微電腦斷層掃描控制系統-以LabVIEW實作

Abstract

電腦斷層系統(Computed tomography, CT)利用非侵入式的方式，產生360度影像資訊並重建出物體內部三維結構的影像，為目前醫學造影一個重要工具；人體試驗前通常會進行動物實驗作為評估的依據，微電腦斷層系統(micro computed tomography, micro-CT)可提供符合小動物需求的高解析度結構性影像。目前自製(組裝)的微電腦斷層系統，由於儀器元件的操作介面各不相同，進行360度影像擷取時，使用者需花費相當多的時間與心力。此研究目的是利用模組化的方式，建構微電腦斷層控制系統，並以LabVIEW作為系統開發工具。同時量測機構平台旋轉參數，計算旋轉度數與脈波數的轉換；設定此參數進行微電腦斷層系統操作，分別每1度、5度、10度取像旋轉共360度量測造影總時間，以及X光造影時間，各3次實驗共9筆資料。 研究結果包含可獨立操控儀器的程式、各模組整合後的微電腦斷層控制系統與圖形化使用者介面。機構平台度數與脈波數的轉換參數為445 pulse/度，量測操作系統造影總時間範圍約在10.3~6.5分鐘之間，X光造影時間範圍約在7.5~3.5分鐘之間。此系統以LabVIEW作為開發工具，整合使用者操作介面，利用模組化實現微電腦斷層系統控制，以Stop & Shoot protocol拍攝流程作為造影模式的參考範例，提供模組化建構醫療儀器系統之雛型。未來可加入不同造影模式，如連續拍攝模式，以符合使用者不同造影需求。

Computed tomography (CT) has become an important tool in medical imaging since it provides three-dimensional internal structure of object in a non-invasive way. Before clinical trial, animal study will be conducted to evaluate the effect. Micro computed tomography (micro-CT) is used in animal experiment for providing higher resolution tomographic image. We have a custom-built micro-CT system in which devices are bought from different companies. While performing 360°imaging, user needs to operate the image acquisition step by step which costs substantial time and effort. The aim of this study is to implement modularity for each component, and further construct a custom-built micro-CT device control application. Besides, LabVIEW was used as system developing environment. The rotation parameter of gantry was measured, and the conversion of pulse number per degree was calculated. Moreover, the gantry conversion parameter was set to measure total scan time and X-ray imaging time for full 360°rotation using 1°,5°, and 10°per projection mechanism under same high speed (HS) = 1 (pulse/ms) condition. Each angle condition was conducted three times and resulted in total nine records. The results included individual device control programs, modularized micro-CT system control application and corresponding graphical user interface. The conversion parameter between pulse number to gantry rotation per degree was 445 (pulse/degree). The range of total scan time was from 10.3 minutes to 6.5 minutes, and X-ray imaging time was from 7.5 minutes to 3.5 minutes. This study provided a prototype of the modularized construction of medical instrumentation automation under LabVIEW environment. Moreover, stop & shoot protocol was implemented as an imaging example. Different imaging mode can be implemented such as continually acquisition mode to meet the users’ requirement.