Abdominal and Pelvic Radiology Practice Questions

Q: A patient with abdominal pain shows a "coffee bean" sign in a plain abdominal X-ray. What is the probable diagnosis?

Sigmoid volvulus. ### Explanation **1. Why Sigmoid Volvulus is Correct:** The **"Coffee Bean" sign** (also known as the Omega sign or Frimann-Dahl sign) is the pathognomonic radiographic feature of **Sigmoid Volvulus**. This condition occurs when the sigmoid colon twists on its mesenteric axis, leading to a closed-loop obstruction. The resulting massive dilation of the sigmoid loop creates a smooth, U-shaped shadow that resembles a giant coffee bean. The "bean" typically points toward the right upper quadrant, and its "cleft" is formed by the two adjacent inner walls of the twisted loop. **2. Analysis of Incorrect Options:** * **Colon Carcinoma:** Typically presents with an **"Apple Core" lesion** (annular constriction) on a barium enema, rather than a single massive dilated loop. * **Duodenal Atresia:** Characterized by the **"Double Bubble" sign** on X-ray, representing air in the stomach and the proximal duodenum, usually seen in neonates. * **Acute Pancreatitis:** Common radiographic findings include the **"Sentinel Loop"** (localized ileus of a jejunal loop) or the **"Colon Cut-off sign"** (abrupt collapse of the colon near the splenic flexure), but not a coffee bean appearance. **3. High-Yield Clinical Pearls for NEET-PG:** * **Bird’s Beak Sign:** Seen on a barium enema at the site of the twist in sigmoid volvulus. * **Whirl Sign:** The classic appearance of twisted mesentery on a CT scan. * **Management:** Initial treatment is often **sigmoidoscopic detorsion** (unless gangrene is suspected), followed by elective surgery to prevent recurrence. * **Cecal Volvulus:** Unlike sigmoid, the dilated loop in cecal volvulus usually has only one air-fluid level and tends to point toward the left upper quadrant.

Q: What does the cholangiogram show?

Klatskin Tumor. ***Klatskin Tumor*** - Cholangiogram shows **abrupt cut-off** or **stricture** at the **hepatic duct confluence** (Klatskin tumor location), with **bilateral intrahepatic ductal dilatation**. - Classic **"pruned tree" appearance** with dilated intrahepatic ducts proximal to the obstruction and absence of contrast beyond the hilar region. *Gall stones* - Gallstones appear as **filling defects** within the gallbladder on cholangiography, not as ductal strictures. - Would show **mobile radiolucent areas** within the gallbladder contrast, without upstream biliary dilatation. *Choledocholithiasis* - Shows **filling defects** within the **common bile duct** rather than hilar strictures. - Characterized by **ductal dilatation proximal** to the stone with **abrupt transition** at the stone location, not at the hepatic duct confluence. *Porcelain gall bladder* - Appears as **rim-like calcification** of the gallbladder wall on imaging, not visible on cholangiography. - Cholangiogram would show **non-filling** or **non-visualization** of the gallbladder due to chronic inflammation and calcification.

Q: The 'bowler hat' sign is radiographically observed in which of the following conditions?

Sessile colonic polyp. **Explanation:** The **'Bowler Hat' sign** is a classic radiological sign seen on a **double-contrast barium enema**. It represents a **sessile colonic polyp** or a pedunculated polyp viewed head-on. **Why it occurs:** When a polyp is coated with barium and surrounded by air, it projects into the lumen. Depending on the orientation of the polyp relative to the X-ray beam, the barium collects in the "moat" or the angle between the polyp and the colonic wall, creating a ring-like shadow. The "dome" of the hat represents the surface of the polyp, and the "brim" represents the barium at the base. * **Crucial distinction:** If the "hat" points **toward** the center of the lumen, it is a polyp. If it points **away** from the lumen, it represents a diverticulum. **Analysis of Incorrect Options:** * **Sigmoid Volvulus:** Characterized by the **'Coffee Bean' sign** or 'Omega' sign on X-ray, and the 'Bird’s Beak' sign on barium enema. * **Midgut Volvulus:** Classically shows the **'Whirlpool' sign** on Doppler USG/CT and a 'Corkscrew' appearance of the distal duodenum on contrast studies. * **Intussusception:** Associated with the **'Target' or 'Donut' sign** on USG and the **'Coiled Spring' appearance** on barium enema. **NEET-PG High-Yield Pearls:** * **Polyp 2cm:** High risk of malignancy. * **Mexican Hat Sign:** Another name for the bowler hat sign when seen head-on. * **Apple Core Deformity:** Classic sign for annular Constricting Carcinoma of the colon.

Q: What does the term "pseudo kidney" refer to in medical imaging?

A thickened bowel loop on ultrasonography. ### Explanation **1. Why Option A is Correct:** The **"Pseudo-kidney sign"** is a classic ultrasonographic finding where a segment of bowel mimics the appearance of a kidney. In a cross-sectional or longitudinal view, a **thickened bowel wall** (which is hypoechoic/dark) surrounds the **central mucosal/luminal contents** (which are hyperechoic/bright). This creates an appearance similar to the renal cortex surrounding the echogenic renal sinus. It is most commonly associated with: * **Intussusception** (Target or doughnut sign in transverse; pseudo-kidney in longitudinal). * **Gastrointestinal malignancies** (e.g., Adenocarcinoma of the colon or Lymphoma). * **Inflammatory Bowel Disease** (e.g., Crohn’s disease). **2. Why the Other Options are Incorrect:** * **Option B (Hydronephrosis):** This refers to the dilation of the renal pelvis and calyces due to obstruction. On USG, it appears as a branching, fluid-filled (anechoic) collecting system, not a bowel-like structure. * **Option C (Unascended kidney):** Also known as an **Ectopic Kidney** (e.g., Pelvic kidney). While the kidney is in an abnormal location, it is a true kidney, not a "pseudo" mimic. * **Option D (Undescended testes):** This refers to **Cryptorchidism**. On USG, an undescended testis appears as an oval, homogeneous, hypoechoic structure, usually located in the inguinal canal. **3. Clinical Pearls for NEET-PG:** * **Target/Doughnut Sign:** The transverse equivalent of the pseudo-kidney sign, highly characteristic of **Intussusception**. * **Hayfork Sign:** Another USG sign of intussusception seen in the longitudinal plane (representing the layers of the intussusceptum). * **High-Yield Tip:** If a "pseudo-kidney" is seen in an elderly patient with weight loss, think **Colonic Carcinoma**. If seen in a child with colicky pain, think **Intussusception**.

Q: Multiple air-fluid levels in a child are seen in which condition?

Ileal obstruction. **Explanation:** The presence of **multiple air-fluid levels** on an erect abdominal X-ray is a hallmark sign of **distal small bowel obstruction**, such as **Ileal obstruction**. 1. **Why Ileal obstruction is correct:** In distal obstructions, a large segment of the small intestine (jejunum and ileum) proximal to the blockage fills with swallowed air and secreted fluid. On an upright film, gravity causes the fluid to settle, creating multiple "stair-step" air-fluid levels. Generally, more than 2–3 air-fluid levels are considered pathological in children. 2. **Why other options are incorrect:** * **Gastric obstruction:** Typically presents with a single large air-fluid level in the left upper quadrant (the dilated stomach) and a "gasless abdomen" distally. * **Duodenal obstruction:** Classically presents with the **"Double Bubble Sign"** (air in the stomach and proximal duodenum). There are usually only two air-fluid levels; the rest of the distal bowel is gasless. * **Esophageal atresia:** If there is no tracheoesophageal fistula (TEF), the abdomen will be completely gasless. If a distal TEF is present, there may be gas, but it does not typically present with multiple air-fluid levels unless a secondary lower obstruction exists. **NEET-PG High-Yield Pearls:** * **Double Bubble Sign:** Duodenal Atresia, Annular Pancreas, Midgut Volvulus. * **Triple Bubble Sign:** Jejunal Atresia. * **Step-ladder pattern:** Classic description for multiple air-fluid levels in small bowel obstruction. * **Coiled Spring Sign:** Seen on contrast studies in Intussusception. * **String Sign of Kantor:** Seen in Crohn’s disease (terminal ileum).

Q: Which of the following liver metastases appear hypoechoic on ultrasound?

Carcinoma of the breast. ### Explanation Liver metastases are the most common malignant tumors of the liver. Their appearance on ultrasound depends on the vascularity, cellularity, and collagen content of the primary tumor. **1. Why Carcinoma of the Breast is correct:** Breast carcinoma metastases are typically **hypoechoic** because they are often highly cellular with minimal stroma or internal architecture. Hypoechoic lesions are the most common presentation for metastases from lymphomas and most solid organ primaries, including the breast and lung. **2. Analysis of Incorrect Options:** * **Carcinoma of the Colon (Option A):** These are characteristically **hyperechoic**. This is due to the high degree of vascularity or the presence of microcalcifications and fibrous tissue within the metastatic deposits. * **Carcinoma of the Bladder (Option C):** While variable, urothelial cell metastases often present with mixed echogenicity or hyperechoic patterns compared to the more consistently hypoechoic breast metastases. * **Mucinous Adenocarcinoma (Option D):** These typically appear **hyperechoic** or may show cystic components. The presence of mucin and associated calcifications increases the acoustic impedance, leading to a brighter (hyperechoic) appearance. **3. High-Yield Clinical Pearls for NEET-PG:** * **Hyperechoic Metastases:** Think "GI and Vascular"—Colon (most common), Renal Cell Carcinoma, Carcinoid, and Choriocarcinoma. * **Hypoechoic Metastases:** Think "Solid and Lymphatic"—Breast, Lung, and Lymphoma. * **Target/Bull’s Eye Sign:** A hypoechoic halo around a liver lesion is highly suggestive of malignancy (metastasis). * **Calcified Metastases:** Most commonly associated with **Mucinous Adenocarcinoma of the Colon**. * **Cystic Metastases:** Often seen in Cystadenocarcinoma of the ovary or pancreas, and Sarcomas (due to central necrosis).

Q: The 'Mexican hat sign' is characteristically seen in which of the following conditions?

Pedunculated polyp. ### Explanation The **'Mexican hat sign'** is a classic radiological sign seen on a **double-contrast barium enema**. It represents a **pedunculated colonic polyp** viewed "en face" (head-on). **Why it occurs:** A pedunculated polyp consists of a head and a stalk. When the patient is positioned so that the X-ray beam passes vertically through the polyp, the barium coats the surface of both the head and the stalk. This creates two concentric rings: 1. The **outer ring** represents the barium coating the head of the polyp. 2. The **inner ring** represents the barium coating the stalk. Together, these resemble a traditional Mexican hat (sombrero). **Analysis of Incorrect Options:** * **Sigmoid volvulus:** Characterized by the **'Coffee bean sign'** on plain X-ray and the **'Bird’s beak sign'** on a barium enema. * **Midgut volvulus:** Classically shows the **'Whirlpool sign'** on Doppler ultrasound or CT, and a **'Corkscrew appearance'** of the duodenum on an upper GI series. * **Sessile colonic polyp:** These lack a stalk. On a double-contrast study, they typically appear as a single line or a **'Bowline sign'** (crescentic shadow) rather than concentric rings. **High-Yield Clinical Pearls for NEET-PG:** * **Target Sign / Bull’s Eye Sign:** Often used to describe intussusception on ultrasound/CT. * **Apple Core Lesion:** Characteristic of annular constricting carcinoma of the colon. * **Lead Pipe Colon:** Seen in chronic ulcerative colitis due to loss of haustrations. * **Thumbprinting:** Indicates bowel wall edema, classically seen in ischemic colitis.

Q: Keyhole appearance on ultrasound is seen in which of the following conditions?

Posterior urethral valve. **Explanation:** The **"Keyhole appearance"** on antenatal or postnatal ultrasound is a pathognomonic sign of **Posterior Urethral Valves (PUV)**. **Why it occurs:** PUV is the most common cause of bladder outlet obstruction in male infants. The "keyhole" is formed by the combination of a **thick-walled, distended urinary bladder** (the head of the keyhole) and a **dilated posterior urethra** (the neck of the keyhole) situated superior to the obstructing valves. This appearance is best visualized in the transverse plane of the pelvis. **Analysis of Incorrect Options:** * **Polycystic Kidney:** Characterized by multiple cysts of varying sizes. In Autosomal Recessive PCKD, kidneys appear bilaterally enlarged and hyperechoic ("bright") on ultrasound. * **Hydronephrosis:** Refers to the dilatation of the renal pelvis and calyces. While PUV causes secondary hydronephrosis, the term "keyhole sign" specifically describes the bladder and urethral morphology. * **Intracapsular breast implant rupture:** This is associated with the **"Linguine sign"** (on MRI) or the **"Stepladder sign"** (on Ultrasound), representing the collapsed elastomer shell within the fibrous capsule. **High-Yield Clinical Pearls for NEET-PG:** * **PUV Triad:** Distended bladder, dilated posterior urethra, and bilateral hydroureteronephrosis. * **Gold Standard Investigation:** Voiding Cystourethrogram (VCUG) is the definitive test to diagnose PUV postnatally. * **Associated Findings:** Oligohydramnios (in utero) and "Potter sequence" (pulmonary hypoplasia, limb deformities, and abnormal facies) due to prolonged lack of amniotic fluid. * **Management:** Initial bladder drainage followed by endoscopic primary valve ablation.

Question 1

A patient with abdominal pain shows a "coffee bean" sign in a plain abdominal X-ray. What is the probable diagnosis?

Accepted Answer

Sigmoid volvulus

Answer

Colon carcinoma

Answer

Duodenal atresia

Answer

Acute pancreatitis

Question 2

Non-visualization of the gastric fundic bubble with an air-fluid level in the retrocardiac region suggests which of the following?

Accepted Answer

Achalasia cardia

Answer

Carcinoma esophagus

Answer

Esophageal web

Answer

Congenital hypertrophic pyloric stenosis

Question 3

What does the cholangiogram show?

Accepted Answer

Klatskin Tumor

Answer

Gall stones

Answer

Choledocholithiasis

Answer

Porcelain gall bladder

Question 4

The 'bowler hat' sign is radiographically observed in which of the following conditions?

Accepted Answer

Sessile colonic polyp

Answer

Sigmoid volvulus

Answer

Midgut volvulus

Answer

Intussusception

Question 5

What does the term "pseudo kidney" refer to in medical imaging?

Accepted Answer

A thickened bowel loop on ultrasonography

Answer

Hydronephrosis

Answer

An unascended kidney

Answer

Undescended testes

Question 6

Multiple air-fluid levels in a child are seen in which condition?

Accepted Answer

Ileal obstruction

Answer

Gastric obstruction

Answer

Duodenal obstruction

Answer

Esophageal atresia

Question 7

Which of the following are true features of cholecystitis on ultrasonography?

Accepted Answer

Thick fibrosed gallbladder wall

Answer

Stone impacted at the neck of the gallbladder

Answer

Pericholecystic halo

Answer

Increased vascularity

Question 8

Which of the following liver metastases appear hypoechoic on ultrasound?

Accepted Answer

Carcinoma of the breast

Answer

Carcinoma of the colon

Answer

Carcinoma of the bladder

Answer

Mucinous adenocarcinoma

Question 9

The 'Mexican hat sign' is characteristically seen in which of the following conditions?

Accepted Answer

Pedunculated polyp

Answer

Sigmoid volvulus

Answer

Midgut volvulus

Answer

Sessile colonic polyp

Question 10

Keyhole appearance on ultrasound is seen in which of the following conditions?

Accepted Answer

Posterior urethral valve

Answer

Polycystic kidney

Answer

Hydronephrosis

Answer

Intracapsular breast implant rupture

Abdominal and Pelvic Radiology — MCQs

Abdominal and Pelvic Radiology — MCQs

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