Cerebral Sparganosis: The Differential Features between Live and Degenerated Worms on CT and MR Images

Abstract

Purpose: The purpose of this study is to describe the characteristic features of cerebral sparganosis with live worm on CT and MRI as compared with the characteristic CT and MRI features of degenerated cerebral worms. Materials and Methods: Twelve patients with surgically-proven live worms (the live group) and 13 patients with degenerated worms (the degenerated group) were included in this study. We retrospectively reviewed the CT scans of all the patients and the MR images of 19 patients. Results: The live group showed highly attenuated lesion (50-70 HUs for the CT number) on precontrast CT with surrounding enhancement extending to the cortical surface, a mass effect and change of the location and shape of the enhancing lesion on the follow-up images, whereas the degenerated group showed punctate calcification (more than 130 HUs) with surrounding enhancement and cerebromalacia in 77% of the subjects (p<.01). The highly attenuated lesion had an amorphous nodular or nodulotubular shape, and these lesions were slightly hyperintense on the T1-weighted MR images and hypointense on the T2-weighted MR images. Conclusion:In patients with cerebral sparganosis, live worm infection is highly suggested if there is a focal amorphous hyperattenuated lesion on the precontrast CT with a surrounding mass effect, irregular nodulotubular enhancement extending to the pial surface and change of the enhancing lesion on the follow-up images.

Recurred Sparganosis 1 Year after Surgical Removal of a Sparganum in a Korean Woman

“…Furthermore, ELISA of the cerebrospinal fluid (CSF) is also suggested as an effective diagnostic tool for cerebral sparganosis [ 15 ]. Neuroradiologic imaging is very sensitive and also provides differential features between live and degenerating spargana [ 16 ]. However, neuroradiologic imaging alone is not sufficient for a definite identification of the lesion although it can confirm the presence of a lesion in a specific site.…”

Migration characteristics as a prognostic factor in cerebral sparganosis

“…"Bead-shaped" lesions and the "tunnel sign" are the most characteristic imaging manifestations of cerebral sparganosis (Abdel Razek et al, 2011), followed by nodular or solitary ring enhancement. Moreover, the "tunnel sign" and "migration sign" are considered to be characteristics of cerebral sparganosis with live worms (Lai P, 2010, Li et al, 2013, Liao et al, 2016, YICK, 2010. However, evidence of the correlation of migration modes and other characteristic imaging manifestations with live worm capture and remote prognosis is limited because of a lack of related studies and long-term follow-up.…”

Letter to the editor: Is there a clear role of imaging in the diagnosis of cerebral sparganosis at present?

“…However, there is still a lack of complete data on the diagnostic value of the test (sensitivity, specificity, accuracy and predictive value). Most of the quoted studies described the neuroimaging characteristics of cerebral sparganosis without comparison to other neurological conditions [3][4]. In addition, most reports still indicate the requirement for clinical data and immunological investigation.…”