Val M. Runge, MD – ASNR 2015 – Pearls and Pitfalls in Neuroradiology of Cerebrovascular Disease – The Essentials with MR and CT

This educational exhibit was presented at the ASNR 2015 meeting, with imaging performed on a 3 T Siemens Skyra MR system. The full reference for the exhibit is given below. Runge V, Smoker W, Valavanis A. Pearls and Pitfalls in Neuroradiology of Cerebrovascular Disease – The Essentials with MR and CT. ASNR 53rd Annual Meeting, […] [...]

Val M. Runge, MD – ASNR 2015 – Simultaneous Multi-Slice (Slice Accelerated) Diffusion EPI

This educational exhibit was presented at the ASNR 2015 meeting, with imaging performed on a 3 T Siemens Skyra MR system. The full reference for the exhibit is given below. Runge V, Richter J, Beck T, Piccirelli M, Valavanis A. Simultaneous Multi-Slice (Slice Accelerated) Diffusion EPI. ASNR 53rd Annual Meeting, April 25-30, 2015, Chicago, Illinois […] [...]

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 […] [...]

Ankylosing spondylitis, chronic disease

There is marked irregularity and sclerosis of the sacroiliac joints bilaterally. Fatty changes are noted as well, in the sacrum, bordering the joint. There is little edema within the bone adjacent to the sacroiliac joints. All are findings consistent with long standing disease. Part of the on-line supplement to Neuroradiology – The Essentials with MR […] [...]

Ankylosing spondylitis, hip disease

One-third of individuals with AS develop hip and shoulder involvement. Bilateral disease, with joint effusions and synovial enhancement are characteristic. Additional less common findings include subchondral bone marrow edema, erosive destruction, and fatty accumulation. (Case provided courtesy of Reto Sutter, MD, Leitender Arzt, Radiologie, Uniklinik Balgrist, Zürich) Part of the on-line supplement to Neuroradiology – […] [...]

Ankylosing spondylitis, sacroiliac joint disease

In this patient with long standing disease, joint space irregularity and adjacent fatty changes predominate. (Case provided courtesy of Reto Sutter, MD, Leitender Arzt, Radiologie, Uniklinik Balgrist, Zürich) Part of the on-line supplement to Neuroradiology – The Essentials with MR and CT (© 2015) [...]

Ankylosing spondylitis, with bony ankylosis of the sacroiliac joints

In this 44-year-old patient, coronal images of the pelvis reveal fusion of the sacroiliac joints bilaterally. Sagittal images of the lumbar spine show vertebral body squaring and a bamboo like appearance due to diffuse ankylosis (and syndesmophytes). There is vertebral body fusion at multiple levels, with loss of disk space height and abnormal signal intensity […] [...]

Anterior and posterior fusion defects of C1

Note the well corticated margins and absence of a discrete fracture line. Such fusion defects are congenital in nature, and are primarily incidental findings. Incomplete posterior fusion can be seen in normal children up to the age of 10, with bony fusion typically occurring by age 5. Clefts of the posterior arch occur in 5% […] [...]

Cervical cord hemangioblastoma

Cervical cord hemangioblastoma, in a patient with von Hippel Lindau syndrome. A small enhancing intramedullary lesion is noted at C4, with mild accompanying vasogenic edema. 75% of spinal cord hemangioblastomas are sporadic, 25% occur in association with von Hippel Lindau syndrome. Spinal cord hemangioblastomas most commonly occur posteriorly within the cord, as in this patient. […] [...]

Chondrosarcoma of the cervical spine

The left lamina of C2 is involved by a focal mass lesion, which is slightly expansile in nature. A somewhat characteristic feature of the histologic diagnosis, reflecting hyaline cartilage, is the marked hyperintensity on the T2-weighted scan. There is moderate enhancement post-contrast, which as with the other findings (with the exception of the appearance on […] [...]

Chronic dens fracture

A type II odontoid fracture is present, with non-union (pseudoarthosis). (Case provided courtesy of Reto Sutter, MD, Leitender Arzt, Radiologie, Uniklinik Balgrist, Zürich) Part of the on-line supplement to Neuroradiology – The Essentials with MR and CT (© 2015) [...]

DISH (diffuse idiopathic skeletal hyperostosis) in the cervical spine

In DISH (also known as Forestier disease) there is calcification and ossification of ligaments and entheses (the connective tissue between bone and a tendon or ligament) involving the vertebral column. Ossification of the anterior longitudinal ligament is common (and often marked), and may occur in conjunction with ossification of the posterior longitudinal ligament (OPLL). Both […] [...]

Epidural hematoma, spine, illustrating image composition

Composed sagittal T2-weighted, T1-weighted, and post-contrast T1-weighted images are presented. Each image is an automatically generated composition of two high-resolution independent cervicothoracic and thoracolumbar image acquisitions. The patient was on aspirin and Plavix, and presented with urinary retention and poor anal sphincter tone, consistent with a lesion compressing the conus medullaris. A predominantly deoxyhemoglobin epidural […] [...]

Hydatid cysts of the sacrum, ileum and L5

In the spine, with hydatid disease, there is typically slow resorption of trabeculae, without bony expansion, with a conglomeration of daughter cysts. This accounts for the multilocular appearance on MR, with high signal intensity on T2-weighted sequences. (Case provided courtesy of Reto Sutter, MD, Leitender Arzt, Radiologie, Uniklinik Balgrist, Zürich) Part of the on-line supplement […] [...]

Hyperflexion injury with a clay-shoveler fracture

CT depicts an avulsion fracture of the spinous process of C6. MR reveals additional important findings, including the extensive posterior paraspinal muscular injury (edema), disruption of the interspinous ligament, compression fractures (marrow edema) involving multiple contiguous cervical and thoracic vertebral bodies, and extensive prevertebral edema as well as fluid (hemorrhage). Note that the cord appears […] [...]

Ivory vertebra, metastatic prostate carcinoma

The ivory vertebra describes a dense sclerotic vertebral body on plain film or CT, with the correlate on MR being very low signal intensity on both T1- and T2-weighted sequences. L2 and S2 are involved in this fashion in the presented case, with additional metastatic lesions noted posteriorly in L1 and L3, together with mild […] [...]

Klippel-Feil

There is vertebral nonsegmentation at two levels, one involving a hemivertebra, together with a prominent scoliosis of the cervical spine. Also present is an anterior fusion defect of C1. (Case provided courtesy of Reto Sutter, MD, Leitender Arzt, Radiologie, Uniklinik Balgrist, Zürich) Part of the on-line supplement to Neuroradiology – The Essentials with MR and […] [...]

Lipoma, tethered cord, hydromyelia, block vertebrae

The cord extends at least to the S1 level, with dilatation of the central canal within that portion visualized (hydromyelia). A small lipoma is noted within the bony spinal canal posteriorly at the S1 level. The axial scan at this level reveals the cord near its termination/posterior tethering, with the lipoma immediately contiguous bilaterally. Fusion […] [...]

Meningioma (WHO grade I, meningotheliomatous in type), cervical spine

A large, homogeneously enhancing, intradural extramedullary mass lesion is noted anteriorly within the thecal sac at the C2 level. There is prominent deformity and compression of the cord, long standing in nature, without evidence of edema or gliosis. Note the characteristic flat margin of the lesion along the dura. Part of the on-line supplement to […] [...]

Migrated disk fragment

There is mild loss of disk space height (and thus substance) at L5-S1. A left paracentral disk herniation is noted, at this level, together with superior migration. Note the slight hyperintensity of the superiorly migrated portion of the disk on the T2-weighted scan, consistent with a free fragment (which is also suggested by the extent […] [...]

Multiple sclerosis, cervical and thoracic cord lesions

An enhancing cervical cord lesion is noted on sagittal and axial images, located at the C2 level, with an additional thoracic lesion (which did not enhance) depicted on a lower axial T2-weighted section. Neither lesion respects gray-white matter boundaries, as seen on the axial T2-weighted scans, a common finding for MR lesions of the cord. […] [...]

Neurofibromatosis type 1

Dural ectasia and a lateral meningocele are present. Also noted are scalloped vertebrae and scoliosis. All are characteristic findings. (Case provided courtesy of Reto Sutter, MD, Leitender Arzt, Radiologie, Uniklinik Balgrist, Zürich) Part of the on-line supplement to Neuroradiology – The Essentials with MR and CT (© 2015) [...]

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 […] [...]

Paget disease of the lumbar spine and pelvis

Both the L1 and L2 vertebral bodies (together with their respective posterior elements) are involved, with the vertebral bodies expanded in the antero-posterior dimension and L2 a characteristic “picture frame” vertebra. There is involvement as well of the pelvis together with the sacral vertebral bodies. Coarse and thickened trabeculae are particularly evident in the iliac […] [...]

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 […] [...]

Cholesterol granuloma

A large expansile lesion is noted in the right petrous apex, hyperintense on both T1- and T2-weighted scans, without diffusion restriction or internal contrast enhancement. The imaging findings are characteristic, with one exception – that a peripheral hemosiderin rim is not present. The lesion was resected through a transnasal, transclival route. Part of the on-line […] [...]

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 […] [...]

Cholesterol granuloma, orbit

More common sites for a cholesterol granuloma include the petrous apex, middle ear and mastoid antrum. The lesion, when in the orbit, presents as an extraconal mass, in the superior-temporal quadrant. Differential diagnosis includes the lacrimal gland tumors. Although post-contrast T1-weighted scans are presented, the lesion was hyperintense pre-contrast (and specifically demonstrated only peripheral enhancement). […] [...]

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 […] [...]

Pancoast tumor

An apical soft tissue mass is present, with invasion of the adjacent vertebral body (visualized by the lucent defect therein). (Case provided courtesy of Reto Sutter, MD, Leitender Arzt, Radiologie, Uniklinik Balgrist, Zürich) Part of the on-line supplement to Neuroradiology – The Essentials with MR and CT (© 2015) [...]

Scheuermann disease

Only a sagittal midline T2-weighted scan is presented. However this is sufficient to visualize the characteristic thoracic kyphosis, with involvement of 3 contiguous vertebrae. There is anterior wedging of the vertebral bodies and disk space narrowing, the latter greatest anteriorly. (Case provided courtesy of Reto Sutter, MD, Leitender Arzt, Radiologie, Uniklinik Balgrist, Zürich) Part of […] [...]

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) [...]

Chronic maxillary sinusitis

There is thickening of the walls (seen as a thin line of low SI) of the right maxillary sinus, mild circumferential mucosal thickening, and complete opacification (with the contents partially low signal intensity, suggestive of fungal infection and/or dessication), with these findings all seen on the T2-weighted scan and consistent with chronic sinusitis. The subsequent […] [...]

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 […] [...]

Craniosynostosis

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 […] [...]

Schwannoma (WHO grade I)

A lobulated uniformly enhancing mass lesion is noted with the bulk of the mass paraspinal in location, extending into the foramen at the T4-5 level on the right, with epidural extent and mild displacement of the cord to the left. The intervertebral foramen is enlarged. The well-circumscribed nature of the lesion, and location, favor the […] [...]

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 […] [...]

Juvenile angiofibroma, in a 16-year-old male

A large, intensely enhancing, mass lesion is seen within the left nasal cavity posteriorly which extends to fill the sphenoid sinus. There is bone destruction and remodeling on CT. The blood supply was predominantly from the external carotid artery, specifically from branches of the internal maxillary artery and ascending pharyngeal artery. On DSA there is […] [...]

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 […] [...]