Hess Annika, Nekolla Stephan G, Meier Martin, Bengel Frank M, Thackeray James T
Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
Department of Nuclear Medicine, Technical University of Munich, Munich, Germany.
J Nucl Cardiol. 2020 Aug;27(4):1317-1327. doi: 10.1007/s12350-019-01713-z. Epub 2019 May 1.
Quantitative cardiac contractile function assessment is the primary indicator of disease progression and therapeutic efficacy in small animals. Operator dependency is a major challenge with commonly used echocardiography. Simultaneous assessment of cardiac perfusion and function in nuclear scans would reduce burden on the animal and facilitate longitudinal studies. We evaluated the accuracy of contractile function measurements obtained from electrocardiogram-gated nuclear perfusion imaging compared with anatomic imaging.
In healthy C57Bl/6N mice (n = 11), Tc-sestamibi SPECT and N-ammonia PET underestimated left ventricular volumes (23 to 28%, P = 0.02) compared to matched anatomic images, though ejection fraction (LVEF) was comparable (%, SPECT: 73 ± 8 vs CMR: 72 ± 6, P = 0.1). At 1 week after myocardial infarction (n = 13), LV volumes were significantly lower in perfusion images compared to CMR and contrast CT (P = 0.003), and LVEF was modestly overestimated (%, SPECT: 37 ± 8, vs CMR: 27 ± 7, P = 0.003). Nuclear images exhibited good intra- and inter-reader agreement. Perfusion SPECT accurately calculated infarct size compared to histology (r = 0.95, P < 0.001).
Cardiac function can be calculated by gated nuclear perfusion imaging in healthy mice. After infarction, perfusion imaging overestimates LVEF, which should be considered for comparison to other modalities. Combined functional and infarct size analysis may optimize imaging protocols and reduce anaesthesia duration for longitudinal studies.
定量评估心脏收缩功能是小动物疾病进展和治疗效果的主要指标。操作者依赖性是常用超声心动图的一大挑战。在核扫描中同时评估心脏灌注和功能将减轻动物负担并便于进行纵向研究。我们评估了与解剖成像相比，通过心电图门控核灌注成像获得的收缩功能测量值的准确性。
在健康的C57Bl/6N小鼠（n = 11）中，与匹配的解剖图像相比，锝-司他比SPECT和氮-氨PET低估了左心室容积（23%至28%，P = 0.02），不过射血分数（LVEF）相当（%，SPECT：73±8 vs CMR：72±6，P = 0.1）。在心肌梗死后1周（n = 13），与CMR和对比增强CT相比，灌注图像中的左心室容积显著降低（P = 0.003），且LVEF被适度高估（%，SPECT：37±8，vs CMR：27±7，P = 0.003）。核图像在阅片者内部和阅片者之间表现出良好的一致性。与组织学相比，灌注SPECT准确计算出梗死面积（r = 0.95，P < 0.001）。
在健康小鼠中可通过门控核灌注成像计算心脏功能。梗死后，灌注成像高估了LVEF，在与其他检查方法进行比较时应予以考虑。功能和梗死面积联合分析可能优化成像方案并减少纵向研究的麻醉时间。
