Dizdarevic Sabina, Singh Nitasha, Nair Sunil, de Belder Adam, Ryan Nicola, Aplin Mark, Vara Anil, James Rachael, McCready V Ralph, Peters A Michael
Departments of aNuclear Medicine bCardiology, Royal Sussex County Hospital, Brighton and Sussex University Hospitals NHS Trust cBrighton Sussex Medical School, Brighton, UK.
Nucl Med Commun. 2015 Apr;36(4):386-91. doi: 10.1097/MNM.0000000000000258.
The aim of the study was to investigate whether myocardial perfusion imaging at 15 min after injection (T15) is more accurate in detecting coronary artery disease than that at 45 min (T45).
Two-day stress/rest 99mTc-tetrofosmin gated SPECT was performed at T15 and T45 in 50 patients. Coronary angiography was considered when poststress and resting images were discordant. Tracer washout rates were calculated for the myocardium, liver, and subdiaphragmatic region. Perfusion sum difference scores were derived using QPS software.
T15 and T45 were discordant in 18/50 (36%) patients. In 16/18 patients (89%) discordant deficits were more apparent at T15. A total of 13/16 patients underwent coronary angiography, of whom 12 had coronary artery disease. Poststress, but not resting, left ventricular ejection fraction was lower at T15 (P=0.02). Sum difference scores were higher at T15 [2.2 (1.9)] than at T45 [1.6 (1.7); P<0.05]. Tracer washout rates from the liver [46 (13.3)%] and subdiaphragmatic region [36 (21.3)%] were significant (P<0.0001), but there was no change in myocardial activity.
T15 detected more abnormalities than did T45. The reduction in left ventricular ejection fraction after stress may result from adenosine-induced poststunning at T15. Accordingly, the T15 protocol may be useful in the assessment of hibernating myocardium. Contrasting myocardial and hepatic washout rates may be attributable to differential ABC transporter expression.
本研究旨在调查注射后15分钟（T15）的心肌灌注成像在检测冠状动脉疾病方面是否比45分钟（T45）时更准确。
对50例患者在T15和T45时进行了为期两天的负荷/静息99mTc - 替曲膦门控单光子发射计算机断层显像（SPECT）。当负荷和静息图像不一致时考虑进行冠状动脉造影。计算心肌、肝脏和膈下区域的示踪剂洗脱率。使用QPS软件得出灌注总和差异评分。
50例患者中有18例（36%）T15和T45结果不一致。在18例不一致的患者中，16例（89%）在T15时灌注缺损更明显。共有13/16例患者接受了冠状动脉造影，其中12例患有冠状动脉疾病。负荷后而非静息时，T15时左心室射血分数较低（P = 0.02）。T15时的总和差异评分[2.2（1.9）]高于T45时[1.6（1.7）；P < 0.05]。肝脏[46（13.3）%]和膈下区域[36（21.3）%]的示踪剂洗脱率有显著差异（P < 0.0001），但心肌活性无变化。
T15比T45检测到更多异常。负荷后左心室射血分数降低可能是由于T15时腺苷诱导的心肌顿抑。因此，T15方案可能有助于评估冬眠心肌。心肌和肝脏洗脱率的差异可能归因于不同的ABC转运蛋白表达。
