Diagnostics imaging evaluation of a right frontal cortical-subcortical AVM

This 32 year old male presented with a new onset of epileptic seizures. Neurological examination was unremarkable.
CT examination revealed a right frontal enhancing lesion, suggesting a vascular malformation. A combined MRI-MRA examination was performed to better characterize the lesion. The diagnosis of an AVM was subsequently confirmed by conventional catheter based cerebral angiography.
Partial occlusion of the lesion was obtained by endovascular embolization, requiring complementary surgical excision of the residual nidus.

Frontal cortical-subcortical avm, 0.5 T
Examination 1
Fig.1 Transverse contrast-enhanced CT image. A markedly enhancing irregular shaped right frontal lesion is detected.

Examination 2
Fig.2 Sagittal T1-weighted spin-echo images. The right frontal intracerebral lesion exhibits a typical honeycomb appearance consisting of punctate or tubular signal voids, suggesting an arteriovenous malformation.
Fig.3 Transverse proton density weighted fast spin-echo images. The topography and extension of the nidus of the lesion, as well as dilated cortical draining veins are well appreciated.
Fig.4 Transverse T2-weighted fast spin-echo images. No associated parenchymal lesion is seen.
Fig.5 Sagittal survey 2D PC MR angiograms with different Venc values. At the lower Venc value (30 cm/s) the nidus and the cortical draining veins are optimally seen (above). A higher Venc value selection (60 cm/s) enhances visualization of the arterial feeders but also the frontal segment of the superior sagittal sinus, suggesting significantly increased flow and primary drainage of the lesion towards this venous pathway. The cortical draining vein apparently has an accessory role in this case.
Fig.6 Sagittal reconstruction from a 3D PC MRA acquisition data set, with an intermediate (50 cm/s) Venc value selection.
Fig.7 The DSA images (lateral views) after selective injection of the right internal carotid artery in the early arterial (above) and late arterial (below) phase are in good overall agreement with the previous MR angiogram. However, the small frontobasal congested cortical veins were not detected on the MRA image, although they constitute a high risk factor for a hemorrhagic complication.

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