SLC6A3 and Parkinson disease: Dopamine transporter imaging with [123I]FP-CIT (N-(3-Fluoropropyl)-2β-carbomethoxy-3β-(4-[123I]iodophenyl) nortropane) single photon emission computed tomography (SPECT) and [18F]FP-CIT(N-(3-[18F]fluoropropyl)-2β-carboxymethoxy-3β-(4-iodophenyl)nortropane) positron emission tomography (PET) are in vivo molecular imaging techniques used to investigate loss of dopaminergic neurons in the striatum in patients suspected of having PD.