European Journal of Radiology Extra 75 (2010) e81–e85 Contents lists available at ScienceDirect European Journal of Radiology Extra journal homepage: intl.elsevierhealth.com/journals/ejrex Microcystic meningioma: Two cases examined with perfusion-weighted imaging Guido Wilms a,* , Geert Heirwegh a , Steven De Vleeschouwer b , Raf Sciot c , Johannes van Loon b a Department of Radiology University Hospitals Leuven, Herestraat 49, B-3000 Leuven, Belgium b Department of Neurosurgery, University Hospitals Leuven, Herestraat 49, B-3000 Leuven, Belgium c Department of Pathology, University Hospitals Leuven, Herestraat 49, B-3000 Leuven, Belgium article info Article history: Received 7 September 2009 Accepted 8 June 2010 Keywords: Meningioma Microcystic Magnetic resonance Perfusion-weighted imaging abstract Purpose: Microcystic meningioma is a rare morphological variant of meningioma with multiple radiolog- ical presentations. To date only the findings on CT and conventional MRI have been described. We report two cases of microcystic meningioma examined with perfusion-weighted MR. Methods: Two patients with a cystic meningioma were examined with gradient-echo perfusion MR. Results: A convexity microcystic meningioma showed low rCBV in one patient. In the other patient with a microcystic falx meningioma high rCBV was noted, probably reflecting hypervascularity, but also impaired venous outflow and contrast-medium leakage. The vascularity of the tumor as demonstrated by perfusion MR correlated well with the intra-operative findings. Conclusion: The vascularity of microcystic menigioma seems variable and multifactorial. In our two patients rCBV correlated well with intra-operative findings. Further larger studies will have to confirm that perfusion MR can predict the vascularity of a meningioma with cystic appearance. © 2010 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Microcystic meningioma is a rare pathological variant of menin- gioma [1]. Apart from one large series of 16 patients [2] most publications on this rare tumor are case reports [3,4]. The MR- characteristics of microcystic meningioma are variable [2]. The most constant finding is that of an extra-axial mass with high T2- intensity and low T1-intensity with extensive peritumoral edema [2]. The contrast enhancement though seems extremely variable ranging from total absence to intense enhancement and reflects the vascularity of the tumor on selective cerebral angiography [2]. We wish to describe two cases of pathologically proven meningiomas with microcystic components examined with perfusion-weighted MR (PWI) and to correlate these findings with the findings at neu- rosurgery. 2. Materials and methods MRI was performed in two patients presenting with hypodense extra-axial lesions on CT. In the first patient PWI was done in the * Corresponding author. Tel.: +32 16 34 37 81; fax: +32 16 34 37 65. E-mail addresses: guido.wilms@uz.kuleuven.ac.be (G. Wilms), geert.heirwegh@uz.kuleuven.ac.be (G. Heirwegh), steven.devleeschouwer@uz.kuleuven.ac.be (S. De Vleeschouwer), raf.sciot@uz.kuleuven.ac.be (R. Sciot), johannes.vanloon@uz.kuleuven.ac.be (J. van Loon). same session. In the second patient, PWI was performed in a sepa- rate session. For the standard diagnostic MR-sequences both patients were examined on a 1.5 T Magnetom Symphony whole-body imager (Siemens, Erlangen, Germany) with a standard head coil. The exam- ination was started by performing a T2-weighted sequence (TE: 126 ms, TR 5000 ms, slice thickness 7 mm), a FLAIR sequence (TE 114 ms, TR 2500 ms, TI 2500 ms, slice thickness 5 mm) and a non- enhanced T1-weighted sequence (TE 12, TR 630 ms, slice thickness 6 mm). A multislice spin-echo EPI sequence was used for diffusion- weighted imaging. Contrast-enhanced T1-weighted images in the axial, sagittal and coronal direction were performed after PWI in the first patient and after IV injection of Gd-DTPA at a dose of 0.1 mmol/kg in the second patient. For perfusion-weighted imaging (PWI) a contrast-agent bolus of Gd-DTPA at a dose of 0.1 mmol/kg was injected via an anticubital vein with a pressure injector at a rate of 4 ml/s. For the first patient, scanned on a 1.5 T Magnetom Symphony (Siemens, Erlangen, Germany), following parameters were used for the gradient-echo T2*-weighted EPI: TR/TE of 1510/52 ms, flip angle of 90, acquisition matrix of 128 × 128, 15 slices, slice thick- ness of 5 mm, slice gap of 1.5 mm, 15 slices, 50 dynamics in a total scan time of 1 min 22 s. For the second patient, scanned on a 3 T Achieva system (Philips, Eindhoven, The Netherlands) following parameters were used for the gradient-echo T2*-weighted EPI: TR/TE of 1350/30 ms, flip angle of 75, acquisition matrix of 112 × 112, 24 slices, slice thick- 1571-4675/$ – see front matter © 2010 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ejrex.2010.06.005