Retention Kinetics of the 18F-Labeled Sympathetic Nerve PET Tracer LMI1195: Comparison with 11C-Hydroxyephedrine and 123I-MIBG.

In vivo norepinephrine transporter (NET) blockade with desipramine confirmed specific neural uptake of (18)F-LMI1195, (11)C-hydroxyephedrine, and (123)I-MIBG in rabbit hearts. (11)C-hydroxyephedrine cardiac retention was sensitive to a NET inhibitor chase, indicating a cycle of continuous NET uptake and release at the nerve terminals. In contrast, (18)F-LMI1195 and (123)I-MIBG demonstrated stable storage at the nerve terminal with resistance to a NET inhibitor chase, mimicking physiologic norepinephrine turnover.