- 期刊
鉈-201心肌灌注檢查加作俯臥位造影的助益
Differentiating Diaphragmatic Attenuation by An Additional Acquistion in the Prone Position in 201TI Myocardial SPECT
摘要
前言：鉈-201心肌灌注掃描一般探用仰臥位造影，常見横膈膜周圍軟组織的衰减造成心肌下壁缺損假影。國外文獻認爲在再分佈相時加照俯臥位造影可有效幇助判别。本研究爲觀察東方人是否也有一樣的效果。方法：24位無心肌梗塞病史及3位有陳舊性下壁梗塞病史之病人接受鉈-201心肌灌注掃描，踏步運勤負荷採改良式布魯士踏步機方法，如受檢者無法自己運勤，則使用dipyridamo1e静脈注射。做完壓迫相檢查後4小時作一次再分佈相造影。分析後影像出现不可逆輕微缺损现象懷疑可能是軟组織衰减假影，於再分佈相取俯臥位再造影一次。俯臥位影像處理後舆壓迫相及再分佈相的仰臥位影像一起分析，鑑别心肌下壁的活性是否有增加。结果：俯臥位造影於24例無心肌梗塞病史病人中，21例(87.5％)有下壁活性增加，3例没有活性增加(12.5％)。3例有下壁梗塞病史之病人，其下壁活性均無增加。因此，加照俯臥位造影的確可幇助區别心肌下壁的不可逆輕微缺損現象是否爲软组織衰減所照成的假影。结論：使用未配置透射掃描的機器進行仰臥位鉈-201心肌灌注掃描時，如果心肌下壁出現不可逆輕微缺損影像，懷疑是軟组織的衰减所造成的假影，加作俯队位造影是很有幇助的。
並列摘要
Background: The supine position is the most commonly used position for 201Tl myocardial SPECT. However, artifacts caused by diaphragmatic attenuation in the inferior wall are often noticed. The overseas studies showed the prone decubitus would minimize the effect of diaphragmatic attenuation. This study is aimed at the evaluation of this effect in the Oriental. Methods: Twenty-four patients without and 3 patients with prior inferior myocardial infraction underwent stress 201Tl myocardial SPECT using either treadmill exercise or intravenous dipyridamole. Both the stress and 4-h redistribution images were acquired in the supine position. An additional acquisition in the prone position was performed if irreversible perfusion defect in the inferior wall was noticed. Three sets of images were then compared together to identify the tracer activity especially in the inferior wall. Results: Using the prone position, increased tracer activity in the inferior wall was noticed in 21 (87.5%) of 24 patients without prior myocardial infarction. All 3 patients with prior infarction showed no increase in the inferior activity. Conclusion: Using the scintillation camera system without transmission attenuation correction, an additional set of images taken in the prone position is useful in the differentiation of the artifact in the inferior wall caused by diaphragmatic attenuation.