RT Journal Article SR Electronic T1 Signal Extraction and Separation in In Vivo Animal PET Studies with Masked Volumewise Principal-Component Analysis JF Journal of Nuclear Medicine Technology JO J. Nucl. Med. Technol. FD Society of Nuclear Medicine SP 53 OP 60 DO 10.2967/jnmt.110.075085 VO 38 IS 2 A1 Engbrant, Fredrik A1 Monazzam, Azita A1 Svensson, Per-Edvin A1 Olsson, Johan A1 Bengtsson, Ewert A1 Razifar, Pasha YR 2010 UL http://tech.snmjournals.org/content/38/2/53.abstract AB The standardized uptake value is commonly used as a tool to supplement visual interpretation and to quantify the images acquired from static in vivo animal PET. The preferred approach for analyzing PET data is either to sum the images and calculate the standardized uptake value or to use kinetic modeling. The aim of this study was to investigate the performance of masked volumewise principal-component analysis (MVW-PCA) used in dynamic in vivo animal PET studies to extract and separate signals with different kinetic behaviors. Methods: PET data were acquired with a small-animal PET scanner and a fluorine tracer in a study of rats and mice. After acquisition, the data were reconstructed by use of 4 time protocols with different frame lengths. Data were analyzed by use of MVW-PCA with applied noise prenormalization and a new masking technique developed in this study. Results: The resulting principal-component images showed a clear separation of the activity in the spine into the first MVW-PCA component and the activity in the kidneys into the second MVW-PCA component. In addition, the different time protocols were shown to have little or no impact on the results obtained with MVW-PCA. Conclusion: MVW-PCA can efficiently separate different kinetic behaviors into different principal-component images. Moreover, MVW-PCA is a stable technique in the sense that the time protocol chosen has only a small impact on the resulting principal-component images.