Diagnostic accuracy of 18F-FDG-PET in abdominal sepsis in rats

Abstract Purpose The objective of this study was to investigate the accuracy of 18F-FDG-PET in the diagnosis of multibacterial abdominal sepsis by cecum ligation and puncture (CLP) in rats. Methods Adult Wistar rats ( Rattus norvegicus ), weighing 227±35g, were allocated into a sepsis group by CLP (n=10) and sham group (n=10). 18F-FDG-PET using microPET was performed on all rats after 24 hours. Results All animals survived for postoperative 24h. The abdomen/liver ratio of the standardized uptake value (SUV) percentage was significantly higher in the sepsis group than in the sham (p=0.004). The ROC curve showed an accuracy of 18F-FDG-PET to detect abdominal sepsis of 88.9% (p=0.001), sensitivity of 90% and specificity of 88.9%. When a cut-off point of 79% of the ratio between the SUV on the abdominal region and liver was established, the sensitivity was 90%, specificity of 88.9%; positive and negative predictive values of 90.0% and 88.9%, respectively. Conclusions The diagnostic accuracy of 18F-FDG-PET in rats with abdominal sepsis was significantly high. It was also demonstrated the predictive ability of the abdomen/liver SUV ratio to diagnose abdominal sepsis. These findings may have implications for the clinical setting, locating septic foci with PETscan.

Anatomo-radiological correlation using 18-FDG-PET in abdominal sepsis model in rats. A preliminary study

Abstract Purpose: To examine a correlation of micro-PET images with photographic images of the digestive organs in abdominal sepsis model. Methods: Male Wistar rats weighing 265±18g were used. Abdominal sepsis was induced by ligature and cecal puncture. Micro-PET Images from abdominal cavity septic foci were obtained using 18-Fluoro-deoxyglucose, looking for a correlation with photographic images of abdominal cavity organs. Pearson's correlation test was used. Results: The mean standard uptake values (SUV) and lesion areas were 2.58±0.63SUVbwg/ml and 546.87±300.95mm2, respectively. There was a strong positive correlation between the two variables (r=0.863, p=0.137), which resulted in a coefficient of determination r2?0.75, meaning that 75% of SUV variation is explained by the lesion areas of digestive organs. Conclusion: Micro-PET allows high throughput assessment of lesion count and volume in pre-clinical rat model of CPL abdominal sepsis.

Ventral abdominal wall defect correction in rats with contaminated meshes

ABSTRACT PURPOSE: To investigate whether there is a difference between Marlex(r) and Dynamesh PP-light Marlex(r) meshes, in the abdominal wall defect correction, on rats in contaminated surgical site. METHODS: Twenty-eight Wistar rats were divided into two groups of 14, and four subgroups of seven animals. All subgroups underwent similar surgical procedure. One group received the mesh Marlex(r) and the other Dynamesh PP-light(r) for correction of the defect. Before implanting, the meshes went through a contamination process, on which was used standard solution containing 10 UFC of Escherichia coli. Fragments of the animal's abdominal wall received macroscopic, microscopic and microbiological analysis. RESULTS: There was no statistical significance in the analysis of macroscopic variables. Accentuated inflammatory process was shown in all subgroups. The foreign body type reaction was mild in all subgroups, except Dynamesh(r)-14, which was moderate with no statistical significance. The microbiological analysis of the meshes was also similar between the subgroups. CONCLUSION: There was no difference between the meshes of Marlex(r) and Dynamesh PP-light(r) in the ventral abdominal wall defect correction on rats in contaminated surgical site.