| 摘要: | 在醫院急診室的病患中，主訴有急性胸痛的患者為第二大宗。在造成急性胸痛原因中，包含(1)胸主動脈剝離、(2)肺動脈栓塞和(3)冠狀動脈疾病以及部分非血管性疾病的原因所造成，例如：肺炎、心包膜發炎…等原因。而在以往臨床上診斷急性胸痛徵狀，主要以患者病史、心電圖和生理性指標(biomarkers)為診斷依據；近年來，伴隨著電腦斷層技術及心電圖調控(ECG-gated)的進步，衍生出三合一掃描方法(triple rule-out protocol)可同時診斷上述三種造成胸痛的原因，為急性胸痛病人提供了醫學影像上的資訊。然而，此三合一掃描範圍包含主要輻射敏感器官(根據ICRP103定義，組織加權大的器官或組織)，例如:肺臟、胸部…等，在使用上必須注意其輻射劑量。本研究中，使用擬人型假體(Rando-phantom)和影像品質假體(Catphan 600)針對兩台電腦斷層儀器進行三合一掃描，根據ICRP 103報告的組織加權因數計算進一步得到全身有效劑量；另外，依照影像品質假體中不同模組(modules)量化影像品質。最後考量到劑量和影像之間權衡(trade-off)，提供FOM(figure of merit)進行掃描條件的最佳化評估。本研究目的，主要針對三合一掃描時提供兩台電腦斷層儀的輻射劑量和影像品質之間掃描參數的最佳化設定。
In emergency department, the number of patients complain of acute chest pain occupied second. There are many reasons lead to acute chest pain including three life-threaten diseases : (1) aortic dissection, (2) pulmonary embolism, and (3) coronary diseases. Also some non-vascular syndromes. For example: pneumonia, inflammation of the pericardium and etc. The first step excludes disease depend on patients’ history, ECG result, and biomarkers. For these years, developed CT system accompany with potential ECG-gated technology, triple-rule-out examination has been investigated. However, scan range from triple-rule-out examination involved higher radiation-sensitive organs (based on ICRP 103 report, much higher tissue-weighting factor). For instances, such as, lung, breast, and above stomach. Due to the reason, we must take the radiation dose to consideration before clinical practice. This study, two Rando-phantom and Catphan 600 phantom was used to investigate the performance of radiation dose and image quality in two different vender CT systems. Furthermore, trade off the image quality and radiation dose, we provide FOM(figure of merit) to quantum the result. |
