Abdominal and Pelvic Radiology Practice Questions

Q: A 40-year-old male presents with severe epigastric pain radiating to the back. On examination, his heart rate is 110/min, respiratory rate is 22/min, and blood pressure is 100/70 mmHg. His abdominal X-ray is shown below. What does the X-ray depict?

Colon cut-off sign. ***Colon cut-off sign*** - **Abrupt termination** of gas in the **transverse colon** due to spasm from adjacent pancreatic inflammation, classic finding in **acute pancreatitis**. - The **colon appears cut off** at the splenic flexure region, indicating pancreatic involvement causing colonic spasm. *Sentinel loop sign* - Represents **localized ileus** with a **single dilated loop** of small bowel, typically seen in **small bowel obstruction** or localized peritonitis. - Not specific to **pancreatitis** and would show a **dilated small bowel loop**, not colonic cut-off pattern. *Renal halo sign* - A **radiological finding** seen in **retroperitoneal bleeding** where there's a **lucent rim** around the kidney outline. - Not associated with **acute pancreatitis** and doesn't correlate with the clinical presentation of epigastric pain. *Obliteration of psoas shadow* - Loss of the **normal psoas muscle outline** due to **retroperitoneal fluid** or inflammation, seen in conditions like **appendicitis** or **retroperitoneal hemorrhage**. - While **pancreatitis** can cause retroperitoneal inflammation, the **colon cut-off sign** is more specific and characteristic.

Q: What is the diagnosis suggested by the barium study film?

Crohn's disease. ***Crohn's disease*** - Barium studies show characteristic **string sign** (narrowed bowel segments), **skip lesions** (normal bowel between diseased areas), and **cobblestone mucosa** appearance. - **Rose-thorn ulcers** and **aphthous ulcers** create a distinctive pattern on barium enema, indicating transmural inflammation. *Toxic megacolon* - Barium studies show **massive colonic dilatation** (>6cm transverse colon) with **loss of haustral markings** and smooth colonic contour. - **Thumbprinting** may be present due to mucosal edema, but **skip lesions** and **string sign** are not characteristic features. *Intestinal perforation* - Barium studies would show **contrast extravasation** outside the bowel lumen into the **peritoneal cavity** or **retroperitoneum**. - **Free air** under the diaphragm or **pneumoperitoneum** may be visible, not the characteristic inflammatory changes of Crohn's disease. *Intussusception* - Barium enema demonstrates a **filling defect** with **coiled spring appearance** or **cup-shaped** obstruction at the intussusception site. - **Target sign** or **sausage-shaped mass** may be visible, but **transmural inflammation** and **skip lesions** are not present.

Q: Renal tuberculosis can be diagnosed earliest by which imaging modality?

Intravenous pyelogram (IVP). **Explanation:** **1. Why Intravenous Pyelogram (IVP) is the Correct Answer:** Renal tuberculosis (TB) is a "disease of the calyces." The earliest pathological changes occur at the renal papillae (papillitis), leading to erosion and ulceration. **Intravenous Pyelogram (IVP)** is the most sensitive modality for detecting these subtle, early mucosal changes. The earliest radiological sign of renal TB on IVP is **"moth-eaten" calyces**, which represents irregular ulceration of the papillary tips. As the disease progresses, IVP can also demonstrate "Phantom Calyx" (infundibular stricture causing non-visualization of a calyx). **2. Why Other Options are Incorrect:** * **CT Scan:** While Contrast-Enhanced CT (CECT) is the "Gold Standard" for staging and assessing the extent of advanced renal TB (showing "Putty Kidney" or calcifications), it lacks the spatial resolution required to detect the very earliest mucosal ulcerations seen on IVP. * **Ultrasonography (USG):** USG is non-specific. It may show hydronephrosis or debris, but it cannot visualize early papillary erosions or subtle calyceal distortions. * **Angiography:** This is an invasive procedure used to assess vascularity. It has no role in the early diagnosis of renal TB and would only show non-specific findings like decreased perfusion in end-stage "autonephrectomy." **3. High-Yield Clinical Pearls for NEET-PG:** * **Earliest Sign on IVP:** Moth-eaten calyces. * **Most Common Sign on IVP:** Hydrocalycosis (due to strictures). * **Putty Kidney:** A small, shrunken, non-functioning kidney with autonephrectomy (seen in end-stage TB). * **Thimble Bladder:** A small-capacity, fibrotic bladder resulting from chronic TB cystitis. * **Kerr’s Kink:** A characteristic narrowing at the pelviureteric junction (PUJ) seen in renal TB.

Q: What is the most common cause of 'target lesion' in the stomach?

Melanoma. **Explanation:** The **'Target lesion'** (also known as the **'Bull’s eye' lesion**) on a barium study or CT scan refers to a large, solitary or multiple submucosal nodules with a central crater or umbilication. This central depression is caused by ulceration at the apex of the mass. **1. Why Melanoma is Correct:** Metastatic **Melanoma** is the most common cause of multiple target lesions in the gastrointestinal tract, particularly the stomach. Melanoma has a high predilection for hematogenous spread to the submucosa of the GI tract. As the submucosal nodule grows, it outstrips its blood supply, leading to central necrosis and ulceration, which creates the classic "bull's eye" appearance when barium fills the central crater. **2. Analysis of Incorrect Options:** * **Carcinoid:** While carcinoid tumors are submucosal, they typically present as small, firm, yellowish nodules and rarely ulcerate to form a classic target lesion compared to melanoma. * **Lymphoma:** Gastric lymphoma usually presents with markedly thickened rugal folds or large infiltrating masses. While it can occasionally ulcerate, it is not the "most common" cause of this specific radiological sign. * **Fibroma:** These are rare benign mesenchymal tumors. They are usually smooth and do not typically undergo central umbilication. **3. Clinical Pearls for NEET-PG:** * **Differential Diagnosis of Target Lesions:** Metastatic melanoma (most common), Kaposi sarcoma, Lymphoma, and occasionally GIST (Gastrointestinal Stromal Tumor). * **Ectopic Pancreas:** If a target lesion is seen specifically in the **antrum** of the stomach, an ectopic pancreas (pancreatic rest) is a high-yield differential. * **Key Imaging Sign:** The "Target sign" in **ultrasound** is different; it typically refers to **Intussusception** (concentric rings of bowel). Always distinguish between the "Target lesion" on barium/CT (ulcerated mass) and the "Target sign" on USG.

Q: The Seagull sign is seen in which of the following conditions?

Gallstone ileus. **Explanation:** The **Seagull sign** in abdominal radiology refers to the characteristic appearance of **gas within the biliary tree (pneumobilia)**. In the context of **Gallstone ileus**, this occurs because a large gallstone erodes through the gallbladder wall into the duodenum (cholecystoenteric fistula). This fistula allows air from the bowel to enter the biliary tract, appearing on an X-ray or CT as Y-shaped or branching lucencies in the right upper quadrant, resembling a seagull in flight. Gallstone ileus is classically defined by **Rigler’s Triad** on a plain abdominal radiograph: 1. **Pneumobilia** (Seagull sign) 2. **Small bowel obstruction** (dilated loops) 3. **Ectopic gallstone** (usually in the ileocecal valve) **Analysis of Incorrect Options:** * **Chronic pancreatitis:** Characterized by "Chain of Lakes" appearance (ductal dilatation) or speckled calcifications on X-ray/CT. * **Appendicitis:** Associated with an appendicolith (fecalith) or the "Target sign" on ultrasound/CT, but not pneumobilia. * **Acute cholecystitis:** Typically shows gallbladder wall thickening, pericholecystic fluid, or a positive sonographic Murphy’s sign. **NEET-PG Clinical Pearls:** * **Rigler’s Triad** is a high-yield diagnostic cluster for Gallstone ileus. * The most common site of obstruction in gallstone ileus is the **ileum** (narrowest part of the small bowel). * **Bouveret Syndrome** is a specific variant where the gallstone impacts in the duodenum, causing gastric outlet obstruction. * *Note:* In vascular radiology, the "Seagull sign" can also refer to the celiac trunk and its branches (hepatic and splenic arteries) on CT/US, but in the context of abdominal pathology questions, it almost always refers to pneumobilia.

Q: An incidental finding in a 56-year-old female patient who underwent CECT abdomen is suggestive of which of the following?

Porcelain gall bladder. ***Porcelain gall bladder*** - **Mural calcification** of the gallbladder wall appears as a characteristic **rim-like calcification** on CECT, commonly found as an incidental finding. - Predominantly affects **middle-aged females** and is associated with increased risk of **gallbladder carcinoma**, requiring prophylactic cholecystectomy. *Carcinoma gall bladder* - Typically presents with **symptomatic disease** including abdominal pain, weight loss, and jaundice, not as an incidental finding. - On imaging, shows **irregular wall thickening**, **mass lesions**, or **invasion** into adjacent structures rather than rim calcification. *Gall bladder polyp* - Appears as **intraluminal filling defects** or **pedunculated lesions** projecting into the gallbladder lumen on contrast studies. - Does not demonstrate **mural calcification** and typically appears as soft tissue densities rather than calcified structures. *Hydatid cyst* - Shows characteristic **daughter cysts** within the parent cyst and **rim calcification** of the cyst wall, not gallbladder wall. - Usually presents as a **space-occupying lesion** in the liver parenchyma rather than involving the gallbladder wall specifically.

Q: Which type of mesenteric ischemia is best visualized by CECT?

Acute mesenteric venous thrombosis. **Explanation:** **Contrast-Enhanced Computed Tomography (CECT)** is the gold standard for diagnosing **Acute Mesenteric Venous Thrombosis (MVT)**. In MVT, CECT demonstrates a high sensitivity (>90%) by showing a filling defect (hypodensity) within the superior mesenteric vein (SMV), often associated with significant bowel wall thickening, "target sign" enhancement, and mesenteric stranding due to venous congestion. **Why the other options are incorrect:** * **A & B (Embolic Occlusion & Arterial Thrombosis):** While CECT can detect arterial occlusions, **CT Angiography (CTA)** with thin-section arterial phase reconstruction is the preferred modality for arterial causes. Embolic events often occur at the origin of the SMA or distal to the middle colic artery, requiring high-resolution arterial imaging to visualize the "cutoff" sign. * **C (Non-occlusive Mesenteric Ischemia - NOMI):** NOMI is caused by low-flow states (e.g., shock, vasopressors). CECT findings are often non-specific or normal in early stages. **Digital Subtraction Angiography (DSA)** remains the gold standard for NOMI as it allows for both diagnosis (showing "string-of-beads" appearance) and therapeutic infusion of vasodilators like papaverine. **High-Yield Clinical Pearls for NEET-PG:** * **MVT Hallmark:** Look for the **"Target Sign"** or **"Halo Sign"** on CECT, representing submucosal edema. * **Pneumatosis Intestinalis:** Presence of air in the bowel wall on CT indicates advanced ischemia/infarction (poor prognosis). * **SMA vs. SMV:** Arterial ischemia (SMA) usually presents with "paper-thin" bowel walls due to lack of inflow, whereas venous ischemia (SMV) presents with "thickened" walls due to congestion. * **Gold Standard for Arterial Ischemia:** CT Angiography (CTA).

Q: What is the most sensitive investigation for pancreatic carcinoma?

CT scan. **Explanation:** **CT scan (specifically Multidetector Helical CT or MDCT)** is the investigation of choice and the most sensitive modality for diagnosing and staging pancreatic carcinoma. Its high sensitivity (95–100%) stems from its ability to provide thin-section, multiphasic imaging (pancreatic and portal venous phases). This allows for the detection of small hypoattenuating masses, assessment of vascular invasion (resectability), and identification of distant metastases or lymphadenopathy in a single study. **Why other options are incorrect:** * **Angiography:** Historically used to detect vascular involvement, it is invasive and has been entirely replaced by non-invasive CT angiography. * **ERCP:** While highly sensitive for detecting biliary or pancreatic ductal obstruction (showing the "Double Duct Sign"), it is an invasive procedure. It is now primarily reserved for therapeutic interventions (stenting) rather than primary diagnosis. * **Ultrasound:** Often the initial screening tool for jaundice, but its sensitivity is limited by overlying bowel gas and body habitus. It cannot reliably stage the tumor or detect small lesions in the pancreatic tail. **Clinical Pearls for NEET-PG:** * **Investigation of Choice:** MDCT (Dual-phase CT). * **Most Sensitive for Small Tumors (<2cm):** Endoscopic Ultrasound (EUS) is technically more sensitive than CT for very small lesions and allows for FNA, but CT remains the standard "best" initial investigation for diagnosis and staging. * **Classic Sign:** "Double Duct Sign" (dilatation of both common bile duct and pancreatic duct) on imaging suggests a tumor in the head of the pancreas. * **Tumor Marker:** CA 19-9 (used for monitoring recurrence, not for primary screening).

Question 1

A 40-year-old male presents with severe epigastric pain radiating to the back. On examination, his heart rate is 110/min, respiratory rate is 22/min, and blood pressure is 100/70 mmHg. His abdominal X-ray is shown below. What does the X-ray depict?

Accepted Answer

Colon cut-off sign

Answer

Sentinel loop sign

Answer

Renal halo sign

Answer

Obliteration of psoas shadow

Question 2

What is the diagnosis suggested by the barium study film?

Accepted Answer

Crohn's disease

Answer

Toxic megacolon

Answer

Intestinal perforation

Answer

Intussusception

Question 3

Renal tuberculosis can be diagnosed earliest by which imaging modality?

Accepted Answer

Intravenous pyelogram (IVP)

Answer

CT scan

Answer

Angiography

Answer

Ultrasonography (USG)

Question 4

What is the most common cause of 'target lesion' in the stomach?

Accepted Answer

Melanoma

Answer

Carcinoid

Answer

Lymphoma

Answer

Fibroma

Question 5

The Seagull sign is seen in which of the following conditions?

Accepted Answer

Gallstone ileus

Answer

Chronic pancreatitis

Answer

Appendicitis

Answer

Acute cholecystitis

Question 6

What is the diagnosis suggested by the provided X-ray of the abdomen?

Accepted Answer

Sigmoid volvulus

Answer

Small intestine obstruction

Answer

Intussusception

Answer

Pneumatosis intestinalis

Question 7

An incidental finding in a 56-year-old female patient who underwent CECT abdomen is suggestive of which of the following?

Accepted Answer

Porcelain gall bladder

Answer

Carcinoma gall bladder

Answer

Gall bladder polyp

Answer

Hydatid cyst

Question 8

Which type of mesenteric ischemia is best visualized by CECT?

Accepted Answer

Acute mesenteric venous thrombosis

Answer

Mesenteric ischemia by embolic occlusion

Answer

Acute mesenteric artery thrombosis

Answer

Non-occlusive mesenteric ischemia

Question 9

Parallel shotgun appearance on Ultrasound is seen in which of the following conditions?

Accepted Answer

Obstructive jaundice

Answer

Portal hypertension

Answer

Biliary ascariasis

Answer

Sclerosing cholangitis

Question 10

What is the most sensitive investigation for pancreatic carcinoma?

Accepted Answer

CT scan

Answer

Angiography

Answer

ERCP

Answer

Ultrasound

Abdominal and Pelvic Radiology — MCQs

Abdominal and Pelvic Radiology — MCQs

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