Neuroradiology Indian Medical PG Practice Questions and MCQs
Practice Indian Medical PG questions for Neuroradiology. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Neuroradiology Indian Medical PG Question 1: A patient presents with fever and a rim-enhancing lesion with an air-fluid level on brain CT. What is the most likely diagnosis?
- A. Glioblastoma
- B. Metastasis
- C. Tuberculoma
- D. Brain abscess (Correct Answer)
Neuroradiology Explanation: ***Brain abscess***
- The presence of **fever** points towards an infectious etiology, and a **rim-enhancing lesion with an air-fluid level** on CT is highly characteristic of a brain abscess. The air-fluid level suggests gas-forming organisms or communication with an air-containing structure like a paranasal sinus.
- An abscess is a collection of pus, and the "rim-enhancement" indicates the inflammatory capsule surrounding the infection, while the **air-fluid level** is virtually pathognomonic for an abscess containing gas.
*Glioblastoma*
- While glioblastoma can be a **rim-enhancing lesion**, it is a primary brain tumor and typically does not present with **fever** or an **air-fluid level**.
- It often shows **irregular, thick enhancement** and typically causes significant surrounding edema, but the key differentiating factors here are the fever and air-fluid level.
*Metastasis*
- Brain metastases often present as **multiple, rim-enhancing lesions**, but they are tumors and do not typically cause **fever** (unless very large with extensive necrosis) or exhibit **air-fluid levels**.
- The clinical context (e.g., history of cancer) would be important for metastasis, but the **air-fluid level** strongly differentiates this case.
*Tuberculoma*
- A tuberculoma is a **granulomatous lesion** that can also show **rim enhancement**, especially with central caseous necrosis. However, it typically does not present with an **air-fluid level**.
- While fever can be present in tuberculosis, the **air-fluid level** is the most discriminating feature pointing away from tuberculoma and towards an abscess.
Neuroradiology Indian Medical PG Question 2: A lady presented with a 4 cm tumor in the left parietal lobe for which she underwent surgery and radiotherapy. After 3 months she presented with headache and vomiting. Which of the following would characterize the lesion in the patient?
- A. Digital subtraction angiography with dual source CT scan
- B. Gd-enhanced MRI
- C. 99Tc-HMPAO SPECT brain
- D. 18FDG PET Scan (Correct Answer)
Neuroradiology Explanation: ***18FDG PET Scan***
- This patient, presenting with new neurological symptoms after **surgery and radiotherapy** for a cerebral tumor, faces a diagnostic dilemma: differentiating between **tumor recurrence** and **radiation necrosis**.
- **18FDG PET scans** effectively distinguish between these two conditions because viable tumor cells exhibit high metabolic activity and thus actively take up **fluorodeoxyglucose (FDG)**, while radiation necrosis is metabolically inactive and shows little to no FDG uptake.
*Digital subtraction angiography with dual source CT scan*
- **Digital subtraction angiography (DSA)** is primarily used to visualize **vascular structures** and is not the modality of choice for differentiating tumor recurrence from radiation necrosis.
- A **dual-source CT scan** is useful for rapid imaging and dynamic studies but lacks the metabolic information needed for this specific differentiation.
*Gd-enhanced MRI*
- While **Gd-enhanced MRI** is excellent for detecting **structural changes** and **blood-brain barrier disruption**, it often cannot definitively differentiate between **tumor recurrence** and **radiation necrosis**.
- Both conditions can present with similar **enhancement patterns** on MRI, making differentiation challenging without additional metabolic information.
*99Tc-HMPAO SPECT brain*
- **99mTc-HMPAO SPECT** measures **regional cerebral blood flow (rCBF)**, which can be altered in both tumors and areas of radiation injury.
- However, it does not provide the specific metabolic information (glucose metabolism) needed to reliably distinguish between **viable tumor cells** and **radiation necrosis** as effectively as FDG PET.
Neuroradiology Indian Medical PG Question 3: Which imaging modality is most sensitive for detecting early ischemic stroke?
- A. Ultrasound
- B. PET scan
- C. CT
- D. MRI with DWI (Correct Answer)
Neuroradiology Explanation: ***MRI with DWI***
- **Diffusion-weighted imaging (DWI)** within an MRI scan is highly sensitive in detecting **cytotoxic edema** within minutes of **ischemic stroke** onset. This makes it crucial for early diagnosis and treatment decisions.
- DWI can identify areas of restricted water diffusion, which is a hallmark of acute cellular injury due to **ischemia**, even before changes are visible on conventional T1 or T2-weighted MRI sequences.
*CT*
- While frequently used in acute stroke settings, **non-contrast CT** is primarily used to **rule out hemorrhagic stroke** and may only show subtle or no signs of acute ischemia in the first few hours.
- Early ischemic changes on CT, often referred to as the **"ischemic penumbra"**, may appear hours after stroke onset, making it less sensitive for very early detection compared to DWI.
*Ultrasound*
- **Transcranial Doppler (TCD) ultrasound** can evaluate blood flow velocities in intracranial arteries and detect stenoses or occlusions but is not a primary imaging modality for directly visualizing brain parenchymal ischemia.
- Cervical ultrasound (e.g., **carotid duplex**) assesses extracranial vessels but cannot directly detect **ischemic changes** within the brain tissue itself.
*PET scan*
- **PET (Positron Emission Tomography)** can assess brain metabolism and blood flow but is typically not the preferred or most sensitive modality for **early detection of acute ischemic stroke** due to its complexity, cost, and limited availability in emergency settings.
- PET is more commonly used in research or for assessing chronic conditions and **metabolic abnormalities**, rather than acute stroke diagnosis.
Neuroradiology Indian Medical PG Question 4: A man presents to the emergency department with a head injury following a vehicular accident. What is the investigation of choice?
- A. MRI
- B. CECT
- C. NCCT (Correct Answer)
- D. X-ray
Neuroradiology Explanation: ***NCCT***
- **Non-contrast Computed Tomography (NCCT)** of the head is the **investigation of choice** for acute head trauma due to its rapid acquisition, wide availability, and excellent sensitivity for detecting acute hemorrhage, fractures, and mass effects.
- It rapidly identifies life-threatening conditions such as **epidural, subdural, and intracerebral hemorrhages**, which require immediate intervention.
*MRI*
- **MRI** is superior for detecting subtle brain tissue injuries, diffuse axonal injury, and non-hemorrhagic lesions but is generally **not the first-line investigation** in acute trauma due to longer scan times, limited availability in the emergency setting, and inability to detect acute hemorrhage as clearly as CT.
- Its use is typically reserved for follow-up studies or when CT findings are inconclusive or specific soft tissue detail is required.
*CECT*
- **Contrast-enhanced CT (CECT)** of the head is reserved for specific indications like evaluating vascular lesions (e.g., aneurysms, arteriovenous malformations) or tumors, which are generally **not the primary concern** in the initial assessment of acute head trauma.
- Administering contrast agents can delay imaging, may pose risks to patients with renal impairment or allergies, and does not significantly improve the detection of acute traumatic hemorrhage compared to NCCT.
*X-ray*
- **X-rays** of the skull are useful for detecting **skull fractures**, but they provide **limited information** regarding intracranial injuries or soft tissue damage, which are critical in head trauma.
- They have largely been superseded by CT scans, which offer a more comprehensive view of both bony structures and intracranial contents.
Neuroradiology Indian Medical PG Question 5: A woman presenting with abrupt onset of "the worst headache of her life" Which is the best investigation?
- A. Vessel carotid Doppler
- B. NCCT of the head (Correct Answer)
- C. No imaging
- D. MRI
Neuroradiology Explanation: ***NCCT of the head***
- A **non-contrast CT scan of the head** is the immediate and most appropriate first imaging study for a suspected **subarachnoid hemorrhage (SAH)**, often presenting as the "worst headache of her life" [1].
- It can rapidly detect blood in the **subarachnoid space** with high sensitivity, particularly within the first 6-12 hours of symptom onset [1], [2].
*Vessel carotid Doppler*
- **Carotid Doppler ultrasound** is primarily used to assess **carotid artery stenosis** or dissection, which would not be the initial investigation for a sudden severe headache [2].
- It does not visualize intracranial blood or vascular abnormalities within the brain parenchyma or subarachnspace.
*No imaging*
- Given the severe, abrupt onset "worst headache of her life," **subarachnoid hemorrhage (SAH)** is a critical differential, making no imaging an inappropriate and potentially dangerous choice.
- Delaying imaging could lead to severe neurological consequences if SAH is missed.
*MRI*
- While **MRI** can detect SAH, it is generally less accessible, takes more time to perform, and is less suitable for the initial rapid assessment of **acute SAH** compared to NCCT [3].
- **MRI** is often used for follow-up evaluation or when CT findings are equivocal, but not as the first-line emergency investigation.
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