電腦輔助系統在核子醫學的實踐

Implementations of Novel Computer-Aided System in Nuclear Medicine Practice

黃嘉彥(Jia-Yann Huang)

指導教授 ： 陳永盛

元智大學/電機通訊學院/電機工程學系/博士(2011年)

https://doi.org/10.6838/YZU.2011.00070

摘要

核子醫學影像有多種類別，包含平面掃描影像，單光子射出電腦斷層影像和正子斷層掃描影像等，檢查前先給病人少劑量的放射性藥物再進行攝影，觀察放射性藥物在人體內的吸收特性，以了解病人的生理狀態。攝影完成後，核子醫學醫師藉由目視檢查閃爍掃描影像所提供的資訊，以了解病人的組織、器官、器官系統生理狀況，而且在臨床運作和研究上，經由量化所得的資料，更可以用來觀查病患生化和生理上有意義的變化過程。
由於最近核醫掃描成像技術的大幅進步，使核醫解剖性影像，功能性影像，動態影像的造影過程有很大的改善。但由於核醫成像的光子統計特性差，只能產生低解析度的影像而且需要相對較長的掃描時間。基於這些缺點，核醫低解析度影像需要一些電腦輔助系統幫助核子醫學醫師在檢視影像時，能更加確定判斷影像中不正常的位置。在本論文中，我們提出四個核子醫學電腦輔助系統即核子醫學全身骨骼掃描電腦輔助自動診斷系統，核醫骨骼掃描電腦輔助全自動測量腸關節與薦椎對放射性同位素的攝取比，腎絲球過濾率檢查腎動態影像電腦輔助全自動腎臟區域圈選，核醫放射碘平面影像電腦輔助全自動測量葛瑞夫茲氏病甲狀腺體積。四個電腦輔助系統演算法的構成主要是以模糊集合影像灰階分佈圖閥值判定，適應性閥值判定法，解剖知識為基礎的影像分割方法，雙亮度影像對比強化方法及形態學處理方法所組成。實驗結果證明我們所提出的演算法是可信賴的，希望可運用在臨床上，幫助核子醫學醫師對低解析度閃爍影像的判讀。

關鍵字

核子醫學 ； 模糊集合閥值判定 ； 適應性閥值判定 ； 雙亮度影像對比強化

並列摘要

Nuclear medicine imaging, including planar scintigraphy, single photon emission computed tomography (SPECT), and positron emission tomography (PET), relies upon the tracer principle, in which a slight quantity of a radiopharmaceutical is administered into the body to monitor the patient’s physiological condition. Practically, scintigrams are interpreted visually to assess the physiological condition of tissues, organs, and organ systems, moreover, can be estimated quantitatively to survey biochemical and physiological processes of significance in both clinical practices and research.
Recent advances in radionuclide imaging systems have resulted in important improvements in the fields of anatomical, functional, and dynamic imaging procedures. But, radionuclide images inherently have poor photon statistics, are produced with only modest spatial resolution, and need relatively long scan time. As the disadvantages mentioned about, the low spatial resolution scintigrams required some computer-aided systems for helping nuclear physicians to identify the abnormalities in the interpretation procedure. In this thesis, our computer-aided system is divided into four sub-systems: computer-aided diagnosis in nuclear medicine whole body bone scan images, computer-aided sacroiliac joint index analysis for bone scintigraphy, region of interest selection in glomerular filtration rate estimation from 99mTc-DTPA renogram, and thyroid volume estimation in Graves’ disease using radioiodine planar scintigrams. These sub-systems are based on anatomy knowledge-based segmentation method, fuzzy sets histogram thresholding, adaptive thresholding, intensity-pair image contrast enhancement, and morphological operations. Experimental results reveal the superior performance in these sub-systems; we expect that these computer-aided systems may be applied to help nuclear medicine physicians in clinical practice.

並列關鍵字

Nuclear medicine ； Fuzzy sets histogram thresholding ； Adaptive thresholding ； Intensity-pair image contrast enhancement

參考文獻

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