Possibilities of Hybrid SPECT/CT with 123I-MIBG for Visualizing the Ganglia of the Cardiac Autonomic Nervous System in Healthy Volunteers

Objective – to study the characteristics of the distribution and visualization of ganglionated plexuses in the left atrium (LAGP) in healthy volunteers. Objective and methods . The investigation enrolled 15 healthy volunteers (median age 31 [26; 41] years). The investigation participants successively underwent cardiac computed tomography (CT) and SPECT using the neurotropic radiopharmaceutical 123I-MIBG. The obtained images were combined to identify and assess sympathetic activity foci (SAF) in the left atrium. The identified SAFs were ranked with a confidence probability (CP) on the basis of their correspondence to the anatomical location of LAGP, as well as the discreteness and prevalence of the surrounding structures. Results. A total of 36 SAFs (median per participant was 2 [2; 3]) were identified; of them 20 (56%) had a low CP (median per participant was 1 [1; 2]); 16 (44%) had intermediate and/or high CP (median per participant was 1 [1; 1]). Three investigation participants (3/15) were found to have no SAFs with an intermediate and/or high CP. SAFs with an intermediate and/or high CP most frequently corresponded to the location of the left and right upper LAGPs (4/16 and 3/16 cases, respectively). Conclusion. Hybrid SPECT/CT with the neurotropic 123I-MIBG allows the identification of SAFs in healthy volunteers, which correspond to the typical location of LAGPs.