Other imaging tests that may help identify dementia with Lewy bodies include Positron emission tomography (PET) of the brain with fluorine-18 (18F) - labeled deoxyglucose (fluorodeoxyglucose, or FDG) Myocardial scintigraphy with iodine 123-meta-iodobenzylguanidine (MIBG; in dementia with Lewy bodies, cardiac uptake of MIBG is reduced because the postganglionic cardiac sympathetic system is denervated) However, these tests are not routinely used in clinical practice.