利用雙頭注射器於非洲灰鸚的電腦斷層掃描及評估主要動脈的直徑和造影效果

Abstract

動脈硬化可能是鸚鵡最常見的心血管疾病。目前在鳥的生前診斷仍然困難；而在人類，電腦斷層血管攝影已被廣泛應用於診斷動脈硬化。因此，就現時來說，針對鳥類心血管系統的評估，電腦斷層血管攝影似乎是個可行的方式。本研究的目的是希望透過雙頭注射器的使用來建立非洲灰鸚電腦斷層掃描的標準流程，以及在不同視窗下，主要動脈血管造影程度和直徑的參考值。本研究使用16切螺旋式電腦斷層，針對六條主要動脈進行掃描。在開始之前，實驗動物會先接受健康及心臟功能檢查，確認無異常後才納入研究。而在掃描過程中，動物會被全身麻醉；以雙頭注射器來協助造影劑及生理食鹽水的投予，期間以造影追蹤技術監控上行主動脈造影程度的變化，當達到最高點時，即以手動方式啟動掃描。掃描後，由兩位醫師以雙盲的方式進行測量，並針對其結果建立於不同視窗下的參考值。結果顯示，觀察者間的一致性於造影後/ 體視窗的測量下最高。因此，我們會建議於此條件下進行鸚鵡的電腦斷層血管攝影；然而，未來還是需要更多研究來增進電腦斷層血管攝影於鸚鵡動脈硬化診斷的潛力及實用性。

Atherosclerosis is probably the most common cardiovascular disease in parrots. Nowadays, ante-mortem diagnosis of atherosclerosis in birds is still difficult. In humans, CT-A has long been used as a non-invasive, sensitive tool to identify calcified and non-calcified plaques in major arteries. At this time, it seems to be a promising method to evaluate the avian cardiovascular system. The objective of our study was to establish the CT-A protocol using the dual-headed power injector in African Grey parrots (Psittacus erithacus) as well as reference range of attenuation value and diameters of the major arteries. 16-slice CT scanning was used to measure the region of interest (ROI) in 6 major arteries. Before scanning, each bird underwent physical, blood, and cardiologic examination and were considered healthy. Each bird was under general anesthesia during CT-A procedure. The dual-headed power injector with saline chaser technique was used to administer contrast medium and saline flush. We used the real-time bolus-tracking method, and triggered the scan manually once the peak enhancement of ascending aorta was reached. The measurements were obtained by 2 clinicians double-blindly. The reference range before and after contrast medium administration via body, pulmonary, and bone window were set up accordingly. Inter-observer consistency in measurements was high in post-contrast values via a body window. Hence, we suggested performing CT-A in parrots with contrast medium administration in body window. However, further studies will be needed to improve the potential and utility of CT-A in diagnosis of atherosclerosis in parrots.