I-123 DaTscan SPECT Brain Imaging in Parkinsonian Syndromes: Utility of the Putamen-to-Caudate Ratio.

Although PCR can intrinsically be a useful indication of disease, this ratio obtained in our analysis by using one of the clinically available automatic semiquantitative methods has large variability and might not be a reliable numeric marker in interpretation of [I-123]ioflupane studies. This may be due to difficulty in separating caudate from putamen on SPECT images, as well as the nonuniform decreased Ioflupane uptake in both putamen and caudate.