Dural arteriovenous shunt of the superior sagittal sinus in the parietal region

This 59 year old male without any contributory medical history presented with recurrent vertigo.
The initial head CT examination with contrast revealed a markedly enhancing left parietal lesion. Subsequently conventional MRI, followed by MRA was performed in order to complete the diagnostic work-up.

(Dural AVS of the superior sagittal sinus, 1.5 T)
Fig.1 Sagittal T1-weighted spin echo images of a dAVS of the superior sagittal sinus. Dilated blood vessels (cortical veins?) are seen in the interhemispheric fissure in the parieto-occipital region.
Fig.2 Transverse T2-weighted fast spin-echo images. The abnormal interhemispheric cortical veins are clearly depicted again, suggesting a small cortical-pial arteriovenous malformation. The surrounding high signal intensity areas raise the possibility of secondary brain lesions.
Fig.3 Transverse FLAIR images fail to demonstrate any signal abnormality in the brain and therefore rule out the hypothesis of associated parenchymal lesions. This sequence is particularly useful in the differentiation between dilated CSF containing cortical sulci and cortical parenchymal lesions as in this case.
Fig.4 Sagittal 2D PC MR angiogram (Venc: 25 cm/s). Clear demonstration of the abnormal vascular structures in the parietal region is obtained by this rapid survey study (Tac: 1 min). The presence of transcranial blood supply from external carotid artery branches is well appreciated, shifting the diagnosis towards a dural arteriovenous shunt.
Fig.5 Coronal 2D PC MR angiogram (Venc: 25 cm/s). Bilateral blood supply to the lesion is noted with participation from the meningeal and the extracranial branches of the external carotid arteries.
Fig.6 Sagittal (above and middle) and coronal (below) targeted MIP reconstructions from a 3D PC MRA acquisition data set. These images provide more vascular detail compared to the 2D PC MR angiograms. No blood supply from cortical arteries to the lesion is detected. Otherwise same observations as on Fig.4. and Fig.5.
Fig.7 Transverse targeted MIP reconstruction from the 3D PC MRA acquisition data set. The bilateral meningeal and transcranial blood supply to the lesion is clearly demonstrated.
Fig.8 DSA images (lateral views) after selective injection of the left external carotid artery. Confirmation of the diagnosis of the dAVS of the superior sagittal sinus. Note the marked cortical venous stagnation in the late venous phase.

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