Radiocaine Safety Study

Inclusion Criteria: * 18 years and older * Able to provide written consent * Willing and able to undergo ECG, imaging, blood sampling, and complete self-assessment rating scales at the specified time points * Willing and able to participate in all imaging procedures and complete the self-assessment rating scales at the specified time points Exclusion Criteria: * Body mass index (BMI) of 32 or greater, weight \>300 lbs * Diagnosis of severe depression/anxiety (PROMIS score \> 95%) or suicidal ideation * History of opioid abuse or opioid use disorder * History of seizures or epilepsy * History of major Axis I or Axis II psychiatric disorder that might, in the opinion of the investigator, make it difficult for the subject to complete all the procedures (e.g. obsessive-compulsive disorder, bipolar disorder, schizophrenia, or schizoaffective disorder) * History of cardiac arrhythmia * History of major orthopedic surgery within the last 12 months * Recent history (previous 6 months) of sodium channel blocker use, including, but not limited to: carbamazepine, lamotrigine, lidocaine, phenytoin, propranolol, or valproate * Any significant systemic illness or medical condition that could lead to difficulty complying with the study protocol * Creatinine clearance (calculated using the Cockcroft-Gault formula or measured) \< 60 mL/min or serum creatinine \>1.5 x ULN * QTcF \>470 msec for females and QTcF \>450 msec for males on screening ECG * MRI-incompatible implants, large tattoos, previous shrapnel injury * Pregnancy or lactating * History of contact sport participation, such as football, hockey, or rugby * Known claustrophobia related to MR or PET-MRI scanners * Recent blood donation/draw of \>1 unit (previous 4 weeks) * History of hypersensitivity to local anesthetics of the amide type * Family or personal history of familial malignant hyperthermia