An enlarged left adrenal gland is an indirect sign of infection on F-18-FDG PET/CT

{Objectives To determine whether hypermetabolisms of the spleen and bone marrow and an enlarged adrenal gland are significant indirect signs of infection on fluorine-18-fluorodeoxyglucose (F-18-FDG) PET/CT performed in patients with known or suspected infectious disease. Patients and methods Potential indirect signs of infection were as follows: (i) investigated in a retrospectively selected group of patients referred to F-18-FDG PET/CT for a known or suspected infectious disease and among whom the presence or absence of infectious foci was ascertained in 43 and 12 cases, respectively, and (ii) further validated in groups prospectively constituted of 12 patients with severe sepsis and of 39 control patients with no sign of any infectious disease. Standardised uptake values were determined on left adrenal gland, spleen and bone marrow, whereas the size of left adrenal gland was assessed by its maximal surface on unenhanced axial computed tomography (CT) slices. Results Only the maximal surface of the left adrenal gland was a predictor in the initial study group (infection: 2.72 +/- 0.99 cm(2) vs. no infection: 1.85 +/- 0.76 cm(2)