QUESTION-1:
What the following MRI images represented of:
Correct Answer: Glioblastoma
- The previous images shows well-defined intra-axial lesion involving Posterior left Parietal region exhibits heterogeneous enhancement in post contrast study and exerting a positive mass effect upon Posterior horn of left lateral ventricle. Multiple areas of intralesional necrosis are noted … this typical picture of GBM.
- Mets : typical appear at Grey-white matter junction , and more multi-focal and have more edema.
- Medulloblastoma: not its place, as Medulloblastoma arise in posterior fossa.
Differential Diagnosis:
- Mets : typical appear at Grey-white matter junction , and more multi-focal and have more edema.
- Lymphoma: Usually Homogenous Enhancement, more at AIDS patients.
- Cerebral Abscess: have Central restricted diffusion is helpful (however, if GBM is hemorrhagic then assessment may be difficult ) + double rim sign (two concentric rims surrounding the abscess cavity in T2W and SWI , outer one of which is hypointense, and the inner one relatively more hyperintense.)
Pearls:
- Glioblastomas are typically large tumors at diagnosis. They often have thick, irregular-enhancing margins and a central necrotic core, which may also have a hemorrhagic component. They are surrounded by vasogenic-type edema, which in fact usually contains infiltration by neoplastic cells.
- Multifocal disease, which is found in ~20% of cases, is that where multiple areas of enhancement are connected to each other by abnormal white matter signal, which represents microscopic spread to tumor cells. Multicentric disease, on the other hand, is where no such connection can be seen.
References:
- Radiopedia
- Crack the Core
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Correct Answer Explanation
QUESTION-2:
What the following MRI images represented of:
Correct Answer: NeuroFibromatosis Type II
- The Previous images shows Multiple Shwanoma(s), Meningioma and Ependymoma , this typical picture of Neurofibromatosis Type II.
- Neurofibromatosis Type I is more peripheral organ disease , yet its CNS manifestations include Optic nerve Glioma , sphenoid wing dysplasia + Spinal Astrocytoma + Peripheral nerve sheath tumor
- Sturge-Weber syndrome is a phakomatosis characterized by facial port wine stains and pial angiomas.
Pearls:
- MSME (Multiple Shwanoma”s” + Meningioma “s” + Ependymoma “s”).
- Chromosome 22
- Autosomal Dominant
- No racial predilection
- 1 in 30,000 – 40,000
- Bilateral Acoustic Schwannomas
- 1st Degree relative
- Meningioma
- Glioma
- Schwannoma
References:
- Radiopedia
- Crack the Core
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Correct Answer Explanation
QUESTION-3:
Following MRI Images of 11 years old patient represented of:
Correct Answer: Pilocytic astrocytoma
- The Previous images shows Supra-sellar Cystic-solid mass with post-contrast vivid enhancement in a child , this can occur with Optic pathway Glioma (don’t have cystic degeneration) , Craniopharyngoma (in children must have calcifications) , so this picture of pilocytic astrocytoma.
Differential Diagnosis:
- Optic pathway glioma: Mainly solid with variable enhancement, no cystic component.
- Craniopharyngioma has two types:
- a) Papillary Type : can have similar picture to the previous images but come mainly at Adults.
- b) Adamantinomatous Type: in children but must have calcifications.
Pearls:
- Usually occurs in first decade
- Usually Mural nodule with cystic components
- Can have multilobulated appearance
- Rarely calcifies
- Occur Mainly in Cerebellum (60%) then Optic Pathway (30%)
References:
- Radiopedia
- Crack the Core
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Correct Answer Explanation
QUESTION-4:
Following MRI Images of a patient represented of:
Correct Answer: Ependymoma
- The Previous show CPA Cystic mass lesion that follow CSF signal intensity on T1WI and T2WI, and it show higher (dirty) signal than CSF on FLAIR.this is typical for epidermoid , the latter FLAIR dirt signal is what differentiate it from Arachnoid Cyst.
- Ependymona doesn’t follow CSF signal on T1WI and T2WI.
- GBM is a supratentorial tumor.
Differential Diagnosis:
- Shwanoma (Vestibular): Solid Enhancing Tumor
- Meningioma: has dural base and doesn’t follow CSF signal.
- Arachnoid Cyst: similar to epidermoid but follow CSF signal on FLAIR.
Pearls:
- Benign tumor with slow growth due to epithelial lining desquamation.
- Path shows solid lesion with keratinaceous debris.
- “Black” epidermoid: follows CSF.
- Cholesterol in solid crystalline state, keratin within tumor, CSF within tumor interstices.
- “White” epidermoid: hyperintense on T1, iso T2.
- Caused by TG’s and polyunsaturated FA’s.
- DWI, shows restriction.
References:
- Radiopedia.
- Crack the Core.
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Correct Answer Explanation
QUESTION-5:
Following MRI Images of a patient represented of:
Correct Answer: Arachnoid Cyst
- The Previous show Posterior Fossa Space Occupying Cystic lesion that follow CSF signan intensity on T1WI and T2WI, and FLAIR, it doens’t show restricted signal on DWI.
- Ependymona doesn’t follow CSF signal on T1WI and T2WI.
- DNET: usually appear in temporal lobe and it have high signal 'bubbly appearance on T2W and show bright rim sign on FLAIR.
Differential Diagnosis:
- Mega cisterna magna.
- Epidermoid cyst:
* Heterogeneous/dirty signal on FLAIR.
* Restricted diffusion.
* More lobulated. - leptomeningeal cyst: post-traumatic.
Pearls:
- illed with CSF, follow CSF on all sequences, including FLAIR and DWI. distinguished from epidermoid cysts.
- Very thin wall , seen by displacement of surrounding structures.
- 1% of all intracranial masses.
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Correct Answer Explanation
QUESTION-6:
Following MRI Images of a 15 Years old Patient patient represented of:
Correct Answer: Cavernoma
- The Previous MRI images shows Left High Parietal small space occupying lesion that shows mixed signal intensity (fluid-fluid level) on T1W and hyperintense signal on T2WI with hypointense rim, and show blooming artefact signal on Gradient image . it contains few small calcifications within, this typical picture of Cavernoma.
- There is nearby prominent cerebral vein suggestive of Deep Venous malformation (DVA).
- Meningioma is dural based and don’t appear like this.
- Astrocytoma has different picture than this.
Differential Diagnosis:
- Subacute to chronic parenchymal bleed.
- Amyloid angiopathy.
- Radiation therapy-associated hemorrhage.
- Hemorrhagic mets.
- Melanotic melanoma mets.
- Infection (esp treated Toxo).
- If don’t see classic features can do f/u exam to see evolution.
Pearls:
- Most in superficial and subcortical location.
- Involves deep stuctures (BG, thalamus, and internal capsule) 10%.
- 25% in infratentorial compartment (brainstem and cerebellum equally).
- Extraaxial and spine cord location is rare.
- Multiple in 20-30% with familial association in 10-15% cases.
- Symptoms: 40-60% are symptomatic with seizure, hemorrhage, or progressive neurologic deficit (more common with infratentorial lesions).
- Risk of hemorrhage .1-1.0%/yr.
- Lesion is not encapsulated, no interposing brain tissue.
- Often associated with venous angioma.
Imaging:
- Angiographically occult lesion
- CT... slight inc. density lesion with variable calcification. Minimal enhancment... often difficult to see.
- MRI... focal central heterogeneity with circumferential complete rings of dark T2 signal.
- No mass effect of edema or feeding vessels.
- Often demonstrate enhancement.
- Gradient echo can increase sensitivity.
Location:
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QUESTION-7:
The Following CT and MRI images of a Post-Trauma Patient who show progressive drop in Glasgow Coma S:
Correct Answer: Diffuse Axonal Injury (DAI)
- The Previous CT images of pos-trauma patient appear normal which doesn’t correlate with patient GCS , the following MRI images show few bilateral grey-white matter foci of hemorrhage more prominent at SWI.
- Toxoplasmosis has difference clinical presentation and imaging findings.
- There is no evidence of vascular abnormality.
Differential Diagnosis:
- Cortical contusions: typically located superficially, involving the cortex (rather than at the grey-white matter junction) and are usually associated with variable amounts of extra-axial blood (subarachnoid and subdural).
- Diffuse vascular injuries.
- Amyloid angiopathy.
- Chronic hypertensive encephalopathy.
- Cavernoma type IV.
Pearls:
- Diffuse axonal injury (DAI), also known as traumatic axonal injury (TAI), is a severe form of traumatic brain injury due to shearing forces. It is a potentially difficult diagnosis to make on imaging alone, especially on CT as the finding can be subtle, however, it has the potential to result in severe neurological impairment.
- The diagnosis is best made on MRI where it is characterised by several small regions of susceptibility artifact at the grey-white matter junction, in the corpus callosum, and in more severe cases in the brainstem, surrounded by FLAIR hyperintensity.
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QUESTION-8:
What’s Following MRI Images represented of:
Correct Answer: Meningioma
- The Previous MRI images show Supratentorial Lt Occipital Parasagittal Dural based Space Occupying lesion that exhibit iso-intense signal on T1WI and T2WI and show intense enhancement on Postcontrast Study, it’s seen surrounded by mild to moderate vasogenic brain edema .. this typical picture of Meningioma.
- DNET and Cavernoma have different pattern.
Differential Diagnosis:
- Hemangio-pericytoma: more aggressive, destructing adjacent bones.
- Dural mets (mainly breast cancer): typical multiple.
Pearls:
- Suggestive Signs
- Peripheral, broadly based along calvarium
- Overlying bone changes
- Enhancement of adjacent meninges
- Displacement of brain from skull
DEFINITIVE SIGNS of Extra-Axial Mass
- CSF cleft between brain and lesion
- Vessels interposed
- Cortex between mass and (edematous) white matter
- Dura between (epidural) mass and brain
- Onion skin bowing of cortex vs intraaxial likes to spread the sulci.
MENINGIOMAS
- 15% of operated brain tumors. But incidence 1.5% population.
- Age: rare in peds… often more malignant Older adults…8% multiple….2:1 M:F
- Can arise anywhere there are meningeal rests….dural based, intraventricular, bone
- Types….Fibroblastic, Transitional cell, Syncicial, Angioblastic (mult subtypes ie hemangioblastic to hemagiopericytic ?not meningiomas by WHO) ….rare..Lipoblastic, Malignant, Post radiation
- Imaging characteristics
- T1….75-80% hypo to iso to cortex
- T2….variable depending on the histologic type….syncycial and angioblastic hyper... Transitional cell and fibroblastic iso to hypointese.
- Most (85%) are heterogenous on T2…secondary to vascularity, calcification, or cystic changes.
- 20% have cystic or calcification.
- CSF and pial blood vessel interface seen in approx. 80% (big veins peripherally).
- Can go through dura to other side…. Intraxial primary tumors almost never invade dura unles prior surgery. (mets exeption).
- Likes to encase and narrow vessels.. Often see flow voids even after contrast.
- Venous sinus invasion…important for resection issues….thrombosed or not.
- Often are en plaque.
- Calcification usually not an issue unless ?met dz…then CT can help.
- Brain edema (50%)….varies….TCC and fibroblastic have a little and angioblatic/ syncycial have more.
- Brain invasion (often with lots of edema) by definition constitutes malignant form by some authors….very tough call by imaging.
- Intraventricular….arachnoid cell of tela choroidea of lateral ventricles..
- Papilloma vs meningioma….. Age and location of lesion. Papilloma in lat vent usually in kids and often have diffuse hydro.
Extra-axial Mass Lesion:
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QUESTION-9:
What’s Following MRI Image represented of:
Correct Answer: Leptomeningeal Carcinomatosis
- The Previous image is MRI Brain FLAIR show CSF hyperintensity within sulci especially posteriorly, this picture likely representing Leptomeningeal carcinomatosis.
- Meningioma and Angioma have different imaging characters.
Differential Diagnosis:
- Leptomeningeal inflammation: Leptomeningitis.
- Slow flow in vessels.
- Propofol, high oxygen tension, and subarachnoid blood can all elevate sulcal FLAIR signal.
- Others; sarcoid, lymphoma, TB, other inflammatory (can say inflammatory or infectious process; granulomatous).
Pearls:
- Leptomeningeal metastases: spread of malignant cells through the CSF space.
- These cells can originate from primary CNS tumours (e.g. drop metastases): GBM- Medulloblastoma - ependymoma.
- As well as from distant tumours that have metastasised via haematogenous spread: Lung carcinoma - breast cancer - melanoma - etc.
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QUESTION-10:
What’s Following MRI Images represented of:
Correct Answer: Bilateral Meso-temporal Sclerosis.
- The Previous image show hyperintense T2 signal of both medial temporal lobes , suggestive of medial temporal sclerosis.
- Parkinson disease shows mild T2 hyperintensity of substantia nigra and red nuclei in Brain stem.
- Chronic Small vessel ischemia appear in peri-ventricular region.
Pearls:
- Bilateral is relatively rare, but still seen.
- Usually look for hyperintensity of the hippocampus and parahippocampal gyrus.
- If infectious history and if there is evidence of hemorrhage would include HSV as a diff dx.
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QUESTION-11:
What’s Following CT Image represented of:
Correct Answer: Clivus Chordoma.
- The Previous CT Skull base Image shows Clivus Midline Central Expansile Lytic mass lesion with extensive soft tissue component.
- Meneingiom en plaque causing sclerosis of the bone not destructing.
- Ewing has very different image findings.
Differential Diagnosis:
- Chondrosarcoma.
- Metastatic disease (remember neuroblastoma in peds).
Pearls:
- Clivus Chordoma: Sacrum more commonly involved with chordoma.
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QUESTION-12:
What’s Following CT & Conventional Angio Images represented of:
Correct Answer: ICA Agenesis.
- The Previous Angiography shows congenital absence of Lt ICA , CT Skull base bone show congenital absence of Lt Carotid canal.
Pearls:
- It is a rare anomaly (less than 0.01% of the population).
- Most common type of collateral flow is through the circle of Willis, through the anterior communicating artery (ACOM) and posterior communicating artery (PCOM).
- Although many of these cases remain asymptomatic and go undetected, it is associated with cerebral aneurysms. Also, these anomalies have important implications during carotid endarterectomy and transsphenoidal hypophyseal surgery, and in the setting of thromboembolic disease.
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QUESTION-13:
What’s Following MRI Images represented of:
Correct Answer: Hemimegaloencephaly.
- The Previous MRI images show Moderate enlarged of Lt Sided Cerebral hemisphere with normal Rt one , and ipsi-lateral Lt ventricular mild dilatation , typical picture of Hemimegaloencephaly.
- GBM and hemangiopericytoma , both are cerebral masses with different pictures.
Pearls:
- Hemimegaloencephaly: is a rare congenital disorder of cortical formation with hamartomatous overgrowth of all or part of a cerebral hemisphere.
- No racial or gender predilection.
- Presented with focal and generalised infantile spasms. Developmental delay, hemiparesis and hemianopia.
- Often normocephalic , however may be macrocephaly >> Impossible normal vaginal delivery . No Increased intracranial pressure.
- Can presented isolated or part of syndrome( NF1-Tuberus sclerosis -Klippel-Trenaunay- McCune-Albright).
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QUESTION-14:
What’s Following MRI Images represented of:
Correct Answer: ACA Acute infarction.
- The Previous MRI image shows LT para-sagittal fronto-parietal hyperintense signal intensity on FLAIR that shows restricted diffusion on DWI.
- Hematoma and meningioma have different imaging findings.
Pearls:
- Embolus
- Vasospasm
- mass effect
- Subfalcine brain herniation
DWI:
- Acute infarct : Restricted diffusion
- Restriction persists for 1-2 weeks
Causes of ACA acute infarction:
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QUESTION-15:
What’s Following MRI Images represented of:
Correct Answer: HSV I Encephalitis.
- Answer : the previous MRI images show hyperintense T2 signal intensity of Limbic System , suggestive of HSV type I Encephalitis.
Differential Diagnosis:
- HSV I encephalitis
- Limbic encephalitis
- HHV6
Pearls:
- Herpes simplex (HSV) encephalitis is the most common cause of fatal sporadic fulminant necrotising viral encephalitis and has characteristic imaging findings.
- Two subtypes are recognised which differ in demographics, virus, and pattern of involvement:
- Neonatal herpes encephalitis: commonly Type II
- Childhood and adult herpes encephalitis: Commonly Type I.
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QUESTION-16:
What’s Following CT / MRI and Angiography Images represented of:
Correct Answer: Dural Sinus thrombosis.
- Answer : the previous Angiography image show attenuated and loss of signal of superior sagittal sinus. MRI Image shows hyperintense signal on Dural Venous confluence on T2W and Hypointense signal on T1WI. CT image show hypodensity within the Posterior Course of Superior Sagittal Sinus.
- There is no findings of Angioma or Aneurysm.
Differential Diagnosis:
- DeoxyHb is T2 dark.
- Enhancing thrombus
- MetHb and flow are bright on TOF MRV
- Look for:
- Hyperdensity on NC CT
- T1 flow void
- Heterogeneous T2 signal
- Secondary signs of venous infarction
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QUESTION-17:
What’s Following MRI Images represented of:
Correct Answer: Optic Chiasm Glioma.
- Answer : the previous MRI images show T1WI(+C) Enhanced Optic chiasm mass lesion involving both optic nerve pathway suggestive of Optic chiasm Glioma.
- Lymphoma and neurofibroma has different imaging features.
Differential Diagnosis:
- Optic Nerve Meningioma: have tram-track sign, and may have calcifications.
- Pituatry region mass.
- Parasagittal Oedema, Hemorrhage, leptomeningeal enhancement, hydrocephalus
Pearls:
- CT for infraorbital masses.
- MR (fat suppressed, enhanced) for rest of optic tract:
- Optic radiation involvement
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QUESTION-18:
The Following MRI Images of 5 years Old child, what’s the most likely diagnosis:
Correct Answer: Chroid plexus Papilloma.
- The Previous MRI imges show intra-ventricular (trigone) Frond like mass lesion that show homogenous enhancement in post-contrast study and associated moderate hydrocephalus changes, likely representing Chroid Plexus Papilloma.
- Coloid Cyst appear in that place but have very different imaging characters.
- This is not optic glioma site.
Differential Diagnosis:
- PNET.
- Ependymoma.
- Atypical rhabdoid.
Pearls:
- In Adults it's in the 4th Ventricle, in Kids it's in the lateral ventricle (usually trigone).
- In Adults it's in the 4th Ventricle, in Kids it's in the lateral ventricle (usually trigone).
- Carcinoma type is ONLY SEEN IN KIDS - and are therefore basically ONLY SEEN IN LATERAL VENTRICLE / TRI GONE.
- Carcinoma association with Li-Fraumeni syndrome (bad p53).
- Angiography may show enlarged choroidal arteries which shunt blood to the tumor.
- Carcinoma type of this tumor looks very similar (unless it's invading the parenchyma) and is almost exclusively seen in kids.
Papilloma:
- Lobulated, homogeneous.
- T2-hypointense (*).
- Intense enhancement.
- Ca2+ / blood.
- Parenchymal invasion in anaplastic subtypes.
Carcinomas:
- Heterogeneous
- Parenchymal invasion /edema
- Hemorrhage, cysts
Choroid Plexus Tumor:
References:
- https://radiopaedia.org/articles/choroid-plexus-papilloma-1?lang=gb
- Crack the Core Volume II
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QUESTION-19:
What’s the Following MRI Images most likely diagnosis:
Correct Answer: Multiple Sclerosis.
- The Previous images show Peri-ventricular T2 hyperintense signal variable sized oval shaped plaques seen radiation from the ventricular body (Dawson finger) characteristic for Multiple Sclerosis.
- Toxoplasmosis and TB Meningitis have different imaging characters.
Differential Diagnosis:
- Atrophy
- Callosal thinning
- Serration of inferior surface of corpus callosum
- Infratentorial/cervical lesions
- Waxing/waning lesions
Other MS features:
References:
- https://radiopaedia.org/articles/intracranial-dermoid-cyst-1?lang=gb
- Crack the Core Volume II
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QUESTION-20:
What’s the Following CT/MRI Images most likely diagnosis:
Correct Answer: Rupture Dermoid Cyst.
- The Previous images are Axial T1WI and CT brain show disseminated fat signal intensity on Sub-Arachnoid Spacem with evidence of Interventricular Well defined fat signal lesion.
- Ependymoma and Toxoplasmosis have very different image characters.
Differential Diagnosis:
- Homogeneous fat attenuation/signal intensity
- Chemical shift artifact
Intracranial Epidermoid Cyst:
- attenuation similar to CSF
- restricted diffusion on DWI
Intracranial Teratoma:
- Immature
- Usually occur in the pineal region
Craniopharyngioma:
- Most are strikingly hyperintense on T2
- Most enhance strongly
Intracranial lipoma:
Pearls:
- Contains epidermal appendages such as hair follicles, sweat glands and sebaceous glands; does not contain fat tissue.
- Low attenuation (fat density) on CT and high signal intensity on T1-weighted MR images.
- May rupture: droplets in the subarachnoid space and chemical meningitis.
References:
- https://radiopaedia.org/articles/intracranial-dermoid-cyst-1?lang=gb
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QUESTION-21:
What’s the Following MRI Images most likely diagnosis:
Correct Answer: Sub ependymal nodular heterotopia.
- The Previous images show few nodular lesion seen at ependymal surface of Lt Ventricle that follows grey matter on all sequences , this is picture of Sub ependymal nodular heterotopia.
- Band and focal sub-cortical type have difference site.
Differential Diagnosis:
- Sub ependymal hamartomas of TS: usually brighter on T2W than grey matter and may be calcified.
- Smooth ovoid masses.
- Isointense with grey matter on all sequences (*).
- No contrast enhancement.
Pearls:
- Collections of nerve cells in abnormal locations.
- Isolated or associated with other anomalies.
- Most present with seizures.
- Types:
- Sub ependymal (sporadic/familial)
- Focal subcortical
- Band
References:
- https://radiopaedia.org/articles/subcortical-heterotopia?lang=gb
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QUESTION-22:
What the Following MRI images representive of:
Correct Answer: Osmotic Demyelination.
- The Previous Images representing Central pontine Central region that exhibit hypointense signal on T1WI and Hyperintense signal on FLAIR.
- Pilocytic Astrocytoma and Oligodendroglioma have very different imaging characters.
Differential Diagnosis:
- DDx of multifocal or extrapontine involvement:
- MS
- ADEM
- Ischemia
- Encephalitis
Pearls:
- Other structures that may be involved:
- Deep grey and white matter.
- Internal / External capsules.
- Cerebellum.
References:
- https://radiopaedia.org/articles/osmotic-demyelination-syndrome?lang=gb
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QUESTION-23:
What the Following MRI images representive of:
Correct Answer: Vestibular Schwannoma.
- The Previous images show Axial and Coronal T1WI images show Rt CPA hypo intense mass lesion that show extension into Internal Auditory Canal.
- Epidermal Cyst , or GBM have very different imaging characters.
Differential Diagnosis:
- DDx of CP angle masses:
- Schwannoma
- Meningioma
- Metastasis
- Epidermoid
Pearls:
- IAC extension
- Widening of porus acousticus
- No dural enhancement
- “ice-cream cone”
Features favoring meningioma:
- Center of mass eccentric to porus acousticus
- No expansion of IAC
- Enhancing dural tail
Features favoring schwannoma:
References:
- https://radiopaedia.org/articles/vestibular-schwannoma?lang=gb
- Crack the Core Volume II
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QUESTION-24:
The Following Patient of 6 years old , which the following images representative of:
Correct Answer: Ependymoma.
- The Previous CT/MRI images shows Posterior Fossa Mass seen at the roof of the 4th Ventricle. thaty appear iso-dense mass on non contrast CT with few calcification within and show homogenous enhancement on Postcontrast CT Study. it also exhibit hypointense signal on T1WI and post- contrast homogeneous enhancement on Postcontrast Study.
- Ependymoma one of the DD , but it appear in the floor of 4th ventricle and show heterogeneous enhancement.
- Pilocystic Astrocytoma appear cystic lesion with mural nodule.
Differential Diagnosis:
- DDx of midline posterior fossa masses in childhood:
- Medulloblastoma
- Ependymoma
- Astrocytoma less common
Features favoring Ependymoma:
- CSF cleft around mass
- Calcification in 40%
- Hemorrhage more common
- Foraminal extension (50%)
Features favoring medulloblastoma:
- Compression of IV ventricle
- Calcification/hemorrhage in 20%
- Foraminal extension atypical
- Subarachnoid spread at presentation (30%)
References:
- https://radiopaedia.org/articles/medulloblastoma?lang=gb
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QUESTION-25:
The Following MRI images of 17 years old child suggestive of:
Correct Answer: Pilocytic Astrocytoma.
- The Previous images show Rt Cerebellar cystic lesion that follow MRI fluid signal intensity with mural nodule that enhance in post-contrast study, Regarding patient age picture suggestive of Pilocytic astrocytoma.
Differential Diagnosis:
- Posterior fossa cystic mass with mural nodule DDx:
- Cystic juvenile pilocytic astrocytoma
- Hemangioblastoma
- Metastasis
Pearls:
- Prominent vessels on angio
- VHL
JPA:
- Younger age
- Nodule may be hypovascular at angiography
Hemangioblastoma:
References:
- https://radiopaedia.org/articles/pilocytic-astrocytoma?lang=gb
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QUESTION-26:
What the following CT image representative of:
Correct Answer: Thyro-glossa duct Cyst.
- The previous Axial CT image show mid-line well defined Cervical Cystic lesion likely representative Thyroglossal Duct Cyst.
- Most common midline neck mass in young patients.
Location:
- A) Suprahyoid: 20-25%
- B) At the level of hyoid bone: ~30%
- C) Infrahyoid: ~45%
Differential Diagnosis:
- Branchial cleft cyst: three times less common, and usually well away from the midline.
- Delphian adenopathy
- Epidermoid cyst: superficial to the strap muscles
- Thyroid cyst or thyroid neoplasm
- Laryngocele
- Ranula
- Parathyroid adenoma
- Ectopic thyroid
References:
- https://radiopaedia.org/articles/thyroglossal-duct-cyst?lang=gb
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QUESTION-27:
What is the following CT image representive of:
Correct Answer: Sub-Dural Hematoma.
- The previous image show right parietal iso-dense extra-axial subdural collection , likely representing subacute subdural hematoma.
Differential Diagnosis:
- Hyperdense crescent
- Central hypodensity represents active bleeding
- Acute bleed mixed with CSF may appear less dense
- Density is variable in coagulopathic patients.
Subacute:
- Over the first couple of weeks, the blood is broken down
- Density approaches that of the brain
- They may be tricky to see
Chronic:
- Over time, the haematoma approaches CSF density.
SDH on CT:
Acute:
References:
- https://radiopaedia.org/articles/subdural-haemorrhage?lang=gb
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QUESTION-28:
What’s the following CT Image representative of:
Correct Answer: Cholesteatoma.
- The Previous CT image shows Soft tissue attenuation region in middle ear cavity, eroding scutum and ear ossicles, extending into mastoid... suggestive of Cholesteatoma.
Differential Diagnosis:
- The main differentials, which unlike cholesteatoma show a high signal on the ADC map, are:
- Cholesterol Granuloma
- Inflammation
Pearls:
- Cholesteatomas of the temporal bone and middle ear can be divided into:
- Primary (no history of chronic otomastoiditis)
- Secondary (the vast majority):
- Pars flaccida
- Pars tensa
- Congenital cholesteatoma: accounting for only 2%
- Acquired cholesteatoma: 98%
- External ear canal cholesteatoma
- Mural cholesteatoma
- Petrous apex cholesteatoma
Cholesteatoma:
References:
- https://radiopaedia.org/articles/cholesteatoma?lang=gb
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QUESTION-29:
What’s the following CT Image representative of:
Correct Answer: Thalassemia.
- The Previous CT Image show expanding of Skull Diploic Space with characteristic hair on end appearance, suggestive of thalassemia.
Differential Diagnosis:
- Ddx - Sickle cell, glycogen storage diseases, other marrow infiltrative processes.
- Hair on end appearance of skull films.
References:
- https://radiopaedia.org/articles/thalassaemia?lang=gb
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QUESTION-30:
What’s the following MRI Image representative of:
Correct Answer: Posterior reversible encephalopathy syndrome.
- The Previous MRI image shows Bilateral occipital near symmetrical T2WI hyperintense signal suggestive of PRES.
Differential Diagnosis:
- Posterior Reversible Encephalopathy Syndrome: this patient immunocompromised after BMT.
- Differential includes hypertension, eclampsia.
References:
- https://radiopaedia.org/articles/posterior-reversible-encephalopathy-syndrome-1?lang=gb
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QUESTION-31:
What’s the following MRI Image representative of:
Correct Answer: Schizencephaly.
- Bilateral clefts extending from the cortical surface to the ventricles filled with CSF, suggestive of bilateral open Schizencephaly.
Differential Diagnosis:
- Gray matter lined CSF cleft.
- Extends from ventricle to cortex.
- Strong association with agenesis of the corpus callosum.
References:
- https://radiopaedia.org/articles/schizencephaly?lang=gb
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QUESTION-32:
What’s the following MRI Image representative of:
Correct Answer: External Auditory Canal Atresia.
- The Previous CT images show absence of Lt Sided External Auditory Canal.
Differential Diagnosis:
- Approximately 1:10,000 births.
- Associated with:
- Trisomy 13
- Turner Syndrome
- Maternal Rubella
- Craniofacial Dysostosis (Crouzon)
- Mandibulofacial dysostosis (Treacher Collins)
- Oculoauriculovertebral dysplasia (Goldenhar)
Pearls:
- Microtia (associated pinna abnormality is common).
- EAC derived from 1st branchial cleft with some components from 1st and 2nd arches.
- The first arch gives rise to: Incus, malleolus, portion of stapes.
References:
- https://radiopaedia.org/articles/external-auditory-canal-atresia?lang=gb
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QUESTION-33:
Patient with chronic head ache:
Correct Answer: Choroid plexus papilloma
- Enhancing lobulated mass in the 3rd vent
- Dilated ventricles
Findings:
Differential Diagnosis:
- Intraventricular meningioma
- Metastasis
Pearls:
- Choroid plexus papillomas (CPPs) are extremely rare (0.5%–3% of intracranial tumors in children).
- Usually, histologically benign fetal intracranial tumors, arising from the choroid plexus and classified as primary tumor grade I.
- The tumor causes ventriculomegaly or hydrocephaly in approximately 85% of cases.
- Typically become symptomatic during the first year of life with signs of increased intracranial pressure.
References:
- https://bit.ly/3ygBqjb
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QUESTION-34:
Which is true regarding orbital anatomy?:
Correct Answer: the ophthalmic vein is superior to ophthalmic artery
- CN VI innervates lateral rectus.
- The trochlea is in the superomedial aspect of the orbit.
- The orbital septum and globe separate the anterior and posterior compartments.
- The annulus of Zinn is a fibrous band at the apex of the orbit to which the extraocular muscles attach.
- Superior orbital fissure contains the ophthalmic branch of CN V, as well as CN III, IV, and VI, superior and inferior ophth. vein, meningeal branch of lacrimal artery and orbital branch of middle meningeal artery
- Dahnert 5th 336-337
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