Ventriculoperitoneal shunt catheter and cerebral spinal fluid infection initially detected by FDG PET/CT scan.

Whole body F-18 fluorodeoxygluocose (FDG) position emission tomography (PET) computed tomography (CT) in a 75-year-old woman with right lung cancer revealed linear increased FDG activity at the distal end of the ventriculoperitoneal (VP) shunt catheter in the pelvis and in the scalp reservoir. Culture of the later removed VP-shunt catheter demonstrated Gram-positive Staphylococcus. No increased FDG activity was identified in the cerebrospinal fluid (CSF) in the ventricles, probably due to interference from nearby cerebral cortex uptake. However, the sagittal images demonstrated mild intermittent linear FDG uptake in the spinal canal. The vertebral marrow FDG uptake obscured the mild CSF activity in spinal canal on the coronal or transaxial images. Sagittal projection images of the spinal canal are critical for PET/CT evaluation of suspected CSF infection. Key Words: fluorodeoxyglucose, position emission tomography, cerebrospinal fluid, ventriculoperitoneal shunt, infection