Diagnostic Accuracy of Visual Assessment of an Initial DaT-Scan in Comparison to a Fully Automatic Semiquantitative Method

626 Objectives: Visual interpretation of DaT-SPECT is often straightforward, in particular with obvious presynaptic dopamine transporter deficits. However, challenging borderline cases might inherit the risk of erroneously ruling out parkinson’s disease and (semi)automatic methods using template regions of interest (ROIs) should improve the reader’s confidence. We aimed to elucidate the diagnostic accuracy of visual assessment of an initial DaT-SPECT by both an experienced and unexperienced reader with comparison to results using a fully automatic semiquantitative method. Material and Methods: In a mono-centric setting, 382 patients with clinically uncertain parkinsonian syndrome (168 females, median age, 66y) were included. For assisting in diagnosis, an initial DaT-SPECT was performed by IV administration of 3-5 mCi 123I-Ioflupane. One experienced nuclear medicine physician (>10 years of experience, >1,000 DaT-SPECTs) and one unexperienced resident (