Abdominal and Pelvic Radiology Practice Questions

Q: What is this appearance, seen in early pregnancy, known as?

Double bleb sign. ***Double bleb sign*** - Seen on **transvaginal ultrasound** at approximately **5-6 weeks gestation**, representing the **amnion** and **yolk sac** as two distinct fluid-filled structures within the gestational sac. - This sign confirms **early intrauterine pregnancy** and indicates normal embryonic development with proper formation of extraembryonic structures. *Yolk sac sign* - Refers to the **single yolk sac** visualization within the gestational sac, typically seen around **5-5.5 weeks**. - Does not involve the characteristic **two separate blebs** (amnion + yolk sac) that define the double bleb sign. *Double decidual sac sign* - An earlier ultrasound finding seen around **4-5 weeks** showing **two concentric rings** of decidual tissue around the gestational sac. - Represents the **decidua capsularis** and **decidua parietalis**, not the amnion and yolk sac structures. *Twin peak sign* - A finding in **dichorionic diamniotic twin pregnancies** showing a **triangular projection** of placental tissue at the membrane insertion site. - Used to differentiate **chorionicity** in multiple pregnancies, not relevant to single early pregnancy appearances.

Q: What is the initial investigation for suspected gallbladder stones?

Ultrasound (USG). **Explanation:** **Ultrasound (USG)** is the **initial and gold standard investigation** for suspected gallbladder stones (cholelithiasis). It has a high sensitivity and specificity (>95%) for detecting stones. The underlying medical concept relies on the fact that gallstones are dense structures that reflect sound waves, appearing as **hyperechoic foci** with characteristic **posterior acoustic shadowing**. Additionally, USG is non-invasive, cost-effective, lacks radiation, and can simultaneously assess for signs of inflammation (e.g., gallbladder wall thickening or pericholecystic fluid). **Analysis of Incorrect Options:** * **Fasting Respiratory Correlate Pulmonary (FRCP):** This is a distractor term and not a standard radiological investigation for biliary disease. (Note: Do not confuse with ERCP, which is an invasive therapeutic procedure). * **MRCP:** While highly sensitive for detecting stones in the *bile ducts* (choledocholithiasis), it is expensive and time-consuming. It is reserved as a second-line investigation when USG is inconclusive or ductal stones are suspected. * **CT Scan:** CT is inferior to USG for gallstones because many stones are "iso-attenuating" (radiolucent) to bile, making them invisible on a standard CT. CT is, however, the best modality for detecting complications like gallbladder perforation or emphysematous cholecystitis. **High-Yield Clinical Pearls for NEET-PG:** * **WES Triad:** (Wall-Echo-Shadow) is a classic USG sign seen when the gallbladder is completely filled with stones. * **HIDA Scan:** The most sensitive/accurate test for **Acute Cholecystitis** (shows non-visualization of the gallbladder). * **Oral Cholecystography:** Historically used but now obsolete; it relied on the functional ability of the gallbladder to concentrate dye.

Q: Which pattern is seen in the jejunum on an X-ray?

Valvulae connivantes. **Explanation:** The correct answer is **A. Valvulae connivantes**. **1. Why Valvulae connivantes is correct:** Valvulae connivantes (also known as Plicae circulares or Kerckring folds) are the mucosal folds of the small intestine. They are most prominent in the **jejunum**. On an abdominal X-ray, especially in cases of small bowel obstruction, these folds appear as thin, closely spaced lines that **span the entire width of the bowel lumen**. This "stack of coins" appearance is a classic radiologic hallmark used to distinguish the jejunum from the ileum (which has fewer folds and appears smoother) and the large intestine. **2. Why the other options are incorrect:** * **B. Taenia coli:** These are three longitudinal bands of smooth muscle found in the **large intestine**. On X-ray, the contraction of these bands creates **haustrations**. Unlike valvulae connivantes, haustral folds are thicker, further apart, and **do not span the entire diameter** of the bowel. * **C. Reverse 3 sign:** This is a specific radiologic sign seen on a barium swallow or during an ERCP, typically associated with **Carcinoma of the Head of the Pancreas** or periampullary tumors (Frostberg’s sign), where the duodenal loop is indented. It is not a normal pattern of the jejunum. **High-Yield Clinical Pearls for NEET-PG:** * **Jejunum vs. Ileum:** Jejunum is in the LUQ (Left Upper Quadrant) with prominent folds; Ileum is in the RLQ (Right Lower Quadrant) with a featureless/smooth appearance. * **Small Bowel Obstruction (SBO):** Characterized by dilated loops (>3 cm), valvulae connivantes, and multiple air-fluid levels on erect films. * **Large Bowel Obstruction (LBO):** Characterized by peripheral distribution and haustrations that do not cross the entire lumen.

Q: A 30-year-old female presents with right hypochondrial pain. CT scan reveals floating membranes in the liver. What is the most likely diagnosis?

Hydatid cyst. ### Explanation **Correct Answer: B. Hydatid Cyst** The presence of **"floating membranes"** within a hepatic cystic lesion is a pathognomonic radiological sign for **Hydatid disease** (Cystic Echinococcosis), caused by *Echinococcus granulosus*. This is known as the **Water-Lily Sign**. It occurs when the endocyst (the inner germinal layer) ruptures and detaches from the pericyst (the host-derived outer layer), causing the collapsed membranes to float within the cyst fluid. **Why other options are incorrect:** * **Amoebiasis (Amoebic Liver Abscess):** Typically presents as a "anchovy sauce" appearance on aspiration. On CT, it appears as a well-defined, low-attenuation lesion with a peripheral enhancing rim, but it lacks internal membranes or daughter cysts. * **Tuberculosis:** Hepatic TB usually presents as hepatomegaly with multiple small "miliary" granulomas or a large "tuberculoma" which may show central necrosis or calcification, but not floating membranes. * **Hepatocellular Carcinoma (HCC):** This is a solid, hypervascular tumor showing "wash-in" (arterial phase enhancement) and "wash-out" (venous/delayed phase) on contrast CT. It is not primarily a cystic lesion. **High-Yield Clinical Pearls for NEET-PG:** * **Gharbi Classification:** Used to stage Hydatid cysts (Type I: Pure fluid; Type II: Floating membranes; Type III: Daughter cysts/honeycomb; Type IV: Solid/Heterogeneous; Type V: Calcified wall). * **Other Signs:** **"Honeycomb sign"** (multiple daughter cysts) and **"Eggshell calcification"** of the cyst wall. * **Treatment:** PAIR (Puncture, Aspiration, Injection of scolicidal agent, Re-aspiration) or surgical resection, always covered with **Albendazole**. * **Risk:** Avoid simple aspiration if Hydatid is suspected due to the risk of **anaphylactic shock** from spillage of cyst contents.

Q: Radiographic findings of cardiac achalasia include all except?

Diffuse esophageal spasm. **Explanation:** **Achalasia Cardia** is a primary esophageal motility disorder characterized by the failure of the Lower Esophageal Sphincter (LES) to relax and the absence of progressive peristalsis. **Why Option D is correct:** **Diffuse Esophageal Spasm (DES)** is a distinct clinical entity and a differential diagnosis for achalasia, not a radiographic finding of it. In DES, the esophagus shows uncoordinated, simultaneous contractions, leading to a characteristic **"Corkscrew" or "Rosary bead" appearance** on a barium swallow. In contrast, Achalasia is defined by aperistalsis. **Why the other options are incorrect:** * **Esophageal Dilatation (A):** Chronic obstruction at the LES leads to proximal pooling of food and saliva, causing the esophagus to dilate (Megaesophagus). On a chest X-ray, this may appear as a widened mediastinum with an absent gastric air shadow. * **Rat-tail appearance (B):** Also known as the **"Bird’s beak" appearance**, this represents the smooth, symmetric, conical narrowing of the distal esophagus at the level of the gastroesophageal junction. * **Failure of LES to relax (C):** This is the hallmark pathophysiologic and manometric finding of Achalasia. On fluoroscopy, the "beak" only opens intermittently and incompletely, often requiring the hydrostatic pressure of a large column of barium to force it open. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard Investigation:** Esophageal Manometry (shows incomplete LES relaxation and aperistalsis). * **Heller’s Myotomy:** The surgical treatment of choice. * **Chagas Disease:** Can cause secondary achalasia (Pseudoachalasia) due to destruction of the myenteric (Auerbach’s) plexus by *Trypanosoma cruzi*. * **Sigmoid Esophagus:** The term used for the advanced, tortuous stage of esophageal dilatation in achalasia.

Q: What is the best investigation to diagnose Meckel's diverticulum?

Technetium-99m pertechnetate scan. **Explanation:** **Technetium-99m (Tc-99m) pertechnetate scan**, also known as the **Meckel’s scan**, is the investigation of choice for diagnosing Meckel’s diverticulum. The underlying medical concept relies on the fact that approximately 50–60% of symptomatic Meckel’s diverticula contain **ectopic gastric mucosa**. Tc-99m pertechnetate has a high affinity for the mucin-secreting cells of the gastric mucosa. When injected intravenously, the radionuclide concentrates in the ectopic tissue in the ileum, appearing as a "hot spot" on scintigraphy, typically in the right lower quadrant. **Why other options are incorrect:** * **X-ray Abdomen:** Generally non-specific. It may show signs of intestinal obstruction or perforation (pneumoperitoneum) but cannot visualize the diverticulum itself. * **Ultrasonography:** While it may occasionally detect a diverticulum as a blind-ending tubular structure (especially during complications like diverticulitis), it is operator-dependent and lacks the sensitivity of nuclear imaging. * **Barium Study:** Small bowel follow-through or enteroclysis often fails to fill the diverticulum due to its narrow neck or the presence of heterotopic tissue, leading to a high false-negative rate. **High-Yield Clinical Pearls for NEET-PG:** * **Rule of 2s:** 2% of the population, 2 feet from the ileocecal valve, 2 inches long, 2 types of ectopic tissue (Gastric > Pancreatic), and usually presents before age 2. * **Sensitivity:** The Meckel’s scan is most sensitive in children (up to 90%) but less so in adults due to a lower incidence of ectopic gastric mucosa. * **Pharmacological Enhancement:** To increase the sensitivity of the scan, **Pentagastrin** (increases uptake), **H2 blockers like Cimetidine** (prevents release of pertechnetate from cells), or **Glucagon** (decreases peristalsis) can be used.

Q: A 30-year-old patient presents with acute abdominal pain and obstipation. An X-ray is provided. What is the most likely diagnosis?

Small bowel obstruction. ***Small bowel obstruction*** - Classic X-ray findings include **central dilated small bowel loops** with **valvulae conniventes** (complete mucosal folds) and **stepladder air-fluid levels**. - **Paucity of colonic gas** distally is characteristic, as obstruction prevents bowel contents from reaching the colon. *Large bowel obstruction* - X-ray shows **peripheral dilated colonic loops** with **haustrations** (incomplete mucosal folds), not central small bowel dilation. - **Cecal dilation** is often prominent, and small bowel may appear normal or minimally dilated. *Gastric outlet obstruction* - X-ray typically shows **marked gastric distension** with a **dilated stomach** containing air-fluid levels. - **Minimal small bowel gas** is present, as obstruction occurs at the **pylorus** or **duodenum**. *Duodenal atresia* - Characteristic **double-bubble sign** on X-ray showing dilated **stomach** and **proximal duodenum**. - This condition occurs in **neonates**, not 30-year-old patients, and presents shortly after birth.

Q: Which of the following investigations is NOT used for the diagnosis of protein-losing enteropathy?

Technetium-labeled seclomumab scan. **Explanation:** Protein-losing enteropathy (PLE) is characterized by the excessive loss of serum proteins into the gastrointestinal tract. Nuclear medicine plays a crucial role in diagnosing and localizing the site of protein loss. **Why Option D is Correct:** **Technetium-labeled seclomumab** is a monoclonal antibody scan used specifically for imaging **inflammatory bowel disease (IBD)** to detect areas of active inflammation by targeting granulocytes. It is not a diagnostic tool for the generalized quantification or localization of protein leakage in PLE. **Why the Other Options are Incorrect:** * **Technetium-labeled albumin (99mTc-HSA) scan:** This is the most commonly used radionuclide study for PLE. Since albumin is the primary protein lost in this condition, labeling it allows for the visualization of tracer leakage into the bowel loops. * **Technetium-labeled dextran scan:** 99mTc-Dextran is an alternative tracer. It has a smaller molecular size than albumin and is often used to detect protein loss, especially when rapid clearance or specific localization is required. * **Indium-labeled transferrin scan:** $^{111}$In-transferrin is a highly effective tracer for PLE. It has a longer half-life than Technetium, allowing for delayed imaging (up to 24–48 hours), which increases sensitivity for detecting intermittent or low-grade protein loss. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard for Diagnosis:** The biochemical gold standard is the **alpha-1 antitrypsin clearance test** (measured in stool). * **Imaging Goal:** While the alpha-1 antitrypsin test confirms the diagnosis, **Radionuclide scans** are superior for **localizing** the specific segment of the gut where the protein loss is occurring. * **Common Causes of PLE:** Primary intestinal lymphangiectasia (Waldmann's disease), Menetrier’s disease, and post-Fontan procedure complications.

Question 1

What is this appearance, seen in early pregnancy, known as?

Accepted Answer

Double bleb sign

Answer

Yolk sac sign

Answer

Double decidual sac sign

Answer

Twin peak sign

Question 2

The Carman meniscus sign in a barium meal is pathognomic of which of the following conditions?

Accepted Answer

Malignant gastric ulcer

Answer

Lipoma of the stomach

Answer

Gastric polyposis

Answer

Gastric lymphoma

Question 3

What is the initial investigation for suspected gallbladder stones?

Accepted Answer

Ultrasound (USG)

Answer

Fasting Respiratory Correlate Pulmonary (FRCP)

Answer

Magnetic Resonance Cholangiopancreatography (MRCP)

Answer

CT scan

Question 4

Which investigation is most sensitive for detecting minimal intraperitoneal free air?

Accepted Answer

Chest x-ray

Answer

Standing x-ray of the abdomen

Answer

Right lateral decubitus x-ray of the abdomen

Answer

Left lateral decubitus x-ray of the abdomen

Question 5

Which pattern is seen in the jejunum on an X-ray?

Accepted Answer

Valvulae connivantes

Answer

Taenia coli

Answer

Reverse 3 sign

Answer

None of the above

Question 6

A 30-year-old female presents with right hypochondrial pain. CT scan reveals floating membranes in the liver. What is the most likely diagnosis?

Accepted Answer

Hydatid cyst

Answer

Amoebiasis

Answer

Tuberculosis

Answer

Hepatocellular carcinoma

Question 7

Radiographic findings of cardiac achalasia include all except?

Accepted Answer

Diffuse esophageal spasm

Answer

Esophageal dilatation

Answer

Rat-tail appearance

Answer

Failure of lower esophageal sphincter to relax

Question 8

What is the best investigation to diagnose Meckel's diverticulum?

Accepted Answer

Technetium-99m pertechnetate scan

Answer

X-ray abdomen

Answer

Ultrasonography

Answer

Barium study

Question 9

A 30-year-old patient presents with acute abdominal pain and obstipation. An X-ray is provided. What is the most likely diagnosis?

Accepted Answer

Small bowel obstruction

Answer

Large bowel obstruction

Answer

Gastric outlet obstruction

Answer

Duodenal atresia

Question 10

Which of the following investigations is NOT used for the diagnosis of protein-losing enteropathy?

Accepted Answer

Technetium-labeled seclomumab scan

Answer

Technetium-labeled albumin scan

Answer

Technetium-labeled dextran scan

Answer

Indium-labeled transferrin scan

Abdominal and Pelvic Radiology — MCQs

Abdominal and Pelvic Radiology — MCQs

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