Infection imaging using whole-body FDG-PET

Abstract

The purpose of this study was to evaluate fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) for the detection of soft tissue and bone infections. Forty-five PET examinations in 39 patients (26 male, 13 female, age range 27-86 years) with suspected infectious foci were examined with whole- or partial-body PET scans using FDG. Twenty-seven scans were done in patients with soft tissue and 18 in patients with bone infections. Corrected and uncorrected transaxial PET images were acquired. Seven hundred and twelve body regions in these 45 PET scans were evaluated. Pathological findings were graded using a confidence scale from A to E (A, definitive infection; E, no infection). Disease status was defined in all patients by culture, biopsy or surgery and clinical follow-up. In 45 PET scans there were 40 true-positive, four false-positive and one false-negative findings. Twelve foci suspected to be infectious in nature on the basis of other imaging examinations were identified as negative by PET, thus representing true-negative findings. Sensitivities for the patients with soft tissue (STI) and bone infections (BI) and for the pooled data were 96%, 100% and 98%, respectively. As the calculation of specificity is not straightforward, it was calculated on a per lesion as well as on a per body region basis to permit estimation of an upper and a lower limit. On a per lesion basis, specificities were 70% (STI), 83% (BI) and 75% for the pooled data and on a per body region basis (dividing the body into 22 regions) they were 99% (STI), 99% (BI) and 99% for the pooled data. One false-negative result was found in a patient with cholangitis. It is concluded that PET appears to be a highly sensitive method to detect infectious foci. Specificity is more difficult to estimate, but is probably in the range from 70% to above 90%.

Bilateral Tubo-Ovarian Abscess Mimics Ovarian Cancer on MRI and 18F-FDG PET/CT

“…Rectal involvement was present in our case, which contributed to the suspicion of malignancy. 18 F-FDG PET/CT has been used in the evaluation of a large variety of infectious processes, including abscesses [5]. On PET/CT, abscesses often exhibit a hypometabolic center surrounded by an intensely FDG-avid rim [24,25], although they can also exhibit solid uniformly intense FDG uptake throughout, as in our case [26].…”

“…Atypical or equivocal cases often require further imaging with computed tomography (CT) or magnetic resonance imaging (MRI); however, CT and MRI findings can also be non-specific and TOA has been mistaken for ovarian tumors on CT as well as MRI [4]. 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT has been successfully used to image a wide variety of infectious processes, including abscesses [5]; however, the PET/CT literature on TOA is very limited. It is important for PET/CT readers to be aware of this benign differential diagnosis of bilateral FDG-avid adnexal masses, even in the context of CT or MRI findings suspicious for malignancy, as this may impact clinical management with consideration to important patient-related issues, such as maintaining fertility in premenopausal women.…”

18F‐fluorodeoxyglucose positron emission tomography in the diagnosis and followup of idiopathic retroperitoneal fibrosis

“…However, lymphocytes, macrophages, neutrophils, and fibroblasts also avidly take up 18 F-FDG, particularly under activation conditions (8). Thus, primary inflammatory diseases (such as sarcoidosis) as well as infectious diseases (such as tuberculosis or aspergillosis) can be imaged by means of 18 F-FDG-PET (9).…”

Increased striatal serotonin synthesis following cortical resection in children with intractable epilepsy

“…These studies revealed decreased glucose metabolism in the ipsilateral caudate 3-7 months posthemispherectomy, with recovery nearing pre-surgical levels in scans acquired 12-30 months posthemispherectomy and support a role for the caudate nucleus in compensatory changes following hemispherectomy (Chugani and Jacobs, 1994). There is a great deal of evidence that inflammatory processes can lead to increased FDG-PET uptake in animal studies (Ishimori et al, 2002) and in human disease (Bakheet and Powe, 1998;Brudin et al, 1994;Guhlmann et al, 1998;Stumpe et al, 2000). If striatal inflammation were responsible for increased AMT uptake in the current study, then we would expect a similar temporo-spatial pattern of FDG and AMT uptake in the ipsilateral striatum.…”