This document discusses various types of aneurysms and vascular malformations that can be identified through clinical imaging. It provides 10 figures with descriptions that show examples of different types of aneurysms seen on CT scans, MRI, and catheter angiograms. These include aneurysms of the anterior communicating artery, posterior communicating artery, middle cerebral artery, basilar artery, posterior inferior cerebellar artery, as well as giant aneurysms, post-traumatic aneurysms, developmental venous anomalies, capillary telangiectasias, and vein of Galen aneurysms. The images demonstrate how different imaging modalities can help differentiate between these vascular conditions.

1. 31Aneurysms and Vascular
Malformations

2. CLINICAL IMAGAGING
AN ATLAS OF DIFFERENTIAL DAIGNOSIS
EISENBERG
DR. Muhammad Bin Zulfiqar
PGR-FCPS III SIMS/SHL

3. • Fig SK 31-1 Anterior communicating artery
aneurysm. (A) Axial CT scan shows clot (h) in the
left gyrus rectus. There is blood in the anterior
interhemispheric fissure and sylvian fissures.
Note the hydrocephalus. (B) Oblique view from a
catheter angiogram shows an aneurysm in the
anterior communicating artery (A).6

4. • Fig SK 31-2 Posterior communicating artery
aneurysm. (A) Axial CT and (B) MR images
show subarachnoid hemorrhage (h) in the
basilar cisterns.6

5. • Fig SK 31-3 Middle cerebral artery bifurcation
aneurysm. (A) Axial CT scan shows
subarachnoid hemorrhage confined mostly to
the right sylvian fissure (arrows). (B) Frontal
view from a catheter angiogram shows an
aneurysm (A) at the bifurcation of the right
middle cerebral artery.6

6. • Fig SK 31-4 Basilar artery tip aneurysm. (A)
Contrast-enhanced CT scan shows a large
aneurysm (L) at the level of the basilar artery
tip. (B) Frontal projection from a catheter
angiogram shows a giant aneurysm (A) arising
from the tip of the basilar artery.6

7. • Fig SK 31-5 Posterior inferior cerebellar artery
aneurysm. (A) Axial CT scan shows
hemorrhage (arrow) in the fourth ventricle.
(B) Lateral projection of a posterior fossa
catheter angiogram shows an aneurysm (A)
arising in the supratonsillar segment of a
posterior inferior cerebellar artery.6

8. • Fig SK 31-6 Post-traumatic aneurysm. (A) CT
scan obtained 2 weeks after head injury shows
a hematoma (h) as well as a central enhancing
abnormality (a), which was shown at
angiography (B) to represent a post-traumatic
aneurysm (arrow) in the pericallosal artery.6

9. • Fig SK 31-7 Giant aneurysm. (A) Coronal T1-weighted
MR image shows a large intrasellar aneurysm (arrow).
(B) Axial postcontrast CT scan in another patient shows
opacification of the lumen (L) of a giant aneurysm
arising in the bifurcation of the right middle cerebral
artery. Note the concentric and hyperdense layers of
clot along the walls of this aneurysm.6

10. • Fig SK 31-8 Developmental venous anomaly.
Postcontrast axial T1-weighted MR image
shows a venous angioma in the right temporal
lobe. Slow flow results in enhancement of the
lesion.6

11. • Fig SK 31-9 Capillary telangiectasia.
Postcontrast T1-weighted MR image shows
enhancement in this pontine lesion (arrow).
The non-contrast images showed no
abnormality.6

12. • Fig SK 31-10 Vein of Galen aneurysm. (A)
Coronal sonogram shows a hypoechoic and
dilated vein of Galen. (B) T2-weighted MR
image confirms the aneurysmal dilatation of
the vein of Galen (A).6