Usefulness of Fluorine-18 Positron Emission Tomography/Computed Tomography for Identification of Cardiovascular Implantable Electronic Device Infections

OBJECTIVES: This study evaluated the usefulness of fluorodesoxyglucose marked by fluorine-18 ((18)F-FDG) positron emission tomography (PET) and computed tomography (CT) in patients with suspected cardiovascular implantable electronic device (CIED) infection. CIED infection is sometimes challenging to diagnose. Because extraction is associated with significant morbidity/mortality, new imaging modalities to confirm the infection and its dissemination would be of clinical value.

METHODS: Three groups were compared. In Group A, 42 patients with suspected CIED infection underwent (18)F-FDG PET/CT. Positive PET/CTwas defined as abnormal uptake along cardiac devices. Group B included 12 patients without infection who underwent PET/CT 4 to 8 weeks post-implant. Group C included 12 patients implanted for >6 months without infection who underwent PET/CT for another indication. Semi-quantitative ratio (SQR) was obtained from the ratio between maximal uptake and lung parenchyma uptake.

RESULTS: In Group A, 32 of 42 patients with suspected CIED infection had positive PET/CT. Twenty-four patients with positive PET/CT underwent extraction with excellent correlation. In 7 patients with positive PET/CT, 6 were treated as superficial infection with clinical resolution. One patient with positive PET/CT but negative leukocyte scan was considered false positive due to Dacron pouch. Ten patients with negative-PET/CT were treated with antibiotics and none has relapsed at 12.9 ± 1.9 months. In Group B, patients had mild uptake seen at the level of the connector. There was no abnormal uptake in Group C patients. Median SQR was significantly higher in Group A (A = 2.02 vs. B = 1.08 vs. C = 0.57; p < 0.001).

CONCLUSIONS: PET/CT is useful in differentiating between CIED infection and recent post-implant changes. It may guide appropriate therapy. 

PMID: 22538331

Posted in Computed Tomography, Nuclear Imaging and tagged , , , , .

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