Objective Striatal Analysis (OSA)
In order to apply OSA, a patient is referred for a scan to a nuclear medicine imaging center. The patient is injected with a unit to dose of DaTSCAN, and is placed under the SPECT camera 4 hours after injection. The camera acquires tomographic images of the patient's brain over the next 30 minutes. The radiotracer image highlights areas of the brain demonstrating the distribution of dopamine receptor sites and OSA is used to analyze this distribution. OSA is fully automated (all processing is accomplished without any manual intervention) and is completed within 2 minutes, 90% of which time is needed for 3-dimensional registration to align the patient’s brain to a standard geometric orientation. Parameters (2*iwid+1 and ra) for the OSA program are selected to optimally target the areas of the caudate and putamen (seen as small white circular regions).
The 1388 dopamine receptor scans shown here were both analyzed using the OSA automated algorithm and by conventional manually placed ROIs on the stratum. In both cases the Striatal Binding Ratios (referred to as V3") were calculated and compared in this scatter graph. We note that with a slope of 1.05 and y-intercept of -0.1, the correlation between these scans (R2=0.934) is excellent. This comparison shows the ability of automated, non-interactive computer algorithms to deliver quantitative diagnostic values equivalent to those obtained by manual methods.