Spotters Avadhoot Bhate

30/11/2015

1. Progressive muscle weakness since the last 2 years

Amyotrophic lateral sclerosis

• Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig disease or Charcot disease, is the most common form of motor neuron disease , resulting in progressive weakness and eventual death.

• MRI• The earliest MR manifestation is hyperintensity on

T2/FLAIR in the corticospinal tracts, seen earliest in the internal capsule, as the fibres are most concentrated here. Eventually, the entire tract from motor strip to the spinal cord is affected by increased T2 signal and volume loss

2.

Fronto - Nasal Encephalocele

• Cystic changes in the involved brain.• Abnormal signal intensity in the rest of the

brain. • Pachygyria in the frontal region.• Absent crista galli with enlarged foramen

caecum• Tonsillar herniation.• Ass:- corpus callosal agenesis, Dandy

walker malformation & lobar holoprosencephaly.

3

Holoprosencephaly

• Monoventricle.• Decreased white matter volume.• Absent falx cerebri.• Corpus callosal agenesis.• Three types - alobar, semilobar and

lobar.

4

• Colloid cysts of the third ventricle are a benign epithelial lined cyst with characteristic imaging features. Although usually asymptomatic, they can rarely present with acute and profound hydrocephalus

• Classical MR signal morphology.• Hypointense in T2W images.• Hyperintense in T1W images.

Colloid cyst

5

Giant cerebral aneurysms are ones that measure >25 mm in greatest dimension.

Clinical presentationPatients can present with symptoms and signs of mass effect or subarachnoid haemorrhage 1,2.

PathologyMost commonly represent saccular cerebral aneurysms but may also be fusiform or serpentine in morphology . They are thought to develop via two pathways :• internal elastic lamina de novo defect• enlargement from a smaller aneurysm

.

ACom Aneurysm

MRI

On MRI also the patent and thrombosed aneurysm display different imaging features:

T1most of the patent aneurysm appears as flow void, or they may show heterogeneous signal intensityin thrombosed aneurysm appearance depends on the age of clot within the lumenT2typically hypointenselaminated thrombus may show a hyperintense rim

6. 35 yr/ m, chronic alcoholic on treatment develops sudden onset of mental confusion and seizures 

• Osmotic demyelination syndrome refers to acute demyelination seen in the setting of osmotic changes, typically with the rapid correction of hyponatraemia. It is the more recent term replacing central pontine myelinolysis

•  usually in the setting of rapidly corrected electrolyte disturbance:

• chronic alcoholics• chronically debilitated patients• transplant recipient

•  in the lower pons. Signal characteristics of affected region include:

• T1: mildly or moderatly hypointense• T2: hyperintense, sparing the periphery and

corticospinal tracts• PD: hyperintense• FLAIR: hyperintense• DWI: hyperintense• ADC: signal low or signal loss• T1 C+ (Gd): usually there is no enhancement,

but some authors reported that it may occur 

7.

Sturge-Weber syndromeSturge-Weber syndrome (SWS), or encephalotrigeminal angiomatosis, is a

phakomatosis characterised by facial port wine stains and pial angiomas

CTdetects subcortical calcification at an earlier age than plain film and can also demonstrate associated parenchymal volume loss'tram-track' subcortical calcification

MRIT1: signal of affected region largely normal, with anatomic volume loss evident at older ageT1 C+ (Gd) prominent leptomeningeal enhancement in affected areaT2 low signal in white matter subjacent to angioma representingcalcification later in lifeabnormal deep venous drainage seen as flow voidsGE/SWI/EPI: sensitive to calcification, seen as regions of signal drop out

8.

État cribléÉtat criblé, also known as status cribrosum, is a term that describes the diffusely widened perivascular spaces (Virchow-Robin spaces) in the basal ganglia, especially in the corpus striatum. It is usually symmetrical, with the perivascular spaces showing CSF signal and without diffusion restriction

9.

Carotid-Cavernous Fistula• Direct CCF: high-flow, single hole fistula

between ICA and cavernous sinus• Etiology: trauma (MC), ruptured aneurysm,

iatrogenic, spontaneous (Ehlers-Danlos, Marfan)• Indirect CCF: dural AVF of cavernous sinus,

typically supplied by numerous ECA +/- cavernous ICA branches

• Etiology: mostly idiopathic• Pulsatile exophthalmos, orbital bruit,

glaucoma

10.

Orbital Cellulitis• Orbital septum acts as a barrier to infection

• Most infections preseptal, involving lid and conjunctiva • Postseptal can lead to spread to globe, optic nerve,

caverous sinus (+/- thrombosis), meninges, epidural or cerebral abscess

• Suspect if see stranding in intraconal fat• Most from Staph or Strep from adjacent sinusitis,

especially maxillary• Other causes: postsurgical, derm infection, trauma

• Painful ophthalmoplegia, proptosis, chemosis, decreasing visual acuity

11.

Ranula• Cystic lesion due to obstruction of sublingual gland

duct from infection, trauma, or calculi• Simple = above mylohyoid muscle• Plunging = through the muscle• Wall usually enhances• Pointed edge along anterior extent in sublingual

space• Rupture can cause encapsulated mucus-containing

infection in deep tissues of neck• DDx: dermoid, lymphatic malformation• Tx: intraoral (simple) vs. cervical (plunging) surgical

approach

12.

Cavernous Malformation• Thin-walled sinusoidal vessels (neither arteries nor

veins) • May present w/seizures or small parenchymal

hemorrhages• CT

• High density regions on noncontrast CT• May have associated calcifications and enhance

• MR• Copious amounts of hemosiderin surrounding various

circumscribed regions of hemorrhage (methemoglobin)• Complete rim of hemosiderin (as opposed to tumors)

• Angiography: usually occult

13.

Intracranial hypotension• CT

• subdural collection• cerebellar tonsillar herniation into the foramen magnum: tonsillar ectopia• dural venous sinus distention

• MRI

• diffuse brain swelling 3• sagging brainstem• subdural effusions• increased fluid around optic nerves • bulbous dilatation of sheath behind globes• rounding of the cross-section of the dural venous sinuses (venous distension sign)• enlarged pituitary • ventricular angle less than 120 degrees: angle between medial wall of the frontal

horns on coronal plane• contrast-enhanced MR imaging demonstrates

• venous sinus engorgement• pachymeningeal enhancement (infra- and supratentorial)• enlargement of the pituitary gland

14

LaryngocoeleA laryngocoele refers to a dilatation of the laryngeal ventricular saccule

CT• Typically seen as a well defined, air or fluid filled lesion related

to the paraglottic space, which has continuity with the laryngeal ventricle. The extent will obviously depend on sub type.

Attenuation characteristics may vary depending on laryngocoele content (e.g. air, fluid, mucus etc).

Complications:infection - infected laryngocoele is known as a pyolaryngocoeleincreased risk of laryngeal carcinoma

20. 15.

External auditory canal atresiaExternal auditory canal atresia (EACA) is characterised by complete

or incomplete bony atresia of the external auditory canal (EAC)

Findings in the middle ear are variable and the inner ear and inner auditory canal are typically normal

number of syndromes are associated with external auditory canal atresia 2. These include:• Crouzon syndrome• Treacher Collins syndrome• Goldenhar syndrome• Pierre Robin syndrome

16. 40 yr, Recurrent TIA and dementia

CADASILCerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is characterised by recurrent lacunar and subcortical white matter ischaemic strokes and vascular dementia in young and middle age patients without known vascular risk factors

autosomal dominant trait

recurrent TIA and dementiaMRI: widespread confluent white matter hyperintensities . More circumscribed hyperintense lesions are also seen in the basal ganglia, thalamus and pons

There is relative sparing of the occipital and orbitofrontal subcortical white matter 2, subcortical U-fibers and cortex

17. Seropositive status

CMV encephalitis

MRI

In CMV encephalitis, there is usually only non specific increased T2/FLAIR signal in the white matter. If ventriculitis is also present then enhancement of the ependymal surface and hydrocephalus may also be seen.

high T2 white matter change most prominent in a periventricular distribution

no enhancement (unless ventriculitis present, in which case 30% or so will enhance)no mass effect (often seen with concurrent atrophy)

Cytomegalovirus (CMV) encephalitis is a CNS infection that almost always develops in the context of profound immunosuppression

18.

Adrenoleukodystrophy Adrenoleukodystrophy (ALD) is a x-linked inherited metabolic peroxisomal disorder characterised by lack of oxidation of very long chain fatty acids (VLCFAs) that results in severe inflammatory demyelination of the periventricular deep white matter with posterior-predominant pattern and early involvement of the splenium of the corpus callosum and periatrial white matter changesMRIA majority of cases tend to show symmetrical cerebral white matter signal change involving the posterior (occipitoparietal) periventricular white matter (i.e. posterior cerebral, around splenium and peritrigonal white matter).Signal intensityT1central zone: hypo-intenseT2 central zone: markedly hyperintenseintermediate zone: isointense to hypointenseperipheral zone: moderately hypointense

19.

Lhermitte-Duclos Disease• AKA dysplastic cerebellar gangliocytoma• Mass-like lesion usually seen in the cerebellum

as a diffusely infiltrative process• Unclear whether this lesion is a neoplasm,

hamartoma, or dysplasia• WHO grade I• Increased intracranial pressure and/or ataxia• Half of pts also have Cowden disease

• Autosomal dominant phakomatosis assoc w/colonic polyps, cutaneous tumors, meningioma, glioma, thyroid and breast neoplasms

20.

• A "growing" skull fracture (GSF), also known as "post-traumatic leptomeningeal cyst" or "craniocerebral erosion," is a rare lesion that occurs in just 0.3-0.5% of all skull fracture

• GSFs develop in stages and slowly widen over time. In the first "prephase," a skull fracture (typically a linear or comminuted fracture) lacerates the dura, and brain tissue or arachnoid membrane herniates through the torn dura.

• GSFs demonstrate a progressively widening and unhealing fracture. A lucent skull lesion with rounded, scalloped margins and beveled edges is typical. CSF and soft tissue are entrapped within the expanding fracture Most GSFs are directly adjacent to post-traumatic encephalomalacia, so the underlying brain often appears hypodense

21. Sign??

Mount Fuji sign• Mount Fuji" sign of tension

pneumocephalus is seen as bilateral subdural air collections that separate and compress the frontal lobes

• The frontal lobes are displaced posteriorly by air under pressure and are typically pointed where they are tethered to the dura-arachnoid by cortical veins, mimicking the silhouette of Mount Fuji

22. 35 yr/M, History of assault

Gun shot injury• Series of NECT scans depicts findings from a

patient with a large-caliber, high-velocity gunshot wound. The entrance wound is through the squamous portion of the right temporal bone. A mass of blood, imploded bone, and a few bullet fragments  is seen under the entrance wound.

• The radiologist's report should identify the entry site, describe the missile path including bone fragmentation and ricochet paths, and evaluate for exit wound. Possible damage to critical blood vessels should be noted along with secondary effects such as ischemia and herniation syndromes

23. 28 yr post-partum with severe headache.

Postpartum cerebral angiopathy 

• Postpartum cerebral angiopathy (PPCA) is a rare but important neurological complication of pregnancy.

• Patients often have a history of migraines and generally present with sudden severe ("thunderclap") headache and variable hypertension.

• Multiple foci of segmental narrowing in the intracranial circulation is the typical finding on imaging studies

24. Newborn infant

Congenital Cytomegalovirus infection

• NECT in a newborn with CMV shows large ventricles, shallow sylvian fissures , striking periventricular Ca++

• NECT scans show intracranial calcifications and ventriculomegaly in the majority of symptomatic infants. Calcifications are predominantly periventricular, with a predilection for the germinal matrix zones. Calcifications vary from numerous bilateral thick calcifications to subtle or faint punctate unilateral foci. 

25. Seropositive status

Benign lymphoepithelial lesions of the salivary glands

• lesions of the salivary glands• Benign lymphoepithelial lesions of HIV (BLL-HIV)

are nonneoplastic cystic masses that enlarge salivary glands. Bilateral lesions are common. The parotid glands are most frequently affected 

• NECT scans show multiple bilateral well-circumscribed cysts within enlarged parotid glands.

• A thin enhancing rim is present on CECT scans • The cysts are homogeneously hyperintense on

T2WI and demonstrate rim enhancement on T1 C+