Abstract
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Objectives Purpose of the work was to compare three methods to calculate SBR ratio to assess which of them allow the best correlation between SBR values calculated from data acquired by two different SPECT systems. The methods compared were: the 3-D BasalGangliaMatchingTools (BGMT) the semi-automated QuantiSpect (QS) and a method based on manually drawn regions of interest (MR) .
Methods After injection FPCIT 10 patients were scanned consecutively by Prism3000 with LEUHRFAN collimators and by IRIX with LEHRPAR. SBR for each patient was assessed with all three methods. For all methods the relationship of the SBRs given by both SPECT systems to each other was investigated by linear regression analyses to calculate the regression coefficient (RC) as an index of correlation. Data processing was performed twice for four patients with all 3 methods to evaluate intra-operator variability of SBR expressed as Coefficient of Variance (CVSBR).
Results The RC values were 0.95 (p<0.0001) for BGMT 0.93 (p<0.0001) for QS and 0.92 (p<0.0001) for MR.The mean value of CVSBR were 3.8±2 for BGMT 5.7±3 for MR and 10.2±7 for QS.
Conclusions For all the methods we found a good correlation between both SPECT systems for evaluation of FPCIT SPECT studies which seems to enable a direct comparison, by a linear transformation, of striatal uptake ratio results acquired through these two gamma-cameras. Best correlation with lowest variability was achieved by using the BasalGanglia-Matching Tools quantification method.
- © 2009 by Society of Nuclear Medicine