To determine the role played by 18-Fluro-FDG PET Brain and 99m-TC- TRODAT-1-SPECT imaging in supporting the clinical diagnosis in patients with Idiopathic Parkinson’s Disease (IPD), Vascular Parkinsonism (VP) and Progressive Supranuclear Palsy (PSP) ,and to outline their common imaging findings.

Idiopathic PD, PSP and VP largely remain clinical diagnoses , however nuclear imaging can be an added tool that helps us in differentiating between the diseases. 

21 such patients were identified. Among them, 10 were diagnosed with Idiopathic PD (47.6%), 7 with PSP (33.3%) and 4 with VP (19%)

In those with Idiopathic PD, PET Brain revealed Hypometabolism in prefrontal, cingulate and parietal cortices, which was seen in 4 (40%) of the patients. 3 had normal PET findings. 

TRODAT was characteristic of IPD in 8 patients (80%). Reduced presynaptic dopamine transporters in the Putamen was the commonest finding.

In patients with PSP, PET showed hypometabolism predominantly in the Caudate nucleus, Midbrain and Prefrontal cortices. This was noted in 6 patients (85%).

TRODAT was suggestive of PSP in 5 patients (71%) and they had reduced presynaptic dopamine transporters in the caudate nucleus.

In VP, 75% had hypometabolism pertaining to the vascular territory in PET Brain .TRODAT was abnormal in 1 patient , and showed severely reduced presynaptic dopamine transporters in both the Basal Ganglia.

PET Brain was characteristically abnormal in 61.9% of the patients and TRODAT in 66.6% . Of note is the fact that even when PET Brain was normal , TRODAT seemed to pick up abnormalities and vice versa. Thus ,the combination of both imaging modalities can serve as useful adjuncts and a potential tool when diagnosis seems elusive.