Contrast and Radiological Procedures Practice Questions

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.

Q: What is the imaging of choice for urethral trauma?

Ascending urethrogram. **Explanation:** The imaging of choice for suspected urethral trauma is an **Ascending Urethrogram (RGU - Retrograde Urethrogram)**. **Why Ascending Urethrogram is Correct:** In cases of suspected urethral injury (often indicated by clinical signs like blood at the meatus, high-riding prostate, or inability to void), the primary goal is to assess the integrity of the urethral lumen. RGU involves the retrograde injection of water-soluble contrast into the external meatus. It is the most sensitive and specific test for identifying the **site, nature, and extent of a urethral tear** (partial vs. complete) before any attempt at catheterization, which could convert a partial tear into a complete one. **Why Other Options are Incorrect:** * **Descending Urethrogram (MCU/VCUG):** This requires the bladder to be full of contrast, usually via a suprapubic catheter or by waiting for excreted IV contrast. It is better for evaluating the posterior urethra during voiding but is not the initial investigation for acute trauma. * **Ultrasound (USG):** While useful for evaluating the bladder or scrotal hematomas, USG lacks the resolution to accurately map urethral mucosal disruptions or extravasation in an acute setting. * **CT Scan:** CT is the gold standard for evaluating stable blunt abdominal trauma and pelvic fractures, but it is insensitive for identifying specific urethral mucosal injuries. **Clinical Pearls for NEET-PG:** * **Classic Triad of Urethral Injury:** Blood at the meatus, inability to void, and a palpable distended bladder. * **Membranous Urethra:** The most common site of injury in pelvic fractures (Posterior Urethra). * **Bulbar Urethra:** The most common site of injury in "straddle" injuries (Anterior Urethra). * **Contraindication:** Never perform a blind Foley catheterization if urethral trauma is suspected; perform an RGU first.

Q: Sialography of a normal salivary gland reveals the ductal architecture as having what appearance?

Leafless tree. **Explanation:** **Sialography** is the radiographic visualization of the salivary glands following the retrograde injection of water-soluble iodinated contrast into the main duct. 1. **Why "Leafless Tree" is correct:** In a **normal** sialogram, the contrast outlines the primary duct (Stensen’s or Wharton’s), which then branches into progressively smaller secondary and tertiary ducts. These ducts appear sharp, smooth, and taper towards the periphery. Because the contrast does not normally fill the glandular acini (the "leaves"), the resulting image resembles a **leafless tree** or a "winter tree." 2. **Analysis of Incorrect Options:** * **Sausage-string appearance:** This is characteristic of **Chronic Sialadenitis**. It occurs due to segments of ductal stenosis alternating with segments of dilatation (ectasia). * **Fruit-laden tree (or "Bunch of Grapes"):** This is the hallmark of **Sjögren’s Syndrome**. It represents punctate sialectasis, where contrast puddles in the damaged acini, resembling fruit hanging from branches. * **Bailin hand:** This is a distractor term; however, a "hand-less" or "pruned tree" appearance can sometimes be seen in malignant tumors where the peripheral ducts are destroyed. **High-Yield Clinical Pearls for NEET-PG:** * **Indications:** Sialography is primarily used to detect ductal calculi (sialolithiasis), strictures, and fistulae. * **Contraindications:** It is strictly contraindicated during **acute infection** (risk of spreading infection) and in patients with **iodine allergy**. * **Submandibular Gland:** The most common site for sialolithiasis (80%) due to the long, upward course of Wharton’s duct and the alkaline, calcium-rich nature of the saliva.

Question 1

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 2

All of the following are advantages of the paralleling technique except?

Accepted Answer

The shadow of the zygomatic bone frequently overlies the roots of the upper molars

Answer

An excellent bone level assessment

Answer

No elongation or foreshortening seen in the periapical region

Answer

Interproximal caries is clearly indicated

Question 3

What is the imaging of choice for urethral trauma?

Accepted Answer

Ascending urethrogram

Answer

Descending urethrogram

Answer

Ultrasound (USG)

Answer

CT scan

Question 4

Sialography of a normal salivary gland reveals the ductal architecture as having what appearance?

Accepted Answer

Leafless tree

Answer

Sausage string

Answer

Fruit-laden tree

Answer

Bailin hand

Question 5

Which of the following is true regarding the principle of Magnetic Resonance Cholangiopancreatography (MRCP)?

Accepted Answer

Use of heavily T2-weighted images without contrast to create a three-dimensional image of the biliary tree using the Maximum Intensity Projection (MIP) algorithm.

Answer

Intraluminal dye is used to create a three-dimensional view of the structures.

Answer

Dye is instilled percutaneously first, then MRI is used.

Answer

Use of systemic Gadolinium as a contrast agent to create a three-dimensional image of the biliary tree.

Contrast and Radiological Procedures — MCQs

Contrast and Radiological Procedures — MCQs

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