Abstract
1571
Objectives: Cardiac 123I-metaiodobenzylguanidine (123I-MIBG) innervation scintigraphy with heart-to-mediastinum ratio (HMR) can be used to differentiate Parkinson Disease (PD) and Lewy Body Disease (LBD) from other parkinsonian syndromes. We assessed the HMR feasibility and reproducibility using cardiac scintigraphy with the simultaneous acquisition of 123I-MIBG and 99mTc-tetrofosmin. Methods: We included 26 patients (12 F, 14 M, aged 70 ± 11 years) with a clinical parkinsonian syndrome, without neuroleptic, myocardial infarction or diabetes. Cardiac dual isotope acquisition with 99mTc-tetrofosmin and 123I-MIBG was performed with a CZT camera (D-SPECT) from November 2016 to November 2017. 123I-MIBG injection (152.69 ± 8.25 MBq) was administrated 4 hrs and 99mTc-tetrofosmin injection (386.20 ± 110.04 MBq) 1 hr before dual acquisition (13 ± 1 min). The images were re-oriented, heart and mediastinum regions of interest were placed on perfusion imaging and the HMR was calculated on innervation imaging. Results: The perfusion imaging was homogeneous in all patients. Based on the HMR calculation, PD was diagnosed in 11 patients (HMR = 1.244 ± 0.195), LBD in 4 patients (0.989 ± 0.099) and others parkinsonian syndromes in 11 patients (1.779 ± 0.250). An intraclass correlation coefficient, calculated in 17 patients with three different investigators to estimate reproducibility, was 0.986 (IC 95%; 0.959 - 0.995; p<0.001). Conclusions: Cardiac dual isotope (123I-MIBG/99mTc-tetrofosmin) is feasible using CZT camera and HMR reproducibility is excellent in parkinsonian syndromes.