Kiat H, Germano G, Friedman J, Van Train K, Silagan G, Wang F P, Maddahi J, Berman D
Department of Imaging (Division of Nuclear Medicine), Cedars-Sinai Medical Center, Los Angeles, California 90048.
J Nucl Med. 1994 Apr;35(4):542-8.
Separate or simultaneous rest 201Tl/stress 99mTc-sestamibi dual-isotope SPECT are potentially efficient myocardial perfusion imaging protocols which combine the use of a high-resolution 99mTc tracer for stress perfusion assessment and 201Tl, the current single-photon agent of choice, for viability assessment.
To investigate the feasibility of dual-isotope myocardial perfusion SPECT protocols using rest 201Tl and stress sestamibi, 201Tl crosstalk into the 99mTc acquisition window (Group 1, n = 26 patients) and 99mTc crosstalk into 201Tl windows (Group 2, n = 25) were studied. For Group 1, treadmill exercise with sestamibi injection and poststress SPECT ("virgin" sestamibi images) were performed, followed by rest 201Tl injection and SPECT acquisition using dual-isotope windows (contaminated or "dual" images). For Group 2, the order was reversed: rest 201Tl SPECT (virgin 201Tl images) was performed first, followed by exercise sestamibi injection and dual-isotope SPECT.
The contribution of 201Tl scatter to the dual sestamibi images (Group 1) was measured to be 2.9% +/- 2.1%, while 99mTc crosstalk contributed 26.7% +/- 13.0% to the dual 201Tl images (Group 2). Image quality was considered good to excellent in 92% of the sestamibi (virgin and dual) images and 88% of the virgin 201Tl SPECT, but only in 23% of the dual 201Tl studies.
Technetium-99m crosstalk into 201Tl windows is substantial; therefore, simultaneous dual-isotope protocols, which involve assessment of 201Tl images contaminated by 99mTc, are not recommended. On the other hand, because of the small amount of 201Tl crosstalk into the 99mTc window, a separate acquisition dual-isotope approach employing the rest 201Tl (virgin)/stress sestamibi sequence is acceptable.
静息201铊/负荷99锝-甲氧基异丁基异腈双同位素单光子发射计算机断层扫描（SPECT），无论是分开进行还是同时进行，都是潜在有效的心肌灌注成像方案，该方案结合使用高分辨率的99锝示踪剂进行负荷灌注评估，以及使用当前首选的单光子剂201铊进行存活心肌评估。
为了研究使用静息201铊和负荷甲氧基异丁基异腈的双同位素心肌灌注SPECT方案的可行性，研究了201铊串扰到99锝采集窗（第1组，n = 26例患者）以及99锝串扰到201铊窗（第2组，n = 25例）的情况。对于第1组，进行踏车运动并注射甲氧基异丁基异腈以及负荷后SPECT（“原始”甲氧基异丁基异腈图像），随后注射静息201铊并使用双同位素窗进行SPECT采集（受污染或“双”图像）。对于第2组，顺序相反：首先进行静息201铊SPECT（原始201铊图像），随后进行运动甲氧基异丁基异腈注射和双同位素SPECT。
测得201铊散射对双甲氧基异丁基异腈图像（第1组）的贡献为2.9%±2.1%，而99锝串扰对双201铊图像（第2组）的贡献为26.7%±13.0%。在92%的甲氧基异丁基异腈（原始和双）图像以及88%的原始201铊SPECT中，图像质量被认为良好至优秀，但在双201铊研究中仅为23%。
99锝串扰到201铊窗的情况很显著；因此，不推荐涉及评估受99锝污染的201铊图像的同时双同位素方案。另一方面，由于201铊串扰到99锝窗的量较少，采用静息201铊（原始）/负荷甲氧基异丁基异腈序列的单独采集双同位素方法是可以接受的。
