Datscan is indicated for detecting loss of functional dopaminergic neuron terminals in the striatum: - In adult patients with clinically uncertain Parkinsonian Syndromes, for example those with early symptoms, in order to help differentiate Essential Tremor from Parkinsonian Syndromes related to idiopathic Parkinson's Disease Multiple System Atrophy and Progressive Supranuclear Palsy. - Datscan is unable to discriminate between Parkinson's Disease Multiple System Atrophy and Progressive Supranuclear Palsy. - In adult patients to help differentiate probable dementia with Lewy bodies from Alzheimer's disease. Datscan is unable to discriminate between dementia with Lewy bodies and Parkinson's disease dementia