Diagnostic utility of (18)F-FDG PET/CT in inflammation of unknown origin
Hans Balink1, Roel J Bennink, Nic J G M Veeger
1From the *Department of Nuclear Medicine, Medical Center Leeuwarden, Leeuwarden; †Department of Nuclear Medicine, Academic Medical Center, University of Amsterdam, Amsterdam; and ‡Department of Epidemiology, University Medical Center Groningen, Groningen, the Netherlands.
Objectives:
The goal of this multicenter retrospective study was to evaluate the contribution of F-FDG PET/CT in the diagnosis of patients with inflammation of unknown origin (IUO). In addition, C-reactive protein (CRP) level and erythrocyte sedimentation rate were assessed as possible predictors for the outcome of F-FDG PET/CT.
Methods:
Inflammation of unknown origin was defined as prolonged and perplexing inflammation, with repeated CRP levels more than 20 mg/L or erythrocyte sedimentation rate more than 20 mm/h, body temperature of less than 38.3°C, and without a diagnosis after a variety of conventional diagnostic procedures.A total of 140 patients with IUO (67 men, 73 women; mean age, 64.2 years; age range, 18-87 years) underwent F-FDG PET/CT. F-FDG PET/CT was considered helpful when the imaging findings led to a diagnosis, either confirmed by histopathology, microbiological assays, clinical and imaging follow-up, or response to treatment.
Results:
In 104 patients (73%), a final diagnosis could be established as follows: infection in 35 patients, malignancy in 18 patients, noninfectious inflammatory disease in 44 patients, and a variety of uncommon conditions in 7 patients. F-FDG PET/CT was true positive in 95 patients, true negative in 30 patients (ie, self-limiting conditions), false positive in 6 patients, and false negative in 9 patients (predominantly systemic diseases). In this population, the positive predictive value, negative predictive value, and diagnostic accuracy of F-FDG PET/CT were 94%, 77%, and 89%, respectively. In a multivariate analysis, CRP was the only independent predictor for the outcome of F-FDG PET/CT.
Conclusions:
F-FDG PET/CT correctly identified or excluded a causal explanation in approximately 90% of patients with IUO. However, a negative F-FDG PET/CT is indicative for a self-limiting condition only after systemic diseases are excluded by other diagnostic tests.
More Related Videos
10:04Analysis of 18FDG PET/CT Imaging as a Tool for Studying Mycobacterium tuberculosis Infection and Treatment in Non-human Primates
Published on: September 5, 2017
10:28Gene Regulation and Targeted Therapy in Gastric Cancer Peritoneal Metastasis: Radiological Findings from Dual Energy CT and PET/CT
Published on: January 22, 2018
Related Concept Videos
Positron Emission Tomography
One of the main requirements of a PET scan is a positron-emitting radioisotope, which is produced in a cyclotron and then attached to a substance used by the part of the body...
Imaging Studies II: Positron Emission Tomography and Scintigraphy
Fundamental Principles of PET
Radiological Investigation III: Pulmonary Angiogram and PET Scan
Pulmonary Angiogram
A Pulmonary Angiogram is an invasive procedure involving injecting a contrast medium through a catheter threaded into the pulmonary artery or the right side of the heart to visualize the pulmonary vasculature. Computed Tomography (CT) scans have mainly replaced this...
![Quantification of Atherosclerotic Plaque Activity and Vascular Inflammation using [18-F] Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography FDG-PET/CT](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F3777.jpg&w=3840&q=50)