Detection and quantification of acute reperfused myocardial infarction in rabbits using DISA-SPECT/CT and 3.0 T cardiac MRI

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• 作者：Yuanbo Feng ; Marlein Mir ; a Cona ; Kathleen Vunckx ; Yue Li ; Feng Chen ; Johan Nuyts ; Olivier Gheysens ; Lin Zhou ; Yi Xie ; Raymond Oyen ; Yicheng Ni
• 关键词：Autoradiography ; 123I-hypericin ; MRI ; Myocardial infarction ; Rabbit model ; SPECT
• 刊名：International Journal of Cardiology
• 出版年：2013
• 出版时间：9 October, 2013
• 年：2013
• 卷：168
• 期：4
• 页码：4191-4198
• 全文大小：1863 K

文摘

Background

Necrosis avid tracer ¹²³I-hypericin (¹²³I-HYP) enables hot-spot imaging on acute myocardial infarction (MI). We explored dual-isotope simultaneous acquisition single photon emission computed tomography/computed tomography (DISA-SPECT/CT) by using ¹²³I-HYP and standard ^99mTc-sestamibi (^99mTc-MIBI), in comparison with cardiac magnetic resonance imaging (cMRI), autoradiography (AutoRx) and histomorphometry.

Methods

Acute MI was induced by 90-min coronary artery occlusion and 24-h reperfusion in 9 rabbits. They were scanned with cMRI at 3.0 T, followed by intravenous injections of ¹²³I-HYP, and 8 h later, of ^99mTc-MIBI. Then, they were imaged with DISA-SPECT/CT for detection and localization of MI. The excised heart was sectioned for AutoRx, triphenyltetrazolium chloride (TTC) histochemistry, and haematoxylin-eosin (HE) staining. DISA-SPECT/CT and cMRI were co-registered, and MI was compared between different modalities and techniques for correlation with ex vivo findings. Tracer/contrast uptakes were quantified on polar maps. One way-ANOVA and Bonferroni's tests were used for comparison of multiple techniques. Linear regression and Bland-Altman analysis were used to compare measurements of MI.

Results

MI volumes were not significantly different as by ^99mTc-MIBI-SPECT, ¹²³I-HYP-SPECT, cMRI and TTC (38.94 ¡À 13.97 % , 37.76 ¡À 13.16 % , 35.19 ¡À 12.53 % and 33.26 ¡À 10.65 % ; p > 0.05). The MI areas were 41.13 ¡À 18.70 % , 40.19 ¡À 18.45 % , 38.23 ¡À 16.86 % , 36.83 ¡À 16.70 % , 36.16 ¡À 16.15 % and 35.03 ¡À 14.75 % on ^99mTc-MIBI-SPECT, ¹²³I-HYP-SPECT, cMRI, AutoRx, TTC and HE. There was no significant differences between each of two techniques (p = 0.9). Tracer/contrast uptakes were well correlated (¹²³I-HYP vs ^99mTc-MIBI r² = 0.66; ¹²³I-HYP vs cMRI r² = 0.63; ^99mTc-MIBI vs cMRI r² = 0.64). Infarct/normal myocardium activity ratio was 40/1 and 23/1 by AutoRx and ¦Ã-counting.

Conclusion

¹²³I-HYP has shown pronounced necrosis-avidity, which proves complementary for imaging MI with potential clinical applicability for myocardial viability determination.