Bejoy Thomas MBBS, MD, Presenter: Nothing to Disclose

Atul Mishra MD, Abstract Co-Author: Nothing to Disclose

Girish Menon, Abstract Co-Author: Nothing to Disclose

V.V. Radhakrishnan, Abstract Co-Author: Nothing to Disclose

Tirur Raman Kapilamoorthy, Abstract Co-Author: Nothing to Disclose

Vestibular schwannomas (VS) may  sometimes be difficult to be differentiated from cerebellopontine angle (CPA) meningiomas. Demonstration of foci of blooming on Susceptibility Weighted Imaging (SWI) has the potential to differentiate VS from CPA meningiomas.

In this retrospective study of 59 consecutive patients of CPA tumors (schwannomas and meningiomas), SWI was analysed for presence of multiple tiny foci of blooming. In five cases of schwannomas, where both 2D gradient echo (GRE) and SWI sequences were available, the conspicuity, size and number of blooming foci were also compared. Histopathological diagnosis after surgery was compared in all the cases. 

There were 49 patients in the VS group and 10 in the meningioma group. SWI showed presence of foci of blooming (due to microhemorrhages) in all the cases of CPA Schwannomas. In the Meningioma group, 9 cases showed no blooming within the lesion; 1 case showed blooming which was confirmed due to calcification. For the detection of foci of blooming (microhemorrhages) and predicting histopathologic diagnosis of schwannoma pre-operatively, SWI showed a sensitivity of 100%, specificity of 90 %, positive predictive value of 98%, and negative predictive value of 90%. The Fisher exact test showed a statistically significant difference in the differentiation of VS from meningioma on the basis of detection of of blooming (P < 0.0001). Moreover, the conspicuity, size and number of foci of blooming was higher compared to T2*-weighted GRE in the five cases where both the sequences were available for comparison. 

All the patients with VS in our study demonstrate foci of blooming on SWI. This finding may be useful to differentiate VS from CPA meningiomas. 

SWI gives insight into the histopathological feature of  microbleeds within Scwannomas in differentiating it from Meningiomas preoperatively

Thomas, B, Mishra, A, Menon, G, Radhakrishnan, V, Kapilamoorthy, T, Susceptibility Weighted Imaging in Differentiation of Cerebro-Pontine Angle Schwannomas and Meningiomas.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12022759.html