case_images: PMC9479517_01
case_images: (a) Preoperative axial computed tomography (CT) demonstrating ventriculomegaly. (b) Postoperative Axial CT demonstrating decrease in ventricle size following endoscopic third ventriculostomy. Pneumocephalus is evident on scan.
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case_images: PMC9479517_01_SNI-13-331-g001.jpg
case_images: F1
case_images: Findings were consistent with chronic hydrocephalus [Figure 1]. Postoperative head CT demonstrated a significant decrease in hydrocephalus [Figure 1b].
case_images: Axial T2 sequence magnetic resonance imaging (MRI) illustrating cortical subarachnoid hemorrhage (SAH)/siderosis from chronic SAH.
case_images: SNI-13-331-g002.jpg
case_images: PMC9479517_01_SNI-13-331-g002.jpg
case_images: F2
case_images: Magnetic resonance imaging (MRI) of the brain demonstrated chronic cortical SAH (cSAH)/superficial siderosis of the parasagittal frontoparietal sulci and left anterior frontal sulci [Figure 2].
case_images: Arrows point to multifocal stenosis of medium to small caliper cerebral arteries demonstrated on angiography. (a) Red arrow: R. posterior cerebral artery; White arrow: R. superior cerebellar artery; Orange arrow: R. anterior inferior cerebellar artery; Black arrow: L. superior cerebellar. (b) Yellow arrow: R. anterior cerebral artery; Red arrow: R. posterior cerebral artery. (c) Blue arrows: L. middle cerebral artery.
case_images: SNI-13-331-g003.jpg
case_images: PMC9479517_01_SNI-13-331-g003.jpg
case_images: F3
case_images: CT angiogram. Cerebral angiography confirmed these results [Figures 3a-c].
case_images: MRI/cerebrospinal fluid: cerebrospinal fluid flow study. Red arrow: arachnoid cyst membrane; Orange arrow: splayed optic tracks; Blue arrow: flattened infundibular recess; Yellow arrow: stenotic cerebral aqueduct.
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case_images: PMC9479517_01_SNI-13-331-g004.jpg
case_images: F4
case_images: CSF flow study was subsequently performed, revealing partial obstruction of the cerebral aqueduct [Figure 4]. CSF obstruction was found at the junction of the cerebral aqueduct and the superior aspect of the fourth ventricle.
case_images: Intraventricular arachnoid cyst: Endoscopic third ventriculostomy screenshot.
case_images: SNI-13-331-g005.jpg
case_images: PMC9479517_01_SNI-13-331-g005.jpg
case_images: F5
case_images: Intraoperative endoscopy located a large cyst within the third ventricle obscuring the ventricular floor [Figure 5].