2012 四月份核醫月會 - 心臟篇 (2/3)
Post date: 2012/4/21 下午 02:43:40
由於台大擁有全國最多的半導體心臟掃描儀，雖然長庚比台大早購進這款儀器，
但台大目前已經累積了近 5000 例個案經驗，堪稱全國最多案例的醫學中心，這個經驗也成為這次會議討論的重點。
本次討論由顏若芳醫師主持，先由黃奕琿放射師 (目前是博士班學生) 報告CZT攝影機的基本原理，以及優於傳統造影設備的特點!
其中，CZT攝影機可以提供
- 較傳統設備高的能量解析度，
- pixellated structure 配合適當的準直儀，可以提供高解析度造影，
- 此外，CZT轉換光子的敏感度也較閃爍晶體為高，
- 所以有機會降低放射劑量，或是加快造影速度的優點。
臨床上，第一台設備在2011/5/3裝機，而第二台於2011/6/8裝機，
兩台設備裝機雖不到一年，但每天共可以服務近30位病患，而個案總數已經累積到近5000例。
其中，有23.5%為treadmill病患，其餘為dipyridamole stress個案。
CZT的影像診斷正確性表現不錯，與文獻報告類似， 利用SDS (summed difference score) 或是SSS (summed stress score) 的定量判讀方式，其AUC可來到0.79~0.79。
- The SSS (summed stress score) is a semiquantitative index obtained by adding the individual scores derived from the 17 segments that are analyzed and scored during a stress study. Each segment is scored on a 5-point scale: 0 = normal, 1 = slight reduction of tracer uptake (equivocal), 2 = moderate reduction of uptake (usually implies a significant abnormality), 3 = severe reduction of uptake, and 4 = absence of uptake. An SSS in the normal range indicates a lack of significant abnormality, while higher SSSs reflect greater extent and severity of perfusion defects.
- The SRS (summed rest score) is the summed total of each individual segment score obtained during the rest study.
- The SDS (summed difference score), which indicates the amount of ischemia and the degree of defect reversibility (it is also called the summed reversibility score), is the difference between the SSS and the SRS.
最後，柯紀綸醫師總結 CZT camera 對判讀正確性，以及減少劑量以及造影時間有極大的幫助。