Presentation

Altered sensorium following traumatic brain injury.

Patient Data
AGE: 40 years
GENDER: Male

MRI

Coronal T2


Axial T2


Axial FLAIR


Coronal T1


Axial T1


Axial Gradient Echo


Axial DWI

There are crescentic collections in the convexity of bilateral frontal, temporal and parietal bones which appears hyperintense on T1, T2 and FLAIR sequences consistent with bilateral late subacute subdural hematoma. The subdural collections demonstrate fluid-fluid levels anteriorly. There is mass effect evidenced by effacement of the sulci and gyri. No midline shift. The ventricles are within normal limits.

Case Discussion
Subdural hematoma is a collection of blood in the potential space between the dura and arachnoid mater of the meninges of the brain. it occurs in all age groups, most frequently due to trauma.

MRI findings are in keeping with bilateral late subacute subdural hematoma following traumatic brain injury. The MRI was performed 10 days post injury.

Subdural hemorrhage (SDH) (also commonly called a subdural hematoma) is a collection of blood accumulating in the subdural space, the potential space between the dura and arachnoid mater of the meninges around the brain. SDH can happen in any age group, is mainly due to head trauma and CT scans are usually sufficient to make the diagnosis. Prognosis varies widely depending on the size and chronicity of the hemorrhage. 

Epidemiology
Subdural hematomas, most frequently due to trauma, are seen in all age-groups although etiology will vary :

infants: non-accidental injury
young adults: motor vehicle accidents, vascular lesions
elderly: falls (although a definite history of trauma may be lacking)
They are present in ~15% (range 10-20%) of all head trauma cases and occur in up to 30% of fatal injuries.

In addition to trauma, there are numerous other far less common causes: 

glutaric aciduria type 1  (infants and children, rare)
vascular malformations (all ages)
Intracranial hypotension

Presentation

Right hemiplegia of 2 hours duration.

Patient Data
AGE: 80 years
GENDER: Female

MRI

Sagittal T1


Axial T1


Axial FLAIR


Coronal T2


Axial Gradient Echo


MRA source images MRA


Axial DWI


Axial ADC


MRA 3D-TOF

The MRI sequences demonstrate areas of restricted diffusion in the distribution of the left middle cerebral artery (MCA) territory, not visible on FLAIR sequences. No hemorrhagic transformation was seen on the GE sequence. The MRA 3D-TOF shows complete occlusion of the left middle cerebral artery.

Case Discussion
MRI features of an early hyperacute middle cerebral artery (MCA) territory infarct.

The middle cerebral artery territory is the most commonly affected territory in a cerebral infarction, due to the size of the territory and the direct flow from the internal carotid artery into the middle cerebral artery, providing the easiest path for thromboembolism.

Clinical presentation
The neurological deficit will depend on the extent of the infarct and hemispheric dominance, and include:

contralateral hemiparesis
contralateral hemisensory loss
hemianopia
aphasia: if the dominant hemisphere is involved; may be expressive in anterior MCA territory infarction, receptive in posterior MCA stroke, or global with extensive infarction
neglect: non-dominant hemisphere
Radiographic features
Generally, the features are those of cerebral infarction, similar to those seen in any other territory. As such these features are discussed in the generic article: cerebral infarction.

There are however certain features specific to middle cerebral artery infarct, and these are discussed below. For both CT and MRI it is worth dividing the features according to the time course.

It should also be noted that middle cerebral artery infarcts are often incomplete affecting only perforator branches or one or more distal branches. As such in many cases, only parts of the middle cerebral artery territory are affected.

Presentation

This child presents with developmental regression.

Patient Data
AGE: 7 year old
GENDER: Female

MRI

Sagittal T1


Sagittal T2


Axial T2


Coronal STIR


Axial FLAIR


Axial T1 C+


Axial DWI


Axial ADC

There is extensive white matter T2 hyperintensity with some islands of spared white matter resulting in a tigroid pattern. There is also relative sparing of the subcortical U fibers. There is a mix of T2 shine through and diffusion restriction related to the white matter. Diffusion restriction is most pronounced related to the corpus callosum. There is enhancement of multiple cranial nerves. 

Case Discussion
MRI findings are consistent with metachromatic leukodystrophy (MLD). Confirmatory genetic testing showed two pathogenic mutations in the ARSA gene as well as two copies of ARSA variants associated with reduced enzyme activity, compatible with the diagnosis of MLD. 
 
Metachromatic leukodystrophy is a rare lysosomal storage disorder related to decreased arylsulfatase A (ARSA) activity. This patient presents with the juvenile form of the disease. There are also late infantile and adult forms. A bone marrow transplant can be used to delay the progression of the disease. Patients eventually have neurologic and cognitive impairment and early death. 

Metachromatic leukodystrophy (MLD) is the most common hereditary (autosomal recessive) leukodystrophy and is one of the lysosomal storage disorders. It has characteristic imaging features including peri-atrial and to a lesser extent frontal horns leukodystrophy as well as periventricular perivenular sparing results in "tigroid pattern" on fluid-sensitive MRI sequences. 

Epidemiology
It has an estimated prevalence of ~1:100,000 and typically manifests between 12 to 18 months of age. The disease can sometimes be classified according to the time of onset:

late infantile: most common ~65% (range 50-80%)
juvenile (onset between 3-10 years)
adult (after age 16)

References
Schlotawa L, Preiskorn J, Ahrens-Nicklas R, Schiller S, Adang LA, Gärtner J, Friede T. A systematic review and meta-analysis of published cases reveals the natural disease history in multiple sulfatase deficiency. J Inherit Metab Dis. 2020 Nov;43(6):1288-1297. doi: 10.1002/jimd.12282. Epub 2020 Jul 22. PMID: 32621519.
Schlotawa L, Preiskorn J, Ahrens-Nicklas R, Schiller S, Adang LA, Gärtner J, Friede T. A systematic review and meta-analysis of published cases reveals the natural disease history in multiple sulfatase deficiency. J Inherit Metab Dis. 2020 Nov;43(6):1288-1297. doi: 10.1002/jimd.12282. Epub 2020 Jul 22. PMID: 32621519.

Presentation

Headache.

Patient Data
AGE: 35 years
GENDER: Female

MRI

Axial T2


Sagittal T2


Axial FLAIR


Coronal


Axial DWI


Axial ADC


Axial T1


Sagittal T1


Axial T1 C+


Sagittal T1 C+

There is cortically based, bubbly, lobulated, mass at the posterior part of the left frontal bone measuring (27 x 16 x 16 mm), shows focal rim enhancement of the small part of the tumor (10 x 6 mm), but shows no restricted diffusion neither mass effect. The mass shows suppressed center on FLAIR with a rim of hyperintense signal but no surrounding edema, picture suggestive of DNET.

Differential diagnosis is multinodular and vacuolation neuronal tumor.

Case Discussion
The 'bubbly' appearance can be seen also in multinodular and vacuolating neuronal tumors (MVNT) which are however in the juxtacortical white matter, rather than in the cortex.

Multinodular and vacuolating neuronal tumors (MVNT) are a newly recognized cytoarchitectural pattern in the recently revised 2016 edition of the WHO classification of CNS tumors.

Radiologically, MVNTs appear as small 'bubbly' indolent subcortical tumors that sometimes present with seizures. These tumors have been most frequently identified in the temporal lobe, although that is likely to be due to that location being more likely to result in seizures than necessarily a predilection for that lobe .

Epidemiology
The true epidemiology of these tumors is unknown as they have only been recently described and many are asymptomatic and thus likely undiagnosed (or misdiagnosed). Reported cases are mostly in young to middle-aged individuals with adult-onset epilepsy . 

Clinical presentation
Many of these lesions are probably asymptomatic and may be found incidentally on imaging for other reasons, and have, over the years, been misinterpreted a variety of other lesions (see differential diagnosis below). In some individuals these tumors are epileptogenic. 

Presentation

Chronic headaches.

Patient Data
AGE: 5 years
GENDER: Female

MRI

Coronal T1


Axial T2


Sagittal T2


Coronal T2


Sagittal 3D FIESTA


Axial T1 C+


Sagittal T1 C+


Axial ADC


Axial DWI

The MRI sequences demonstrate a suprasellar cyst of CSF signal on all sequences, compressing and displacing the 3rd ventricle superiorly and optic chiasma and infundibulum anteriorly with an asymmetrical dilatation of the lateral ventricles. The 4th ventricle is of normal size and shape.

Case Discussion
MRI features most consistent with a suprasellar arachnoid cyst compressing the 3rd ventricle with biventricular hydrocephalus.

Suprasellar arachnoid cysts can be challenging to diagnose and, unlike many other arachnoid cysts, are usually symptomatic. 

For a general discussion, please refer to the article on arachnoid cysts.

Clinical presentation
As can be expected from its location, suprasellar arachnoid cysts manifest clinically in the same way as other suprasellar masses, with visual symptoms due to compression and distortion of the optic pathways. Often these lesions extend superiorly, invaginating into the third ventricle and obstruct the outflow of the lateral ventricles, resulting in obstructive hydrocephalus . 

Distortion of the pituitary infundibulum can also cause endocrine dysfunction . 

Radiographic features
As with arachnoid cysts elsewhere, they are very thin walled (often imperceptible except on dedicated high-resolution T2 imaging) cystic lesions which follow CSF on all imaging modalities. There is no solid component and no enhancement (for further general discussion, please refer to the comprehensive article on arachnoid cysts). 

These cysts invaginate superiorly into the third ventricle, and may even extend into one or both foramina of Monro. They are in such cases, associated with obstructive hydrocephalus. 

Presentation

Left tongue weakness.

Patient Data
AGE: 70 years
GENDER: Male

MRI

Axial T1
Axial T1 weighted images demonstrate a T1 hyperintense crescent (arrow) related to the tortuous distal left ICA, consistent with dissection. This is immediately adjacent to the left hypoglossal canal. 

CT

Axial C+ arterial phase
Axial CTA images demonstrate a tortuous distal left ICA with a curvilinear hypodense rim (long arrow), consistent with a dissection. This is located adjacent to the hypoglossal canal (short arrows).

Case Discussion
There is a distal left cervical ICA dissection, just below the skull base, in this patient presenting with left hypoglossal neuropathy.  Mass effect on the adjacent hypoglossal nerve is the rare cause of this patient's neuropathy.

References
Giuseppe Cruciata, Rikesh Parikh, Meera Pradhan, Jay Shah, Eric Greif, Evan G. Stein, Internal carotid artery dissection and pseudoaneurysm formation with resultant ipsilateral hypoglossal nerve palsy, Radiology Case Reports, Volume 12, Issue 2, 2017, Pages 371-375, ISSN 1930-0433, https://doi.org/10.1016/j.radcr.2017.01.016.
Jurkiewicz MT, Stein JM, Learned KO, Nasrallah IM, Loevner LA. Hypoglossal nerve palsy due to carotid artery dissection: an uncommon presentation of a common problem. Neuroradiol J. 2019;32(2):123-126. doi:10.1177/1971400918825485
Allingham W, Devakumar V, Herwadkar A, Punter M. Hypoglossal Nerve Palsy Due to Internal Carotid Artery Dissection. Neurohospitalist. 2018;8(4):199. doi:10.1177/1941874417736711

Presentation

Gait abnormalities, poor vision, inability to dress and feed self.

Patient Data
AGE: 10 years
GENDER: Male

MRI

Axial T2


Coronal T2


Sagittal T2


Axial FLAIR


Axial T1


Axial T1 C+


Coronal T1 C+


Axial DWI


Axial ADC

There are extensive bilaterally symmetrical T1 hypointensities and T2/FLAIR hyperintensities in the parieto-occipital white matter, corpus callosum, corticospinal tracts and the cerebellar white matter. The lesions in the parieto-occipital regions show peripheral enhancement post gadolinium administration. No diffusion restriction on DWI/ADC. 

Case Discussion
Adrenoleukodystrophy is an X-linked inherited peroxisomal disorder that can affect children and adults, although most cases are diagnosed in childhood. Clinical presentation includes memory impairment, emotional instability and progressive deterioration of vision, hearing and motor function1.

MRI is essential in the evaluation of patients with adrenoleukodystrophy. MRI features, in this case, support the diagnosis of adrenoleukodystrophy in this patient.

References
Ji Hyung Kim, Hyon J. Kim. Childhood X-linked Adrenoleukodystrophy: Clinical-Pathologic Overview and MR Imaging Manifestations at Initial Evaluation and Follow-up1. (2005) RadioGraphics. doi:10.1148/rg.253045118

Presentation

Left upper limb weakness in a patient with a background of IV drug abuse

Patient Data
GENDER: Female

CT
CT post contrast

Axial C+ arterial phase



Axial C+ arterial phase
Multiple well defined ring enhancing lesion with significant perilesional edema and mass effect.

MRI

Axial T2


Axial DWI


Axial ADC


Axial T1 C+


Coronal T1 C+

Multiple ring-enhancing lesion noted in the right high frontal lobe, temporal lobe and left anterior frontal lobe as seen on the CT with significant perilesional edema. These lesions show central low signal on T1 weighted images, high signal on T2/FLAIR and appears to show central true restricted diffusion. 

Periphery of the lesion appears hypo-intense on the T2 weighted images. Dual rim sign is appreciated on T2-weighted imaging.

There is mass-effect with cortical sulcal over the right cerebral cortex and body of lateral ventricle.

Presentation

Family history subarachnoid hemorrhage. Screening.

Patient Data
AGE: 35 years
GENDER: Female

MRI

Axial MRA
Unusual pattern of apparently arterialized flow within the left cavernous sinus, extending posteriorly as far as the transverse sinus and internal jugular vein on the left.

The left-sided location and extent of high signal over multiple slabs is also typical for incidental jugular reflux. 

A carotid-cavernous fistula or dural arteriovenous fistula can have a similar appearance, however, the lack of superior ophthalmic vein dilatation would be unusual. 

DSA (ANGIOGRAPHY)

Frontal left CCA


Lateral left CCA


Frontal left CCA


Lateral left CCA


Frontal left ICA


Lateral left ICA


Frontal left ECA


Lateral left ECA


Oblique left ECA


Oblique left ECA


Frontal right CCA


Frontal right CCA


Lateral


Frontal right ECA


Lateral right ECA


Frontal vertebral artery


Lateral vertebral artery


Frontal right vertebral artery


Lateral right vertebral artery
DSA (angiography)
Frontal left CCA
Despite the venous anatomy, and earlier MRI, a DAVF could not be identified. As the patient is asymptomatic, and no definite abnormality found on the DSA, if subsequent non invasive follow up is planned, suggest inclusion of pre and post contrast imaging, and contrast enhanced MRV.

MRI

Axial T2


Axial MRA


Axial DWI


Axial ADC


Axial SWI


Axial FLAIR


Axial time-resolved angiography


Coronal time-resolved angiography


Sagittal time-resolved angiography

Early flow is again shown in the left cavernous sinus, extending to the transverse sinus, stable compared with the prior MRI. Time-resolved angiography demonstrates retrograde flow up the left internal jugular reflux and across to the right side accounting for the MRA TOF findings. 

Case Discussion
Reflux of the left IJV is a recognized cause of abnormal appearing MRA 1. 

References
1. Caton MT, Callen AL, Copelan AZ, Narsinh KH, Smith ER, Amans MR. Jugular Venous Reflux Can Mimic Posterior Fossa Dural Arteriovenous Fistulas on MRI-MRA. (2021) AJR. American journal of roentgenology. 216 (6): 1626-1633. doi:10.2214/AJR.20.24012 - Pubmed

Presentation

Presents to ED with sudden right hemianopia and dysphasia on a background of 5 days of left-sided headache and tinnitus. On examination, the patient was GCS 13 and had left periorbital purpura.

Patient Data
AGE: 50 years
GENDER: Female

CT

Axial non-contrast


Coronal non-contrast


Axial venogram


Sagittal venogram


Coronal venogram

Left temporo-parieto-occipital hematoma with intraventricular extension and likely small subdural extension, as suggested by high density material along the left side of the tentorium and the posterior falx cerebri. Subsequent rightward midline shift and early hydrocephalus, as indicated by dilated right temporal horn.

Hyperdensity of the left transverse sinus, left sigmoid sinus, and left internal jugular vein on non-contrast imaging, in conjunction with non-opacification of these structures on venogram, is consistent with cerebral venous sinus thrombosis. Hyperdensity and distension of the left superior ophthalmic vein on non-contrast imaging, with asymmetric opacification on venogram, suggests thrombosis. Non-opacification of the posterior left cavernous sinus is suspicious for further thrombosis.

Case Discussion
Blood tests revealed severe thrombocytopaenia (18 x 109/L) and significantly elevated D-Dimer (29000 ng/mL). Given a history of AstraZeneca COVID-19 vaccine 12 days prior to presentation, suspicion was raised for vaccine induced thrombotic thrombocytopaenia. Enzyme-linked immunosorbent assay (ELISA) detection of platelet factor 4 (PF4) antibodies confirmed the diagnosis.

Dural venous sinus thrombosis (plural: thromboses) is a subset of cerebral venous thrombosis, often coexisting with cortical or deep vein thrombosis, and presenting in similar fashions, depending mainly on which sinus is involved.

As such, please refer to the cerebral venous thrombosis article for a general discussion.

Epidemiology
Any age women on the contraceptive pill are over-represented. Please refer to the article on cerebral venous thrombosis for a broad discussion on epidemiology and risk factors.

Clinical presentation
Presentation is variable and can range from asymptomatic to coma and death. Typically patients complain of headache, nausea, and vomiting. Neurological deficits are variable.

Pathology
Superior sagittal sinus or the dominant transverse sinus thrombosis can affect the arachnoid granulation absorption of cerebrospinal fluid; consequent cerebral swelling may occur . The subsequent venous hypertension can lead to edema and hemorrhage.

References
Favarolo EJ. Laboratory testing for suspected COVID-19 vaccine–induced (immune) thrombotic thrombocytopenia. Int J Lab Hematol. 2021 Jun 17. doi:10.1111/ijlh.13629
THANZ (Thrombosis and Haemostasis Society of Australia and New Zealand). Suspected Vaccine Induced Prothrombotic Immune Thrombocytopenia (VIPIT)/Vaccine induced immune thrombotic thrombocytopenia VITT): THANZ Advisory Statement for Haematologists. 2021 Apr.