Sang-Moo Lim

Assessment of Cerebral Glucose Metabolism in Cat Deafness Model: Strategies for Improving the Voxel-Based Statistical Analysis for Animal PET Studies

PurposeThe aim of this study was to establish the procedures for 3D voxel-based statistical analysis of 2-deoxy-2-[18F]fluro-d-glucose-positron emission tomography (FDG-PET) images of a cat’s brain obtained using a small animal-dedicated PET system and to assess the utility of this approach in investigating the cerebral glucose metabolism in an animal model of cortical deafness.ProceduresThis study compared several different strategies for the spatial processing of PET data acquired twice from eight cats before and after inducing deafness in terms of the comparability of the statistical analysis results to the established pattern of the cerebral glucose metabolic changes in the deaf animals.ResultsThe accuracy of the spatial preprocessing procedures and the statistical significance of the comparison were improved by removing the background activities outside the brain regions. The use of the spatial normalization parameters obtained from the mean image of the realigned data set for individual data also helped improve the statistical significance of the paired t testing. It was also found that an adjustment of the registration options was also important for increasing the precision of the realignment.ConclusionsA method for voxel-based analysis of the PET data of a cat’s brain was optimized. The results demonstrated the high localization accuracy and specificity of this method, which is expected to be useful for examining the brain PET data of medium-sized animals such as cats.

Experimental condition and registration method for the tumor detection of lung metastasis small animal PET and CT whole body images

Small animal PET scanning with 18F-FDG is increasingly used in murine tumor model. Experimental condition of animal handling impacts on the biodistribution of 18F-FDG in mouse study. The aim of this study was to optimize experimental conditions of animal handling and registration method for imaging lung metastasis tumor by using 18F-FDG small animal PET and CT. The experimental conditions for 18F-FDG biodistribution and animal PET imaging were 20 plusmn 2 h fasting and warming kept at 30degC. Biodistribution, standard uptake value (SUV) image and glucose SUV (SUVG) of 18F-FDG were evaluated and blood glucose level was also measured. Female C57BL/6 mice were injected intravenously with 2 times 105 of B16-F10 melanoma cells which developed metastasis tumors in lung. In lung metastasis tumor model, 18F-FDG images was obtained in optimized anesthesia condition and registered with anatomical clinical CT image. The small animal PET and CT images were registered using the hardware fiducial markers and small animal contour point in both data sets to perform a point- based rigid registration. Isoflurane 0.5 condition was chosen for lung metastasis tumor imaging. Lung metastasis tumor was clearly visualized by 18F-FDG PET image with Iso 0.5 anesthesia. Tumor imaging in lung region with 18F-FDG small animal PET should be considered feeding, temperature, and especially choice and level of anesthetic for minimizing background radioactivity. Fused imaging with small animal PET and CT image could be useful for the detection of metastatic tumor. This method improves the quantitative accuracy and interpretation of the tracer.