Sample the RadioQBank neuroradiology bank below — every question is a real published item with the full explanation, exam pearl, and reference shown. These cover high-yield brain, cavernous sinus, demyelination, and head & neck themes that recur in NEET SS and INI-SS papers. Work through them exactly as you would in the exam: read the stem, commit to an answer, then check the reasoning.
Question 1 · JNA / Cranial Nerve Palsy · easy
A patient with JNA (Juvenile Nasopharyngeal Angiofibroma) undergoes pre-operative embolization. The primary blood supply to JNA is from which artery?
- a. Anterior ethmoidal artery (from ophthalmic artery)
- b. Internal maxillary artery (IMAX — from external carotid artery)
- c. Ascending pharyngeal artery
- d. Posterior ethmoidal artery
Answer: B. JNA derives its primary vascular supply from the internal maxillary artery (IMAX), a terminal branch of the external carotid artery (ECA). The sphenopalatine branch of the IMAX is the dominant feeder and is the primary target for pre-operative embolization to reduce intraoperative blood loss. Some large tumours also receive secondary supply from the internal carotid artery (ophthalmic artery, cavernous branches), which cannot be safely embolized. Pre-operative embolization is performed 24–48 hours before surgery.
Exam pearl: JNA primary supply = IMAX (ECA branch). Embolize 24–48h pre-op. Secondary ICA supply (ophthalmic) = cannot embolize safely.
Kandarpa & Machan IR Handbook 5th ed; Grainger & Allison 7th ed Ch 55
Question 2 · Skull Base · easy
A 65-year-old man with known prostate cancer presents with new-onset headache and cranial nerve palsies (CN III, IV, V1, V2, VI). MRI shows abnormal enhancement and soft tissue infiltration of the right cavernous sinus. What is the most likely diagnosis?
- a. Cavernous sinus meningioma
- b. Metastatic carcinoma to the cavernous sinus
- c. Carotid-cavernous fistula
- d. Tolosa-Hunt syndrome
Answer: B. Metastatic disease to the cavernous sinus most commonly originates from prostate, breast, and lung cancers. Perineural spread (along CN V branches) is a common pathway. MRI shows asymmetric enhancement and infiltration of the cavernous sinus, often with destruction of the adjacent skull base. The known history of prostate cancer with new multiple cranial nerve palsies in this region should raise strong suspicion for metastasis or perineural spread. Differential consideration is leptomeningeal carcinomatosis.
Exam pearl: Known cancer + cavernous sinus CN palsies = metastasis/perineural spread (Tolosa-Hunt is a diagnosis of exclusion).
Osborn's Brain 3rd ed; Radiographics 2016
Question 3 · Aneurysms · moderate
A 58-year-old woman presents with episodic headaches and is found to have a 3 mm cavernous sinus ICA aneurysm. She has mild intermittent CN VI palsy. On MRI, the aneurysm compresses the CN VI in the cavernous sinus. What is the most appropriate management?
- a. Urgent surgical clipping as cavernous sinus aneurysms frequently rupture intracranially
- b. Conservative management or flow diversion — cavernous ICA aneurysms rarely cause intracranial SAH
- c. Direct transdural puncture of the cavernous sinus under CT guidance
- d. Thrombin injection into the aneurysm sac
Answer: B. Cavernous ICA aneurysms are enclosed within the bony cavernous sinus — if they rupture, they form a direct carotid-cavernous fistula (CCF) rather than SAH, because the cavernous sinus is extradural. The risk of life-threatening intracranial haemorrhage is very low. Treatment is reserved for symptomatic cases (CN VI, III, IV palsy, pain, visual loss from optic nerve compression). Endovascular options include parent artery occlusion (with bypass if needed) or flow diversion. Small asymptomatic cavernous aneurysms can be observed.
Exam pearl: Cavernous ICA aneurysm = extradural; rupture = CCF (not SAH); treat symptomatic cases with endovascular flow diversion or parent artery occlusion.
Osborn's Brain 3rd ed; AJNR 2015; Grainger & Allison 7th ed
Question 4 · White Matter Disease · moderate
A 25-year-old man with known HIV (CD4 count 180 cells/μL) is initiated on highly active antiretroviral therapy (HAART). Two weeks later, he develops worsening neurological symptoms. MRI shows new areas of T2/FLAIR hyperintensity with rim enhancement around previously identified HIV-related white matter lesions, now with surrounding oedema and mass effect. No new infectious focus is identified. What is the most likely diagnosis?
- a. New opportunistic infection — start broad-spectrum antibiotics
- b. Immune reconstitution inflammatory syndrome (IRIS)
- c. HAART toxicity — drug-induced leukoencephalopathy
- d. HIV viral encephalitis — HAART failure
Answer: B. Immune reconstitution inflammatory syndrome (IRIS) occurs in HIV-positive patients 2–8 weeks after starting HAART, when the recovering immune system mounts an inflammatory response against previously subclinical or treated opportunistic pathogens. Two forms: unmasking IRIS (reveals new infection) and paradoxical IRIS (previously treated infection worsens). MRI: pre-existing WM lesions show new enhancement, surrounding oedema, and mass effect — reflecting restored immune-mediated inflammation around the original lesion. Treatment: corticosteroids (if severe), continue HAART. Common triggers: TB (most common globally), cryptococcal meningitis, PML-IRIS.
Exam pearl: IRIS: HIV patient 2–8 weeks post-HAART → new enhancement/oedema at pre-existing lesions = paradoxical IRIS. Treat with corticosteroids if severe. Continue HAART.
Osborn's Brain 3rd ed; Radiographics 2018;38(5):1536–1561
Question 5 · Demyelination · hard
A 30-year-old woman presents with a single episode of optic neuritis. MRI brain shows no white matter lesions. MRI spine shows no lesion. AQP4-IgG is negative, MOG-IgG is positive. What is the most likely diagnosis and what is the expected MRI finding of the optic nerve?
- a. MS — optic neuritis with retrobulbar optic nerve T2 signal
- b. MOGAD — bilateral optic nerve enhancement with perineural sheath enhancement and involvement of the optic nerve head
- c. NMOSD — longitudinal optic nerve involvement to the chiasm
- d. Isolated demyelinating optic neuritis — no specific pattern
Answer: B. MOG antibody-associated disease (MOGAD) is a distinct inflammatory demyelinating disorder associated with MOG-IgG (anti-myelin oligodendrocyte glycoprotein antibodies). Optic neuritis in MOGAD has a characteristic perineural optic nerve sheath enhancement pattern — enhancement surrounds the optic nerve sheath ("tram-track" or "ring" pattern), often bilateral, and extends to the anterior optic nerve and optic disc (nerve head). This differs from MS optic neuritis (unilateral, retrobulbar, no sheath enhancement) and NMOSD optic neuritis (posterior long-segment, to chiasm, severe vision loss).
Exam pearl: MOGAD optic neuritis: perineural sheath enhancement (tram-track), anterior/disc involvement, often bilateral. Distinct from MS (retrobulbar) and NMOSD (posterior to chiasm).
Wingerchuk et al., Lancet Neurol 2021; Radiographics 2022;42(3):888–906
Question 6 · Head & Neck Radiology · hard
A 70-year-old man with a 40-pack-year smoking history presents with a left lateral neck mass for 3 months, painless and non-tender. No prior oral cavity, oropharyngeal, or laryngeal lesion found on initial exam. CT shows a cystic nodal mass with thick walls and nodular septations at level II. HPV status is pending. What is the most important next step in management?
- a. Reassure — likely branchial cleft cyst and observe
- b. CT-guided biopsy or FNA of the neck mass; endoscopy under anaesthesia to find the primary
- c. MRI of the neck and immediate neck dissection
- d. PET-CT only; proceed to radiotherapy
Answer: B. A cystic lateral neck mass in a patient over 40 (especially with smoking history) must be considered metastatic cystic lymphadenopathy from an occult primary until proven otherwise — not a branchial cleft cyst. Oropharyngeal SCC (HPV-positive) commonly metastasises to level II–III nodes as cystic masses. The standard approach is FNA/core biopsy of the neck mass PLUS systematic examination under anaesthesia (EUA) with targeted biopsies of the nasopharynx, base of tongue, tonsils, and piriform sinus to identify the occult primary. PET-CT is useful to guide biopsies.
Exam pearl: Cystic level II neck node >40 years = occult HNSCC (not branchial cleft cyst) — biopsy + EUA first.
Radiographics 2020; AJNR 2019