NEET-PG 2015 - Radiology Practice Questions

Q: Investigation of choice for acute intracerebral hemorrhage is -

NCCT. ***NCCT*** - **Non-contrast Computed Tomography (NCCT)** is the investigation of choice for acute intracerebral hemorrhage because it can **rapidly and reliably detect acute blood** within the brain parenchyma. - Acute hemorrhage appears as a **hyperdense (bright) lesion** on NCCT, allowing for quick diagnosis and management vital in emergency settings. *MRI* - While MRI can detect hemorrhage, its sensitivity for **acute hemorrhage** can be variable, and it is **less readily available** and takes longer to perform than NCCT. - MRI is generally preferred for subacute or chronic hemorrhage, or to investigate the **underlying cause** of the bleed (e.g., tumor, vascular malformation). *PET scan* - **Positron Emission Tomography (PET) scan** primarily measures **metabolic activity** and blood flow within the brain. - It is **not suitable for detecting acute bleeding** and is typically used for diagnosing conditions like tumors, epilepsy, or neurodegenerative diseases. *None of the options* - This option is incorrect because **NCCT** is indeed the gold standard for diagnosing acute intracerebral hemorrhage.

Q: Investigation of choice to evaluate intracranial hemorrhage of less than 48 hours is -

CT scan. ***CT scan*** - **Non-contrast CT** is the most sensitive and rapid imaging modality for detecting acute intracranial hemorrhage, appearing as a **hyperdense** (bright) area within the brain parenchyma or subarachnoid space. - It is readily available in emergency settings and is crucial for immediate diagnosis to guide management, especially within the first **48 hours**. *MRI* - While MRI can detect hemorrhage, its sensitivity for **acute hemorrhage** (especially within the first few hours) is less than CT, and it is more time-consuming. - MRI is superior for detecting older hemorrhage or subtle lesions, but it is not the **first-line investigation** for acute bleeding. *PET* - **Positron Emission Tomography** (PET) scans are primarily used to assess metabolic activity and blood flow in the brain, often for conditions like cancer, epilepsy, or dementia. - It does not directly visualize fresh blood and therefore is not used for the diagnosis of **acute intracranial hemorrhage**. *SPECT* - **Single-Photon Emission Computed Tomography** (SPECT) is used to evaluate cerebral blood flow and neuronal activity, similar to PET but with different tracers and resolution. - It is not indicated for the rapid assessment of **acute intracranial hemorrhage** as it does not directly image blood.

Q: Cobra head appearance on excretory urography is suggestive of?

Ureterocele. ***Ureterocele*** - A **cobra head appearance** on excretory urography is a classic sign of a **ureterocele**, which is a cystic dilation of the distal ureter that protrudes into the bladder. - This appearance is due to the dilated ureter appearing like an oval or round filling defect within the bladder lumen, surrounded by a thin radiolucent halo created by the ureteral wall and urine. *Horseshoe kidney* - A horseshoe kidney is characterized by the fusion of the lower poles of the kidneys, causing a **"U" shape** across the midline, often identified by the isthmus. - It does not present with a cobra head appearance but rather a typical anatomical variation of renal position and fusion. *Duplication of renal pelvis* - Duplication of the renal pelvis involves two separate collecting systems draining one kidney, which can be seen as two distinct pelvicalyceal systems. - This condition does not create a cobra head appearance; instead, it shows an abnormal number of collecting systems within a single kidney. *Simple cyst of kidney* - A simple renal cyst typically appears as a **well-defined, anechoic (on ultrasound) or hypodense (on CT) mass** within the kidney parenchyma. - It does not involve the ureter or bladder and thus does not produce a cobra head appearance on urograms.

Q: On CT chest, the 'halo sign' is particularly associated with which condition in immunocompromised patients?

Invasive pulmonary aspergillosis. ***Invasive pulmonary aspergillosis*** - The **halo sign** on CT chest, characterized by a ground-glass opacity surrounding a nodule, is a classic radiographic finding in **invasive pulmonary aspergillosis**, especially in immunocompromised patients. - This sign represents hemorrhage around the fungal nodule and indicates active tissue invasion by *Aspergillus* species. *Pulmonary hydatid cyst* - Hydatid cysts are typically well-defined, thin-walled cystic lesions, often displaying the **water lily sign** if complicated by rupture, which is different from the halo sign. - These cysts are caused by the larval stage of *Echinococcus granulosus* and are not associated with a peripheral ground-glass opacity. *Round pneumonia* - Round pneumonia is a localized, **spherical consolidation** often seen in children, which does not typically exhibit the perilesional ground-glass opacity characteristic of the halo sign. - It usually represents bacterial infection and resolves with antibiotics, unlike the invasive fungal disease suggested by the halo sign. *Bronchiectasis* - Bronchiectasis is characterized by **irreversible dilation of the bronchi**, often appearing as "tram-track" opacities or "signet ring" signs on CT. - It is a chronic condition related to airway damage and mucus retention, and not associated with acute nodular lesions or the halo sign.

Q: What condition is best diagnosed using a Skyline view X-ray?

Patellofemoral problem. ***Patellofemoral problem*** - The **Skyline view**, also known as the **Merchant view** or tangential patella view, is specifically designed to visualize the **patellofemoral joint**. - It is crucial for assessing conditions like **patellar subluxation**, tracking disorders, and **chondromalacia patellae** by showing the articulation between the patella and the femoral trochlea. *Radioulnar problem* - Problems with the **radioulnar joint** are typically evaluated with standard **AP and lateral views of the forearm and elbow**. - The Skyline view offers no diagnostic value for the radioulnar joint as it focuses on the knee. *Tibiofibular problem* - Issues concerning the **tibiofibular joints** (proximal or distal) are best assessed using **AP and lateral views of the lower leg or ankle**, depending on the specific joint. - The Skyline view is not used to evaluate these structures. *Skull fracture* - **Skull fractures** are diagnosed using standard **skull X-rays** (e.g., AP, lateral, Towne, Caldwell views) or more commonly, a **CT scan of the head**. - The Skyline view is specific to the knee and entirely inappropriate for evaluating the skull.

Q: Which of the following statements about lipoma is radiologically true?

Low attenuation on CT scan. ***Low attenuation on CT scan*** - Lipomas, being composed of **fat**, appear as areas of **low attenuation** (typically -50 to -150 Hounsfield Units) on computed tomography (CT) scans. - This low attenuation is a **key diagnostic characteristic** that helps differentiate lipomas from other soft tissue masses. *Hyperechoic on ultrasound* - Lipomas typically appear **isoechoic to hypoechoic** on ultrasound, not consistently hyperechoic. - They may have a thin echogenic capsule, but the internal contents are usually similar to or less echogenic than adjacent subcutaneous fat. *Hyperintense on fat-suppressed sequences* - This is **incorrect** - lipomas show **signal dropout** (become dark/hypointense) on fat-suppressed sequences (STIR, fat-sat T1/T2). - Signal suppression on fat-saturated sequences is actually a **diagnostic feature** confirming the fatty nature of the lesion. - Note: Lipomas ARE hyperintense on standard T1-weighted imaging due to fat content. *Hyper-intense on T2-weighted MRI* - Lipomas typically show **intermediate to slightly hyperintense signal** on T2-weighted MRI, but not markedly hyperintense like fluid. - They are less bright than fluid-filled structures or highly vascular lesions on T2-weighted sequences.

Q: Epidural hematoma on CT scan shows which of the following?

Biconvex hyperdense lesion. ***Biconvex hyperdense lesion*** - An epidural hematoma is characterized by a **biconvex** (lens-shaped) collection of blood between the dura mater and the skull. - Since it is an acute hemorrhage, the blood appears **hyperdense** (bright white) on a CT scan. *Crescent-shaped hyperdense lesion* - A **crescent shape** is characteristic of an **acute subdural hematoma**, not an epidural hematoma. - While acute subdural hematomas are also hyperdense, their crescent shape (following the contour of the brain) distinguishes them from the biconvex epidural hematomas. - Epidural hematomas are limited by suture lines and appear lens-shaped, while subdural hematomas can cross suture lines. *Biconcave hypodense lesion* - A **biconcave** shape is not a standard description in neuroradiology and does not represent epidural hematoma. - **Hypodense** would indicate an older lesion or other pathology, not acute hemorrhage. *Ring-enhancing hypodense lesion* - **Ring-enhancing lesions** are typically associated with abscesses, glioblastoma, or metastatic tumors, not an acute hematoma. - A **hypodense** (darker) center with enhancement would indicate an abscess or necrotic tumor, not a fresh extravasation of blood.

Q: Tigroid pattern on MRI is seen in -

Metachromatic leukodystrophy. ***Metachromatic leukodystrophy*** - The **tigroid pattern** on MRI, characterized by **perivascular sparing** within demyelinated white matter, is highly characteristic of metachromatic leukodystrophy. - This pattern results from the accumulation of **sulfatides** in oligodendrocytes and macrophages, leading to central demyelination with spared U-fibers and white matter adjacent to vessels. *Wilson's disease* - Wilson's disease involves **copper accumulation** and typically presents with abnormalities in the **basal ganglia**, thalami, and brainstem. - While it causes neurodegeneration, it does not produce a characteristic tigroid demyelination pattern. *Parkinsonism* - Parkinsonism refers to a group of neurological disorders characterized by motor symptoms like **bradykinesia, rigidity, tremor, and postural instability**. - MRI findings in Parkinsonism often show **nigral degeneration** but do not typically involve a tigroid pattern of leukodystrophy. *GB syndrome* - **Guillain-Barré syndrome (GBS)** is an acute autoimmune peripheral neuropathy affecting the **peripheral nerves and nerve roots**. - It does not involve central nervous system demyelination or display a tigroid pattern on brain MRI.

Q: Which of the following X-ray findings is associated with Chilaiditi syndrome?

Pseudopneumoperitoneum. ***Pseudopneumoperitoneum*** - Chilaiditi syndrome is characterized by the **interposition of a loop of colon (usually transverse colon) or, less commonly, small intestine** between the liver and the right hemidiaphragm. - This anatomical variation can mimic **free air under the diaphragm** on an X-ray, leading to the misdiagnosis of pneumoperitoneum. *Pseudopneumothorax* - This term describes the appearance of **air in the pleural space** that is not actually present, which is not associated with Chilaiditi syndrome. - While Chilaiditi syndrome involves misinterpretation of air, it specifically relates to the **abdominal cavity**, not the thoracic cavity. *Pneumothorax* - A **true pneumothorax** is the presence of air in the pleural cavity causing partial or complete lung collapse, which is a significant medical emergency. - It is distinct from Chilaiditi syndrome, which involves **abdominal content displacement** mimicking abdominal free air. *Hydropneumothorax* - This condition involves the presence of both **fluid and air in the pleural cavity**. - It is a pathology of the thoracic cavity and has **no direct association** with the abdominal interposition of bowel loops seen in Chilaiditi syndrome.

Q: Investigation of choice for soft tissue sarcoma is -

MRI. ***MRI*** - **Magnetic Resonance Imaging (MRI)** is the investigation of choice for soft tissue sarcomas due to its superior **soft tissue contrast resolution**, allowing for detailed assessment of tumor size, location, and extent within muscle, fat, and neurovascular structures. - MRI is crucial for **surgical planning**, helping to define tumor margins and evaluate involvement of adjacent critical structures. *CT* - While CT scans can identify masses, they have **limited soft tissue contrast resolution** compared to MRI, making it less effective for precise delineation of soft tissue sarcomas. - CT is often used for **staging to detect metastatic disease**, particularly in the lungs, rather than for primary tumor characterization. *Ultrasound* - **Ultrasound** is a good initial screening tool for soft tissue masses due to its accessibility and lack of radiation, but it is **operator-dependent** and has limitations in assessing deep or large lesions. - It can help differentiate cystic from solid lesions and guide biopsies but **lacks the comprehensive detail** of MRI for definitive diagnosis and staging. *X-ray* - **X-rays** are primarily used to visualize **bone abnormalities** and are generally not effective for evaluating soft tissue masses unless there is associated calcification or bone erosion. - They provide **minimal information** regarding the internal structure or extent of a soft tissue sarcoma.

Question 1

Investigation of choice for acute intracerebral hemorrhage is -

Accepted Answer

NCCT

Answer

MRI

Answer

PET scan

Answer

None of the options

Question 2

Investigation of choice to evaluate intracranial hemorrhage of less than 48 hours is -

Accepted Answer

CT scan

Answer

MRI

Answer

PET

Answer

SPECT

Question 3

Cobra head appearance on excretory urography is suggestive of?

Accepted Answer

Ureterocele

Answer

Horseshoe kidney

Answer

Duplication of renal pelvis

Answer

Simple cyst of kidney

Question 4

On CT chest, the 'halo sign' is particularly associated with which condition in immunocompromised patients?

Accepted Answer

Invasive pulmonary aspergillosis

Answer

Pulmonary hydatid cyst

Answer

Round pneumonia

Answer

Bronchiectasis

Question 5

What condition is best diagnosed using a Skyline view X-ray?

Accepted Answer

Patellofemoral problem

Answer

Tibiofibular problem

Answer

Skull fracture

Answer

Radioulnar problem

Question 6

Which of the following statements about lipoma is radiologically true?

Accepted Answer

Low attenuation on CT scan

Answer

Hyperechoic on ultrasound

Answer

Hyperintense on fat-suppressed sequences

Answer

Hyper-intense on T2-weighted MRI

Question 7

Epidural hematoma on CT scan shows which of the following?

Accepted Answer

Biconvex hyperdense lesion

Answer

Crescent-shaped hyperdense lesion

Answer

Biconcave hypodense lesion

Answer

Ring-enhancing hypodense lesion

Question 8

Tigroid pattern on MRI is seen in -

Accepted Answer

Metachromatic leukodystrophy

Answer

Wilson's disease

Answer

Parkinsonism

Answer

GB syndrome

Question 9

Which of the following X-ray findings is associated with Chilaiditi syndrome?

Accepted Answer

Pseudopneumoperitoneum

Answer

Pseudopneumothorax

Answer

Pneumothorax

Answer

Hydropneumothorax

Question 10

Investigation of choice for soft tissue sarcoma is -

Accepted Answer

MRI

Answer

CT

Answer

Ultrasound

Answer

X-ray

NEET-PG 2015 — Radiology