case_images: PMC11021061_01
case_images: (a) Axial non-contrast computed tomography head demonstrates a round, heterogeneously hyperdense mass lesion in the right middle cranial fossa with calcifications in both the center and its periphery. (b) Axial gadolinium-contrast magnetic resonance imaging brain reveals a well-defined, round lesion that is iso- or even hypo-intense and is partially enhanced by intravenous gadolinium, and it is extra-axial mass along the right medial temporal convexity, closely adjacent to the right sphenoid wing. (c) Cerebral digital subtraction angiography (DSA) - Lateral view illustrates a fusiform giant aneurysm in the cavernous segment of the right internal carotid artery (ICA); the aneurysm seems to originate in the cavernous segment and likely terminates at the transition of cavernous to ophthalmic segment with measurements shown in the image. In addition, it displays the dilated and tortuous supra clinoid portion of the right ICA. (d) Cerebral DSA - Anteroposterior view shows the same fusiform giant aneurysm in the cavernous segment of the right ICA with measurements. It also highlights the dilated and tortuous supra clinoid portion of the right ICA, which is compared to the lumen size of the proximal ICA. Furthermore, it points out the hypoplastic right A1 anterior cerebral artery and normal right middle cerebral artery supply.
case_images: SNI-15-98-g001.jpg
case_images: PMC11021061_01_SNI-15-98-g001.jpg
case_images: F1
case_images: A prior non-contrast computed tomography scan showed a hyperdense mass in the right middle cranial fossa, eroding the right petrous bone [Figure 1a]. Post-contrast imaging hinted at a large calcified aneurysm or calcified meningioma [Figure 1b]. The proximal ICA measured 2.37 mm, while the distal ICA was dilated (8.53 mm) [Figures 1c and d].
case_images: (a) Intraoperative right common carotid artery injection - anteroposterior view displays the proximal right internal carotid artery (ICA) and peripheral enhancement of vasa vasorum within the spontaneously thrombosed aneurysm (blue solid arrow). It also demonstrates the obliteration of the ICA distal to the aneurysm (white solid arrow) and collateral circulation provided by a branch of the right external carotid artery (red arrow) to the distal right ICA and subsequently to the right middle cerebral artery (MCA). (b) Intraoperative left ICA injection - anteroposterior view shows the filling of bilateral A2 ACA from the left ACA. Cross-compression demonstrates no cross-flow to the right A1 ACA. (c) Right vertebral artery injection, AP view, demonstrates collateral flow into the right MCA from the right posterior communicating artery. (d) Fluoroscopic image of the skull-lateral view reveals a relatively well-defined mass at the base of the skull with a clear superior margin, situated superior to the sphenoid wing. Peripheral radiopaque margins may indicate calcification. There is no evidence of sella widening, and the sphenoid sinus appears normal. ACA: Anterior cerebral artery
case_images: SNI-15-98-g002.jpg
case_images: PMC11021061_01_SNI-15-98-g002.jpg
case_images: F2
case_images: Collateral circulation from extracranial sources, contralateral circulation, and posterior circulation ensured sufficient supply to the right cerebral hemisphere [Figures 2a-d].
case_images: (a) Follow-up cerebral digital subtraction angiography - Right internal carotid artery (ICA) injection - lateral view depicts the truncated proximal ICA with minimal contrast blush within the proximal portion of the thrombosed aneurysm lumen with filling of distal ICA by right posterior communicating artery. (b) Follow-up left ICA injection - AP view shows the filling of bilateral A2 ACA from the left ACA, with no cross flow to the right A1 ACA observed during cross-compression. AP: Antero=posterior, ACA: Anterior cerebral artery
case_images: SNI-15-98-g003.jpg
case_images: PMC11021061_01_SNI-15-98-g003.jpg
case_images: F3