QUANTITATIVE COMPARISON OF 3-DIMENSIONAL AND 2-DIMENSIONAL PET WITH HUMAN BRAIN STUDIES

The aim of this study was to test the quantitation accuracy of three-d imensional PET in brain scanning. Methods: Three-dimensional data from 11 human subjects were tested using C-11-dihydrotetrabenazine, C-11-S chering 23390 and F-18-FDG as tracers. Two-dimensional scans were perf ormed on the same subjects and the distribution volume, distribution v olume ratio and local metabolic rate of glucose (LMRGlu) values obtain ed from these were used as reference. Three-dimensional data were proc essed as follows: iterative convolution subtraction scatter correction , detector normalization including radial and axial geometric factors, attenuation correction extracted from a two-dimensional transmission scan, Kinahan-Rogers reconstruction and region-of-interest-based sensi tivity calibration. Results: No major systematic differences between t he two methods were found. The agreement between the two-dimensional a nd three-dimensional data was within 5%. Although statistical analysis generally did not show this difference to be significant, reliability analysis indicated that comparing two-dimensional and three-dimension al data might introduce some inaccuracies. Conclusion: Three-dimension al PET yields quantitatively valid results for brain scanning.