Abdominal and Pelvic Radiology — MCQs

Which of the following statements about hepatocellular carcinoma (HCC) is true? 1. On CECT, rapid wash-in and washout of contrast are seen in HCC. 2. HCC is the most common primary malignant tumor of the liver. 3. LI-RADS provides an algorithm for the diagnosis of HCC. 4. Fibrolamellar HCC has a better prognosis than classic HCC. 5. Alpha-fetoprotein is raised in 50-60% of HCC cases.

Q646

Which of the following is characterized by a "cobra head deformity"?

Abdominal and Pelvic Radiology Indian Medical PG Practice Questions and MCQs

Question 641: What is the best investigation to diagnose a hydatid cyst in the liver?

A. MRI
B. MRCP
C. Ultrasound (Correct Answer)
D. CT scan

Explanation: ***Ultrasound*** - It is often the **initial imaging modality** of choice due to its non-invasiveness, accessibility, and high sensitivity for detecting the characteristic features of **hydatid cysts**, such as the **double-wall sign**, **daughter cysts**, and **hydatid sand**. - Ultrasound can effectively visualize the **cystic nature** of the lesion and its internal architecture, crucial for differentiating it from other liver lesions. *MRI* - While MRI provides excellent soft tissue contrast, it is typically reserved for cases where **ultrasound findings are equivocal** or for better defining the anatomical relationship of the cyst to surrounding structures, especially if surgical intervention is planned. - It can identify complex cyst features but is not usually the **first-line diagnostic tool** due to its higher cost and longer scan time compared to ultrasound. *MRCP* - **Magnetic Resonance Cholangiopancreatography (MRCP)** is specifically designed to visualize the **biliary and pancreatic ducts**. - It is not the primary investigation for diagnosing hydatid cysts themselves, although it may be used if there is suspicion of **biliary tree involvement** or rupture into the bile ducts. *CT scan* - A **CT scan** is also a highly effective imaging modality for identifying hydatid cysts, especially for showing calcifications in the cyst wall and providing a comprehensive view of the abdominal organs. - However, for initial diagnosis, **ultrasound is preferred** due to its lower cost, lack of radiation exposure, and comparable diagnostic accuracy for typical cyst appearances.

Question 642: In a suspected case of ovarian cancer, imaging work-up is required for all of the following EXCEPT:

A. Characterization of lesion
B. Assess resectability
C. Detection of adnexal lesion
D. Staging (Correct Answer)

Explanation: ***Staging*** - **Clinical staging** for ovarian cancer is primarily surgical, meaning the definitive stage is determined during exploratory laparotomy rather than pre-operative imaging. - While imaging helps assess the extent of disease, the final **FIGO stage** relies on direct visualization and biopsy or resection of suspicious lesions during surgery. *Characterization of lesion* - Imaging modalities like **ultrasound**, **CT**, or **MRI** are crucial for determining features such as **cyst vs. solid**, size, septations, and presence of ascites, helping to differentiate benign from malignant masses. - This characterization guides the initial management plan, including the need for surgery or further investigations. *Assess resectability* - Imaging is essential to evaluate the **extent of tumor spread**, particularly to assess for widespread peritoneal carcinomatosis, bowel involvement, or distant metastases. - This information helps surgeons plan for optimal **cytoreductive surgery** and determine if a complete resection is feasible. *Detection of adnexal lesion* - The initial detection of an adnexal mass often occurs via imaging, typically **transvaginal ultrasound**, when a patient presents with symptoms or during a routine examination. - Imaging confirms the presence and location of the lesion, which is the first step in the diagnostic work-up for suspected ovarian cancer.

Question 643: Which of the following conditions is associated with the "Rim sign" in a nephrogram?

A. Polycystic kidney disease
B. Pyelonephritis
C. Renal cell carcinoma (hypernephroma) (Correct Answer)
D. None of the options

Explanation: ***Renal cell carcinoma (hypernephroma)*** - The **"Rim sign"** (also called **peripheral capsular enhancement**) on a nephrogram refers to the **peripheral enhancement pattern** seen in **renal cell carcinoma**, particularly during the early arterial phase of contrast-enhanced CT. - This sign reflects the **hypervascular nature** of RCC and its **fibrous pseudocapsule** that enhances peripherally, creating a rim of enhancement around the tumor. - This is distinct from central heterogeneous enhancement and is a helpful diagnostic feature in differentiating RCC from other renal masses. *Pyelonephritis* - Acute pyelonephritis typically presents with **wedge-shaped areas of decreased enhancement** or **striated nephrogram** pattern, not the peripheral rim enhancement seen in RCC. - The inflammation primarily involves the **renal parenchyma** and collecting system with patchy, striated areas rather than a defined peripheral rim. *Polycystic kidney disease* - This condition is characterized by **multiple cysts** of varying sizes throughout both kidneys, which appear as **non-enhancing, fluid-filled lesions** on imaging. - The cysts themselves may show **thin septations** but do not demonstrate the tumor-associated rim sign of RCC. *None of the options* - This option is incorrect as **renal cell carcinoma** is indeed associated with the peripheral rim enhancement pattern on nephrogram.

Question 644: In the context of abdominal imaging, which condition is associated with the 'Claw sign'?

A. Volvulus
B. Pyloric stenosis
C. Peptic ulcer
D. Intussusception (Correct Answer)

Explanation: ***Intussusception*** - The **"Claw sign"** is a radiologic finding observed in intussusception, where the invaginated segment of the bowel (intussusceptum) is surrounded by the receiving segment (intussuscipiens), creating a crescent-shaped or claw-like appearance. - This sign is crucial for diagnosing intussusception on imaging studies such as **CT scans** or **ultrasound**, indicating the telescoping of one bowel segment into another. *Volvulus* - Volvulus refers to the **twisting of a loop of bowel** around its mesentery, leading to obstruction and potential ischemia. - Imaging findings typically include a **"whirl sign"** (swirling of mesenteric vessels) or a **dilated U-shaped loop** of bowel, not a claw sign. *Pyloric stenosis* - Pyloric stenosis involves the **narrowing of the pyloric channel**, often seen in infants, leading to gastric outlet obstruction. - Characteristic imaging findings include an **elongated and thickened pyloric canal** (the "cervix sign" or "donut sign" on ultrasound), not the claw sign. *Peptic ulcer* - A peptic ulcer is an **open sore in the lining of the stomach or duodenum**, often caused by *H. pylori* infection or NSAID use. - Imaging may show **crater defects with surrounding edema** or signs of perforation, but it does not present with a "claw sign."

Question 645: Which of the following statements about hepatocellular carcinoma (HCC) is true? 1. On CECT, rapid wash-in and washout of contrast are seen in HCC. 2. HCC is the most common primary malignant tumor of the liver. 3. LI-RADS provides an algorithm for the diagnosis of HCC. 4. Fibrolamellar HCC has a better prognosis than classic HCC. 5. Alpha-fetoprotein is raised in 50-60% of HCC cases.

A. 1. True, 2. False, 3. True, 4. True, 5. True
B. 1. True, 2. True, 3. True, 4. True, 5. True (Correct Answer)
C. 1. True, 2. True, 3. False, 4. True, 5. True
D. 1. True, 2. True, 3. True, 4. False, 5. True

Explanation: ***All statements are TRUE (Option: 1. True, 2. True, 3. True, 4. True, 5. True)*** - This is the **correct answer** because all five statements about hepatocellular carcinoma (HCC) are medically accurate. - **Statement 1 (Contrast enhancement)**: HCC characteristically shows **arterial phase hyperenhancement** (rapid wash-in) followed by **washout** in portal venous or delayed phases on CECT, which is a key diagnostic feature. - **Statement 2 (Most common primary liver cancer)**: HCC accounts for approximately **75-85% of primary liver malignancies**, making it the most common primary hepatic malignancy worldwide. - **Statement 3 (LI-RADS system)**: The **Liver Imaging Reporting and Data System (LI-RADS)** provides a standardized algorithm for diagnosing and categorizing liver lesions, particularly HCC in at-risk patients. - **Statement 4 (Fibrolamellar variant)**: **Fibrolamellar HCC** is a rare variant (5% of HCC cases) that typically occurs in younger patients without cirrhosis and has a **better prognosis** than conventional HCC, with 5-year survival rates of 30-50% vs 10-20%. - **Statement 5 (Alpha-fetoprotein)**: **AFP is elevated** (>20 ng/mL) in approximately **50-70% of HCC cases**, though it has limited sensitivity for early detection and can be normal in small tumors. *Option stating Statement 2 is FALSE* - This is incorrect because HCC **is definitively the most common** primary malignant liver tumor, comprising the vast majority of primary liver cancers globally. *Option stating Statement 3 is FALSE* - This is incorrect because **LI-RADS is a well-established** imaging algorithm specifically developed for HCC diagnosis and risk stratification in at-risk populations. *Option stating Statement 4 is FALSE* - This is incorrect because fibrolamellar HCC **does have a better prognosis** than classic HCC, with improved resectability and survival outcomes, particularly in younger, non-cirrhotic patients.

Question 646: Which of the following is characterized by a "cobra head deformity"?

A. Cystitis
B. Ureterocele (Correct Answer)
C. Bladder tumour
D. Posterior urethral valve

Explanation: ***Ureterocele*** - A "cobra head deformity" is a classic radiographic sign seen on an intravenous pyelogram (IVP) or ultrasound, referring to the characteristic appearance of a **ureterocele** within the bladder. - This appearance is due to the dilated, cystic end of the ureter that protrudes into the bladder lumen, surrounded by a thin, radiolucent halo created by the ureteral wall and urine. *Cystitis* - **Cystitis** is inflammation of the bladder and does not typically result in a "cobra head deformity" on imaging. - Inflammatory changes may lead to wall thickening or irregular contour but not to this specific type of filling defect. *Bladder tumour* - A **bladder tumour** can present as a filling defect within the bladder, but its appearance is usually irregular or polypoid, not resembling a "cobra head." - Tumours can vary widely in shape and size, and typically show enhancement on contrast imaging. *Posterior urethral valve* - **Posterior urethral valve** is a congenital obstructive lesion in the male urethra, primarily affecting urine outflow from the bladder. - It leads to bladder wall hypertrophy and reflux, but does not cause a "cobra head deformity" in the bladder.

Practice by Chapter

Imaging of Liver

Practice Questions

Biliary Tract Imaging

Practice Questions

Pancreatic Imaging

Practice Questions

Spleen and Lymphatic System

Practice Questions

Gastrointestinal Tract Imaging

Practice Questions

Renal and Urinary Tract Imaging

Practice Questions

Adrenal Imaging

Practice Questions

Female Pelvic Imaging

Practice Questions

Male Pelvic Imaging

Practice Questions

Abdominal Trauma Imaging

Practice Questions

Acute Abdomen Imaging

Practice Questions

Imaging of Peritoneal Cavity and Retroperitoneum

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free