乳房攝影的發展概況-print

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1 乳房攝影的發展概況沈里國 Li-Kuo Shen, R.T., B.S., M.S. 大綱前言傳統乳房攝影 vs. 數位乳房攝影 Digital Breast Tomosynthesis 結語 1 2 前言醫學影像品質管理的必要性衛生署 2011 年國人十大死因統計 2011 年國人平均餘命, 男性為 76.0 歲, 女性為 82.7 歲與 2010 年相較, 男性減少 0.2 歲, 女性相同患者所接受的輻射劑量落差大 (CXR) ( 清大某教授曾於十餘年前統計國內城鄉胸部照射輻射劑量差距很大 ) 由乳房篩檢評核經驗, 輻射劑量有落差為求不同品牌儀器能達到低輻射高品質影像品管必須全面執行年國人癌症, 連續 30 年排名十大死因之首 (1) 惡性腫瘤占 28.0%;(2) 心臟疾病占 10.9%;(3) 腦血管疾病占 7.1%;(4) 糖尿病占 6.0%;(5) 肺炎占 6.0%;(6) 事故傷害占 4.4%;(7) 慢性下呼吸道疾病占 3.9%;(8) 慢性肝病及肝硬化占 3.4%;(9) 高血壓性疾病占 3.0%;(10) 腎炎腎病症候群及腎病變占 2.9% 4

2 衛生署 2011 年國人十大死因統計 2011 年國人癌症為十大死因之首癌症死亡率排名之首為肺癌, 第 2 名肝癌及第 3 名為大腸癌女性第四名為乳癌, 較去年增加 5.6% 有一半乳癌患者死於 57 歲前男性第四名為口腔癌, 從 2009 年的 6.6,2010 年的 7.8 至 2011 年的 7.9 死亡率成長驚人前十大主要癌症, 依粗死亡率排序後之死亡人數占率依序為 :(1) 氣管支氣管和肺癌 20.1% (2) 肝和肝內膽管癌 18.8% (3) 結腸直腸和肛門癌 11.6% (4) 女性乳癌 4.4% (5) 口腔癌 5.8% (6) 胃癌 5.4% (7) 前列腺 ( 攝護腺 ) 癌 2.6% (8) 胰臟癌 3.8% (9) 食道癌 3.5% (10) 子宮頸及部位未明示子宮癌 1.6% 國民健康局乳房 X 光攝影篩檢建議 2010 年起,45 至 69 歲之間, 至少每 2 年做一次乳房攝影如有家族史之婦女, 需和醫師討論增加檢查頻率 5 6 為何做篩檢? 篩檢的意義? 沒有症狀也要做早期發現, 早期治療快速方便可接受的價格檢查本身有很好的敏感度及特異性 (sensitivity & specificity) 乳房攝影扮演篩檢的角色在癌細胞還沒有擴散至其他部份之前即早發現早期之乳癌乳癌的預後 ( 五年存活率 ): 第零期 :~100 % 第一期 :92.9 % 第二期 :80.5 % 第三期 :48.5 % 第四期 :18.5 % 7 8

3 輻射劑量控制乳房攝影品質要求攝影姿勢恰當高解析度高對比度乳房攝影品質保證作業相關法規為提升輻射醫療品質, 保障民眾健康安全, 原能會自 94 年起, 依游離輻射防護法第 17 條, 積極推動醫療曝露品質保證作業游離輻射防護法第 17 條 - 醫療院所使用經主管機關公告應實施醫療曝露品質保證之放射性物質可發生游離輻射設備或相關設施, 應擬訂醫療曝露品質保證計畫, 報請主管機關核准後始得為之輻射醫療曝露品質保證標準輻射醫療曝露品質保證組織與專業人員設置及委託相關機構管理辦法 97 年 7 月開始施行乳房攝影醫療曝露品質保證作業 9 10 何謂輻射醫療曝露品質保證作業乳房攝影品質保證作業品保檢測儀器品保計畫醫療曝露品質保證計畫品保測試儀器醫療曝露品質保證組織品保人員品保組織 11 醫療曝露品質保證專業人員 12

4 乳房攝影品質保證作業配置品保專業人員名執行每日至每半年品保項目之專業人員首次執行前應具備之資格基本資格三小時訓練繼續教育與訓練三小時教育執行年度品保項目之專業人員首次執行前應具備之資格基本資格八小時訓練實作二次輻射醫療曝露品質保證組織與專業人員設置及委託相關機構管理辦法繼續教育與訓練三小時教育 13 每年實作二次醫療院所自辦乳房攝影醫療曝露品質保證專業人員訓練課程規範講師資格 : 具備乳房攝影醫療曝露品保專業人員資格每年應接受 3 小時以上之乳房攝影醫療曝露品質保證繼續教育訓練訓練課程內容 : 傳統乳房攝影或數位乳房攝影 3 小時以上課程包括各項測試步驟說明及原子能委員會公告非年度項目相關資料送予中華民國醫事放射學會審查合格後始得施行, 並留存紀錄備查 14 針對每一部執行醫療曝露品保作業的放射診療儀器核發輻射醫療曝露品質標籤, 供受檢民眾及家屬辨識, 使安心就診 98 年 8 月 7 日於童綜合醫院舉辦醫療曝露有標籤, 民眾健康上上籤 - 原能會啟用醫療曝品質標籤記者會 15 16

5 Screen-Film Mammography 傳統乳房攝影 X 光機 For 35+ years, screen-film has been the gold standard for breast cancer detection FDA Approved Full-Field Digital Mammography Systems 傳統洗片機 19 20

6 That was then this is now! Old Terms New Terms Machine Film Cassettes Processor Film Screen Contact Screen Cleaning Darkroom Fog Fixer Retention Machine Review Workstation Printer Flat Field Uniformity MTF CNR SNR 21 數位式成像設備 22 FFDM Full field digital mammography Flat Field uniformity is an analysis of the homogeneity of the detector field MTF (Modulation Transfer Function) is a measure of image sharpness CNR (Contrast to Noise Ratio) is a measure of the detectors ability to distinguish between objects in an image and the image noise SNR (Signal to Noise Ratio) compares the level of the desired signal to the level of background noise DQE (Detective quantum efficiency) is calculated by comparing the SNR at the detector output with that at the detector input as a function of spatial frequency. 23 GE 2000D General Electric GE DS 24

7 Hologic (LoRad) Siemens Mammomat Novation DR Hologic Selenia 25 Novation 26 Fischer IMS GIOTTO IMAGE Fischer Senoscan 27 IMS Giotto 28

8 GE Unveils Senocase Mobile Mammography A standard field of view Cesium Iodide detector Similar image quality to a full-field digital mammography system A user-friendly interface, operable by a single clinician Cone Beam Breast CT Hologic Film-screen versus Digital Film-screen system is still limited by the fixed dynamic range of film High contrast (gamma) films are used Critical to ensure exposure factors are matched to the film AEC setup and QA very important Siemens 31 32

9 Limitations of SFM in imaging a breast composed of a wide range of tissues. Film-screen versus Digital The advantaged and limitations of the film-screen system: Mahesh M Radiographics 2004;24: Typical response curves for SFM and digital mammography Film-screen versus digital Digital mammography tends to use direct conversion flat panel detectors Better spatial resolution than indirect detectors, but still limited to ~7-10 lp mm -1 Spatial resolution is lower than screen film system. Image processing and window/level controls result in better contrast resolution Lower dose as more efficient (better Detective Quantum Efficiency DQE) and higher beam qualities used Higher throughput Plus all the other advantages of digital (and disadvantages, such as cost!) Mahesh M Radiographics 2004;24:

10 Risks are proportional to Average Glandular Dose Digital Mammography Dose is in general < Film/Screen. (Medical Physics 2006; 33: p. 731) Digital System Patient dose Mean Glandular dose mgy mrad Fischer Fuji (same tech as screen film) GE Lorad Selenia All in study (15% less than SF) Screen-film (SF) 醫療輻射劑量圖 ( 原能會網頁資料 ) 38 Mammography Limitations 39 Prompt annual mammography has shown the ability to reduce the mortality rate from breast cancer in a population by 15% to 50%. 1-3 As many as 20% of breast cancers will be missed by mammography. Approximately 10% of women are recalled for additional workup and a significant portion prove to have no abnormality, resulting in unnecessary anxiety and cost. 1. Smith RA, Duffy SW, Gabe R et al. The randomized trials of breast cancer screening: what have we learned? Radiol Clin N Am 42 (2004) Hendrick RE, Smith RA, Rutledge JH, Smart CR. Benefit of screening mammography in women ages 40-49: a new meta-analysis of randomized controlled trials. Monogr Natl Cancer Inst 1997;22: Tabar L, Vitak B, Tony HH, Yen MF, Duffy SW, Smith RA. Beyond randomized controlled trials: organized mammographic screening substantially reduces breast carcinoma mortality. Cancer 2001;91:

11 3D Mammography Benefits Earlier detection Better visualization: 3D tomosynthesis helps radiologists better see the size, shape and location of an abnormality. In a 2D mammogram, the flattened images can hide this information Fewer callbacks: Why Breast Tomosynthesis (3D mammography)? Tissue superimposition hides pathologies in 2D Tissue superimposition mimics pathologies in 2D How Does 3D Mammography Work? Hologic IMS Giotto degree 40 (-20 to +20) Reconstructed{ Slices 43 44

12 3D Improves Visibility by Reducing Tissue Superimposition Tomosynthesis Digital tomosynthesis can be considered a half-way house between tomography and CT. There are applications (and systems available) in general radiography (tomography), but most common implementation is in digital mammography (tomosynthesis). The basic principle is that a number of projections are acquired over a narrow range of angles, and the images are processed to give a series of planes through the breast (strictly speaking they are not slices like in CT) Tomosynthesis equipment Tomosynthesis Wider angle of projections = better 3D resolution More projections = slower to acquire Data processing is manufacturer specific; Back projection/shift and add for Hologic (7 frames/sec, 5 second exposure, 50 slices,1 mm thick) Filtered back projection (like CT) for Siemens Iterative reconstruction for IMS (like new CTs) 47 48

13 Raw data: low dose mammograms viewing breast at slightly different angles Reconstruction: crosssectional slices, one per mm of compressed breast Tomosynthesis 2D Mammogram Tomosynthesis Series of low-dose images used to reconstruct tomography images at any level From GE Better Sensitivity 52

14 2D Mammogram Tomosynthesis 結語 Digital is more time efficient and radiation dose can be reduced (Higher DQE). Lesion not seen on mammogram 53 Film-screen has better spatial resolution & digital better lower contrast sensitivity. Digital mammographic system Wider dynamic range Window/level adjustment Computer image enhancement Digital breast tomosynthesis (DBT) Better specificity leading to reductions in recall rates Improvements in sensitivity and the depiction of the extent of disease. 54 參考資料 Diekmann F, Bick U. Tomosynthesis and Contrast-enhanced Digital Mammography.European Radiology. 2007;17: Mark A. Helvie, Digital Mammography Imaging: Breast Tomosynthesis and Advanced Applications. Radiol Clin North AM. 2010; 48(5): Niklason LT, Christian BT, Niklason LE. Digital Tomosynthesis in Breast Imaging. Radiology.1997;205: TMAMMOGRAPHYANDTOMOSYNTHESIS.aspx 55 Thank you for your attention 56

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Microsoft PowerPoint - Sens-Tech WCNDT [兼容模式] X-ray data acquisition systems for NDT applications 技股份有限公司先锋科技股份有限公司科技股份有限公司先锋科技股份有限公司 www Sens-Tech Ltd UK based company 40 Staff Specialise in detection and data acquisition systems for light and