透視動態影像數位化系統建置及評估
(以神經放射血管攝影為例)
Design and Evaluation of a DICOM compliant Video-fluoroscopy
Imaging System
(An Investigation in Neuroradiology Angiography)
中文摘要 透視檢查是屬於一種特殊的 X 光檢查，可以即時提供病患身體內部器官或組織 構造之連續 X 光影像或即時動態視訊。在放射線學的檢查中，它被應用於許多 不同的檢查或流程中，例如經皮腎造口術(PCN)、鋇劑食道吞嚥攝影檢查、心導 管等等介入性檢查。這些即時動能透視影像同樣具有診斷回顧、教學及研究的價 值，應該被視為病人的診療紀錄，和病歷一樣的被完整保存。傳統的動態透視影 像可以利用外接的錄放影機，以錄影帶做為媒介儲存、記錄。但受限於錄影帶的 本身的性質，只能從頭開始依序的搜尋段落，即便已經知道想查閱的某段影像在 那個段落，卻也無法直接播放該影像。這使得這些錄影帶的資料無法有效的管 理。在現階段中，DICOM 3.0(Digital Imaging and Communications in Medicine)標 準中已公告支援 MPEG-2 的動態影像壓縮格式。在國內，多數已完成建置影像 儲傳系統(Picture Achieving and Communication Systems,簡稱 PACSs)的醫院，依 據 DICOM 的標準來儲存和管理一般靜態的 X 光影像。現在正是時候將動態透視 影像擷像、數位化並整合到醫院的 PACS 系統中，這樣可以有更佳的儲存方式、 影像資源共享及影像資料管理。雖然 DICOM 標準中定義了支援 MPEG-2 的壓縮 結構，但卻也表示，臨床醫學是否可以接受 MPEG2 失真壓縮的影像，不在 DICOM 標準的研究範圍內。本研究論文的目的在於建立「透視動態影像數位化系統」， 將動態透視影像轉為符合 DICOM MPEG2 標準的影像，並整合入醫院的 PACS 系統中，並且從臨床診斷的觀點評估系統接受度。我們利用現有血管攝影的系統 中，同時具備傳統的錄影機及數位擷像系統的檢查儀器，針對頭頸部之透視檢查 影像，分別錄製「傳統錄影帶的 NTSC 訊號影像」及「DICOM-MPEG2 數位影 像」，請放射專科醫師針對所收集個案進行評估，證實 DICOM MPEG2 格式的動 態透視影像與傳統的錄影帶所記錄影像，且有相同或更佳的影像品質。 英文摘要
Fluoroscopy is a special type of x-ray that provides continuous x-ray images (or live video) of a patient’s organ structures in real time. It is used in many types of
examinations and procedures, such as Percutaneous Nephrostomy (PCN), Barium Swallow, cardiac catheterization, and so on. The live fluoroscopy video is valuable for diagnosis review, teaching and research. They need to be stored as a part of the
patient’s medical records. Traditionally, the live fluoroscopic video can be saved by using video tapes. Since the nature of sequential access to a video tape, we cannot directly play or view a specific image. This makes the management of video tapes inefficient. Currently the DICOM 3.0 (Digital Imaging and Communications in Medicine) Standard supports the MPEG-2 live video compression format. Most hospitals in Taiwan have developed their Picture Achieving and Communication Systems (PACSs) based on the DICOM standard to store and manage static x-ray images. Thus, it is the time for live fluoroscopic video to be captured, digitalized and integrated into the PACS for better storage, sharing and management. Although the DICOM supports the MPEG-2 compression scheme, it indicates that whether the clinicians can accept the lossy compression of MPEG-2 images is beyond the scope of the DICOM Standard. The paper presented here proposes approaches to develop a DICOM MPEG2 compliant fluoroscopic video management system integrated seamlessly with other hospital systems, and presents methods to evaluate the system acceptance from the viewpoint of clinicians. We conclude that the quality of the fluoroscopic video represented by the DICOM MPEG-2 specification is as good as or better than that represented by traditional video tapes.
