Neuroradiology Practice Questions

Q: Tear drop sign is seen in:

Fracture of floor of orbit. **Explanation:** The **Tear Drop Sign** is a classic radiological finding seen on a Water’s view (occipitomental projection) X-ray, indicating a **blow-out fracture of the orbital floor**. **Why it occurs:** When a blunt object (larger than the orbital rim, like a tennis ball or fist) strikes the eye, the intraorbital pressure increases suddenly. This pressure is transmitted to the weakest part of the orbit—the floor (maxillary bone). The fracture allows orbital fat and the **inferior rectus muscle** to herniate downward into the maxillary sinus. On imaging, this herniated soft tissue mass appears as a "tear drop" hanging from the roof of the maxillary sinus. **Analysis of Incorrect Options:** * **B. Fracture of lateral wall of nose:** Usually presents with epistaxis and localized deformity; it does not involve the maxillary sinus roof or orbital contents. * **C. Le Fort’s fracture:** These are complex midface fractures. While Le Fort II and III involve the orbit, they are characterized by specific patterns of craniofacial dissociation rather than the isolated "tear drop" herniation. * **D. Fracture of zygomatic arch:** Typically presents with a "V-shaped" deformity on a Submentovertex view (Jug-handle view) and does not involve the orbital floor. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site of orbital blow-out fracture:** Orbital floor (specifically medial to the infraorbital groove). * **Clinical Presentation:** Enophthalmos (sunken eye), diplopia (due to inferior rectus entrapment), and anesthesia in the distribution of the **infraorbital nerve**. * **Imaging Gold Standard:** Non-contrast CT (NCCT) of the Orbits (Coronal sections are best for visualizing the floor). * **Black Eyebrow Sign:** Another radiological sign of orbital fracture representing intraorbital air (orbital emphysema).

Q: What is the investigation of choice for spinal tuberculosis?

MRI. **Explanation:** **MRI (Magnetic Resonance Imaging)** is the investigation of choice for spinal tuberculosis (Pott’s disease) because of its superior soft-tissue contrast. It is highly sensitive in detecting early marrow edema, disc space narrowing, and the characteristic "pre-vertebral, para-vertebral, and psoas abscesses." Crucially, MRI is the best modality to visualize the spinal cord and nerve root compression, helping to assess the risk of Pott’s paraplegia. **Analysis of Incorrect Options:** * **X-ray:** Often the first investigation performed, but it is insensitive for early diagnosis. Bone destruction is only visible on plain radiographs after 30–50% of mineral content is lost. * **CT-Scan:** Excellent for visualizing bony destruction, sequestrum formation (e.g., "sand-like" sequestra), and guiding fine-needle aspiration. However, it is inferior to MRI for evaluating neural structures and early inflammatory changes. * **Open Biopsy:** While it provides a definitive histopathological diagnosis (the "Gold Standard" for confirmation), it is an invasive procedure and not the primary investigation of choice for initial evaluation. **High-Yield Clinical Pearls for NEET-PG:** * **Earliest sign on X-ray:** Reduction in disc space (due to destruction of the subchondral bone). * **Most common site:** Lower Thoracic and Upper Lumbar vertebrae. * **Paradiscal involvement:** The most common pattern where the infection starts in the vertebral body near the disc. * **Cold Abscess:** Named so because it lacks the typical signs of acute inflammation (heat, redness). * **Gibbus Deformity:** A sharp kyphotic angulation resulting from the collapse of anterior vertebral bodies.

Q: Which of the following is NOT a characteristic feature of meningioma?

Intra-axial tumor. ### Explanation **Meningiomas** are the most common primary intracranial tumors. The core concept to understand here is their anatomical origin: they arise from **arachnoid cap cells** of the leptomeninges, making them **extra-axial** tumors (located outside the brain parenchyma). **Why Option D is the Correct Answer:** Meningiomas are classic examples of **extra-axial** tumors. They compress the brain from the outside rather than infiltrating it from within. Characteristics of extra-axial lesions include the displacement of gray matter, widening of the subarachnoid space (CSF cleft sign), and a broad-based attachment to the dura. Therefore, labeling it an "intra-axial tumor" is factually incorrect. **Analysis of Incorrect Options:** * **A. Calcification:** This is a very common feature, seen in approximately 20–25% of cases. On histopathology, these often appear as **Psammoma bodies**. * **B. Dural tail sign:** This represents thickening and enhancement of the dura mater adjacent to the tumor. While not pathognomonic, it is highly suggestive of meningioma. * **C. Mother-in-law sign:** This is a classic radiological "nickname" referring to the tumor's vascularity on angiography. The tumor "comes early and stays late"—meaning the contrast blush appears early in the arterial phase and persists long into the venous phase. **High-Yield Clinical Pearls for NEET-PG:** * **Most common location:** Parasagittal/Convexity. * **Gender Predilection:** More common in females (due to progesterone receptors). * **Association:** Strongly associated with **Neurofibromatosis Type 2 (NF2)**, especially when multiple. * **MRI Appearance:** Usually isointense to gray matter on T1 and T2; shows **intense, homogenous enhancement** post-gadolinium. * **Bone changes:** Often causes **hyperostosis** (thickening) of the overlying bone.

Q: "Lyre sign" is a feature of:

Carotid body tumor. ### Explanation **Correct Answer: D. Carotid body tumor** The **Lyre sign** is a classic radiological hallmark of a **Carotid Body Tumor (Paraganglioma)**. This sign is observed on conventional angiography or CT/MR angiography. It refers to the characteristic **splaying (widening) of the carotid bifurcation** caused by a highly vascular mass located within the carotid notch. The mass pushes the Internal Carotid Artery (ICA) posterolaterally and the External Carotid Artery (ECA) anteromedially, mimicking the shape of a "lyre" (a U-shaped string instrument). #### Why the other options are incorrect: * **Cystic hygroma:** This is a congenital lymphatic malformation typically found in the posterior triangle of the neck in infants. On imaging, it appears as a multilocular cystic mass that infiltrates tissue planes rather than splaying the carotids. * **Branchial fistula:** Usually arises from the second branchial arch, with an external opening along the lower third of the sternocleidomastoid muscle. It does not present as a vascular mass at the carotid bifurcation. * **Bezold’s abscess:** This is a complication of mastoiditis where pus tracks into the sheath of the sternocleidomastoid muscle. It presents as an inflammatory collection in the neck, not a solid tumor splaying the arteries. #### High-Yield Clinical Pearls for NEET-PG: * **Fontaine’s Sign:** Carotid body tumors are mobile horizontally but fixed vertically (due to their attachment to the carotid bifurcation). * **Salt-and-Pepper Appearance:** On MRI (T2/T1+C), these tumors show a "salt-and-pepper" pattern; "pepper" represents flow voids of high-velocity vessels, and "salt" represents foci of hemorrhage or slow flow. * **Shamblin Classification:** Used to grade these tumors based on their involvement/encasement of the carotid vessels. * **Origin:** They arise from the **chemoreceptor cells** of the carotid body (neural crest origin).

Q: Which structure may be obliterated by a pituitary tumor, as indicated in this MRI scan showing a transaxial section through the head?

Structure C. ***Structure C*** - Structure C represents the **suprasellar/chiasmatic cistern**, which is commonly obliterated by **pituitary macroadenomas** when they extend superiorly beyond the sella turcica. - **Suprasellar extension** of pituitary tumors can compress the **optic chiasm**, leading to **bitemporal hemianopia** and obliteration of the normal CSF-filled cistern on axial MRI. *Structure A* - Structure A likely represents **lateral brain parenchyma** or **temporal lobe structures**, which are not typically affected by pituitary tumor growth. - Pituitary adenomas grow primarily in **superior** and **lateral** directions within the sella, rarely extending far enough laterally to obliterate distant brain structures. *Structure B* - Structure B appears to represent **ventricular system** or **deep brain structures**, which remain unaffected by typical pituitary tumor growth patterns. - Pituitary tumors are **sellar/parasellar lesions** that do not typically extend into the **ventricular system** or cause obliteration of central brain structures. *Structure D* - Structure D likely represents **posterior brain structures** or **brainstem regions**, which are anatomically distant from the pituitary gland. - Pituitary adenomas have **limited posterior extension** due to the **dorsum sellae** and **clivus**, making obliteration of posterior structures highly unlikely.

Q: Which of the following features is a classic radiologic feature of optic nerve glioma?

Kinking of optic nerve. **Explanation:** **Optic Nerve Glioma** (typically a juvenile pilocytic astrocytoma) is the most common primary tumor of the optic nerve, frequently associated with **Neurofibromatosis Type 1 (NF-1)**. **Why "Kinking" is the correct answer:** As the tumor grows within the optic nerve, it causes the nerve to elongate and enlarge. Because the optic nerve is tethered at the optic canal and the globe, this longitudinal expansion leads to a characteristic **vertical or horizontal "kinking" or buckling** of the nerve on CT or MRI. Additionally, the nerve often shows a fusiform (spindle-shaped) enlargement. **Analysis of Incorrect Options:** * **A. Tram-track appearance:** This is the classic radiologic sign of **Optic Nerve Sheath Meningioma**. It occurs because the calcified/enhanced tumor surrounds the radiolucent (non-enhancing) optic nerve. * **C. Multiple cystic spaces:** While some gliomas may show mucinous degeneration, they are typically solid. Multiple cystic spaces are more characteristic of lymphangiomas or certain vascular malformations in the orbit. * **D. Adjacent bony erosion:** Optic nerve gliomas typically cause **concentric enlargement of the optic canal** without bony erosion. Bory erosion is more suggestive of malignant tumors or aggressive lesions like rhabdomyosarcoma. **NEET-PG High-Yield Pearls:** * **Association:** 30–50% of patients with optic nerve glioma have **NF-1**. * **Presentation:** Gradual, painless proptosis and vision loss in a child (usually <10 years). * **Imaging:** MRI is the gold standard. Look for "fusiform enlargement" and "kinking." * **Pathology:** Presence of **Rosenthal fibers** is a classic histopathological finding. * **Management:** Often conservative ("wait and watch") if vision is stable, as these are slow-growing.

Q: Suprasellar calcification is a feature of which of the following tumors?

Craniopharyngioma. **Explanation:** **Craniopharyngioma** is the most common suprasellar tumor in children and is classically associated with calcification. Derived from remnants of **Rathke’s pouch**, these tumors are typically cystic and contain "machinery oil" fluid. Calcification is a hallmark feature, seen in approximately **90% of pediatric cases** and about 50% of adult cases. On imaging, the classic triad includes a suprasellar location, cystic components, and peripheral/nodular calcification. **Analysis of Incorrect Options:** * **Astrocytoma:** While pilocytic astrocytomas can occur in the optic chiasm (suprasellar region), they rarely calcify compared to craniopharyngiomas. * **Oligodendroglioma:** This tumor is famous for having the highest incidence of calcification (70-90%), but it is typically **supratentorial/cortical** (frontal lobe), not suprasellar. * **Meningioma:** While meningiomas can occur at the tuberculum sellae and may show hyperostosis or psammomatous calcification, they are primarily solid, enhancing dural-based masses in adults, not the classic cause of suprasellar calcification in the pediatric population. **High-Yield Clinical Pearls for NEET-PG:** * **Adamantinomatous type:** Common in children; shows "machinery oil" fluid and frequent calcification. * **Papillary type:** Common in adults; usually solid and rarely calcifies. * **Differential Diagnosis for Suprasellar Mass (Sellar/Suprasellar):** Remember the mnemonic **SATCHMO** (Sarcoid/Sellar adenoma, Aneurysm, Teratoma/Tuberculosis, Craniopharyngioma/Cleft cyst, Hypophysitis/Hamartoma, Meningioma/Metastasis, Optic glioma). * **Radiological sign:** "Eggshell calcification" in the suprasellar region is highly suggestive of craniopharyngioma.

Q: Which of the following signs is classic for CT scanning in Graves ophthalmopathy?

Fusiform muscle enlargement with sparing of tendons. **Explanation:** **Graves’ Ophthalmopathy (Thyroid-Associated Orbitopathy)** is the most common cause of both unilateral and bilateral proptosis in adults. The hallmark finding on CT or MRI is the enlargement of the extraocular muscle bellies. 1. **Why Option C is Correct:** In Graves’ disease, there is an accumulation of glycosaminoglycans and edema within the muscle fibers. This characteristically involves the **muscle belly** while **sparing the tendinous insertions** at the globe. This creates a classic **"fusiform" or "coke-bottle" appearance**. This tendon-sparing is a crucial radiological differentiator from orbital pseudotumor. 2. **Why Incorrect Options are Wrong:** * **Option A & B:** Enlargement in Graves is typically smooth and symmetric, not nodular. While it can be unilateral, it most commonly involves multiple muscles (bilateral). * **Option D:** "Kinking" is not a standard radiological descriptor for Graves. Instead, severe enlargement may cause optic nerve compression at the orbital apex. **High-Yield Clinical Pearls for NEET-PG:** * **Order of Muscle Involvement:** Remember the mnemonic **I’M SLOW** (Inferior Rectus > Medial Rectus > Superior Rectus > Lateral Rectus > Obliques). The Inferior Rectus is the most commonly affected. * **Differential Diagnosis:** **Orbital Pseudotumor (Idiopathic Orbital Inflammation)** typically involves the **tendon** (Tendon-loading), which helps distinguish it from Graves. * **Clinical Sign:** **Dalrymple sign** (widened palpebral fissure due to lid retraction) is a classic clinical finding. * **Imaging Choice:** CT is excellent for visualizing muscle enlargement and bony decompression planning; MRI is superior for evaluating optic nerve compression and active edema.

Q: What is the earliest method for diagnosing a pituitary tumor?

CT scan. **Explanation:** The diagnosis of pituitary tumors has evolved significantly with imaging advancements. Among the options provided, **CT scan** is the earliest method for detecting the tumor mass itself, especially when evaluating bony changes in the sella turcica or identifying microcalcifications (common in craniopharyngiomas). While MRI is currently the "Gold Standard" for pituitary imaging due to its superior soft-tissue resolution, CT remains a primary radiological modality for early structural diagnosis when MRI is unavailable. **Analysis of Options:** * **CT Scan (Correct):** It provides high-resolution cross-sectional imaging that can detect small adenomas, bony erosion of the sella, and tumor extension. * **Visual Field Charting (Incorrect):** This is a clinical functional assessment, not a primary diagnostic tool for the tumor itself. Bitemporal hemianopia occurs only when the tumor is large enough (macroadenoma) to compress the optic chiasm. * **Visual Evoked Potential (Incorrect):** This measures the electrical conduction along the visual pathway. While it can detect subclinical compression, it is non-specific and cannot diagnose the presence or nature of a pituitary mass. * **X-ray Skull (Incorrect):** This was historically used to see "Sellar enlargement" or "Ballooning," but it can only detect large tumors that have already caused significant bony remodeling. It lacks the sensitivity to detect microadenomas. **High-Yield Pearls for NEET-PG:** * **Gold Standard Investigation:** MRI with gadolinium enhancement (specifically Dynamic Contrast MRI). * **Earliest Clinical Sign:** Hormonal imbalance (e.g., hyperprolactinemia) often precedes visual symptoms. * **Classic Visual Deficit:** Bitemporal hemianopia (due to compression of the decussating fibers at the optic chiasm). * **Best Imaging for Calcification:** CT scan (highly relevant for differentiating Craniopharyngioma from Pituitary Adenoma).

Question 1

Tear drop sign is seen in:

Accepted Answer

Fracture of floor of orbit

Answer

Fracture of lateral wall of nose

Answer

Le Fort's fracture

Answer

Fracture of zygomatic arch

Question 2

What is the investigation of choice for spinal tuberculosis?

Accepted Answer

MRI

Answer

X-ray

Answer

CT-Scan

Answer

Open biopsy

Question 3

Which of the following is NOT a characteristic feature of meningioma?

Accepted Answer

Intra-axial tumor

Answer

Calcification

Answer

Dural tail sign

Answer

Mother in law sign

Question 4

Which of the following statements about CT scan is FALSE?

Accepted Answer

It is the best imaging modality for diagnosing soft tissue pathology.

Answer

It is the imaging modality of first choice for suspected acute subarachnoid hemorrhage.

Answer

It is the investigation of choice for skull trauma.

Answer

Calcification is better visualized on CT than on MRI.

Question 5

"Lyre sign" is a feature of:

Accepted Answer

Carotid body tumor

Answer

Cystic hygroma

Answer

Branchial fistula

Answer

Bezold's abscess

Question 6

Which structure may be obliterated by a pituitary tumor, as indicated in this MRI scan showing a transaxial section through the head?

Accepted Answer

Structure C

Answer

Structure A

Answer

Structure B

Answer

Structure D

Question 7

Which of the following features is a classic radiologic feature of optic nerve glioma?

Accepted Answer

Kinking of optic nerve

Answer

Tram-track appearance of optic nerve

Answer

Multiple cystic spaces within the optic nerve

Answer

Adjacent bony erosion

Question 8

Suprasellar calcification is a feature of which of the following tumors?

Accepted Answer

Craniopharyngioma

Answer

Astrocytoma

Answer

Oligodendroglioma

Answer

Meningioma

Question 9

Which of the following signs is classic for CT scanning in Graves ophthalmopathy?

Accepted Answer

Fusiform muscle enlargement with sparing of tendons

Answer

Nodular muscle enlargement

Answer

Solitary muscle enlargement

Answer

Kinking of extraocular muscles

Question 10

What is the earliest method for diagnosing a pituitary tumor?

Accepted Answer

CT scan

Answer

Visual field charting

Answer

Visual evoked potential

Answer

X-ray skull

Neuroradiology — MCQs

Neuroradiology — MCQs

On this page

Practice by Chapter

Want unlimited practice?