Pyogenic brain abscess with atypical features resembling glioblastoma in advanced MRI imaging

Abstract

Differentiation between infectious and neoplastic brain processes is crucial for treatment planning. Advanced magnetic resonance imaging techniques, such as diffusion, perfusion, susceptibility weighted imaging, and magnetic resonance spectroscopy, enhance the imaging differences between these two pathologies. However, despite the utilization of these advanced techniques, the pathologic process may be confound by atypical findings. Here, we report a case of an autistic patient with multiple brain lesions with diffusion weighted imaging, susceptibility weighted imaging, and perfusion patterns resembling features of a multicentric glioblastoma, which were confirmed surgically, neuropathologically, and bacteriologically as brain abscesses. We discuss the differentiation of these different entities in the light of advanced magnetic resonance imaging techniques.

Keywords: Diffusion; Infectious; Neoplastic; Perfusion; Susceptibility.

Fig. 1

MRI with DWI (A), ADC (B), SWI (C), corrected rCBV (D), K2 (E) maps of dynamic susceptibility contrast-enhanced perfusion (DSC) obtained by OSVD deconvolution approach, and postcontrast T1 (F) showing atypical features of brain abscess (red arrows) with ring enhancement (F) and ring diffusion restriction with central increased diffusivity (A and B) as well as irregular hypointense circular ring in SWI (C). The rCBV is increased [yellow arrows in (D)] in the ventral part of the ring, and K2 is increased, extending to the neighboring edema [white arrow in (E)]. Notice the perifocal edema located cranially to another lesion in the right frontal lobe [green arrow in (B)] and a third smaller lesion with diffusion restriction in the right parietal lobe [orange arrow in (A)]. MRI, magnetic resonance imaging; DWI, diffusion weighted imaging; SWI, susceptibility weighted imaging; rCBV, relative cerebral blood volume; K2, leakage coefficient.

Fig. 2

Coronal postcontrast T1 showing incomplete enhanced rim medially and increased CSF signal in the left ventral horn (arrow) consistent with ventriculitis. CSF, cerebrospinal fluid.