Differentiation between supratentorial pilocytic astrocytoma and extraventricular ependymoma using multiparametric MRI

Abstract

Background The differentiation of supratentorial pilocytic astrocytomas (STPAs) and supratentorial extraventricular ependymomas (STEEs) is clinically pivotal because of distinct therapeutic management and prognosis, which is sometimes challenging to both neuroradiologists and pathologists. Purpose To explore and compare the conventional and advanced magnetic resonance imaging (MRI) features between STPA and STEE. Material and Methods A total of 23 patients with STPAs and 23 patients with STEEs were reviewed in this study. All patients performed conventional MRI, susceptibility-weighted imaging (SWI), and diffusion-weighted imaging (DWI), and 34 patients (17 with STPAs and 17 with STEEs) examined dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI) in addition. Clinical data, conventional MRI features, minimum relative apparent diffusion coefficient ratio (rADCmin), and maximum relative cerebral blood volume ratio (rCBVmax) were compared between the two groups and subgroups. The optimal cutoff values of rADCmin and rCBVmax with sensitivity and specificity were calculated. Results STPA manifested similar to STEE as a solid-cystic mass but more frequently presented with a marked enhancing deep nodule ( P = 0.02), no peritumoral edema ( P = 0.036), higher rADCmin value (2.0 ± 0.5 vs. 0.9 ± 0.2; P < 0.001), and lower rCBVmax value (2.1 ± 0.4 vs. 14.4 ± 5.5; P < 0.001). The cutoff value of >1.39 for rADCmin and ≤ 2.81 for rCBVmax produced a high sensitivity of 95.65% and 100.0%, respectively, and all produced a specificity of 100.0% in differentiating STPAs from STEEs. Conclusion Multiparametric MRI techniques including conventional MRI, DWI, and DSC-PWI contribute to the differential diagnosis of STPA and STEE.

Dynamic susceptibility contrast perfusion-weighted and diffusion-weighted magnetic resonance imaging findings in pilocytic astrocytoma and H3.3 and H3.1 variant diffuse midline glioma, H3K27-altered

“…DSC perfusion MRI (DSC-MRI) and diffusion-weighted imaging (DWI) play an important role in brain tumor typing and grading. With regard to PA, Zhou et al [9] (supratentorial PA vs. extraventricular ependymoma), Kurokawa et al [10] (infratentorial PA vs. medulloblastoma), and Ho et al [11] (PA vs. pilomyxoid astrocytoma) reported the effectiveness of a combined approach using DSC parameters and ADCs derived from DWI to differentiate between the tumors. However, limited reports exist regarding the diagnostic performance of these sequences, especially DSC-MRI, in differentiating DMG from other tumor types, including PA.…”