Advanced

AJNR - American Journal of Neuroradiology

A, T2-weighted MR image reveals no hyperintense lesion in the left temporo-parietal lobe.

B, Left external carotid angiogram, lateral projection, shows DAVFs adjacent to the left transverse sinus. Venous drainage is retrograde into the left transverse sinus. An accessory drainage route into the superior sagittal sinus is recognized. Multiple varices are seen in the venous drainage path.

C, Schematic diagram of a DAVF with an accessory route (star) in the retrograde venous drainage (single arrows). The accessory route with retrograde flow (top double arrows) and the surrounding venous flow (left and right double arrows) drain into another sinus through this accessory route. F indicates the fistula point; OA, occipital artery; SS, sigmoid sinus; and TS, transverse sinus.

A, T2-weighted MR image reveals a hyperintense lesion in the left parietal lobe.

B, External carotid angiogram, lateral projection, of the left middle meningeal artery, reveals DAVFs at the superior sagittal sinus. The feeder middle meningeal arteries drain directly into the cortical vein. Final venous drainage is into the superior sagittal sinus via a varix. No accessory route is recognized.

C, Schematic drawing of a DAVF without an accessory route in the retrograde venous drainage. The surrounding flow (arrows) cannot drain into another area, resulting in severe venous congestion (shadow). F indicates fistula point; MMA, middle meningeal artery; and SSS, superior sagittal sinus

D, ^99mTc-HMPAO SPECT scan shows an area of hypoperfusion at the site of the lesion.

E, After an acetazolamide challenge, the area of hypoperfusion is increased.

F, Post-treatment T2-weighted MR image shows the disappearance of the hyperintense area.

G, Post-treatment SPECT image reveals normal perfusion of the left parietal lobe.

A, T2-weighted MR image reveals a hyperintense lesion in the left temporo-occipital lobe.

B, External carotid angiogram, lateral projection, of the left occipital artery shows DAVFs adjacent to the left transverse sinus. No accessory route is recognized.

C, ^99mTc-HMPAO SPECT scan shows a hypoperfused area at the site of the lesion.

D, The hypoperfused area is not increased after the acetazolamide challenge.

E, After treatment, the hyperintense area seen on the T2-weighted MR image persists and expands to the left parietal lobe.

F, SPECT image obtained immediately after treatment reveals hyperperfusion in the left parietal lobe.

G, SPECT image obtained 6 months after treatment demonstrates hypoperfusion in the left parietal lobe.