Viva · Specialty
Neuroradiology Viva Questions
Oral-exam style questions and answers on neuroradiology for MD, DNB and super-specialty practical examinations. Each answer links back to the playbook or Library entry it was written from.
- What is ASPECTS?
- ASPECTS is a 10-point topographic NCCT score used to quantify early ischaemic change within the symptomatic middle cerebral artery territory.
- How is ASPECTS calculated?
- Begin with a score of 10 and subtract one point for every ASPECTS region showing definite early ischaemic change. A score of 10 is normal, whereas 0 indicates involvement of all regions.
- Which 10 regions are included in ASPECTS?
- The regions are the caudate nucleus, lentiform nucleus, internal capsule, insular ribbon and six cortical regions designated M1 through M6.
- How are the ganglionic and supraganglionic ASPECTS regions divided?
- C, L, IC, I and M1–M3 are assessed at the ganglionic level. M4, M5 and M6 are the corresponding anterior, lateral and posterior cortical territories immediately superior to M1, M2 and M3.
- Do M1–M6 in ASPECTS represent MCA arterial segments?
- No. In ASPECTS, M1–M6 are predefined cortical regions and must not be confused with the angiographic arterial segments of the MCA.
- Can ASPECTS alone determine eligibility for reperfusion therapy?
- No. ASPECTS describes the extent of visible early ischaemic change but must be interpreted with the clinical deficit, vessel imaging, time window and current thrombolysis or thrombectomy criteria.
- Can standard ASPECTS be used for posterior-circulation stroke?
- No. Standard ASPECTS applies to the anterior circulation, principally the MCA territory. Posterior-circulation stroke uses the separate pc-ASPECTS system.
- On what single variable is the Borden classification of dural arteriovenous fistulas based?
- On the site of venous drainage — whether the shunt drains into a dural venous sinus or meningeal vein, or into subarachnoid cortical veins — and not on the arterial supply.
- Define the three Borden types.
- Type I drains antegradely into a dural venous sinus or meningeal vein without cortical reflux. Type II drains into a dural sinus with retrograde reflux into cortical veins. Type III drains directly and only into subarachnoid cortical veins.
- What do the subtypes a and b denote?
- Subtype a indicates a single fistulous connection and subtype b multiple fistulous connections; the subtype can be applied to any of the three types and predicts difficulty of cure rather than natural history.
- Why does cortical venous drainage matter?
- Arterialised flow into thin-walled subarachnoid veins produces venous hypertension, which is the mechanism of intracranial haemorrhage and of non-haemorrhagic neurological deficit; its presence defines the aggressive types II and III.
- How does Borden map onto the Cognard classification?
- Cognard I and IIa correspond to Borden I, Cognard IIb and combined IIa+b to Borden II, and Cognard III, IV and V to Borden III.
- How does the Borden type alter management?
- Type I lesions are managed conservatively or treated only for disabling symptoms, whereas types II and III are generally treated, with the endpoint being elimination of cortical venous reflux — typically by disconnecting the draining vein at the fistulous point.
- Can a type I fistula change category over time?
- Yes — progressive stenosis or thrombosis of the draining dural sinus can redirect flow into cortical veins, converting a benign type I lesion into a type II or III lesion, so new symptoms warrant repeat angiography.
- What Borden type is a classic spinal dural arteriovenous fistula?
- Type III, because the shunt drains directly into a perimedullary (subarachnoid) vein with no dural sinus involvement.
- What does the Heidelberg Bleeding Classification classify, and why was it developed?
- It classifies intracranial haemorrhage after ischaemic stroke reperfusion therapy (thrombolysis or thrombectomy), extending the older ECASS HI/PH system by adding categories for remote parenchymal haematoma, intraventricular, subarachnoid and subdural haemorrhage, plus explicit symptomatic/asymptomatic criteria for trial reporting.
- List the Class 1 subtypes and their imaging definitions.
- 1a (HI1): scattered small petechiae, no mass effect. 1b (HI2): confluent petechiae, no mass effect. 1c (PH1): haematoma within the infarct occupying less than 30%, no substantive mass effect.
- How is Class 2 (PH2) defined, and why is it clinically important?
- PH2 is a haematoma occupying 30% or more of the infarcted tissue with obvious mass effect. It is the only anatomic category consistently and independently associated with clinical deterioration and worse prognosis.
- What are the four Class 3 subtypes?
- 3a: parenchymal haematoma remote from the infarcted tissue. 3b: intraventricular haemorrhage. 3c: subarachnoid haemorrhage. 3d: subdural haemorrhage.
- How is symptomatic intracranial haemorrhage (sICH) defined under this classification?
- A new intracranial haemorrhage associated with a total NIHSS increase of 4 points or more, or a 2-point increase in one NIHSS subcategory, or a haemorrhage leading to major medical or surgical intervention such as intubation, hemicraniectomy, or external ventricular drain placement, with no alternative explanation for the deterioration.
- How does this system grade relatedness of a haemorrhage to clinical deterioration for trial reporting?
- Class 2 (PH2) is graded as probably related when symptomatic. Classes 1b, 1c and 3 are graded as possibly related. Class 1a is graded as unlikely related.
- What is a common pitfall when applying this classification in practice or reporting?
- Reporting only the ECASS-equivalent HI/PH grade and omitting the class 3 subtypes, or calling a haemorrhage symptomatic based on imaging appearance alone rather than applying the defined NIHSS thresholds.
- How does the Heidelberg Bleeding Classification relate to the older ECASS HI/PH terminology?
- It retains the ECASS HI1, HI2, PH1 and PH2 labels within its Class 1 and Class 2, but adds Class 3 (remote PH, IVH, SAH, SDH) and formal symptomatic/asymptomatic and relatedness criteria that ECASS did not include.
- What is the Koos grading system used for?
- It grades vestibular schwannomas according to internal auditory canal confinement, extension into the cerebellopontine angle and their relationship to the brainstem.
- Enumerate the four Koos grades.
- Grade I is intracanalicular; grade II extends into the CPA without brainstem contact; grade III contacts but does not displace the brainstem; and grade IV displaces the brainstem.
- What defines a Koos grade I vestibular schwannoma?
- It is a small tumour confined entirely to the internal auditory canal, without an extracanalicular CPA component.
- How do Koos grades II and III differ?
- A grade II tumour extends into the CPA but does not contact the brainstem. A grade III tumour occupies the CPA cistern and contacts the brainstem without displacing it.
- What is the defining feature of Koos grade IV?
- Koos grade IV is defined by a large tumour producing displacement of the brainstem and adjacent cranial nerves.
- Can Koos grade be assigned using tumour diameter alone?
- No. Koos grading is primarily anatomical and depends on canal confinement, CPA extension, brainstem contact and brainstem displacement rather than diameter alone.
- Does the Koos grade alone determine treatment?
- No. It communicates tumour extent and mass effect, but treatment also depends on symptoms, hearing status, growth, patient factors and multidisciplinary assessment.
- What are the three components of the Lawton–Young supplementary AVM grade?
- Patient age, haemorrhagic presentation and nidus diffuseness. Age under 20 scores 1, 20 to 40 scores 2 and over 40 scores 3; an unruptured presentation scores 1 and a ruptured one scores 0; a diffuse nidus scores 1 and a compact nidus scores 0.
- What is the range of the supplementary grade and of the supplemented Spetzler–Martin score?
- The supplementary grade runs from 1 to 5. Added to the Spetzler–Martin grade of 1 to 5, the supplemented Spetzler–Martin score runs from 2 to 10, giving nine possible grades.
- Why does an unruptured AVM score a point rather than a ruptured one?
- A ruptured AVM has a haematoma cavity that provides a dissection plane and has already declared a high natural-history risk, so surgery is technically easier and more readily justified. An unruptured AVM lacks that plane and carries a lower untreated risk, so it is the less favourable surgical scenario and attracts the point.
- There was a fourth variable considered in the original study. What was it, and is it in the scale?
- Deep perforating artery supply. It was one of the candidate factors in the derivation study but was not retained in the final three-item scale, although later validation series have found it an independent predictor of unfavourable surgical outcome.
- What Supp-SM score is used as a threshold for surgery, and how should it be applied?
- A Supp-SM of 6 is the conventional cut-off, with 6 or less favouring resection and above 6 favouring conservative or alternative management. It is a risk-stratification aid to be weighed against the untreated natural-history risk and multidisciplinary options, not an automatic rule.
- Why was a supplementary scale needed when the Spetzler–Martin grade already exists?
- The Spetzler–Martin grade uses only size, eloquence and deep venous drainage, and groups most operated patients into grades 2 and 3 without discriminating outcome within them. The supplementary variables add patient and angioarchitectural information, and the combined score predicted postoperative neurological outcome better than the Spetzler–Martin grade alone in both the derivation and an independent validation cohort.
- What is the main pitfall in applying this system?
- Quoting the supplementary grade on its own rather than as an addition to the Spetzler–Martin grade, or reversing the presentation point by scoring the ruptured AVM.
- What is the modified Fisher scale?
- It is a five-grade CT scale that classifies aneurysmal subarachnoid haemorrhage according to the thickness of subarachnoid blood and the presence of intraventricular haemorrhage.
- What is modified Fisher Grade 0?
- Grade 0 means that neither subarachnoid blood nor intraventricular haemorrhage is visible on CT.
- How are modified Fisher Grades 1 and 2 differentiated?
- Both have thin subarachnoid haemorrhage. Grade 1 has no intraventricular haemorrhage, whereas Grade 2 has intraventricular haemorrhage.
- How are modified Fisher Grades 3 and 4 differentiated?
- Both have thick subarachnoid haemorrhage. Grade 3 has no intraventricular haemorrhage, whereas Grade 4 has intraventricular haemorrhage.
- Which modified Fisher grade represents thick SAH with intraventricular haemorrhage?
- Modified Fisher Grade 4.
- What is the principal clinical implication of the modified Fisher grade?
- It stratifies the risk of symptomatic cerebral vasospasm after aneurysmal subarachnoid haemorrhage and helps guide the intensity of neurological monitoring.
- Does intracerebral haemorrhage independently determine the modified Fisher grade?
- No. The modified Fisher grade is determined by subarachnoid blood thickness and intraventricular haemorrhage; intracerebral haemorrhage does not independently define the grade.
- What is the important limitation when interpreting the modified Fisher scale?
- It estimates risk from the initial CT blood pattern but does not itself diagnose vasospasm or delayed cerebral ischaemia and should not replace clinical and physiological monitoring.
- What is pc-ASPECTS?
- pc-ASPECTS is a 10-point semiquantitative score used to describe the extent of early ischaemic change in predefined posterior-circulation regions.
- Which anatomical regions are included in pc-ASPECTS?
- It includes both thalami, both occipital lobes, both cerebellar hemispheres, the pons and the midbrain.
- How is pc-ASPECTS calculated?
- Start with 10 points. Subtract 1 point for each affected thalamus, occipital lobe or cerebellar hemisphere, and subtract 2 points for involvement of the pons or midbrain.
- Why are the pons and midbrain given greater weight?
- They are clinically critical brainstem structures, so involvement of either region produces a 2-point deduction rather than the 1-point deduction used for each paired peripheral region.
- What does a pc-ASPECTS of 10 mean?
- It means that no acute ischaemic change is visible within any of the predefined pc-ASPECTS regions on the imaging sequence being scored.
- How should a low pc-ASPECTS be interpreted?
- A lower score represents more extensive posterior-circulation ischaemia and is associated with a higher likelihood of an unfavourable functional outcome. It should be interpreted with the clinical findings, vascular imaging and the treatment-selection criteria being used.
- What is a common scoring error involving the brainstem?
- A common error is subtracting 2 points for each side of the pons or midbrain. Each structure is scored as a single region and contributes a maximum deduction of 2 points.
Modified Fisher Scale for Aneurysmal Subarachnoid Haemorrhage
Modified Fisher Scale for Aneurysmal Subarachnoid Haemorrhage
Modified Fisher Scale for Aneurysmal Subarachnoid Haemorrhage
Modified Fisher Scale for Aneurysmal Subarachnoid Haemorrhage
Modified Fisher Scale for Aneurysmal Subarachnoid Haemorrhage
Modified Fisher Scale for Aneurysmal Subarachnoid Haemorrhage
Modified Fisher Scale for Aneurysmal Subarachnoid Haemorrhage
Modified Fisher Scale for Aneurysmal Subarachnoid Haemorrhage
Posterior Circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS)
Posterior Circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS)
Posterior Circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS)
Posterior Circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS)
Posterior Circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS)
Posterior Circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS)
Posterior Circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS)