Dual-time point positron emission tomography findings of benign mediastinal lymph nodes in a tuberculosis-endemic region.
OBJECTIVE
We performed dual-time-point positron emission tomography imaging (DTPI) in patients without evidence of mediastinal lymph node metastasis to investigate the characteristics of fluorodeoxyglucose (FDG) uptake in benign mediastinal lymph nodes.


METHODS
A total of 118 mediastinal lesions in 24 patients were included in the study. The size, attenuation, maximum standardized uptake value (SUV), and retention indices (RI) were recorded on early and delayed positron emission tomography images for lymph node characterization.


RESULTS
The mean SUVs on the early and delayed scans of 118 lymph nodes were 3.3 ± 1.2 and 4.2 ± 1.7, respectively. The mean RI was 26.4% ± 24.5%. Higher FDG uptake was observed in patients with calcified nodules and bilateral FDG uptake and in lymph nodes with calcification or a short-axis diameter >10 mm.


CONCLUSIONS
In a tuberculosis-endemic area, increments of SUV or RI were frequently observed in benign mediastinal lymph nodes. Therefore, these values, based on mediastinal FDG uptake, might not be accurate indicators of malignant disease.
Department of Nuclear Medicine and Institute of Wonkwang Medical Science, Wonkwang University School of Medicine, 344-2 Shinyong-Dong, Iksan, Jeollabuk-do 570-711, Republic of Korea.
Dae-Weung
DW
Kim
Chang Guhn
CG
Kim
D000368:Aged; D003937:Diagnosis, Differential; D019353:Endemic Diseases; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis; D008297:Male; D008479:Mediastinal Neoplasms / Q000150:complications / Q000000981:diagnostic imaging*; D008482:Mediastinum / Q000000981:diagnostic imaging*; D015588:Observer Variation; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D014376:Tuberculosis / Q000150:complications*
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18