GIT- Radiology

✅ Duodenal cap
On a barium swallow (upper GI contrast study), immediately following the pylorus, the contrast outlines a triangular or bulb-like structure called the duodenal cap (or bulb). This is the first part of the duodenum. Beyond this, the duodenum forms a C-shaped loop around the head of the pancreas, consisting of its descending, horizontal, and ascending parts.

Incorrect Options

❌ Gastro-ileal junction
There is no direct connection between the stomach and ileum—the stomach connects first to the duodenum.

❌ Fourth part of duodenum
The fourth part is the ascending portion, located much later in the duodenal course, not immediately after the pylorus.

❌ Second part of duodenum
This descending part receives bile and pancreatic ducts, but it comes after the duodenal bulb.

❌ Third part of duodenum
This horizontal part crosses over the aorta and IVC, far beyond the duodenal bulb.

Barium sulphate is the most commonly used radiocontrast agent in gastrointestinal imaging (e.g., barium swallow, barium meal, barium enema). It is radiopaque, meaning it absorbs X-rays effectively, allowing clear visualization of the GI tract. Importantly, it is insoluble and not absorbed by the body, making it safe for imaging (though contraindicated in suspected perforation due to risk of peritonitis).

Incorrect Options

❌ Potassium iodide
This is used medically as an iodine supplement and in thyroid conditions, but it is not used as a radiocontrast dye.

❌ Dihydrooxygen
Not a recognized medical or radiological compound.

❌ Methylene blue
Used as a dye in medical procedures (e.g., sentinel lymph node mapping, staining), but not as a standard radiocontrast agent.

❌ Sodium chloride
This is normal saline, used for IV hydration or as a diluent—not as a radiocontrast dye.

Non-alcoholic steatohepatitis (NASH) is part of the spectrum of non-alcoholic fatty liver disease (NAFLD), involving hepatic fat accumulation with inflammation and hepatocellular injury. Liver function tests (LFTs) are commonly used to evaluate NASH, as they often show elevated ALT and AST (typically ALT > AST, unlike in alcoholic liver disease). While a definitive diagnosis requires liver biopsy, LFTs are a key non-invasive screening tool.

Incorrect Options

❌ Glucose tolerance test
This is used to diagnose diabetes mellitus or impaired glucose tolerance. While insulin resistance is a risk factor for NASH, this test does not directly assess liver inflammation.

❌ Chvostek’s sign
This is a clinical sign of hypocalcemia, unrelated to liver disease.

❌ Complete blood count (CBC)
CBC can show indirect evidence of advanced liver disease (like anemia or thrombocytopenia in cirrhosis), but it is not a test for diagnosing NASH specifically.

❌ Urine test
Urine analysis may show bilirubin or urobilinogen changes in liver disease, but it does not specifically test for NASH.

A lipid profile measures blood lipids to assess cardiovascular risk. It typically includes total cholesterol, triglycerides, HDL, and LDL. Lipoprotein lipase is an enzyme (found on endothelial surfaces of capillaries in adipose tissue and muscle) that hydrolyzes triglycerides in chylomicrons and VLDL—it is not measured in a standard lipid profile.

Incorrect Options

❌ High-density lipoprotein (HDL)
HDL (“good cholesterol”) is included in lipid profiles since higher levels are protective against atherosclerosis.

❌ Triglycerides
A standard lipid profile includes triglycerides, since high levels are linked to pancreatitis and cardiovascular risk.

❌ Cholesterol
Total cholesterol is always measured in a lipid profile.

❌ Low-density lipoprotein (LDL)
LDL (“bad cholesterol”) is a core component of lipid profiles and is strongly linked to coronary artery disease.

X-rays are imaging studies that detect differences in tissue density. They are most effective for assessing bones, air-filled structures, and large soft-tissue shadows.

• Splenomegaly (✅) — Enlargement of the spleen can sometimes be seen on abdominal X-ray as a soft-tissue shadow displacing the stomach bubble medially and the colon inferiorly. Although ultrasound or CT are more accurate, X-ray can suggest splenomegaly.

Why the Others Are Wrong:

• Torn ligament (❌) – Ligaments are soft tissues and not visible on X-ray. MRI is the investigation of choice.

• Nerve compression (❌) – Nerves cannot be directly visualized on X-ray. MRI or CT myelography is used.

• Muscular atrophy (❌) – Muscle changes are not visible on X-ray; MRI or EMG are better suited.

• None of them (❌) – Incorrect because splenomegaly can be seen as a soft-tissue shadow on X-ray

• Since she already underwent endoscopy for her ulcer, the next step is to test biopsy samples for H. pylori.

  • Options include rapid urease test (CLO test), histology, or PCR on biopsy tissue.

• This is the most direct and confirmatory method when endoscopy is already being done.

Other options:

• Hydrogen breath test ❌ – Used for carbohydrate malabsorption (like lactose intolerance), not H. pylori.

• Complete blood count (CBC) ❌ – Can show anemia but not specific for H. pylori.

• Stool culture ❌ – Not practical; stool antigen test is used, but culture is rarely done.

• Urinalysis ❌ – No role in H. pylori diagnosis.

Case summary

• Pregnant (8 months) woman.

• Symptoms: Jaundice (yellow skin & sclera), fever, vomiting.

• Labs:

  • Very high ALT (1236) & AST (900) → hepatocellular injury pattern.

  • High bilirubin (total 11.4, direct 9.7).

  • Mildly raised ALP (432) & GGT (155) → some cholestasis, but not predominant.

Stepwise reasoning

• Acute hepatitis → fits best because:

  • Very high ALT/AST (in thousands, hepatocellular pattern).

  • Direct hyperbilirubinemia.

  • Symptoms: jaundice + fever + vomiting.

• Acute cholecystitis ❌ – Would show RUQ pain, fever, raised ALP/GGT much higher than ALT/AST.

• Malaria ❌ – Can cause jaundice, but would expect anemia, splenomegaly, parasites on smear.

• Hepatic abscess ❌ – Fever + RUQ pain, not such marked transaminase elevation.

• Sepsis ❌ – Can cause cholestatic jaundice, but not massive hepatocellular injury like here.

• Fatty liver (NAFLD/NASH) can be suspected on ultrasound, CT, MRI, or Fibroscan, but none of these can reliably stage the degree of inflammation and fibrosis.

• The gold standard for diagnosis, grading inflammation, and staging fibrosis = liver biopsy.

  • Provides histological detail → distinguishes simple steatosis from steatohepatitis (NASH).

  • Assesses degree of fibrosis and cirrhosis.

Why the others are wrong

• CT scan abdomen ❌ – Can show fatty infiltration, but not inflammation/fibrosis accurately.

• Fibroscan liver ❌ – Non-invasive tool for fibrosis, useful for follow-up, but not gold standard.

• Ultrasound abdomen ❌ – Detects fatty changes but cannot assess severity of inflammation/fibrosis.

• Liver function tests ❌ – Show enzyme elevations but are nonspecific; cannot stage fibrosis.

• Liver biopsy ✅ – Definitive and gold standard.

Correct Answer: Hepatic and portal veins

• Couinaud classification divides the liver into 8 functional segments.

• Portal vein branching → divides the liver horizontally into upper and lower segments.

• Hepatic veins → divide the liver vertically into left, middle, and right sectors.

• Together, these vascular structures form the basis for the 8 segments, each with its own portal triad (portal vein, hepatic artery, bile duct).

❌ Why the Others Are Incorrect

• Hepatic artery and vein – The hepatic artery is part of inflow, not a boundary marker.

• Hepatic artery and portal vein – Both supply blood but don’t define segments.

• Hepatic veins and bile duct – Hepatic veins do mark segments, but bile ducts run within segments alongside portal triads, not as boundaries.

• Portal veins and bile duct – Portal vein divides transversely, but bile ducts again don’t form borders.

Key clinical scenario

• 58-year-old woman with longstanding subacute obstruction, now presenting with constipation, distension, pain, and free fluid in Morrison’s pouch → suspicion of bowel perforation.

• You plan a small bowel dynamic fluoroscopic study.

Correct Answer: Amidotrizoate (Gastrografin) ✅

• In suspected bowel perforation, water-soluble contrast (like Gastrografin, a diatrizoate/ amidotrizoate preparation) is the agent of choice.

• Why?

  • If contrast leaks into the peritoneum, water-soluble contrast is absorbed → less risk.

  • Barium sulphate, if it leaks, causes severe barium peritonitis → contraindicated in suspected perforation.

Why the Others Are Incorrect

• Barium sulphate ❌ – Standard for GI studies, but absolutely contraindicated if perforation is suspected.

• Effervescent pyruvic acid (ENO) ❌ – Used to produce gas in double-contrast studies, not for suspected perforation.

• Methyl cellulose ❌ – Sometimes used as an adjunct for enteroclysis, but not contrast of choice in perforation.

• Normal saline ❌ – Not a contrast medium; provides no radiographic delineation.

Correct Answer: Liver biopsy ✅

• While ultrasound can detect fatty liver and Fibroscan can assess fibrosis non-invasively, the gold standard for:

  • Diagnosis of NAFLD/NASH

  • Assessment of degree of inflammation

  • Extent of fibrosis
    is still liver biopsy.

• It allows histological confirmation (steatosis, ballooning degeneration, Mallory bodies, fibrosis).

Why the Others Are Incorrect

• LFTs ❌ – May be abnormal but are non-specific and cannot grade inflammation/fibrosis.

• Ultrasound abdomen ❌ – Detects steatosis but not inflammation/fibrosis.

• Fibroscan ❌ – Non-invasive and increasingly used, but not considered gold standard (though very useful for follow-up).

• CT scan abdomen ❌ – Can show fatty infiltration, but cannot reliably assess fibrosis or inflammation.

Key findings in the vignette

• Pregnant woman (6 months) → important risk group.

• Symptoms: jaundice, fever, abdominal pain, vomiting, RUQ tenderness.

• Labs:

  • Total bilirubin: 3.4 (Direct 2.7) → predominantly conjugated hyperbilirubinemia.

  • ALT 36, AST 14 → not markedly raised → hepatocellular injury unlikely.

  • ALP 832, GGT 155 → markedly elevated → cholestatic pattern.

This points toward obstructive jaundice (likely gallstones, cholestasis of pregnancy, or biliary obstruction).

Correct Answer: Ultrasound abdomen ✅

• The next step in evaluating obstructive jaundice with RUQ pain/tenderness is abdominal ultrasound.

• It is safe in pregnancy, non-invasive, and excellent for detecting gallstones, biliary dilation, or obstruction.

Why the Others Are Incorrect

• Hepatitis E IgM Ab ❌ – Hepatitis E is dangerous in pregnancy, but here ALT/AST are normal → rules against acute viral hepatitis.

• Hepatitis A IgM Ab ❌ – Again, ALT/AST are not elevated; no acute hepatocellular injury.

• ICT Malarial Parasite ❌ – Malaria can cause jaundice, but labs show clear obstructive pattern (high ALP, direct bilirubin).

• Prothrombin time ❌ – Important for prognosis in liver disease, but not the first diagnostic step.

When a child presents with acute abdominal pain suggestive of appendicitis, imaging is performed on an emergency basis to confirm the diagnosis quickly.

• Ultrasound (USG) is the first-line investigation for suspected appendicitis in children because it is safe, non-invasive, and avoids radiation.

• In emergencies, no bowel preparation or fasting is required — delaying the scan could risk appendiceal rupture or worsening peritonitis.

• Preparation such as fasting or laxatives is sometimes used in elective abdominal ultrasounds (e.g., hepatobiliary or pelvic scans), but not in acute appendicitis.

❌ Why the Other Options Are Wrong

• Nothing orally for 8 hours / 12 hours: Relevant for some abdominal scans (like hepatobiliary), but not in suspected acute appendicitis.

• Laxative must be given: Contraindicated — increases risk of perforation in acute appendicitis.

• Patient is asked to come the next day: Dangerous — appendicitis can rapidly progress to perforation; imaging must be immediate.

• In suspected malabsorption syndromes, the investigation of choice to evaluate the small intestine is a Barium follow through.

• In this test, the patient swallows barium, and serial X-rays are taken at timed intervals as the contrast passes through the small bowel.

• It helps detect:

  • Mucosal pattern changes

  • Dilated loops

  • Transit time abnormalities

  • Diseases like celiac disease, Crohn’s disease, and other malabsorption disorders

Why the other options are wrong

• Barium enema ❌ → Used for large bowel (colon) evaluation, not small bowel.

• Abdominal X-ray ❌ → Can show obstruction, perforation, or gas patterns but not detailed small bowel mucosa.

• Barium swallow test ❌ → Used to study the esophagus.

• Barium meal ❌ → Studies stomach and duodenum only, not the rest of the small intestine.

The most reliable method for diagnosis and staging of gastric carcinoma is contrast-enhanced CT scan of the abdomen and chest.

• Diagnosis: While endoscopy with biopsy is the gold standard for confirming the diagnosis histologically, when the question combines diagnosis with staging, it refers to imaging choice. CT scan is the best modality to evaluate the extent of the primary tumor, local invasion, lymph node involvement, and distant metastases (especially liver and lungs).

• Chest CT is included because lung metastasis is a common route of spread.

Why the Other Options Are Wrong

Ultrasound abdomen ❌

• Useful for detecting liver metastases or ascites.

• However, it is not sensitive enough to evaluate local invasion, nodal spread, or small metastases.

• Cannot reliably stage gastric carcinoma.

MRI abdomen ❌

• Provides excellent soft tissue contrast and can be used for liver metastases or local staging in special cases.

• However, it is not routinely used as the first-line staging tool. CT is more practical and widely available.

PET scan ❌

• PET can detect metabolically active lesions and distant metastases.

• However, gastric carcinoma sometimes has low FDG uptake, making PET less reliable.

• PET may be used as an adjunct but not as the primary staging tool.

X-ray ❌

• Plain X-ray of the abdomen or chest is not useful for diagnosing or staging gastric carcinoma.

• It may show nonspecific findings (e.g., mass effect, obstruction, or lung nodules), but it cannot define extent or staging.

• At the L2 vertebral level, a CT scan of acute pancreatitis usually shows structures in the upper abdomen.

• Present at L2:

  • Duodenum (2nd and 3rd parts)

  • Spleen (lies in the left hypochondrium, extending down to this level)

  • Abdominal aorta (retroperitoneal, anterior to vertebral column)

  • Liver (especially its inferior surface and right lobe extend to this level)

• Sigmoid colon, however, is a pelvic structure, typically found at the level of L4–S1, far below L2.

• Thus, it will not appear in an axial CT slice at the L2 level in pancreatitis.

Incorrect answer explanations:

• Duodenum → The head of the pancreas is surrounded by the duodenum at this level.

• Spleen → Close to the pancreatic tail, visible at L2.

• Abdominal aorta → Major retroperitoneal vessel, present at L2.

• Liver → Inferior margin is still visible around L2.

When a high-frequency transducer (as in endoscopic ultrasound) is used for the esophagus (and other parts of the GI tract), the wall is typically visualized as five alternating echogenic and hypoechoic concentric layers.

• 1st layer (innermost, hyperechoic): Superficial mucosa

• 2nd layer (hypoechoic): Deep mucosa (including muscularis mucosa)

• 3rd layer (hyperechoic): Submucosa

• 4th layer (hypoechoic): Muscularis propria

• 5th layer (hyperechoic): Serosa/adventitia

This “five-layer pattern” is fundamental in endoscopic ultrasonography because it helps in staging tumors (depth of invasion).

❌ Why the other options are incorrect

• 6 concentric layers → Incorrect, standard teaching is 5 layers.

• 2 concentric layers → Too few, may be seen in low-resolution imaging but not with high-frequency endoscopic ultrasound.

• 3 concentric layers → Sometimes described in transabdominal ultrasound, not in high-resolution transluminal sonography.

• 4 concentric layers → Again, an oversimplified version, but not the accepted answer for high-resolution imaging.

Step 1: The clinical context

• A 55-year-old woman with progressive dysphagia to solids → classical presentation of esophageal carcinoma.

• First suspicion should be confirmed with an imaging test that directly evaluates the esophagus.

Step 2: Evaluate the options

Barium enema
❌ This evaluates the colon, not the esophagus. Not appropriate here.

Chest X-ray
❌ Can sometimes show secondary signs (mediastinal widening, mass, aspiration), but it is not diagnostic for esophageal lesions.

Barium follow through
❌ This studies the small intestine after a barium meal. Not useful for esophagus.

Barium meal
❌ Mainly used for stomach and duodenum studies. Not the investigation of choice for esophagus.

Barium swallow examination
✅ Correct. The barium swallow outlines the esophagus and is the best radiological investigation to evaluate dysphagia and suspected esophageal carcinoma. It can show filling defects, irregular narrowing, or “shouldering” of the margins of a tumor.