The aim of this report was to assess the changes in the 18F-fluorodeoxyglucose (18F-FDG) uptake of brown fats on integrated positron emission tomography/computed tomography (PET/CT) imaging. The patient presented with an enlargement of the neck lymph nodes, and was suspicious for tuberculous lymphadenitis. A whole body PET/CT imaging was performed, followed by a delayed imaging of the neck and thoracic regions. A visually increased 18F-FDG uptake was taken as a positive finding. A semi-quantitative evaluation was performed using a maximum standardised uptake value (SUVmax), with a cut-off value above 2.5. There were a number of 18F-FDG avid activity areas seen at the supraclavicular, mediastinal, paravertebral and perirenal regions. These are in keeping with the physiological 18F-FDG uptake in brown fat. The differences in SUVmax between the two images ranged from -20 percent to +20 percent. Based on our observations, dual time point imaging may not be a reliable method for assessing the 18F-FDG uptake of brown fat.
Adipose Tissue, Brown ; diagnostic imaging ; metabolism ; Adult ; Female ; Fluorodeoxyglucose F18 ; Humans ; Positron-Emission Tomography ; methods ; Tuberculosis, Lymph Node ; diagnostic imaging

Aims: To develop a real-time polymerase chain reaction system Vi-qPCR in the detection of Salmonella enterica serovar Typhi (S. Typhi), targeting the vexC gene encoding for Vi antigen (capsular polysaccharide antigen) and to evaluate its sensitivity and specificity performance using pure cultures of S. Typhi and other enteric pathogens. Methodology and results: Microbiological, biochemical and serotyping tests were conducted to determine the phenotypic characteristics of S. Typhi and other enteric pathogens in our collection. Primers were designed using Primer3 software and their in-silico specificity were analysed using Basic Local Alignment System Tool (BLAST). Optimisation of PCR annealing temperature was done prior to assessment of sensitivity and specificity performance against artificial serially diluted seeded stools. The primers were found to be 100% specific in the detection of S. Typhi towards 32 tested clinical strains. Verification of gene amplification by comparing the nucleotide sequences against reference genes in the GenBank database revealed high specificity to S. Typhi. Statistical analysis indicates that this method results in 100% sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Moreover, Vi-qPCR allows the detection of S. Typhi as low as 131.4 CFU/g of stool sample. Conclusion, significance and impact of study A rapid and sensitive method for detection of Salmonella enterica serovar Typhi (S. Typhi) is desired as a diagnostic tool to improve typhoid management. The Vi-qPCR represent a promising non-invasive diagnostic tool for medical microbiology laboratories as a method for the detection of S. Typhi in both pure culture and stool specimens especially in chronic asymptomatic carriers where shedding of S. Typhi is intermittent and sometimes occurs in low level.