背景：門控心肌灌注造影可以同時評估造影藥物注射時的心肌血流和造影時的心室功能。以鉈－201作爲造影藥物時，壓力造影通常在注射後即立刻開始進行，但若以鎝－99m類的造影藥物，則要在注射後30到60分鐘才開始。因此，鉈－201門控心肌灌注造影似乎有較多的機會可以偵測壓力過程所造成的心室功能變化。本研究之目的以壓力－鉈－201門控心肌灌注造影來評估dipyridamole對左心室功能造成的影響，並進一步與心導管的結果作比較。方法：本研究回溯研究150位在3個月內進行dipyridamole鉈－201門控心肌灌注造影與心導管兩種檢查的病患。心肌灌注造影分別在壓力後以及4個小時休息後進行，並以全自動的軟體QGS3.0來計算左心室射出分率(LVEF)。以總和壓力分數(SSS)、總和休息分數(SRS)以及總和差別分數(SDS)來描述心肌血流的異常。病患根據壓力後和休息影像LVEF的差異(△LVEF)分成三組。A組：△LVEF≥5%、B組：5%＞△LVEF≤-5%、C組：△LVEF≤-5%。病患若在心導管上發現有至少一條血管有超過70%的狹窄，則視爲有顯著的冠狀動脈疾病(CAD)。結果：A組有43個病患(29%)、B組有63個(42%)、C組有44個(29%)。A、B、C三組的SSS分別爲9.77±9.90，12.05±10.37和17.07±11.89；SRS爲6.28±7.88，6.03±6.64和7.02±7.33；505爲3.49±4.53同，6.02±7.72 and 10.05±10.37。C組的SSS和SDS顯著高於A和B組(P<0.05)，但SRS在三組之間則無顯著的差異。心導管的檢查發現在A組中有21個(49%)有顯著CAD、B組有38個(62%)、C組有36個(82%)，卡方趨勢檢定(Chi-square test for trend)顯示有顯著差異。結論：Dipyridamole可造成LVEF暫時性的增高或減低。而在鉈－201門控心肌灌注造影中出現dipyridamole造成的LVEF減低與心肌缺血與顯著的CAD有明顯的相關性。

Background: Gated myocardial perfusion SPECT simultaneously evaluates myocardial perfusion at tracer injection and ventricular function at imaging. Stress imaging is usually performed immediately after tracer injection with 201Tl, but 30 to 60 min later with 99mTc tracers. Therefore, 201Tl gated SPECT seems to have more chance to detect the functional changes caused by stress procedures. The purpose of this study was to evaluate the effects of dipyridamole on left ventricular function by stress-rest gated 201Tl myocardial perfusion SPECT. The results were correlated with the coronary angiographic findings. Methods: The study retrospectively included 150 patients who underwent dipyridamole 201Tl gated SPECT and coronary angiography within 3 months. Post-stress and 4-h rest images were obtained and left ventricular ejection fraction (LVEF) was calculated by automated software (QGS 3.0). Summed stress score (SSS), summed rest score (SRS) and summed difference score (SDS) were used for describing perfusion abnormalities. The patients were further divided into three groups according to the difference of LVEF (△ LVEF) between post-stress and rest images. Group A: △LVEF≥5%, group B: 5%>△LVEF>-5%, group C: △LVEF≤-5%. The patients were thought to have signify significant coronary artery disease (CAD) when coronary angiography showed≥70% stenoses in at least one vessel. Results: There were 43 patients (29%) in group A, 63 (42%) in group B, and 44 (29%) in group C. SSS of the three groups were 9.77±9.90, 12.05±10.37 and 17.07±11.89 (group A, B and C); SRS were 6.28±7.88, 6.03±6.64 and 7.02±7.33; and SDS were 3.49±4.53, 6.02±7.72 and 10.05±10.37. The SSS and SDS of group C were significantly higher than those of group A and B (P<0.05), but SRS was not significantly different between the three groups. Significant CAD was noted in 21 patients (49%) for group A, 38 (62%) for group B, and 36 (82%) for group C. Chi-square test for trend showed significant difference (P<0.01) between the three groups of patients. Conclusions: Dipyridamole may cause transient increase or decrease of LVEF. In addition, the dipyridamole-induced decrease of LVEF shown on post-stress and rest gated 201Tl SPECT was significantly correlated to myocardial ischemia and significant CAD.