Contrast and Radiological Procedures — MCQs

Contrast and Radiological Procedures Indian Medical PG Practice Questions and MCQs

Question 251: What is the coverage area of a spiral CT scan in 30 seconds?

A. Coverage of the trunk area (Correct Answer)
B. Coverage of a single organ
C. Coverage of the abdominal region
D. Full body coverage

Explanation: ***Coverage of the trunk area*** - Modern **spiral CT scanners** are capable of imaging the entire **trunk (chest, abdomen, and pelvis)** within a 30-second breath-hold. - This capability is due to **fast gantry rotation** and **multi-slice technology**, enabling rapid volume data acquisition. *Coverage of a single organ* - While a spiral CT can image a single organ with high detail, its capabilities extend far beyond that in 30 seconds. - Limiting the scan to a single organ would not fully utilize the **speed** and **efficiency** of modern spiral CT. *Coverage of the abdominal region* - The abdominal region is certainly covered, but a 30-second spiral CT scan can typically acquire data for a much larger anatomical area. - This option is too restrictive given the **technological advancements** in CT scanning speed. *Full body coverage* - While full body CT scans are possible, they generally take longer than 30 seconds, even with the fastest modern scanners. - Full body protocols typically involve multiple scans or require more extensive acquisition times to cover from head to toe.

Question 252: Which HSG finding is most characteristic of genital Koch's disease?

A. None of the options
B. Golf club appearance of fallopian tubes (Correct Answer)
C. Beaded tubes
D. Honeycomb uterus

Explanation: ***Golf club appearance of fallopian tubes*** - This finding on **hysterosalpingogram (HSG)** is the **most characteristic** sign of **genital tuberculosis (Koch's disease)**, particularly when the fimbrial end of the fallopian tube is dilated and club-shaped. - The **"golf club"** or **"tobacco pipe"** appearance results from fibrotic strictures and scarring at the ampullary-isthmic junction with distal fimbrial dilatation, often leading to **hydrosalpinx** or tubal occlusion—a common cause of infertility in tuberculosis. - This is considered **pathognomonic** when present. *Beaded tubes* - **Beading** or **"rosary bead"** appearance of the fallopian tubes, showing multiple constrictions and dilatations, is also a **classic HSG finding in genital tuberculosis**. - While highly suggestive of TB, it is **less specific** than the golf club appearance as beading can occasionally be seen in other chronic inflammatory conditions. - Both findings may coexist in the same patient. *Honeycomb uterus* - A **"honeycomb" appearance** of the uterus is typically associated with conditions like **adenomyosis**, where endometrial glands and stroma are found within the myometrium. - It is **not a characteristic finding** for genital tuberculosis on HSG. *None of the options* - This option is incorrect because the **golf club appearance** is indeed the most recognized and characteristic HSG finding associated with genital Koch's disease.

Question 253: Which of the following is the most appropriate investigation for an anterior urethral stricture?

A. High frequency ultrasound
B. Micturating cystourethrogram
C. Retrograde urethrogram (Correct Answer)
D. Computed Tomography Urography

Explanation: ***Retrograde urethrogram*** - A **retrograde urethrogram (RUG)** is the **gold standard** for diagnosing and characterizing **anterior urethral strictures**, as it directly visualizes the anterior urethra by injecting contrast medium retrograde from the urethral meatus. - It provides detailed information on the **length, location, and severity** of the stricture, which is crucial for surgical planning. - RUG is particularly superior for **anterior urethral pathology** (bulbar and penile urethra) as the contrast is instilled from below, filling this segment optimally. *Micturating cystourethrogram* - A **micturating cystourethrogram (MCUG/VCUG)** is primarily used to evaluate the **posterior urethra** (prostatic and membranous urethra) and bladder neck during voiding. - It visualizes the urethra as urine flows from the bladder during micturition, making it ideal for posterior urethral pathology and vesicoureteral reflux. - For **complete urethral assessment**, RUG and MCUG are often performed together (combined study), but for isolated **anterior strictures**, RUG alone is most appropriate. *High frequency ultrasound* - While **high-frequency ultrasound** can assess spongiofibrosis and periurethral tissues, it is an **adjunct** rather than the primary investigation. - It provides complementary information about stricture depth and spongiosal involvement but cannot replace RUG for defining urethral lumen anatomy and stricture length. *Computed Tomography Urography* - **CT Urography** is mainly used for imaging the **upper urinary tract** (kidneys, ureters, and bladder) to detect stones, tumors, or anatomical abnormalities. - It provides **poor spatial resolution** for the fine urethral anatomy and is not the primary imaging modality for urethral strictures.

Question 254: All are radioopaque except one.

A. Uric acid (Correct Answer)
B. Calcium oxalate
C. Cystine stones
D. Mixed stones

Explanation: ***Correct: Uric acid*** - **Uric acid stones** are the only common type of kidney stone that is **radiolucent** (NOT radiopaque) - They are composed of uric acid, which has a lower density than calcium or cystine and thus **does not absorb X-rays effectively** - This low X-ray absorption makes them **invisible or very difficult to visualize** on standard **abdominal radiographs (KUB)** - However, they **can be detected on CT scans** or ultrasound - Account for **5-10% of all kidney stones** *Incorrect: Calcium oxalate* - **Calcium oxalate stones** are the **most common type** of kidney stone (~75% of cases) and are **highly radiopaque** - Their high calcium content causes them to absorb X-rays readily, making them **easily visible on plain radiographs** - Appear as dense white shadows on KUB X-ray *Incorrect: Cystine stones* - **Cystine stones** are formed due to a genetic disorder called **cystinuria** and are **faintly to moderately radiopaque** - While not as dense as calcium stones, they are generally **visible on plain radiographs** due to their sulfur content - Often appear with a characteristic **"ground-glass" texture** on imaging - Account for only **1-2% of kidney stones** *Incorrect: Mixed stones* - **Mixed stones** usually contain components that include a **calcium salt**, making them inherently **radiopaque** - Their visibility on imaging depends on the proportion and type of **calcium-containing components** within the stone - Most commonly contain calcium oxalate mixed with calcium phosphate

Question 255: Penny test is done to detect:

A. Light leaks in darkrooms (Correct Answer)
B. Chemical exposure affecting image quality
C. Issues with film sensitivity to radiation
D. Film storage temperature and humidity issues

Explanation: ***Light leaks in darkrooms*** - The **penny test** is a simple method used to determine if a darkroom has **light leaks** that could fog radiographic film. - A film is unwrapped in the darkroom with a penny placed on it for a few minutes; if an outline of the penny appears after processing, it indicates harmful light exposure. *Chemical exposure affecting image quality* - This concern relates to the **processing chemicals** (developer, fixer) and their proper concentration, temperature, and replenishment. - Problems here would manifest as poor contrast, streaking, or incomplete development, not typically identified by a penny test. *Issues with film sensitivity to radiation* - Film sensitivity (or speed) is an inherent property of the film emulsion, affecting the amount of **radiation required for optimal image density**. - This is measured through other quality assurance tests, such as sensitometry, not a simple light leak test. *Film storage temperature and humidity issues* - Improper **storage conditions** (high temperature or humidity) can cause film fog, increased base fog, or premature aging of radiographic film. - These issues affect film quality before exposure but are not detected by the penny test, which specifically tests for **light leaks in the darkroom environment**.

Question 256: PACS in medical imaging stands for:

A. Picture archiving and communication system (Correct Answer)
B. Planned archiving computerized system
C. Planned archiving common system
D. Picture archiving or computerized system

Explanation: ***Picture archiving and communication system*** is the correct answer. - **PACS** is a widely used technology in medical imaging for the **storage, retrieval, management, distribution, and presentation** of medical images - It replaces traditional film-based systems with a **digital imaging and communications approach** - The system enables seamless sharing of images across departments and healthcare facilities *Planned archiving common system* - Incorrect because the "P" in PACS stands for **Picture**, referring to medical images, not "Planned" - The term emphasizes the digital images being handled, not general planning or common systems *Planned archiving computerized system* - Incorrect as PACS focuses on **Picture** and **Communication** in handling medical images - While the system is computerized, this misses the crucial picture archiving and communication functions *Picture archiving or computerized system* - Incorrect because it uses "or" instead of **"and"**, fundamentally changing the system's function - PACS is designed for both **archiving AND communication** of images, not one or the other

Question 257: Non-visualization of the kidney in an excretory urogram is seen in.

A. Renal vein thrombosis
B. Hydronephrosis
C. Hypoplasia
D. Renal agenesis (Correct Answer)

Explanation: ***Renal agenesis*** - **Renal agenesis** is the complete congenital absence of a kidney, which results in **absolute non-visualization** on excretory urogram. - Since there is **no renal tissue present**, there can be no concentration or excretion of contrast material, making this the classic cause of complete non-visualization. - This is a well-established radiological finding and a primary differential diagnosis when a kidney fails to appear on IVU. *Renal vein thrombosis* - **Renal vein thrombosis** typically causes a **delayed or persistent nephrogram**, not complete non-visualization. - The kidney remains perfused via the arterial supply and can still excrete contrast, though it may be delayed and the kidney appears enlarged. - The characteristic finding is a **prolonged nephrogram phase** with poor excretion into the collecting system, but the kidney parenchyma itself visualizes. *Hydronephrosis* - **Hydronephrosis** shows dilation of the renal pelvis and calyces due to obstruction, but the kidney **does visualize** on IVU. - The typical appearance includes a dilated collecting system with delayed contrast washout, not non-visualization. - The nephrogram phase is usually normal, followed by characteristic pelvicalyceal dilation. *Hypoplasia* - **Renal hypoplasia** refers to a congenitally small but otherwise normal kidney that **will visualize** on excretory urogram. - Though smaller than normal, the hypoplastic kidney maintains function and excretes contrast appropriately. - It appears as a small but normally functioning kidney, not as complete non-visualization.

Question 258: Contrast media of choice for a myelogram is

A. Urografin 75%
B. Conray 470
C. Biligrafin
D. Iohexol (Correct Answer)

Explanation: ***Iohexol*** - **Iohexol** is a **non-ionic, low osmolality contrast medium** that is widely considered the contrast agent of choice for myelography due to its safety profile. - It has a lower incidence of neurotoxicity and adverse systemic reactions compared to older ionic contrast agents, making it suitable for direct injection into the **subarachnoid space**. *Urografin 75%* - **Urografin** contains **diatrizoate meglumine and sodium**, which are **ionic contrast agents**. - While suitable for intravenous urography, **ionic contrast agents are generally contraindicated for myelography** due to a higher risk of neurotoxicity, including seizures and arachnoiditis, when injected into the cerebrospinal fluid. *Conray 470* - **Conray 470** contains **iothalamate meglumine**, another **ionic contrast medium**. - Similar to Urografin, its **high osmolality and ionic nature** make it unsuitable for intrathecal administration for myelography, as it can cause significant neurotoxic effects. *Biligrafin* - **Biligrafin** is an **ionic, high osmolality contrast medium** primarily designed for **cholangiography**, typically administered intravenously to visualize the biliary tree. - It is **not used for myelography** due to its neurotoxicity risks and formulation, which is not intended for intrathecal injection.

Question 259: Study of the small intestine using barium is called

A. Barium enema
B. Barium enteroclysis
C. Barium meal follow-through (Correct Answer)
D. Barium swallow (esophagus and stomach)

Explanation: ***Barium meal follow-through*** - This procedure involves the patient drinking a **barium sulfate solution**, which then travels through the esophagus, stomach, and into the entire **small intestine**, allowing for visualization of its mucosal lining and lumen. - It specifically assesses the small bowel for abnormalities such as **Crohn's disease**, enteritis, tumors, or strictures. *Barium enema* - A barium enema is used to visualize the **large intestine (colon and rectum)**, not the small bowel, by introducing barium sulfate rectally. - It is often performed to identify conditions like **colorectal polyps**, diverticulosis, or inflammatory bowel disease affecting the colon. *Barium enteroclysis* - This is a more invasive procedure where barium and methylcellulose are directly infused into the **small intestine** via a nasojejunal tube to distend and coat the intestinal walls. - While it provides detailed views of the small bowel, it is not simply "study of the small intestine using barium" as asked, but a specific, more intricate variant. *Barium swallow (esophagus and stomach)* - A barium swallow primarily examines the **esophagus**, pharynx, and sometimes the **stomach**, assessing swallowing function and structural issues in these upper gastrointestinal organs. - It only visualizes the initial part of the GI tract and does not extend to fully study the small intestine.

Question 260: What is the primary imaging modality used for diagnosing urethral trauma?

A. Ascending urethrogram (Correct Answer)
B. Descending urethrogram
C. USG
D. CT scan

Explanation: ***Ascending urethrogram*** - An **ascending urethrogram** (also known as a retrograde urethrogram) is the **gold standard** for diagnosing urethral trauma. - It involves injecting contrast material directly into the urethra to visualize its integrity and identify any extravasation, strictures, or ruptures. *Descending urethrogram* - A descending urethrogram (or voiding cystourethrogram) is primarily used to evaluate the **bladder and urethra during urination**, often for vesicoureteral reflux or bladder neck dysfunction. - It is not the primary diagnostic tool for acute urethral trauma, as it requires the patient to void, which might be painful or difficult with an injured urethra. *USG* - **Ultrasound** (USG) can be used to assess the presence of peri-urethral hematomas or fluid collections but is generally **not sufficient to definitively diagnose urethral integrity** or the exact location and extent of a tear. - Its utility in urethral trauma is limited compared to direct contrast imaging of the urethra. *CT scan* - A **CT scan** of the pelvis can identify associated injuries, such as **pelvic fractures** or hematomas, that often accompany urethral trauma. - However, it is **less sensitive for direct visualization of the urethral lumen** and diagnosing the extent of a urethral injury compared to an ascending urethrogram.

Practice by Chapter

Iodinated Contrast Media

Practice Questions

MRI Contrast Agents

Practice Questions

Ultrasound Contrast Agents

Practice Questions

Adverse Reactions to Contrast Media

Practice Questions

Management of Contrast Reactions

Practice Questions

Contrast-Induced Nephropathy

Practice Questions

Barium Studies

Practice Questions

Intravenous Urography

Practice Questions

Angiography Techniques

Practice Questions

Lymphangiography

Practice Questions

Contrast Administration Protocols

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Pretesting and Premedication

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