title: Pyogenic abscess from Providencia stuartii mimicking necrotic tumour at perfusion-weighted imaging.
abstract: The purpose of this case report is to increase the knowledge about magnetic resonance spectrum of pyogenic abscesses of the brain. A 74-year-old woman presented with a left frontal lobe cystic mass, developed in the site of post-traumatic contusions after surgical evacuation of a subdural hematoma. MR imaging showed an ipsilateral mass lesion with a thin, regular rim of T1 high-intensity signal, T2 low-intensity signal, and gadolinium-enhancement. Diffusion-weighted imaging with measure of apparent diffusion coefficient value showed inhomogenous diffusion restriction in the lesion core. Perfusion-weighted imaging (PWI) demonstrated high relative cerebral blood volume (rCBV) in both the lesion wall and perilesional area, with a maximal rCBV ratio (rCBV of the lesion/rCBV of the normal contralateral white matter) of 5.65 and 0.58, respectively. As a result, surgery and pathology showed a pyogenic abscess. Cultures grew were Providencia stuartii species. In conclusion, a pyogenic brain abscess from P. stuartii may show high rCBV at PWI, thus mimicking a necrotic tumour.
authors.affiliation: Unit of Neuroradiology, Department of Neurosciences, Azienda Ospedaliera di Rilievo Nazionale Gaetano Rummo, Via dell'Angelo, 1-82100 Benevento, Italy. cfmuccio@yahoo.it
authors.forename: Carmine Franco
authors.initials: CF
authors.lastname: Muccio
authors.forename: Sara
authors.initials: S
authors.lastname: Leonini
authors.forename: Gennaro
authors.initials: G
authors.lastname: Esposito
authors.forename: Alfonso
authors.initials: A
authors.lastname: Cerase
mesh_terms: D000368:Aged; D001922:Brain Abscess / Q000175:diagnosis* / Q000473:pathology; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D004756:Enterobacteriaceae Infections / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D009336:Necrosis; D011532:Providencia / Q000302:isolation & purification*