Shape features as biomarkers in early Parkinson´s disease

In vivo dopaminergic imaging through [123I]FP-CIT Single Photon Emission Computerized Tomography (SPECT) provide useful information which enhances the accuracy of diagnosis of PD. Such imaging techniques have given rise to new class of subjects termed scans without evidence of dopaminergic Deficit (SWEDD) subjects, who are clinically diagnosed as PD but show normal dopaminergic scans. Although it is now established that the appearance of striatal uptake patterns, as seen in the SPECT images, change in shape during PD as compared to Normal or SWEDD subjects, as per our knowledge, there have been no studies on the quantification of the shape of these uptake regions. We in our study, use the [123I]FP-CIT SPECT data from 20 Normal, 20 SWEDD and 20 Early PD subjects from the Parkinson´s Progression Markers Initiative (PPMI) database to segment, followed by quantification of these regions. It is observed that the quantification parameters show good amount of variation in PD as compared to Normal or SWEDD subjects. Hence, it is inferred that these parameters may be useful biomarkers for the early diagnosis of PD.