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 cerebellar hemorrhage

Acute cerebellar hemorrhage, hypertensive. A large acute parenchymal hemorrhage is seen in the left cerebellar hemisphere, on sagittal, axial, and coronal reformatted images from a non-contrast CT exam. Note the vasogenic edema circumferential to this hematoma. Hemorrhage is also seen in the fourth ventricle on the axial image, with interstitial edema and ventricular enlargement noted […] [...]

Acute infarction of the caudate head and lentiform nucleus

Both structures are supplied by the lateral lenticulostriate arteries, which originate from the MCA. The caudate nucleus is also supplied by the medial lenticulostriate arteries, which arise from the ACA. The recurrent artery of Heubner, which supplies the anteromedial caudate nucleus and the anteroinferior internal capsule, is the largest of the medial lenticulostriate arteries, and […] [...]

Acute lacunar infarction, posterior limb of the internal capsule

The patient was hypertensive, and presented for CT (which was negative) with acute hypoesthesia involving the left side of the body. The MR was obtained 15 hours later, and reveals a small acute lacunar infarct in the internal capsule on the right. Due to the ability to detect cytotoxic edema, with diffusion weighted imaging, MR […] [...]

Acute medial medullary infarct

Abnormal hyperintensity is noted in the right medial medulla on both T2- and diffusion-weighted scans, which corresponds to vasogenic and cytotoxic edema, respectively. The medial medulla is most often described as being supplied by the anterior spinal artery. The medial medullary syndrome, also known as Dejerine syndrome, is caused by infarction of this region. It […] [...]

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 superior cerebellar artery (SCA) infarction

Acute superior cerebellar artery (SCA) infarction, with an accompanying small unilateral pontine infarct. Hypodensity is seen on CT in a portion of the SCA territory, with hyperintensity on axial T2-weighted MR (and sagittal FLAIR), both due to vasogenic edema. The presence of restricted diffusion is confirmed on the ADC map, reconstructed from the diffusion scans. […] [...]

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 […] [...]

Anaplastic astrocytoma (WHO grade III), CT and MR

A focal, mildly hyperdense, lesion is noted on CT in the right centrum semiovale, with restricted diffusion and no abnormal contrast enhancement. rCBV is mildly elevated. The hyperdensity on CT is unusual, with the diffusion restriction (confirmed on the ADC map, not shown) correctly suggesting a higher-grade lesion, with the lesion appearing on other scans […] [...]

Anaplastic ependymoma (WHO grade III), in an 18 month old infant

There is a large enhancing extra-axial mass lying within the 4th ventricle and extending into the foramen of Luschka on the left. Heterogeneity of the lesion with cystic and necrotic areas is characteristic, along with the previously described findings. Most patients are one to five years in age, and present – as this child – […] [...]

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 […] [...]

B cell lymphoma

A hyperintense periventricular mass lesion with accompanying vasogenic edema is noted in the right occipital lobe. The mass is hyperintense on DWI, with disruption of the blood-brain barrier (enhancement) demonstrated post-contrast. The mass had restricted diffusion (reflected by the high SI on DWI), which is compatible with primary CNS lymphoma, a diagnosis confirmed at surgery. […] [...]

Brain metastases, melanoma

Pre- and post-contrast axial T1-weighted scans are illustrated. Pre-contrast, several small lesions in the frontal lobes, in particular on the left, demonstrate hyperintensity. Numerous small nodular enhancing lesions are noted post-contrast, all at the gray-white matter junction. Hemorrhagic metastases are seen in up to 15% of brain metastases. A mnemonic for the primary tumors that […] [...]

Calvarial metastasis from breast carcinoma, with hyperostosis frontalis interna

A large lytic skull lesion is noted on CT, along with benign thickening along the inner table of the frontal bone (an incidental finding). MR depicts well the soft tissue mass within the skull, which is slightly expansile and easily distinguished pre-contrast from the adjacent fatty marrow, with enhancement post-contrast. Part of the on-line supplement […] [...]

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 […] [...]

Cerebellar hemangioblastoma

Cerebellar hemangioblastoma on MR, von Hippel Lindau syndrome. Well seen on axial T2- and sagittal post-contrast T1-weighted scans is a cystic cerebellar lesion with an enhancing mural nodule. This lesion is also illustrated on CT in an accompanying figure. A solid enhancing nodule (along the periphery of the cyst) would be the most characteristic imaging […] [...]

Cerebellar hemangioblastoma on CT

Cerebellar hemangioblastoma on CT, von Hippel Lindau syndrome. Post-contrast scans in all three orthogonal planes reveal a cystic cerebellar lesion, with an enhancing mural nodule, the most common imaging presentation for a hemangioblastoma. Part of the on-line supplement to Neuroradiology – The Essentials with MR and CT (© 2015) [...]

Cerebral abscess

A small lesion with a thin, uniform rim of contrast enhancement and moderate associated vasogenic edema is noted in the left postcentral gyrus. Note that the periphery of the lesion is slightly hypointense on the coronal FLAIR scan, which is characteristic of an abscess, together with restricted diffusion (well seen in this patient, but with […] [...]

Choroidal fissure cyst

These are considered a normal variant, and occur in the medial temporal lobe. They have a characteristic spindle shape on sagittal images (not illustrated), demonstrate CSF signal intensity, and expand slightly the choroidal fissure of the temporal lobe. Part of the on-line supplement to Neuroradiology – The Essentials with MR and CT (© 2015) [...]

Convexity meningioma

Axial, sagittal, and coronal images reveal a round extra-axial lesion, with a broad base along the dura of the convexity, and a small associated dural tail. Additional typical findings for the diagnosis include relative isointensity to brain on the T1-weighted scan, slight hyperintensity on T2-weighted scans, and homogeneous contrast enhancement. Part of the on-line supplement […] [...]

Convexity meningioma with invasion of the superior sagittal sinus and the calvarium,CT

An enhancing lesion is identified along and to the left of the falx posteriorly, with occlusion of the superior sagittal sinus (diagnosed by the lack of enhancement). A portion of the sinus and adjacent draining cortical veins are identified along the anterior margin of the lesion. The calvarium is focally involved, with expansion, osteolysis and […] [...]

Convexity meningioma with invasion of the superior sagittal sinus and the calvarium,MR

In an accompanying figure, the CT findings in this case are presented. An extra-axial mass lesion is noted, adjacent to and to the left of the falx. The superior sagittal sinus is occluded. Meningiomas with restricted diffusion (hyperintensity on DWI), as in this example, tend to be malignant or highly atypical. The sagittal post-contrast exam […] [...]


CT reveals a normal right coronal suture, with bony bridging of the suture on the left. The result is an abnormal shape to the skull, which is asymmetrical, and termed plagiocephaly (which can involve either the coronal suture, as in this patient, or the lambdoid suture). No gross structural abnormalities are noted involving the brain. […] [...]

Early subacute infarct along the lateral ventricle, in a patient with extensive chronic small vessel white matter ischemic disease

A large lacunar infarct is seen in the white matter of the corona radiata, immediately adjacent to the left lateral ventricle. The infarct demonstrates both vasogenic edema, seen with abnormal high signal intensity on the T2-weighted scan, and cytotoxic edema, seen as restricted diffusion (low intensity) on the ADC map. Thus, the lesion is early […] [...]

Early subacute pinpoint cortical infarct, left precentral gyrus

The patient presented 6 days prior to the MR exam with right arm and facial paralysis. NIHSS=3 (minor stroke), which improved to 0 (no stroke symptoms). CT at the time of symptom onset was negative. Multiple small focal areas of gliosis or edema (with high signal intensity) are seen on the coronal FLAIR, with a […] [...]

Falx meningioma, with interval growth

The first post-contrast coronal T1-weighted scan was obtained six years prior to the second exam, with coronal FLAIR and post-contrast T1-weighted scans illustrated from the second exam. There has been interval growth of the lesion, substantial when viewed from a volume perspective. The lesion was electively removed, prior to possible involvement of the superior sagittal […] [...]

Focal cortical dysplasia

There is focal cortical thickening and a relatively poorly defined transition between gray and white matter, seen in the left frontal lobe on axial and coronal scans, in this 18 month old with intractable seizures. Part of the on-line supplement to Neuroradiology – The Essentials with MR and CT (© 2015) [...]

Ganglioglioma (cystic)

Presenting with seizure,a small intra-axial mass lesion is noted in the posterior temporal lobe in this young adult male. There is a small amount of associated vasogenic edema. Post contrast, the enhancement is predominantly rim-like in character, with likely both a solid (posteriorly) and a cystic component to the lesion. Part of the on-line supplement […] [...]

Ganglioglioma (solid)

A relatively well defined intraaxial mass lesion is noted in the right temporal lobe, with low- and high signal intensity respectively on T1- and T2-weighted scans, and prominent enhancement. There is only mild accompanying vasogenic edema. Location in the temporal lobe is characteristic for this diagnosis, as was the patient’s age (13 years), with this […] [...]

Glioblastoma, right parietal in location

A relatively well-defined enhancing mass lesion is seen, with prominent accompanying vasogenic edema. Despite the absence of gross central necrosis, the abnormal high signal intensity on FLAIR extends within the splenium of the corpus callosum, and extended (on images not presented) to the left as well. This finding is consistent with infiltration of the corpus […] [...]

Gyriform hyperdensity in a large left MCA and watershed territory infarction, due to prior DSA and not hemorrhage

The patient presented with signs of a large acute left MCA infarct, and proceeded to DSA. The images on the top row were acquired within hours following DSA, and show gyriform hyperdensity in the left MCA and watershed distributions, including the left caudate head. By imaging appearance alone, this could represent either hemorrhage or residual […] [...]

Hemangioblastoma (WHO grade I)

A cerebellar mass lesion is seen on the axial T2-weighted scan, with mild accompanying vasogenic edema. A distinctive additional finding is the many prominent associated vascular structures (flow voids). TOF MRA performed with contrast administration reveals a highly vascular lesion, with prominent early enhancement, and tortuous feeding vessels both anteriorly and posteriorly. There is prominent […] [...]

Late subacute, enhancing PICA infarct

There is slight hyperintensity on DWI, which proved to be T2-shine through (not true restricted diffusion) in a portion of the arterial territory of PICA on the right. Hyperintensity is noted on the axial FSE T2-weighted scan in this region, with only subtle increased signal intensity on the coronal FLAIR. On the post-contrast coronal scan […] [...]

Late subacute, enhancing PCA distribution infarcts, secondary to dissection of the right vertebral artery

Edema is seen in the thalamus, high signal intensity in the hippocampus on DWI (principally T2 shine through), and abnormal enhancement post-contrast in these regions together with the medial occipital lobe (all on the right). CE-MRA reveals the right vertebral artery to be narrowed in its midportion, with a small pseudoaneurysm at the level of […] [...]

Macroadenoma of the pituitary gland, with intra-operative MR

Coronal and sagittal T1-weighted post-contrast scans are presented in a patient with a small macroadenoma, both prior to surgery (upper row) and intraoperatively (lower row). Note that the adenoma enhances less than the normal pituitary, and is located inferiorly within the sella. There is cavernous sinus invasion on the right. On the intra-operative scan, near […] [...]

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) [...]

MCA with accompanying ACA infarcts

At presentation (upper two images), on the unenhanced CT only a small chronic white matter infarct is noted in the left frontal lobe. CTA (thick MIP) reveals a paucity of vessels in the left ACA and MCA distributions. The CT one day later (lower two images) reveals abnormal low density in both the ACA and […] [...]

Metastatic melanoma

A large left frontal metastasis, with prominent enhancement and surrounding vasogenic edema is noted on pre- and post-contrast T1-weighted scans. There are small areas of hemorrhage (methemoglobin) and cystic change (with low signal intensity) therein. The 4 mm coronal post-contrast T1-weighted image raises the question of a small pinpoint cerebellar metastasis on the left. Reformatting […] [...]

Multiple cerebellar hemangioblastomas

Multiple cerebellar hemangioblastomas on MR, perfusion imaging (ASL). Two small nodular enhancing lesions, with mild accompanying vasogenic edema, are noted within the cerebellum in this patient with von Hippel Lindau syndrome. Arterial spin labeling (ASL) is an alternative technique to first pass perfusion MR, the latter acquired during bolus gadolinium chelate administration typically using echoplanar […] [...]

Multiple cerebellar hemangioblastomas on MR, von Hippel Lindau syndrome

Multiple cerebellar hemangioblastomas on MR, von Hippel Lindau syndrome. The highly vascular nature of hemangioblastomas is illustrated on this axial thick MIP from a contrast enhanced, 3D gradient echo, short TE, short TR T1-weighted scan. 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 […] [...]

Multiple sclerosis

The axial FLAIR image reveals numerous punctate, predominantly discrete, small hyperintense foci in the supraventricular white matter. Cord lesions and characteristic callosal lesions on the sagittal FLAIR image confirm the diagnosis of multiple sclerosis, with the caveat that the lesion load is very high in this patient. A post-contrast T1-weighted axial scan reveals lesions without […] [...]

Multiple sclerosis, interval development of a new small callosal lesion on a 2-year follow-up exam

Multiple sclerosis, interval development of a new small callosal lesion on a 2-year follow-up exam. Multiple immediate periventricular small punctate high signal intensity plaques are noted on sagittal FLAIR scans, characteristic for MS. Also present are several plaques within the frontal and occipital white matter. Note the interval development of a small plaque with a […] [...]

Multiple sclerosis, visualization of plaques with differing MR techniques

As with most brain lesions, MS plaques demonstrate low signal intensity on T1- and high signal intensity on T2-weighted scans. Of note is that some MS plaques manifest low signal intensity on T1-weighted scans relative to normal appearing white matter, so called “Black Holes”. These are felt to represent areas of irreversible demyelination and axonal […] [...]

New infarction bordering a chronic infarct, in an 89-year-old patient

The axial FLAIR and FSE T2-weighted scans reveal extensive chronic deep white matter ischemia (with abnormal mild hyperintensity), together with generalized cortical atrophy and more focal atrophy in the left MCA posterior division, reflecting a prior chronic infarct. There is also abnormal high signal intensity adjacent to the largest area of cystic change, which could […] [...]

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 […] [...]

Obstructive hydrocephalus, extraventricular, due to meningitis

The ventricles are prominent, with a generalized absence of sulci. There is abnormal high signal intensity on the FLAIR scans in the immediate periventricular region, consistent with interstitial edema due to increased ventricular pressure. On the post-contrast scans there is diffuse mild enhancement of the leptomeninges, consistent with meningitis. Part of the on-line supplement to […] [...]

Occipital lobe hematoma

Occipital lobe hematoma, in an elderly patient with prominent dilated perivascular spaces and extensive cerebral amyloid angiopathy (chronic microbleeds). A large left-sided parenchymal hemorrhage is seen on CT and MR. The CT was acquired 6 days prior to the MR exam. On MR, there is only mild accompanying vasogenic edema (seen best on the T2-weighted […] [...]

Olfactory groove meningioma

A large, midline, extraaxial lesion is noted within the low frontal region, with homogeneous enhancement on post-contrast coronal and axial images. On the former, the lesion is noted to extend inferiorly to the region of the left olfactory bulb. Part of the on-line supplement to Neuroradiology – The Essentials with MR and CT (© 2015) [...]

Oligodendroglioma, WHO grade II

A mass lesion is noted on the right, in the posterior frontal lobe, somewhat peripherally located and expansile in nature. The lesion is hyperintense on T2-weighted scans, and fairly homogeneous in nature. There was no abnormal contrast enhancement (image not shown). In neoplastic disease, choline is increased and NAA decreased, relative to normal brain, a […] [...]

Pilocytic astrocytoma

A large, relatively well-circumscribed, mass lesion is seen involving the right cerebellum in this 3-year old child. There is marked compression of the fourth ventricle and midbrain, with midline shift. There is a large solid enhancing component medially, with a cystic component laterally and enhancement as well of the cyst wall. Note that the cystic […] [...]

Pineal parenchymal tumor (WHO grade III)

An enhancing mass is noted with its epicenter in the region of the pineal gland. The ventricular system is enlarged, due to compression of the cerebral aqueduct. Hemorrhage is common with pineal parenchymal tumors, and is visualized in the current case (specifically hemosiderin, with low signal intensity) on the T2 FSE and DWI scans, but […] [...]

Pituitary macroadenoma with hemorrhage

The sella is expanded by a mass lesion, which extends superiorly to compress the optic chiasm. There is extensive hemorrhage therein, representing a combination of intracellular and extracellular methemoglobin. Note post-contrast the enhanced pituitary infundibulum, draped over the left side of the mass. The coronal scan on the far right of the figure was obtained […] [...]

Recurrent epidermoid

On the FLAIR scan there is a region of abnormal signal intensity, isointense to brain, to the right of the medulla. This could be related to abnormal soft tissue, or simply reflect artifact due to CSF pulsation. On the FSE T2-weighted scan, and the post-contrast T1-weighted scan, the question of subtle abnormal soft tissue in […] [...]

Skull hemangioma, CT

A solitary, sharply marginated, expansile lesion with a sunburst pattern (on images reconstructed with a bone algorithm) is visualized on unenhanced CT. The inner and outer tables of the skull are intact, with the outer table substantially expanded (and the inner table relatively unaffected). The MR in this patient is presented in a separate accompanying […] [...]

Skull hemangioma, MR

A large, well defined, expansile diploic space lesion is noted involving the left frontal bone, with slight hypo- and hyperintensity relative to brain on T1- and T2-weighted images. There is prominent enhancement, due to the presence of abundant vessels therein, which microscopically can be capillary, cavernous, or mixed in type. Part of the on-line supplement […] [...]

Small acute cerebellar infarct

Small acute cerebellar infarct, superior cerebellar artery (SCA) distribution. A portion of the SCA territory is noted to be involved on the left, with abnormal high signal intensity on both T2- and diffusion weighted scans. The high signal intensity on T2-weighted scans denotes vasogenic edema, with the findings on DWI – specifically restricted diffusion, confirmed […] [...]

Small acute left MCA infarct

Small acute left MCA infarct, with severe chronic small vessel white matter ischemic disease. The CT reveals only severe, bilateral, chronic ischemic disease (with abnormal low attenuation), which is also well seen on the FLAIR scan from the MR exam (with abnormal high signal intensity). The diffusion weighted scan enables detection of a small acute […] [...]

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 […] [...]

Small solid lateral cerebellar hemangioblastoma, in a patient with von Hippel Lindau syndrome

Small solid lateral cerebellar hemangioblastoma, in a patient with von Hippel Lindau syndrome. A small nodular enhancing lesion, with mild surrounding vasogenic edema, is noted in the right cerebellar hemisphere. The appearance on imaging is not specific for any one diagnosis, with metastatic disease likely first in terms of differential diagnosis, in the absence of […] [...]

Small solid superior cerebellar hemangioblastoma

Small solid superior cerebellar hemangioblastoma on MR, with perfusion imaging. Very high CBV is noted in a small nodular enhancing lesion, consistent with a hemangioblastoma, in this 41 year old patient with von Hippel Lindau syndrome and multiple other parenchymal lesions. Although 60% of hemangioblastomas of the brain are cystic, with a mural nodule, 40% […] [...]

Subacute parenchymal hemorrhage

A small fluid collection is noted in the superior left thalamus, with a complete hemosiderin rim demonstrated on the coronal T2* GRE scan. This 50 year old patient presented with a hypertensive hemorrhage on CT in the left thalamus 2 months prior to the MR. The residual of such bleeds on MR can be as […] [...]

Subacute PICA infarct

There is abnormal high signal intensity on T2- and diffusion-weighted axial scans in the left PICA territory. The ADC map however does not demonstrate restricted diffusion, thus identifying the findings on DWI to represent “T2 shine through”. The absence of a true diffusion change dates the infarct to be more than 1 week old, thus […] [...]

Subacute PICA infarct (including AICA)

Subacute PICA infarct, which also includes the AICA territory. Sagittal and axial CT sections reveal abnormal low attenuation in both the PICA and AICA territories (the inferior cerebellum). Note that the tonsil is involved (visualized on the axial CT exam), which is part of the PICA territory. On MR, there is abnormal high and low […] [...]

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, […] [...]

Temporal evolution of a cerebral hematoma on CT

The patient presented with trauma from a fall, with the first scan shown 5 days after hospitalization. The follow-up scan was obtained a month later. A large left acute (hyperdense) occipital hematoma is noted with moderate surrounding vasogenic edema (hypodense). A month later there has been evolution of the hematoma in its CT appearance, with […] [...]

Tentorial meningioma

A large extra-axial mass lesion is seen with a broad base along the tentorium. Note the compression of the cerebral peduncles, best seen on the axial exam. A classic finding is also seen, for the diagnosis of a meningioma, specifically a CSF cleft circumferential to the lesion (well visualized on the axial scan). Such a […] [...]