ABSTRACT
@#【Objective】To assess the value of 18F-FDG PET/CT for imaging liver fibrosis.【Methods】12 male SD rats （170±10 g）were divided into model group（TAA group）and control group. In the model group，200 mg/kg thioacetamide dissolved in sterile saline was administered to rats by means of intraperitoneal injection twice a week for a total of 6 weeks. In the control group，rats were treated with the same volume of saline. At week 6 after injection，18F- FDG PET/CT imaging was performed on two groups and measurement of the liver 18F-FDG uptake in two groups was taken. After PET/ CT scans， all rats were sacrificed to observe anatomical morphological changes. Liver tissues were harvested for hematoxylin and eosin （H&E） staining，Masson staining and measurement of hydroxyproline levels. 【Results】 Liver anatomical morphology of the TAA-induced rats was roughness with brunt margins and coarse surfaces ，while control rats showed sharp margins and smooth surfaces. HE staining showed visible histological changes that hepatocyte and liver sinus area surrounded by plentiful recruited hepatocyte neutrophils in the model group. Masson staining showed that obvious proliferation of fibroblasts and deposition of collagen in liver tissues in the model group. Model group showed higher hydroxyproline content than that in the control group（P<0.001）. The results of 18F- FDG imaging indicated that apparent liver radioactivity concentration in the model group. 18F-FDG uptake value of liver tissues in the model group was higher than that in the control group（P<0.001）.【Conclusion】18F- FDG PET/CT imaging could be used for diagnosis of liver fibrosis noninvasively.
ABSTRACT
The PET tracer 5-([11C]methyloxy)-L-tryptophan (5-(11)CMTP) was prepared by nucleophilic fluorination and alkylation reaction via a two-step procedure in order to develop specific tumor probe. The biodistribution and microPET imaging of 5-(11)CMTP were executed. The results unveiled that the overall radiochemical yield with no decay correction was (14.6 ±7.2) %, the radiochemical purity was more than 95% and high uptake and long retention time of 5-(11)CMTP in liver, kidney and blood were observed but low uptake in brain and muscle were found, furthermore, high uptake of 5-(11)CMTP in tumor tissue was observed. It seems that 5-(11)CMTP will be a potential amino acid tracer for tumors imaging with PET.
Subject(s)
Animals , Amino Acids , Neoplasms , Diagnostic Imaging , Positron-Emission Tomography , Radioactive Tracers , Tissue Distribution , TryptophanABSTRACT
<p><b>AIM</b>To develop S-(2-18F-fluoroethyl)-L-methionine (18FEMET) as an amino acid positron emission tomography (PET) tracer for tumors, and to evaluate the value of 18FEMET in the differentiation of experimental tumor and experimental inflammation.</p><p><b>METHODS</b>18FEMET was prepared by nucleophilic fluorination reaction via a two-step procedure. Biodistribution of 18FEMET in normal mice, carcinoma-bearing mice and inflammatory mice, and 18FEMET PET imaging for carcinoma-bearing mice and inflammatory mice were performed compared with 2-[18F] fluoro-2-deoxy-D-glucose (FDG) and O-(2-[18F] fluoroethyl)-L-tyrosine (FET).</p><p><b>RESULTS</b>The overall radiochemical yield with no decay correction was 15%-25%, the whole synthesis time was about 70 min by manual operation, and the radiochemical purity was above 95%. High uptake and long retention of 18FEMET in pancreas, kidney, colon, liver and heart were observed. But low uptakes in brain and blood were found. Furthermore, high uptake of 18FEMET, FDG and FET in tumor, high uptake of FDG in inflammatory tissue, and almost no uptake of 18FEMET and FET in inflammatory tissue were also observed.</p><p><b>CONCLUSION</b>18FEMET is easy to prepare and can be used to differentiate between tumor and inflammatory tissue. It seems to be a potential amino acid tracer for tumors with PET imaging.</p>