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 (18F-FDG) PET/CT performed in patients with known or suspected infectious disease.
Potential indirect signs of infection were as follows: (i) investigated in a retrospectively selected group of patients referred to 18F-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.
Only the maximal surface of the left adrenal gland was a predictor in the initial study group (infection: 2.72±0.99 cm2 vs. no infection: 1.85±0.76 cm2, P=0.004) and further validation groups (sepsis: 2.79±0.83 cm2 vs. controls: 1.91±0.67 cm2, P=0.001). Patients with a greater than 1.8 cm2 maximal surface had more than two-fold higher infection rate than the other patients in the initial study group [88 (36/41) vs. 36% (4/11), P=0.001], even when only considering the subgroup with no evident infectious focus on 18F-FDG PET/CT [76 (16/21) vs. 30% (3/10), P=0.02].
An enlarged left adrenal gland is a significant sign of infection on 18F-FDG PET/CT, even in the absence of any evident infectious focus on 18F-FDG PET/CT images.
aDepartment of Nuclear Medicine, Centre Georges François Leclerc, Dijon
bDepartment of Infectious and Tropical Diseases
cNuclear Medicine and Nancyclotep Experimental Platform
dDepartment of Cardiology
eMedical Intensive Care Unit, CHRU-Nancy
fINSERM, UMR-1116, University of Lorraine, Nancy, France
Correspondence to Clément Drouet, MD, Department of Nuclear Medicine, Centre Georges François Leclerc, 1 rue du Professeur Marion, 21000 Dijon, France Tel: +33 380 737 522; fax: +33 380 737 732; e-mail: email@example.com
Received November 6, 2018
Received in revised form February 27, 2019
Accepted March 3, 2019