Magnetic resonance imaging features of pathologically proven cerebral sparganosis

Abstract

Objective The purpose of this study was to identify characteristic magnetic resonance imaging (MRI) features of cerebral sparganosis, a rare parasitic disease caused by the plerocercoid larva of Spirometra mansoni. Methods This retrospective study reviewed medical records, computed tomography (CT) and MRI scans and pathological specimens from patients with pathologically proven cerebral sparganosis. The location, signal intensity and contrast enhancement characteristics of the lesions were assessed. Results Records of 12 patients (seven male and five female; age range 8–35 years) were reviewed. A total of 13 lesions were identified: of the 10 patients with supratentorial lesions, nine had a single lesion and one had bilateral hemispheric lesions. Two patients had a single lesion in the ependyma of the 4th ventricle. All lesions were iso-hypointense on T1-weighted images, slightly hypointense on T2-weighted images and surrounded by extensive oedema. Ten of the 13 lesions demonstrated a ‘string-knots sign’, characterized by a tangled string in a knot-like shape on contrast-enhanced MRI. Conclusion A string-knots sign enhancement pattern in cortical–subcortical regions should suggest the diagnosis of cerebral sparganosis.