Intratumoral microhemorrhage detection on susceptibility-weighted imaging can help in preoperative differentiation of cerebellopontine angle vestibular schwannomas from meningiomas: Correlation with pathology findings

Objectives: In this study, we aimed to evaluate whether intratumoral microhemorrhage detection on susceptibility-weighted imaging(SWI) could help in preoperative differentiation of cerebellopontine angle (CPA) vestibular schwannomas (VSs) from meningiomas.Patients and Methods: A total of 75 patients (32 males, 43 females; mean age: 45.5±16.7 years; range, 17 to 68 years) consistingof 61 VSs and 14 meningiomas located in the CPA cistern were retrospectively analyzed. All patients underwent contrast-enhancedmagnetic resonance imaging (MRI) using the SWI sequence. All images in our study were obtained with a 12-channel phased-arrayhead coil on a 1.5-Tesla clinical scanner. The presence of intratumoral microhemorrhages on SWI sequence was evaluated bydemonstrating blooming artifacts as punctate hypointense regions. Both magnitude and phase-contrast images were used to verifymicrohemorrhages. All patients in our patient cohort underwent surgery and resected tumor specimens were evaluated by pathology.Results: All VS cases in our cohort exhibited multiple hypointense small foci causing blooming artifact on magnitude and processedSWI images. In the meningioma population, typical MRI signal intensity characteristics, including an intense homogenous contrastenhancement, were observed. In all the meningioma cases, except for one, there was no blooming artifact due to intratumoralhemorrhage within the mass lesions on SWI images. In only one meningioma case, SWI revealed hypointense microhemorrhageswithin the mass lesion. Following surgical procedures and tumor resections, pathology specimens were evaluated and absence orpresence of intratumoral microhemorrhages were detected. These results were significantly correlated with the SWI findings. Weobtained 100% sensitivity, 92.8% specificity, and 98.6% accuracy in terms of differentiating VSs from meningiomas located in theCPA cistern by using the SWI sequence.Conclusion: Meningiomas and VSs are the two most common masses of the CPA cistern and, in some cases, it seems to be difficultto reach an accurate diagnosis with conventional MRI sequences. The SWI can be helpful to solve this problem by demonstratingwhether intratumoral microhemorrhages are present or not within mass lesions and, thus, can help to assume a probable accuratediagnosis prior to surgery.

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