NEET-PG 2013 - Radiology Practice Questions

Q: A chest X-ray shows bilateral lung infiltrates. What is the next best investigation?

CT. ***CT*** - A **CT scan (preferably HRCT)** provides a more detailed view of the lung parenchyma, allowing for better characterization of the infiltrates (e.g., location, pattern, presence of nodules, ground-glass opacities, or consolidation). - This detailed imagery is crucial for narrowing down the differential diagnosis and guiding further diagnostic or therapeutic interventions. - **CT is the best next investigation** for characterizing bilateral lung infiltrates seen on chest X-ray. *Sputum examination* - While important for identifying infectious causes, **sputum examination** is often only productive in certain types of pneumonia or infections and might not directly clarify the morphology or distribution of the infiltrates as a CT scan would. - It might be a subsequent step once the nature of the infiltrate is better understood through imaging. *Bronchoscopy* - **Bronchoscopy** is an invasive procedure generally reserved for cases where less invasive methods have failed to yield a diagnosis or when specific findings from imaging (like a CT scan) suggest the need for direct visualization, lavage, or biopsy. - It's not typically the immediate next step after identifying bilateral infiltrates on a chest X-ray. *Echocardiography* - **Echocardiography** is useful for evaluating cardiac causes of bilateral infiltrates (such as pulmonary edema from heart failure). - However, it does not directly visualize or characterize the lung parenchymal infiltrates themselves, making CT more valuable as the next investigation.

Q: Which condition is characterized by a specific radiological appearance resembling a sunburst pattern?

Osteosarcoma. ***Osteosarcoma*** - **Osteosarcoma** is known for its classic radiological findings, including the **sunburst (rising sun)** or **spiculated periosteal reaction**, where new bone forms perpendicular to the cortex. - Another characteristic finding is **Codman's triangle**, which is a triangular elevation of the periosteum visible on X-ray. *Chondrosarcoma* - **Chondrosarcomas** are typically characterized by a **"rings and arcs"** pattern of calcification within the cartilaginous matrix on imaging studies. - They tend to appear as lobular masses with endosteal scalloping and soft tissue components rather than the sunburst pattern. *Ewing's sarcoma* - **Ewing's sarcoma** classically presents with an **"onion skin" (lamellated)** periosteal reaction due to layers of parallel new bone formation. - It often appears as an ill-defined lytic lesion with cortical destruction, differing from the sunburst appearance. *Fibrosarcoma* - **Fibrosarcomas** are typically **lytic lesions** with aggressive cortical destruction and soft tissue involvement. - They generally do not produce characteristic periosteal reactions like the sunburst or onion skin appearance, often presenting as non-specific destructive lesions.

Q: In which condition is the 'Picture frame vertebra' seen?

Paget disease. ***Paget disease*** - The "picture frame vertebra" sign is a classic radiographic finding in **Paget disease**, characterized by **cortical thickening** and sclerosis around the vertebral body circumference, resembling a picture frame. - This appearance is due to the disordered bone remodeling processes (increased osteoclastic bone resorption followed by disorganized osteoblastic new bone formation) characteristic of Paget disease. *Osteopetrosis (marble bone disease)* - Osteopetrosis is characterized by **increased bone density** due to defective osteoclast function, leading to bones that are dense but brittle. - It does not typically present with the specific "picture frame" appearance of individual vertebrae, but rather with diffuse sclerosis of bones. *Ankylosing spondylitis (AS)* - Ankylosing spondylitis primarily affects the **axial skeleton**, causing inflammation and eventual fusion of the vertebrae (leading to a "bamboo spine" appearance). - While it involves the spine, it does not produce the "picture frame" vertebral sign seen in Paget disease. *Osteoporosis* - Osteoporosis is characterized by **reduced bone mass** and microstructural deterioration of bone tissue, leading to increased bone fragility and fracture risk. - Radiographically, it shows **decreased bone density** and possible vertebral compression fractures, which is the opposite of the increased bone density and cortical thickening seen in the "picture frame" sign.

Q: Which condition is characterized by a 'moth-eaten' appearance of the bones?

Multiple myeloma. ***Multiple myeloma*** [1][2] - Characterized by **punched-out lytic lesions** in bones, often described as **moth-eaten** appearance on imaging [1]. - Associated with **elevated serum proteins** and **Bence Jones proteins** in urine, confirming the diagnosis [2]. *Eosinophilic granuloma* - Usually presents with **solitary bone lesions** and is linked to **Langerhans cell histiocytosis** rather than the moth-eaten pattern. - Does not typically cause generalized **lytic bone lesions** seen in cases of multiple myeloma. *Chondromyxoid fibroma* - Generally appears as a **well-defined cortical lesion** and is not associated with a moth-eaten appearance. - It predominantly affects the **metaphysis** of long bones and shows a characteristic **cartilaginous matrix**. *Osteoid osteoma* - Presents with a **nidus** of osteoid formation, leading to localized bone pain, and does not exhibit a moth-eaten consistency. - Tends to cause **cortical bone thickening** rather than the diffuse lytic lesions associated with multiple myeloma. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of White Blood Cells, Lymph Nodes, Spleen, and Thymus, p. 608. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 616-617.

Q: Which type of arthritis is characterized by the absence of a periosteal reaction?

Neuropathic arthritis. ***Neuropathic arthritis*** - **Neuropathic arthritis** (**Charcot joint**) is characterized by progressive joint destruction due to loss of proprioception and pain sensation, leading to severe bone and joint damage without a typical **periosteal reaction**. - The absence of normal protective reflexes results in repetitive microtrauma, often leading to bone resorption and fragmentation rather than new bone formation (periosteal reaction). *Psoriatic arthritis* - **Psoriatic arthritis** often presents with distinctive **periosteal reactions**, particularly at entheses and along the shafts of small bones (e.g., "pencil-in-cup" deformities and fluffy periostitis) [1]. - These periosteal changes are a hallmark of the inflammatory process affecting bone and connective tissues in psoriatic arthritis. *Rheumatoid arthritis* - **Rheumatoid arthritis** primarily involves the synovium, leading to erosions rather than prominent periosteal reactions in early stages [1]. - While periostitis can occur in chronic, destructive rheumatoid arthritis, it is not a primary or characteristic finding compared to other inflammatory arthritides. *Reactive arthritis* - **Reactive arthritis** frequently causes **periosteal reactions**, particularly at entheses (where tendons and ligaments attach to bone) and along the shafts of long bones, often described as "fluffy" periostitis [1]. - These new bone formations are a key radiological feature distinguishing it from other types of inflammatory arthritis.

Q: Which condition is associated with the pencil in cup deformity?

Psoriatic arthritis. ***Psoriatic arthritis*** - The **pencil-in-cup deformity** is a classic radiographic finding in advanced psoriatic arthritis, occurring due to **periarticular bone erosion** and phalangeal telescoping. - This specific deformity is characterized by the proximal phalanx eroding and fitting into the expanded distal phalanx, resembling a "pencil in a cup." *Rheumatoid arthritis* - While rheumatoid arthritis causes significant joint destruction, it typically presents with **periarticular erosions** and **joint space narrowing**, but not the characteristic pencil-in-cup morphology. - Common deformities include **swan-neck** and **boutonnière** deformities, and ulnar deviation. *Ankylosing spondylitis* - This condition primarily affects the **axial skeleton**, leading to spinal fusion and **sacroiliitis**. - Peripheral joint involvement is less common and typically does not result in the pencil-in-cup deformity; instead, it can cause **syndesmophytes**. *Avascular necrosis* - **Avascular necrosis** (AVN) involves the death of bone tissue due to lack of blood supply, primarily affecting the femoral head or other major joints. - Radiographic findings include **subchondral collapse**, crescent sign, and eventual joint destruction, but not the specific deformities seen in inflammatory arthritis like pencil-in-cup.

Q: What is the standard radiation dose to point A in the cervix for brachytherapy in the treatment of cervical cancer?

8000 rad. ***8000 rad*** - The standard **total cumulative radiation dose** to **Point A** in the cervix for the treatment of cervical cancer is approximately **8000 rad (80 Gy)**. - This represents the **combined dose** from external beam radiation therapy (EBRT, typically 45-50 Gy) plus intracavitary brachytherapy (typically 30-40 Gy to Point A). - Point A is a classical reference point defined as **2 cm superior to the external cervical os and 2 cm lateral to the uterine canal**, representing the location where the uterine artery crosses the ureter. - This total dose aims to provide adequate tumor control while minimizing toxicity to surrounding organs like the bladder and rectum. *6000 rad* - A total dose of **6000 rad** is insufficient for definitive local control of cervical cancer. - This dose is below the therapeutic threshold and would result in significantly higher rates of local recurrence and treatment failure. - Adequate doses are essential for curative intent in cervical cancer management. *10000 rad* - A dose of **10000 rad** to Point A would be excessively high and significantly increase the risk of severe acute and late toxicities to surrounding tissues. - Such a high dose could lead to serious complications including **rectovaginal or vesicovaginal fistulas, proctitis, cystitis, bowel strictures, and tissue necrosis**. - The therapeutic window would be exceeded, causing more harm than benefit. *4000 rad* - A dose of **4000 rad** would be substantially lower than the standard therapeutic dose for cervical cancer. - This suboptimal dose would likely result in **inadequate tumor control and increased risk of local recurrence**. - It is far below the dose required for curative treatment of cervical cancer.

Q: Frequency of ultrasound waves in USG -

>2 MHz. ***>2 MHz*** - Medical diagnostic ultrasound typically uses frequencies in the **range of 2-15 MHz**, with some applications extending from 1-20 MHz. - Frequencies **above 2 MHz** are considered the standard for diagnostic ultrasonography, providing adequate **spatial resolution** and tissue penetration for imaging internal structures. - **Frequency selection** depends on the application: - **2-5 MHz**: Deep structures (abdominal, obstetric imaging) - better penetration - **5-10 MHz**: Vascular studies, cardiac imaging - **7-15 MHz**: Superficial structures (thyroid, breast, musculoskeletal) - better resolution - Higher frequencies provide better resolution but less penetration; the choice represents a trade-off based on clinical needs. *2000 Hz* - This frequency (2 kHz) falls within the **audible range** for humans (20 Hz to 20 kHz). - Such low frequencies would not provide the necessary **spatial resolution** for diagnostic imaging and lack the characteristics needed for medical ultrasound. *5000 Hz* - At 5 kHz, this is still within the **audible frequency range**. - These frequencies are far too low for medical ultrasound imaging, which requires **megahertz frequencies** to generate diagnostically useful images with adequate detail. * 20 kHz), are generally **below the diagnostic range** for most clinical applications. - Although lower frequencies offer better tissue penetration, frequencies below 2 MHz provide **insufficient spatial resolution** for standard diagnostic medical imaging.

Q: Gyromagnetic property of proton is seen in -

MRI. ***MRI*** - Magnetic Resonance Imaging (MRI) relies on the **gyromagnetic properties of protons**, primarily hydrogen nuclei in water and fat. - These protons align with a strong magnetic field and, when pulsed with radiofrequency waves, emit detectable signals that form the image. *CT* - Computed Tomography (CT) utilizes **X-rays** and their differential absorption by various tissues to create cross-sectional images. - It does not involve the gyromagnetic properties of protons. *PET scan* - Positron Emission Tomography (PET) scans detect **gamma rays** emitted from radiotracers, typically radionuclides like Fluorine-18, that accumulate in metabolically active tissues. - This imaging modality is based on radioactive decay, not proton spin. *USG* - Ultrasonography (USG) generates images by sending **high-frequency sound waves** into the body and detecting the echoes that bounce back from various tissues. - It relies on acoustic properties and tissue interfaces, not magnetic properties of protons.

Question 1

A chest X-ray shows bilateral lung infiltrates. What is the next best investigation?

Accepted Answer

CT

Answer

Sputum examination

Answer

Bronchoscopy

Answer

Echocardiography

Question 2

Which condition is characterized by a specific radiological appearance resembling a sunburst pattern?

Accepted Answer

Osteosarcoma

Answer

Chondrosarcoma

Answer

Fibrosarcoma

Answer

Ewing's sarcoma

Question 3

In which condition is the 'Picture frame vertebra' seen?

Accepted Answer

Paget disease

Answer

Osteopetrosis (marble bone disease)

Answer

Ankylosing spondylitis (AS)

Answer

Osteoporosis

Question 4

Which condition is characterized by a 'moth-eaten' appearance of the bones?

Accepted Answer

Multiple myeloma

Answer

Osteoid osteoma

Answer

Eosinophilic granuloma

Answer

Chondromyxoid fibroma

Question 5

Which type of arthritis is characterized by the absence of a periosteal reaction?

Accepted Answer

Neuropathic arthritis

Answer

Psoriatic arthritis

Answer

Rheumatoid arthritis

Answer

Reactive arthritis

Question 6

Which condition is associated with the pencil in cup deformity?

Accepted Answer

Psoriatic arthritis

Answer

Rheumatoid arthritis

Answer

Ankylosing spondylitis

Answer

Avascular necrosis

Question 7

What is the standard radiation dose to point A in the cervix for brachytherapy in the treatment of cervical cancer?

Accepted Answer

8000 rad

Answer

6000 rad

Answer

10000 rad

Answer

4000 rad

Question 8

What is an X-ray artifact?

Accepted Answer

An unwanted image distortion that doesn't represent actual anatomy

Answer

A radiographic finding that indicates disease pathology

Answer

A normal anatomical structure visible on X-ray

Answer

An image distortion produced when the patient moves during the X-ray procedure

Question 9

Frequency of ultrasound waves in USG -

Accepted Answer

>2 MHz

Answer

2000 Hz

Answer

5000 Hz

Answer

< 2 MHz

Question 10

Gyromagnetic property of proton is seen in -

Accepted Answer

MRI

Answer

CT

Answer

PET scan

Answer

USG

NEET-PG 2013 — Radiology