Abdominal and Pelvic Radiology Practice Questions

Q: What is the investigation of choice for a pregnant patient presenting with an upper abdominal mass?

Ultrasound (USG). **Explanation:** The investigation of choice for a pregnant patient with an upper abdominal mass is **Ultrasound (USG)**. This is primarily due to the **ALARA principle** (As Low As Reasonably Achievable), which prioritizes non-ionizing radiation to protect the developing fetus. **Why Ultrasound is the Correct Choice:** * **Safety:** USG uses high-frequency sound waves rather than ionizing radiation, making it safe for both the mother and the fetus throughout all trimesters. * **Efficacy:** It is highly effective at differentiating between cystic and solid masses and can accurately localize the origin of the mass (e.g., hepatic, pancreatic, or obstetric). * **Accessibility:** It is portable, cost-effective, and allows for real-time evaluation. **Why Other Options are Incorrect:** * **X-ray (B):** Involves ionizing radiation. While a single chest X-ray has low fetal exposure, it provides poor soft-tissue resolution for abdominal masses and is generally avoided unless necessary. * **CT Scan (C):** Contraindicated as a first-line tool due to high doses of ionizing radiation, which poses risks of teratogenesis and childhood carcinogenesis (especially in the first trimester). * **MRI (D):** While safe (non-ionizing) and excellent for soft tissue, it is expensive and less accessible. It is considered the **second-line** investigation if USG results are inconclusive. **High-Yield Clinical Pearls for NEET-PG:** * **IOC for Gallstones/Appendicitis in pregnancy:** Ultrasound. * **IOC for Nephrolithiasis in pregnancy:** Ultrasound. * **MRI in Pregnancy:** Generally avoided in the 1st trimester if possible; Gadolinium contrast is contraindicated as it crosses the placenta. * **Rule of Thumb:** For any acute abdominal or pelvic condition in a pregnant female, **USG is always the initial investigation.**

Q: What is the investigation of choice in suspected gall bladder stone?

Ultrasound. **Explanation:** **Ultrasound (USG)** is the investigation of choice (IOC) for suspected gallbladder stones (cholelithiasis) due to its high sensitivity (>95%) and specificity. The underlying medical concept relies on the fact that gallstones appear as **hyperechoic (bright) structures** within the gallbladder lumen that demonstrate **posterior acoustic shadowing** and move with changes in patient positioning. USG is non-invasive, radiation-free, cost-effective, and can simultaneously evaluate for complications like cholecystitis (e.g., gallbladder wall thickening or pericholecystic fluid). **Why other options are incorrect:** * **X-ray:** Only about 10–15% of gallstones are radiopaque (contain enough calcium to be seen). Most gallstones are cholesterol-based and radiolucent, making X-ray an unreliable screening tool. * **Barium study:** This is used to visualize the gastrointestinal lumen (esophagus, stomach, or bowel). It has no role in visualizing the interior of the gallbladder. * **Oral Cholecystography (OCG):** Historically used to assess gallbladder function and stones, it has been entirely replaced by USG because it is time-consuming, requires contrast ingestion, and depends on adequate hepatic function and intestinal absorption. **Clinical Pearls for NEET-PG:** * **Gold Standard for Choledocholithiasis (CBD stones):** ERCP (Therapeutic) or MRCP (Diagnostic). * **IOC for Acute Cholecystitis:** Ultrasound (look for Murphy’s sign under the probe). * **Most Sensitive/Gold Standard for Acute Cholecystitis:** HIDA scan (Radionuclide scan). * **WES Triad (Wall-Echo-Shadow):** A classic USG finding seen when the gallbladder is completely filled with stones.

Q: Rigler's triad is seen in which of the following conditions?

Gallstone ileus. **Explanation:** **Rigler’s Triad** is a classic radiological finding diagnostic of **Gallstone Ileus**. This condition occurs when a large gallstone erodes through the gallbladder wall into the adjacent bowel (usually the duodenum) via a cholecystoenteric fistula. The stone then travels distally until it impacts, typically at the narrowest part of the small bowel—the **ileocecal valve**. The triad consists of: 1. **Pneumobilia:** Air within the biliary tree (due to the fistula). 2. **Small Bowel Obstruction:** Dilated loops of small bowel with fluid levels. 3. **Ectopic Gallstone:** A radiopaque stone visible in the right iliac fossa or pelvis. *(Note: Presence of two out of three signs is often sufficient for diagnosis on imaging.)* **Analysis of Incorrect Options:** * **A. Pneumoperitoneum:** Characterized by **Rigler’s Sign** (not triad), where air on both sides of the bowel wall makes the wall clearly visible. * **B. Intestinal Obstruction:** While gallstone ileus causes obstruction, "Rigler’s triad" is specific to the etiology involving a gallstone. Simple obstruction lacks pneumobilia. * **D. Ulcerative Colitis:** Associated with "Lead pipe appearance" (loss of haustrations) or "Toxic megacolon," but not Rigler’s triad. **High-Yield Pearls for NEET-PG:** * **Rigler’s Sign vs. Rigler’s Triad:** Do not confuse them. Sign = Pneumoperitoneum; Triad = Gallstone ileus. * **Most common site of impaction:** Terminal ileum. * **Most common fistula:** Cholecystoduodenal fistula. * **Gold standard investigation:** CT Abdomen (more sensitive than X-ray for identifying the triad).

Q: Gas in the great vessels of a fetus indicates which of the following?

Fetal death. **Explanation:** The presence of gas in the great vessels (aorta, vena cava, or heart) of a fetus is known as **Robert’s Sign**. This is a classic radiological sign of **intrauterine fetal death (IUFD)**. **Why the correct answer is right:** Robert’s Sign occurs due to the decomposition of fetal blood, which leads to the release of gases (primarily nitrogen) into the circulatory system. It is one of the earliest radiological signs of fetal demise, often appearing within 12 to 24 hours after death. It is best visualized on a plain X-ray or ultrasound as echogenic foci with shadowing within the fetal heart or large vessels. **Why the incorrect options are wrong:** * **Fetal distress (A):** This is a clinical state (often diagnosed via heart rate monitoring or Doppler) where the fetus is compromised but alive. Gas formation does not occur in a living fetus. * **Postmature fetus (B):** A fetus beyond 42 weeks gestation may show signs of placental insufficiency or meconium staining, but gas in the vessels is not a feature of postmaturity. * **Premature fetus (D):** Prematurity refers to early birth. While premature fetuses are at higher risk, the presence of intravascular gas specifically indicates death, not the gestational age. **High-Yield Clinical Pearls for NEET-PG:** Other radiological signs of fetal death include: 1. **Spalding’s Sign:** Overlapping of fetal skull bones due to loss of liquor and brain liquefaction (usually appears 4–7 days after death). 2. **Deuel’s Halo Sign:** Elevation of the fetal scalp fat due to edema, creating a "halo" appearance. 3. **Brakeman’s Sign:** Abnormal angulation or collapse of the fetal spine. 4. **Ultrasound (Gold Standard):** The definitive diagnosis of IUFD is the absence of fetal cardiac activity on real-time ultrasound.

Q: What is the gold standard investigation for diagnosing cystic echinococcosis?

Ultrasound (USG). **Explanation:** **Cystic Echinococcosis (Hydatid Disease)** is caused by the larval stage of *Echinococcus granulosus*. **Why Ultrasound (USG) is the Gold Standard:** Ultrasound is the primary diagnostic tool and the "gold standard" because it is highly sensitive, non-invasive, and cost-effective. It allows for the visualization of pathognomonic features such as daughter cysts, "hydatid sand," and the "water lily sign" (detached endocyst). Furthermore, the **WHO-IWGE classification**, which guides the management (surgery vs. PAIR vs. medical therapy), is based entirely on USG findings. **Analysis of Incorrect Options:** * **X-ray:** While it may show calcification of the cyst wall or a "double contour" sign in lung hydatids, it lacks the sensitivity and detail required for a definitive diagnosis or staging. * **ELISA:** Serology is a supportive investigation. It is useful for confirming the diagnosis but can yield false negatives in intact or calcified cysts and false positives due to cross-reactivity with other helminths. * **CT scan:** CT is superior for detecting calcification and identifying cysts in extra-hepatic locations (e.g., bone, brain), but it is not the first-line gold standard for routine abdominal screening and staging. **High-Yield Clinical Pearls for NEET-PG:** * **Definitive Host:** Dog; **Intermediate Host:** Sheep (Man is an accidental dead-end host). * **Most common site:** Liver (Right lobe > Left lobe), followed by the Lungs. * **Casoni’s Test:** An immediate hypersensitivity skin test (now largely replaced by ELISA). * **Management:** Small, inactive cysts (CE4/CE5) are monitored; active cysts are treated with **Albendazole** and/or the **PAIR** technique (Puncture, Aspiration, Injection, Re-aspiration).

Q: Which of the following radiographic signs is NOT typically seen in pneumoperitoneum?

Tillaux sign. **Explanation:** **Pneumoperitoneum** refers to the presence of free air within the peritoneal cavity, usually signifying a perforated hollow viscus—a surgical emergency. **Why Tillaux Sign is the Correct Answer:** **Tillaux sign** is a clinical sign associated with **mesenteric cysts**. It refers to a zone of resonance (tympanity) found on percussion over the center of the cyst, surrounded by a zone of dullness. This occurs because the cyst displaces the air-filled bowel loops to the periphery. It is not a radiographic sign of free air. **Analysis of Incorrect Options (Radiographic Signs of Pneumoperitoneum):** * **Football Sign:** Seen on a supine radiograph when a large amount of free air collects under the anterior abdominal wall, outlining the entire peritoneal cavity in an oval shape resembling an American football. * **Rigler’s Sign (Double Wall Sign):** Occurs when air is present on both the inside (intraluminal) and outside (extraluminal) of the bowel wall, making the bowel wall clearly visible as a discrete line. * **Cupola Sign:** Refers to an arcuate lucency seen on a supine chest or abdominal X-ray, representing air trapped under the central tendon of the diaphragm (the "cupola"). **NEET-PG High-Yield Pearls:** * **Gold Standard/Most Sensitive View:** The **Upright (Erect) Chest X-ray** is the most sensitive plain film for detecting free air under the diaphragm (as little as 1–2 ml). * **Alternative View:** If the patient cannot stand, the **Left Lateral Decubitus** view is preferred (air collects over the liver shadow). * **Doge’s Cap Sign:** Another name for air in the Morison’s pouch. * **Falciform Ligament Sign:** Visualization of the falciform ligament due to free air outlining it on both sides.

Q: Which of the following diseases characteristically shows urinary bladder calcification that radiologically resembles a fetal head in the pelvis?

Schistosomiasis. **Explanation** The correct answer is **Schistosomiasis**. **1. Why Schistosomiasis is Correct:** Schistosomiasis (specifically *Schistosoma haematobium*) is a parasitic infection where adult worms reside in the vesical venous plexus. The female deposits eggs in the bladder wall, leading to a chronic granulomatous reaction. Over time, these eggs undergo massive calcification. Radiologically, this appears as a thin, curvilinear, radio-opaque rim outlining the bladder wall. When the bladder is empty, the calcified wall collapses and folds, creating a characteristic **"fetal head"** appearance in the pelvis. This is also known as a "calcified bladder shell." **2. Why Other Options are Incorrect:** * **Tuberculosis (TB):** While TB can cause bladder calcification, it typically results in a small, contracted, and irregular "thimble bladder." Calcification is more common in the kidneys (putty kidney) and ureters than the bladder. * **Chronic Cystitis:** Chronic inflammation (like encrusted cystitis) can cause patchy mucosal calcification, but it does not produce the distinct, continuous curvilinear outline seen in Schistosomiasis. * **Malignancy:** Bladder tumors (like Squamous Cell Carcinoma) may show stippled or irregular internal calcification, but they do not outline the entire bladder wall to resemble a fetal head. **3. NEET-PG High-Yield Pearls:** * **Vector:** *S. haematobium* is transmitted by the **Bulinus snail**. * **Cancer Association:** Chronic Schistosomiasis is a major risk factor for **Squamous Cell Carcinoma (SCC)** of the bladder, rather than the more common Transitional Cell Carcinoma (TCC). * **Diagnostic Feature:** Presence of **terminal spines** on eggs in urine microscopy. * **Treatment:** Praziquantel is the drug of choice.

Question 1

Which of the following is NOT an investigation for the small intestine?

Accepted Answer

Radionuclide enteroclysis, MRI enteroclysis, CT enteroclysis, USG enteroclysis

Answer

Enteroclysis, ABD

Answer

Enteroclysis, ABD, ABCD

Answer

Enteroclysis, ACDE

Question 2

What is the investigation of choice for a pregnant patient presenting with an upper abdominal mass?

Accepted Answer

Ultrasound (USG)

Answer

X-ray

Answer

CT scan

Answer

MRI

Question 3

What is the investigation of choice in suspected gall bladder stone?

Accepted Answer

Ultrasound

Answer

X-ray

Answer

Barium study

Answer

Oral cholecystography

Question 4

Rigler's triad is seen in which of the following conditions?

Accepted Answer

Gallstone ileus

Answer

Pneumoperitoneum

Answer

Intestinal obstruction

Answer

Ulcerative colitis

Question 5

Which of the following renal stones are radio-lucent?

Accepted Answer

Cysteine and Uric acid

Answer

Calcium phosphate and Uric acid

Answer

Calcium phosphate and Xanthine

Answer

Cysteine and Xanthine

Question 6

Gas in the great vessels of a fetus indicates which of the following?

Accepted Answer

Fetal death

Answer

Fetal distress

Answer

Postmature fetus

Answer

Premature fetus

Question 7

What is the best investigation to detect pneumoperitoneum?

Accepted Answer

Plain X-ray chest, erect

Answer

Plain X-ray abdomen, erect

Answer

Left lateral decubitus film

Answer

CT Scan

Question 8

What is the gold standard investigation for diagnosing cystic echinococcosis?

Accepted Answer

Ultrasound (USG)

Answer

X-ray

Answer

ELISA

Answer

CT scan

Question 9

Which of the following radiographic signs is NOT typically seen in pneumoperitoneum?

Accepted Answer

Tillaux sign

Answer

Football sign

Answer

Rigler's sign

Answer

Cupola sign

Question 10

Which of the following diseases characteristically shows urinary bladder calcification that radiologically resembles a fetal head in the pelvis?

Accepted Answer

Schistosomiasis

Answer

Tuberculosis

Answer

Chronic cystitis

Answer

Malignancy

Abdominal and Pelvic Radiology — MCQs

Abdominal and Pelvic Radiology — MCQs

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