FMGE 2026 - Radiology PYQs Practice Questions

Q: What is the best investigation to check for extra thyroid spread of thyroid gland neoplasm ?

MRI. ***MRI*** - **MRI (Magnetic Resonance Imaging)** is the gold standard for evaluating retrosternal extension, airway infiltration, and **extra-thyroidal soft tissue invasion** due to its superior soft tissue contrast resolution. - It provides detailed, cross-sectional anatomy necessary for surgical planning when distinguishing between capsular invasion and surrounding neurovascular bundle involvement. *USG* - **Ultrasonography** is the primary modality for detecting thyroid nodules and regional cervical lymphadenopathy, but it has significant **limitations in evaluating deep structures** or retrosternal extension. - Its field of view is too restricted to assess the full extent of invasive disease beyond the immediate thyroid bed and cervical compartment. *Iodine scan* - **Radioiodine scanning** is primarily used for the functional assessment of differentiated thyroid cancer **metastases** or residual tissue rather than anatomical staging. - It cannot assess structural invasion of contiguous organs or soft tissues like the trachea or larynx. *PET scan* - **PET scanning** (usually with FDG) is highly sensitive for detecting metabolic activity in distant metastases or recurrent disease but lacks the **spatial resolution** of MRI to define local anatomical invasion. - It is generally reserved for de-differentiated tumors or cases where radioiodine scans are negative despite elevated thyroglobulin levels. [Practice more Radiology PYQs on OnCourse]

Q: What is the likely diagnosis of the X -ray below ?

Sialolith. ***Sialolith*** - A **sialolith** or salivary stone appears as a radiopaque mass, commonly located within the **submandibular duct** (Wharton's duct) due to its long, tortuous course and thick mucoid saliva. - Clinical presentation often involves **postprandial swelling** and pain in the submandibular region, which is pathognomonic for obstructive sialadenitis caused by a stone. *Foreign body* - While typically radiopaque, a foreign body usually has a distinct, often irregular shape that does not conform to the anatomic path of a salivary gland duct. - Lack of associated obstructive symptoms like **postprandial swelling** makes a foreign body less likely than a sialolith in the context of glandular region radiopacities. *Dental implant* - A dental implant has a highly characteristic, uniform structure (screw-like or cylinder) composed of dense metal alloy, which appears distinctly different from the calcified, variable density of a **sialolith**. - It is typically anchored within the **alveolar bone** of the mandible or maxilla, rather than appearing as a soft-tissue calcification within the salivary ducts. *RCT abscess* - An abscess of endodontic origin (RCT failure) typically presents as a **radiolucent (dark)** periapical lesion rather than a radiopaque (bright) calcific mass, indicating bone resorption. - It is localized strictly to the apex of a tooth with a history of **root canal therapy**, lacking the ductal anatomy location associated with sialoliths. [Practice more Radiology PYQs on OnCourse]

Q: Identify the radiographic sign seen in the IVP image given below:

Fish hook sign. ***Fish hook sign*** - This appearance is characteristic of a **ureter** that is displaced superiorly and medially by an **enlarged prostate** gland, often seen on an IVP. - The term describes the distal ureters taking an unusual hooked course as they enter the **bladder base** due to prostatic enlargement. *Adder head appearance* - This sign, also known as the **cobra head sign**, represents a **ureterocele** seen on IVP as a cystic dilatation of the distal ureter. - It appears as a round or oval lucency within the **bladder shadow** surrounded by a thin radiopaque rim of contrast. *Ball-on-tee sign* - This radiographic finding is associated with **osteonecrosis** of the femoral head, particularly in later stages. - It describes the fragmented and deformed femoral head sitting on the femoral neck, resembling a ball sitting on a tee. *Spoke-wheel sign* - This is a descriptive term often used in ultrasound or MRI, classically associated with **oncocytomas** of the kidney. - It refers to the central **stellate scar** with radiating vascularity, which is distinct from ureteral findings in IVP. [Practice more Radiology PYQs on OnCourse]

Q: Based on the given ultrasound of the ovary, which radiological pattern is observed?

String of pearls sign. ***String of pearls sign*** - This is a classic ultrasound finding in **Polycystic Ovary Syndrome (PCOS)**, representing multiple small, peripheral **follicular cysts** arranged along the ovarian cortex. - These follicles typically measure **2-9 mm** in diameter and are characteristically distributed in a circular or 'string of beads' pattern. *Chocolate cyst* - Also known as an **endometrioma**, it typically appears as a cyst with **low-level internal echoes** ('ground-glass' echogenicity). - It is associated with **endometriosis** and does not present as a peripheral arrangement of multiple small follicular cysts. *Honeycomb appearance* - This term is often used to describe the ultrasound appearance of a **gestational trophoblastic disease** (specifically **molar pregnancy**) in the uterus, not the ovary. - It represents multiple cystic spaces within the placenta due to **hydropic villi**, distinct from the follicular arrangement seen in PCOS. *Ground -glass appearance* - This sonographic texture is characteristic of an **endometrioma** (chocolate cyst), reflecting the presence of **old blood products**. - It is not associated with the follicular collection pattern seen in polycystic ovaries. [Practice more Radiology PYQs on OnCourse]

Q: Which of the following is the mechanism involved in X -ray production?

Bremsstrahlung radiation. ***Bremsstrahlung radiation*** - This is the **primary mechanism** of X-ray production in an X-ray tube, where high-speed electrons are decelerated by the electric field of the target nucleus, emitting a photon of energy. - It produces a **continuous spectrum** of X-ray energies, making up the majority of the X-ray beam intensities. *Photoelectric effect* - This interaction involves the **complete absorption** of an incident photon by an inner-shell electron of an atom, causing it to be ejected. - It is a mechanism of **X-ray attenuation/interaction with matter** rather than X-ray production generated by an X-ray tube. *Compton effect* - This interaction involves the **scattering of a photon** by an outer-shell electron, resulting in a loss of energy and a change in direction of the incident photon. - It is the primary cause of **scatter radiation** in diagnostic imaging and occupational exposure, not a method of X-ray beam generation. *Paired production* - This process involves the interaction of a high-energy photon with the **nuclear field**, resulting in the creation of an electron and a positron. - It requires a minimum energy of **1.02 MeV**, meaning it does not occur at the diagnostic energy levels typically used in standard X-ray tubes. [Practice more Radiology PYQs on OnCourse]

Question 1

What is the best investigation to check for extra thyroid spread of thyroid gland neoplasm ?

Accepted Answer

MRI

Answer

USG

Answer

Iodine scan

Answer

PET scan

Question 2

What is the likely diagnosis of the X -ray below ?

Accepted Answer

Sialolith

Answer

Foreign body

Answer

Dental implant

Answer

RCT abscess

Question 3

Identify the radiographic sign seen in the IVP image given below:

Accepted Answer

Fish hook sign

Answer

Adder head appearance

Answer

Ball-on-tee sign

Answer

Spoke -wheel sign

Question 4

Based on the given ultrasound of the ovary, which radiological pattern is observed?

Accepted Answer

String of pearls sign

Answer

Chocolate cyst

Answer

Honeycomb appearance

Answer

Ground -glass appearance

Question 5

Which of the following is the mechanism involved in X -ray production?

Accepted Answer

Bremsstrahlung radiation

Answer

Photoelectric effect

Answer

Compton effect

Answer

Paired production

Question 6

A 24-year-old male presents to the emergency department after a road traffic accident. Based on the given CT scan, what is the most likely diagnosis?

Accepted Answer

Epidural hematoma

Answer

Subdural hematoma

Answer

Intracerebral hemorrhage

Answer

Subarachnoid hemorrhage

Question 7

A young female undergoes renal angiography for evaluation of secondary hypertension. Based on her angiogram, what is the most likely diagnosis?

Accepted Answer

Fibromuscular dysplasia

Answer

Polyarteritis nodosa

Answer

Atherosclerotic renal artery stenosis

Answer

Takayasu arteritis

FMGE 2026 — Radiology