ACOM aneurysm

A flow void is noted in the region of the anterior communicating artery (ACOM) on an axial T2-weighted image, with signal intensity corresponding to arterial flow on an axial source image from a 3D TOF MRA. CE MRA images further confirm the aneurysm, with the right A1 segment of the ACA noted to be very […] [...]

ACA aneurysm

Note the prominent pulsation artifact in the first image (a FSE T1-weighted scan at 3 T), seen propagating in the left-right dimension. On the post-contrast image (a short TE GRE scan), the aneurysm is well depicted, other than partial volume effects (due to the 4 mm slice thickness). This 2D scan is relatively immune to […] [...]

Acute parenchymal hemorrhage, due to an underlying AVM

Acute parenchymal hemorrhage, due to an underlying AVM. A large acute parenchymal hematoma is noted in the right frontal lobe. Post-contrast, there is tubular like enhancement within and immediately posterior to the hemorrhage, most consistent with acute extravasation of blood. The coronal thick MIP from the CTA study reveals a small nidus of arterial enhancement […] [...]

Acute subarachnoid hemorrhage from a small ACOM aneurysm

The images presented include an axial unenhanced CT, a coronal MIP from the CTA, and a 3D magnified view of the aneurysm from the CTA, obtained using volume rendering technique (VRT). The latter shows the distal internal carotid artery, the two anterior cerebral arteries, and the small multi-lobulated aneurysm originating from the ACOM, near its […] [...]

Acute subdural and parenchymal hemorrhage, from an underlying AVM

Acute subdural and parenchymal hemorrhage, from an underlying AVM, in a patient with fibromuscular dysplasia (FMD). Intracranial aneurysms are a well known associated finding in FMD, with the occurrence of intracranial arteriovenous malformations less common. On axial CT, both the acute subdural and parenchymal hematomas are well demonstrated, together with midline shift and compression of […] [...]

Aneurysm, cavernous carotid artery

A small mass lesion is noted within the left cavernous sinus on both CT and MR (axial imaging), with CT revealing enhancement therein. MRA confirms this to be an aneurysm, with the DSA provided for comparison (from an initial balloon test occlusion study). This 12 mm aneurysm of the cavernous segment of the internal carotid […] [...]

Cavernous malformation, with an associated developmental venous anomaly

On CT, a small, well delineated, hyperdense, round, focal lesion is seen pre-contrast, to the right and posterior to the fourth ventricle. On axial T2-weighted scans, a complete hemosiderin rim is demonstrated, together a “popcorn ball” appearance centrally, with mixed high and low signal intensity – all characteristic for a cavernous malformation. Just lateral and […] [...]

MCA bifurcation aneurysm

A small multilobulated aneurysm is noted on the left, visualized both on planar imaging post-contrast as well as on MRA. Part of the on-line supplement to Neuroradiology – The Essentials with MR and CT (© 2015) [...]

MCA bifurcation aneurysm, T2 flow void

On the axial T2-weighted scan, a flow void is noted in the region of the MCA bifurcation on the right. Coronal post-contrast imaging reveals enhancement of this aneurysm, which is well visualized on TOF MRA. Part of the on-line supplement to Neuroradiology – The Essentials with MR and CT (© 2015) [...]

Multiple cerebral aneurysms, due to myxomatous emboli

Several small lesions with peripheral hemosiderin are noted on the axial T2-weighted scan, one with marked associated vasogenic edema. Comparison of axial source images from a TOF exam both prior to and with contrast enhancement reveals a small focus of enhancement within one of the previously noted lesions. A lateral projection from DSA confirms multiple […] [...]

Non-obstructing clot/thrombus in the basilar artery

Methemoglobin clot is visualized medially within a focal aneurysmal dilatation of the basilar artery on axial and coronal T1-weighted scans. Evaluation of axial T2-weighted and DWI scans reveals a small acute infarct, located within the brainstem just medial to the clot, and presumed to be secondary to occlusion of small paramedian penetrating branches from the […] [...]

Small cavernous malformation

Small cavernous malformation, best visualized on susceptibility weighted imaging (SWI). Detection of this small, medial, posterior frontal cavernous malformation is poorest on FLAIR, of the presented scans, and best on SWI. Multiple research articles in the scientific literature have shown that SWI is more sensitive for detection of cerebral cavernous malformations than T2-weighted gradient echo […] [...]

Superior cerebellar artery aneurysm

A predominantly hyperintense lesion is noted on the right, anterior to the pons, causing mild adjacent deformity. Additional scans identify the abnormal high signal intensity to represent methemoglobin, in a SCA aneurysm that is predominantly thrombosed and has only a small residual patent component (medially). The TOF exams, with thick coronal and axial MIPs illustrated, […] [...]

Thrombosis of the superior sagittal sinus with resultant parenchymal hemorrhage

Axial and coronal enhanced CT scans reveal parenchymal hemorrhage in the left frontal lobe. Also note the empty delta sign on the coronal scan, consistent with thrombosis of the superior sagittal sinus. The hemorrhage and accompanying vasogenic edema are well seen on the T2-weighted GRE scan, with the low signal intensity consistent with either deoxyhemoglobin […] [...]