In staging pediatric sarcoma, subsidiary FDG-PET scanning depicts important additional information and has a relevant impact on therapy planning when analyzed side-by-side with CIMs.

72 consecutive patients with suspected parkinsonian syndromes (PS) were studied by dopamine transporter (DAT) and D2 receptor SPECT in order to evaluate the accuracy of combined SPECT imaging. In the follow-up, the patients were diagnosed as having Parkinson's disease (PD, n = 25), dementia with Lewy bodies (DLB, n = 6), multiple system atrophy (MSA, n = 13), progressive supranuclear palsy (PSP, n = 8), corticobasal degeneration (CBD, n = 9), and essential tremor (ET, n = 11). Using the iteratively estimated optimal cutoffs, DAT was reduced in 57/61 PS patients, whereas all ET patients were identified as "normal". Reduced D2 receptor binding had 7/13 patients with MSA, 6/8 patients with PSP, 2/9 patients with CBD and no ET, PD or DLB patients. FP-CIT SPECT allows an accurate detection of nigrostriatal affection in neurodegenerative PS. IBZM SPECT is useful to approve the diagnosis of PSP and MSA although a normal finding cannot exclude an atypical PS. IBZM SPECT seems to be of restricted value in CBD.

Fluid intelligence represents the capacity for flexible problem solving and rapid behavioral adaptation. Rewards drive flexible behavioral adaptation, in part via a teaching signal expressed as reward prediction errors in the ventral striatum, which has been associated with phasic dopamine release in animal studies. We examined a sample of 28 healthy male adults using multimodal imaging and biological parametric mapping with 1) functional magnetic resonance imaging during a reversal learning task and 2) in a subsample of 17 subjects also with positron emission tomography using 6-[18F]fluoro-L-DOPA to assess dopamine synthesis capacity. Fluid intelligence was measured using a battery of nine standard neuropsychological tests. Ventral striatal BOLD correlates of reward prediction errors were positively correlated with fluid intelligence and, in the right ventral striatum, also inversely correlated with dopamine synthesis capacity (FDOPA Kinapp). When exploring aspects of fluid intelligence, we observed that prediction error signaling correlates with complex attention and reasoning. These findings indicate that individual differences in the capacity for flexible problem solving may be driven by ventral striatal activation during reward-related learning, which in turn proved to be inversely associated with ventral striatal dopamine synthesis capacity.