Multiple juxtasinusal meningiomas in the parieto-occipital region

This 48 year old patient presented with progressive visual disturbances and signs of intracranial hypertension.
The initial CT revealed a large multinodular meningioma in the left parietal parasagittal region with infratentorial extension and invasion of the superior and transverse sinuses as well as of the torcular. Subsequent, conventional catheter based cerebral angiography was also performed and demonstrated the occlusion of the posterior third of the superior sagittal sinus and the proximal segment of the right transverse sinus.
At the first surgical intervention, partial removal the tumor was achieved.
A combined MRI-MRA examination was used for reassessment of the affected dural sinuses before reoperation two years later.

(Juxtasinusal meningiomatosis, 0.5 T)
Examination 1
Fig.1 Transverse contrast-enhanced CT images. Multiple, confluent meningiomas in proximity to the superior sagittal sinus (SSS) with significant peritumoral edema in the right cerebral hemisphere.

Examination 2
Fig.2 DSA images after selective injection of the left internal carotid (above and below left) and the vertebral artery (below right). The lateral view (above left) shows occlusion of the posterior third of the SSS and a rich cortical collateral venous network draining the patent portion of the SSS towards the cavernous sinus and pterygoid plexus via the middle cerebral vein and sphenoparietal sinus. Same observations on the oblique (above right) and the A-P view (below left). The DSA image (A-P view) after selective injection of the left vertebral artery (below right) suggests partial occlusion of the right transverse sinus.

Examination 3
Fig.3 Sagittal T1-weighted spin-echo images. Demonstration of multiple, confluent meningiomas along the posterior third of the SSS. Note also the grade 4 empty sella, reflecting in this case chronically raised intracranial pressure.
Fig.4 Transverse proton density weighted fast spin-echo images. Disappearance of the normal signal void of the SSS in the parietal region due to tumor invasion with the suspicion of involvement of the right transverse sinus.
Fig.5 Coronal Gadolinium-enhanced T1-weighted images showing the multiple meningioma locations along the SSS and the right transverse sinus.
Fig.6 Sagittal 2D PC MR angiogram (above) and directional phase difference reconstruction (below) of the intracranial midline venous structures. Non-visualization of the posterior third of the SSS and suspicion of involvement of the distal segment of the straight sinus. Reversal of flow (postero-anterior) in the patent proximal SSS (compare the flow direction in the SSS to the known antero-posterior flow in the pericallosal artery and postero-anterior flow in the ascending A2 segment of the anterior cerebral artery). This is considered to be a normal finding after progressive occlusion of the SSS and reflects redistribution of the intracranial venous circulation, in this case towards the fronto- and temporobasal venous outflow pathways (see also DSA images from examination 2).
Fig.7 Transverse averaged modulus (left) and magnitude of complex differences (right) type source images from a Gadolinium-enhanced 3D PC MRA acquisition (Venc: 30 cm/s). Clear demonstration of the patency of the left transverse sinus. Non-visualization of the distal superior sagittal and the proximal right transverse sinus due to tumor invasion.
Fig.8 Sagittal (above) and coronal (below) targeted MIP reconstructions from the Gadolinium-enhanced 3D PC MRA acquisition data set. Non-visualization of a small segment of the distal straight sinus (arrow) and the proximal half of the right transverse sinus. The former probably corresponds to a hemodynamically significant stenosis (see normal A-P flow direction on Fig.6), whereas the latter suggest occlusion.

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