A feasibility study of 99Tc m-MIBI/ 123I-MIBG dual-isotope cardiac imaging using CZT SPECT / 中华核医学与分子影像杂志

ABSTRACT

Objective:To study the feasibility of cardiac 99Tc m-methoxyisobutylisonitrile (MIBI)/ 123I-metaiodobenzylguanidine (MIBG) dual-isotope imaging with cadmium-zinc-telluride (CZT) SPECT. Methods:Using a heart phantom, 99Tc m-MIBI single-isotope imaging and 99Tc m-MIBI/ 123I-MIBG dual-isotope imaging were acquired separately. Model A, B, C represented normal heart, 99Tc m/ 123I matched myocardium, 99Tc m/ 123I mismatched myocardium, respectively. Nineteen patients (9 males, 10 females; age (56±16) years) from September 2018 to June 2020 at Fuwai Hospital were enrolled to participate 99Tc m-MIBI myocardial perfusion imaging and myocardial perfusion/cardiac sympathetic imaging with 99Tc m-MIBI/ 123I-MIBG dual-isotope. Perfusion percent (PP%) and summed rest score (SRS) for all myocardial segments were obtained using quantitative perfusion SPECT (QPS) software by analyzing myocardial perfusion images. Difference and relationship between PP% and SRS were analyzed (Pearson and Spearman correlation analyses). No physical correction was applied for both acquisitions. Analysis of variance for repeated measurement data and Mann-Whitney U test were used. Results:There was no significant difference in myocardial perfusion images between 99Tc m single-isotope and 99Tc m/ 123I dual-isotope imaging with the heart phantom. 123I did not significantly impact on 99Tc m images. For patients, PP% did not differ between 99Tc m single-isotope ((69.2±14.5)%) and 99Tc m/ 123I dual-isotope imaging ((69.5±16.2)%; F=0.005, P=0.946) and correlated well ( r=0.845, P<0.01). SRS for 99Tc m single-isotope was 2(1, 13) and 2(2, 12) for 99Tc m/ 123I dual-isotope imaging ( z=-0.774, P=0.439) and the correlation between the two acquisitions was excellent ( rs=0.975, P<0.01). Conclusions:Even without physical correction, cardiac images interpretation won′t be significantly influenced by the interference of 123I with relatively higher energy on 99Tc m images. Cardiac 99Tc m-MIBI/ 123I-MIBG dual-isotope imaging is feasible.