PMC9282765_01
(a) Coronal computed tomography brain without contrast showing slightly hypodense septal lesion and hyperdense rim causing obstructive hydrocephalus with periventricular hypodensities. (b) Sagittal T1 magnetic resonance imaging (MRI) brain without contrast showing a hyperintense rim of the lesion. (c) Axial T1 MRI brain with contrast showing a nonenhancing interventricular mass within the cavum septum pellucidum. (d) Axial T2 MRI brain showing a thin dark rim of the lesion. (e) Susceptibility-weighted image showing blooming artifact.
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F1
CT of the brain showed anterior interventricular isodense lesion measuring 29 mm (anteroposterior) x 26 mm (transverse) x 27.5 mm (craniocaudal) [Figure 1a]. T1 and T2 with a thin dark rim signal on T2 and a blooming artifact on susceptibility-weighted image (SWI). The lateral ventricles were dilated with transependymal permeation [Figures 1b-e].
(a) Magnetic resonance angiography (MRA) showing the right and left septal veins encasing the lesion and joining into an enlarged right internal cerebral vein. There is azygos anterior cerebral artery. (b) Postoperative MRA showing both septal veins. The right septal vein is very close to the azygos anterior cerebral artery.
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F2
The study did not reveal any aneurysm or AVM [Figure 2a]. The previously mentioned venous anomaly continued to be observed [Figure 2b].
(a) Computed tomography (CT) angiogram arterial phase, there is azygos pericallosal artery with an early origin of the callosomarginal arteries (triplicated anterior cerebral artery). (b) CT angiogram arterial and venous phases showing the close relation of the azygos artery and the septal veins. (c) CT angiogram venous phase, the anterior septal veins of both sides join, and drain into an enlarged right internal cerebral vein at the foramen of Monro where they are joined by the right thalamostriate vein. The small left internal cerebral vein receives only the left thalamostriate vein at the foramen of Monro.
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F3
No associated aneurysm or AVM was identified [Figures 3a and b]. The small left ICV received only the left TSV at the foramen of Monro [Figure 3c].