論文出版年:2009
畢業學年度:97
論文頁數:101
中文關鍵詞:正子放射斷層電腦斷層金屬假影衰減校正
外文關鍵詞:PETCTmetal artifactsattenuation correction
相關次數:
  • 被引用被引用:0
  • 點閱點閱:889
  • 評分評分:
  • 下載下載:71
  • 收藏至我的研究室書目清單書目收藏:0
正子放射斷層掃描(Positron Emission Tomography scanning,
PET) 已廣泛被使用,為核子醫學診斷中的一大利器,就在正子放射
斷層結合電腦斷層後 (Positron Emission Tomography/Computed
Tomography, PET/CT),有助於PET影像做解剖上的定位與衰減校正,
使得PET影像診斷更為準確,特別在癌症的診斷與分期更加是不可或
缺的臨床檢查。然而,使用CT影像的同時,金屬假影會嚴重的降低影
像品質,使得CT影像的CT值扭曲,進而影響PET使用CT影像做衰減校
正的可信度,降低了PET影像定量的準確性。本實驗使用後處理的方
式,提出後處理內插法與Mask修正法,來校正因金屬造成不完整的CT
影像,調整被假影扭曲後的CT值。藉由校正後的CT影像,重新去做PET
的衰減校正,來評估對PET影像定量的影響。我們所提出的後處理修
正法與傳統原始資料修正法比較,有著相似的金屬假影校正效果,但
是我們的方法比較方便處理,而在PET定量上,經過金屬假影校正後,
約可以減少4%定量上的誤差。
The combination of positron emission tomography and computed tomography (PET/CT) has become an effective tool in many clinical imaging applications recently, in particular, for diagnosis, staging, and restaging of the various cancers. CT was mainly used for attenuation correction in PET. One of the major problems with CT is metal artifacts with image distortion caused by the metal objects of high attenuation. The artifacts seriously degrade CT image quality, particularly for those regions near the metal surfaces. These artifacts may cause errors when using CT for the spatial localization of PET findings, and may degrade the PET quantitation through the CT-based attenuation correction. In this study, we propose two post-processing methods for metal artifact correction: post-processing interpolation method and Mask-based method. In addition to evaluate the metal-artifact-corrected CT images by two post-processing methods, we also evaluated the impact of these approaches on the quantification of PET images. The results showed that the proposed post-processing methods were easy to use, and with reduced 4% errors in the PET quantitation than the conventional methods. Future work will include more clinical data validation, and improvement of the proposed mask-based methods.
目錄

頁碼
第一章、前言...............................................1
第二章、正子放射斷層掃描...................................3
2.1 PET的基本造影原理..................................3
2.2 PET衰減校正........................................6
2.3 PET/CT衰減校正.....................................9
(1)影像分割法....................................10
(2)轉換法........................................11
第三章、電腦斷層掃描......................................13
3.1 CT的基本成像原理..................................13
3.2 CT金屬假影的形成..................................17
3.3 常見的校正方法...................................19
(1)造影條件最佳化................................19
(2)CT值的擴展技術...............................20
(3)原始投影資料修正..............................21
(4)疊代式影像重建................................23
(5)後處理影像修正................................26
3.4 金屬假影對PET定量上的影響........................28
第四章、實驗方法與材料....................................29
4.1 後處理金屬假影修正法.............................30
(1)後處理線性內插法..............................30
(2)Mask修正法...................................32
4.2 衰減係數轉換.....................................35
4.3 模擬頭顱實驗.....................................38
4.4 小動物microPET假體實驗...........................41
4.5 臨床PET/CT假體實驗...............................45
第五章 實驗結果與討論....................................48
5.1數位模擬實驗結果..................................49
(1) 模擬頭顱實驗CT影像結果.......................49
(2) 模擬頭顱實驗PET影像結果......................53
5.2小動物microPET假體實驗結果........................62
(1) 小動物假體實驗衰減係數影像結果................62
(2) 小動物假體實驗PET影像結果....................66
5.3臨床PET/CT假體實驗結果............................72
(1) 臨床假體實驗CT影像結果.......................72
(2) 臨床假體實驗PET影像結果......................75
5.4 實驗結果討論.....................................78
第六章 結論..............................................83
參考文獻 ................................................85

圖目錄

頁碼
圖2-1 PET偵測方式.........................................3
圖2-2 正弦圖..............................................5
圖2-3 PET衰減路徑.........................................6
圖2-4 雙線性衰減係數轉換曲線.............................11
圖3-1 CT掃描方式.........................................13
圖3-2 CT成像原理.........................................14
圖3-3 斜波濾波器.........................................15
圖3-4 CT金屬假影影像.....................................18
圖3-5 原始資料內插法.....................................22
圖3-6 疊代式影像重建法...................................25
圖3-7 後處理影像修正法...................................27
圖4-1 後處理線性內插流程圖...............................32
圖4-2 Mask修正法流程圖...................................34
圖4-3 CT影像轉換成PET衰減係數影像........................35
圖4-4 三條線性轉換曲線...................................37
圖4-5 模擬頭顱的CT假體圖與PET假體圖......................40
圖4-6 microPET假體資料...................................41
圖4-7 金屬假牙...........................................42
圖4-8 小球與假牙相關位置.................................43
圖4-9 microPET掃描.......................................44
圖4-10 臨床品保假體......................................45
圖4-11 假體與小球相對位置................................46
圖4-12 臨床假體掃描......................................47
圖5-1 模擬頭顱實驗CT影像.................................49
圖5-2 10:1模擬頭顱實驗PET影像............................53
圖5-3 5:1模擬頭顱實驗PET影像.............................56
圖5-4 2:1模擬頭顱實驗PET影像.............................59
圖5-5 小動物假體實驗衰減係數影像.........................62
圖5-6 8:1小動物假體實驗PET影像...........................66
圖5-7 2:1小動物假體實驗PET影像...........................69
圖5-8 臨床假體實驗CT影像.................................72
圖5-9 10:1臨床假體實驗PET影像............................75
圖5-10 評估金屬假影影響範圍..............................82

表目錄
頁碼
表4-1 CT影像模擬頭顱實驗數值參數表.......................38
表5-1 模擬頭顱實驗CT影像ROI測量..........................51
表5-2 10:1模擬頭顱實驗PET影像ROI測量.....................54
表5-3 5:1模擬頭顱實驗PET影像ROI測量......................57
表5-4 2:1模擬頭顱實驗PET影像ROI測量......................60
表5-5 小動物假體實驗的衰減係數影像ROI測量................64
表5-6 8:1小動物假體實驗PET影像ROI測量....................67
表5-7 2:1小動物假體實驗PET影像ROI測量....................70
表5-8 臨床假體實驗CT影像ROI測量..........................74
表5-9 13:1臨床假體實驗PET影像ROI測量.....................76
參考文獻

1. Hsieh, J., Computed Tomography: Principles, Design, Artifacts, and Recent Advances. 2003: SPIE-Inter.
2. Zaidi, H., M.L. Montandon, and S. Meikle, Strategies for attenuation compensation in neurological PET studies. NeuroImage, 2007. 34(2): p. 518-541.
3. Lemmens, C., et al., Impact of metal artefacts due to EEG electrodes in brain PET/CT imaging. Physics in Medicine and Biology, 2008. 53(16): p. 4417-4429.
4. Goerres, G.W., et al., Artifacts at PET and PET/CT caused by metallic hip prosthetic material. Radiology, 2003. 226(2): p. 577-584.
5. Kamel, E.M., et al., Impact of metallic dental implants on CT-based attenuation correction in a combined PET/CT scanner. European Radiology, 2003. 13(4): p. 724-728.
6. Ay, M.R. and H. Zaidi, Assessment of errors caused by X-ray scatter and use of contrast medium when using CT-based attenuation correction in PET. European Journal of Nuclear Medicine and Molecular Imaging, 2006. 33(11): p. 1301-1313.
7. Kalender, W.A., R. Hebel, and J. Ebersberger, Reduction of CT artifacts caused by metallic implants. Radiology, 1987. 164(2): p. 576-577.
8. Wang, G., et al., Iterative deblurring for CT metal artifact reduction. IEEE Transactions on Medical Imaging, 1996. 15(5): p. 657-664.
9. Mahnken, A.H., et al., A New Algorithm for Metal Artifact Reduction in Computed Tomography: In Vitro and in Vivo Evaluation after Total Hip Replacement. Investigative Radiology, 2003. 38(12): p. 769-775.
10. Lemmens, C., D. Faul, and J. Nuyts, Suppression of metal artifacts in CT using a reconstruction procedure that combines MAP and projection completion. IEEE Transactions on Medical Imaging, 2009. 28(2): p. 250-260.
11. Turkington, T.G., Introduction to PET instrumentation. Journal of Nuclear Medicine Technology, 2001. 29(1): p. 4-11.
12. Fahey, F.H., Data acquisition in PET imaging. Journal of Nuclear Medicine Technology, 2002. 30(2): p. 39-49.
13. Beyer, T., et al. The use of X-ray CT for attenuation correction of PET data. in Nuclear Science Symposium and Medical Imaging Conference, 1994., 1994 IEEE Conference Record. 1994.
14. Kinahan, P.E., B.H. Hasegawa, and T. Beyer, X-ray-based attenuation correction for positron emission tomography/computed tomography scanners. Seminars in Nuclear Medicine, 2003. 33(3): p. 166-179.
15. Robinson, P.J. and L. Kreel, Pulmonary tissue attenuation with computed tomography: Comparison of inspiration and expiration scans. Journal of Computer Assisted Tomography, 1979. 3(6): p. 740-748.
16. LaCroix, K.J., et al., Investigation of the use of X-ray CT images for attenuation compensation in SPECT. IEEE Transactions on Nuclear Science, 1994. 41(6 p 2): p. 2793-2799.
17. Lonn, A.H.R. Evaluation of method to minimize the effect of X-ray contrast in PET-CT attenuation correction. 2003. Portland, OR.
18. Zhang, Y., et al., Reducing metal artifacts in cone-beam CT images by preprocessing projection data. International Journal of Radiation Oncology Biology Physics, 2007. 67(3): p. 924-932.
19. Robertson, D.D., et al., Evaluation of CT techniques for reducing artifacts in the presence of metallic orthopedic implants. Journal of Computer Assisted Tomography, 1988. 12(2): p. 236-241.
20. Luo, Q., Artifacts in X-ray CT. University of Texas health science center, 2003.
21. Klotz, E., et al. Algorithms for the reduction of CT artefacts caused by metallic implants. 1990. Newport Beach, CA, USA: Publ by Int Soc for Optical Engineering.
22. Link, T.M., et al., CT of metal implants: Reduction of artifacts using an extended CT scale technique. Journal of Computer Assisted Tomography, 2000. 24(1): p. 165-172.
23. Zhao, S., et al., X-ray CT metal artifact reduction using wavelets: An application for imaging total hip prostheses. IEEE Transactions on Medical Imaging, 2000. 19(12): p. 1238-1247.
24. Roeske, J.C., et al., Reduction of computed tomography metal artifacts due to the Fletcher-Suit applicator in gynecology patients receiving intracavitary brachytherapy. Brachytherapy, 2003. 2(4): p. 207-214.
25. 張哲堯, 電腦斷層金屬假影直接消去法, in 原子科學系. 94, 國立清華大學. p. 41.
26. Nahmias, C., et al., Does Reducing CT Artifacts from Dental Implants Influence the PET Interpretation in PET/CT Studies of Oral Cancer and Head and Neck Cancer? J Nucl Med, 2008(49): p. 1047-1052.
27. Chow, P.L., F.R. Rannou, and A.F. Chatziioannou, Attenuation correction for small animal PET tomographs. Physics in Medicine and Biology, 2005. 50(8): p. 1837-1850.
QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top