Pediatric Radiology Practice Questions

Q: Which of the following is NOT a radiological feature of ileal atresia?

Double bubble sign. **Explanation:** **Ileal atresia** is a common cause of neonatal intestinal obstruction. The correct answer is **C (Double bubble sign)** because this radiological sign is the hallmark of **Duodenal atresia**, not ileal atresia. 1. **Why "Double bubble sign" is the correct answer:** The double bubble sign represents air in the stomach and the proximal duodenum, with no distal gas. This indicates a proximal obstruction at the level of the duodenum. In contrast, ileal atresia is a distal small bowel obstruction, which typically presents with multiple dilated bowel loops and air-fluid levels on an abdominal X-ray. 2. **Analysis of other options:** * **Obstruction on barium meal (A):** While not the first-line investigation, a barium meal/upper GI series in ileal atresia would show dilated proximal small bowel loops with a complete cutoff (obstruction) in the distal ileum. * **Microcolon on barium enema (B):** This is a classic finding in distal small bowel obstructions like ileal atresia. Because the colon has not been used during fetal life (due to the upstream obstruction), it remains small in caliber (disuse atrophy). * **Apple-peel appearance (D):** This is a specific morphological subtype (Type IIIb) of jejunoileal atresia where the distal bowel twists around a single marginal artery (the ileocolic artery), resembling an apple peel or Christmas tree. **High-Yield Clinical Pearls for NEET-PG:** * **Duodenal Atresia:** Associated with **Down Syndrome** and the "Double Bubble" sign. * **Jejunoileal Atresia:** Usually caused by a **vascular accident** in utero (ischemic necrosis). * **Triple Bubble Sign:** Characteristic of **Jejunal atresia**. * **Ground-glass appearance/Soap bubble sign:** Suggestive of **Meconium Ileus** (associated with Cystic Fibrosis).

Q: Which of the following signs is associated with CHPS?

All of the above. **Congenital Hypertrophic Pyloric Stenosis (CHPS)** is a condition characterized by hypertrophy of the circular muscle of the pylorus, leading to gastric outlet obstruction. Diagnosis is primarily made via ultrasound, where several classic radiological signs are observed: 1. **Target Sign:** On a **transverse** (short-axis) ultrasound scan, the hypertrophied, hypoechoic muscle surrounding the echogenic mucosa resembles a target or a doughnut. 2. **Antral Nipple Sign:** This refers to the protrusion of redundant pyloric mucosa into the gastric antrum, creating a nipple-like appearance on imaging. 3. **Cervix Sign:** On a **longitudinal** scan, the elongated pylorus indenting the fluid-filled antrum resembles the appearance of the uterine cervix protruding into the vagina. **Why "All of the Above" is correct:** All three signs are classic sonographic descriptions of the anatomical changes in CHPS (muscle thickening and mucosal elongation). Since options A, B, and C are all recognized features, D is the correct choice. **High-Yield Clinical Pearls for NEET-PG:** * **Clinical Presentation:** Non-bilious, projectile vomiting in an infant (typically 3–6 weeks old) with a palpable "olive-shaped" mass in the epigastrium. * **Metabolic Abnormality:** Hypochloremic, hypokalemic metabolic alkalosis (due to loss of HCl from vomiting). * **Ultrasound Criteria:** Pyloric muscle thickness **>3 mm** and pyloric canal length **>14–15 mm**. * **Barium Swallow Sign:** "String sign" (narrowed canal) and "Beak sign" (tapering at the antrum). * **Treatment:** Ramstedt’s pyloromyotomy.

Q: What is the initial imaging of choice for suspected acute appendicitis in children?

Ultrasound (USG). **Explanation:** The diagnosis of acute appendicitis in children is primarily clinical; however, when imaging is required, **Ultrasound (USG)** is the **initial imaging of choice**. **1. Why Ultrasound is Correct:** Children are highly sensitive to ionizing radiation. USG is non-invasive, cost-effective, and avoids radiation exposure (ALARA principle—As Low As Reasonably Achievable). In pediatric patients, the abdominal wall is thinner and there is less omental fat, which often allows for better visualization of the appendix compared to adults. A positive finding typically shows a non-compressible, blind-ended tubular structure >6 mm in diameter. **2. Why Other Options are Incorrect:** * **CECT (Option C):** While CECT is the most sensitive and specific modality (the "Gold Standard" for accuracy), it is reserved as a **second-line** investigation if USG is inconclusive. This is due to the high radiation dose and potential risks of IV contrast. * **MRI (Option B):** MRI is highly accurate and avoids radiation, but it is not the "initial" choice due to high costs, lack of universal availability, and the potential need for sedation in young children. * **X-ray (Option D):** Plain radiographs are non-specific. While they may show a fecalith (appendicolith) in 10% of cases or signs of perforation, they cannot reliably diagnose or rule out appendicitis. **Clinical Pearls for NEET-PG:** * **ALARA Principle:** Always prioritize USG over CT in children to prevent secondary malignancies. * **Most common cause of pediatric acute abdomen:** Acute Appendicitis. * **Classic Sign:** Migratory pain to the Right Iliac Fossa (RIF) and rebound tenderness (McBurney’s point). * **Scoring System:** The **Alvarado Score** (MANTRELS) or the **Pediatric Appendicitis Score (PAS)** are used to risk-stratify patients.

Q: Snow storm ascites is seen in which of the following conditions?

Meconium ileus. **Explanation:** **Snow storm ascites** is a classic radiological and ultrasonographic finding associated with **Meconium Peritonitis**, which is a common complication of **Meconium Ileus** (seen in approximately 15-20% of newborns with Cystic Fibrosis). When meconium ileus leads to antenatal bowel perforation, sterile meconium escapes into the peritoneal cavity. This triggers a chemical inflammatory response resulting in the formation of calcium deposits. On ultrasound, these scattered, echogenic calcifications suspended in ascitic fluid create a characteristic "snow storm" appearance. **Analysis of Options:** * **Meconium Ileus (Correct):** Antenatal perforation leads to meconium peritonitis. The resulting intraperitoneal calcifications and fluid produce the "snow storm" effect on imaging. * **Hirschsprung Disease:** While it can cause neonatal intestinal obstruction and potential perforation, it typically presents with postnatal enterocolitis or "egg-shell" calcification (rarely) rather than the diffuse snow storm pattern. * **Ileocaecal Tuberculosis:** Characterized by "wet" or "dry" types of peritonitis. Ultrasound typically shows "matted bowel loops" or "cocoon abdomen," not snow storm ascites. * **Pseudomyxoma Peritonei:** Known for the "scalloping of the liver" and "jelly belly" (mucinous ascites). While the fluid is thick, it does not typically present with the specific echogenic calcification pattern of meconium peritonitis. **High-Yield Clinical Pearls for NEET-PG:** * **Neuhauser’s Sign (Ground-glass appearance):** X-ray finding in Meconium Ileus due to air bubbles trapped in meconium. * **Cystic Fibrosis:** 90% of infants with meconium ileus have CF. * **Microcolon:** A common finding on contrast enema in meconium ileus due to disuse of the distal colon. * **Egg-shell calcification:** Often associated with healed meconium peritonitis or specific lymph nodes in silicosis.

Q: Which tumor is shown in the image?

Sacrococcygeal teratoma. ***Sacrococcygeal teratoma*** - **Sacrococcygeal teratomas** are the most common **congenital tumor** in newborns, arising from the **coccyx** and presenting as a large **external mass** at the base of the spine. - They contain **mixed tissue elements** (ectoderm, mesoderm, endoderm) and are classified by the **Altman classification** based on internal vs external components. *Meningocele* - A **neural tube defect** where the **meninges** protrude through a **spinal defect**, typically appearing as a fluid-filled sac without solid tissue components. - Usually located more **dorsally** along the spine and lacks the **heterogeneous appearance** with calcifications seen in teratomas. *Not recalled* - This is not a diagnostic option and represents **incomplete knowledge** rather than a specific pathological entity. - In medical practice, uncertain cases require **further evaluation** and consultation rather than defaulting to "not recalled." *Infantile fibrosarcoma* - A **malignant soft tissue sarcoma** that typically presents as a **firm, growing mass** in extremities or trunk, not specifically at the sacrococcygeal region. - Shows **homogeneous soft tissue density** on imaging without the **mixed echogenicity** and **calcifications** characteristic of teratomas.

Q: What is the maximum limit of the cardiothoracic ratio in children below 2 years of age?

0.5. **Explanation:** The **Cardiothoracic Ratio (CTR)** is a radiographic measurement used to estimate heart size on a Chest X-ray (CXR). It is calculated by dividing the maximum transverse diameter of the heart by the maximum internal diameter of the thoracic cage. **Why 0.5 is the correct answer:** In adults and children older than 2 years, a CTR of up to **0.5 (50%)** is considered the upper limit of normal. While infants (neonates) can have a physiological CTR of up to **0.6 (60%)** due to a more horizontal heart position, a high diaphragm, and the presence of the thymus, the standard clinical threshold for defining cardiomegaly across pediatric age groups—including those under 2 years—remains **>0.5**. In the context of standard medical examinations like NEET-PG, 0.5 is the established benchmark for the upper limit of a normal heart size. **Analysis of Incorrect Options:** * **A (0.4) & B (0.45):** These values are well within the normal range. A CTR this low would never be considered the "maximum limit" as it would exclude a large portion of the healthy population. * **D (0.55):** While a CTR of 0.55 can be normal in neonates (under 1 month) due to the thymus, it is not the standard "limit" for the broader category of children under 2 years. **High-Yield Clinical Pearls for NEET-PG:** * **The Thymus:** In children 0.5 on a PA view is cardiomegaly.

Q: A patient admitted with an abdominal mass underwent MRI, which revealed bilateral adrenal calcification. What is the most likely diagnosis?

Neuroblastoma. **Explanation:** **Neuroblastoma** is the most common extracranial solid tumor of childhood and the most frequent cause of an abdominal mass in infants. A hallmark radiologic feature of neuroblastoma is the presence of **calcification**, which occurs in approximately 80–90% of cases. While often unilateral, neuroblastoma can present with bilateral adrenal involvement, especially in metastatic or hereditary cases. On MRI or CT, these calcifications appear as stippled or coarse densities within the mass. **Analysis of Incorrect Options:** * **Pheochromocytoma:** While these are "10% tumors" (10% bilateral, 10% extra-adrenal), calcification is rare (less than 10%). They typically present with paroxysmal hypertension and "light bulb" bright appearance on T2-weighted MRI. * **Adrenal Incidentaloma:** This is a clinical term for an unsuspected adrenal mass found on imaging. Most are non-functioning adenomas which rarely calcify. * **Medullary Thyroid Cancer (MTC):** While MTC is associated with MEN 2A and 2B (which include pheochromocytoma), MTC itself is a thyroid malignancy, not an adrenal mass. **Clinical Pearls for NEET-PG:** * **Crossing the Midline:** Unlike Wilms' tumor, Neuroblastoma frequently **crosses the midline** and encases (rather than invades) major vessels. * **VMA/HVA:** 90% of neuroblastomas produce catecholamines, leading to elevated urinary Vanillylmandelic acid (VMA) and Homovanillic acid (HVA). * **Opsoclonus-Myoclonus Syndrome:** A high-yield paraneoplastic syndrome associated with neuroblastoma ("dancing eyes, dancing feet"). * **Bilateral Adrenal Calcification (Other causes):** In neonates, consider **Adrenal Hemorrhage**; in adults, consider **Tuberculosis** or **Waterhouse-Friderichsen Syndrome**.

Q: An infantogram shows the presence of which of the following?

Sacrococcygeal teratoma. ***Sacrococcygeal teratoma*** - Appears on **infantogram** as a large **presacral soft tissue mass** with characteristic **calcifications** and mixed densities. - Most common **congenital tumor** in neonates, easily identified by its **posterior location** and **heterogeneous appearance** on plain radiographs. *Hemangioma* - Represents a **vascular malformation** that appears as soft tissue density without the discrete mass characteristics seen on infantogram. - Typically requires **contrast studies** or **MRI** for proper visualization, not readily apparent on plain film infantogram. *Myelomeningocele* - Shows as a **posterior spinal sac** containing **neural elements** and CSF, representing a **neural tube defect**. - Associated with **spina bifida** and **vertebral arch defects**, distinct from the presacral mass pattern of teratoma. *Arnold-Chiari malformation* - A **hindbrain anomaly** involving **cerebellar tonsillar herniation** through the foramen magnum. - Not visible on **plain film infantogram** and requires **MRI** or **CT** for diagnosis of this intracranial abnormality.

Q: What is the first sign of hydrocephalus in children?

Sutural diastasis. **Explanation:** In pediatric patients, the skull is not yet a rigid box because the cranial sutures have not fused. When intracranial pressure (ICP) rises due to hydrocephalus, the skull compensates by expanding at these points of least resistance. **1. Why Sutural Diastasis is correct:** Sutural diastasis (widening of the cranial sutures) is the **earliest radiological sign** of increased ICP and hydrocephalus in infants and young children (typically up to 10–12 years of age). On a skull X-ray, a suture width of **>2 mm** is generally considered abnormal. This occurs before the bone itself thins or the head circumference reaches the 95th percentile. **2. Analysis of Incorrect Options:** * **Large head (Macrocephaly):** While a hallmark of hydrocephalus, it is a clinical finding rather than the earliest radiological sign. It occurs as a consequence of prolonged sutural diastasis. * **Post clinoid erosion:** This is a classic sign of increased ICP in **adults** or older children with fused sutures. In infants, the open sutures decompress the pressure, protecting the sella turcica from early erosion. * **Thinned out vault:** This is a late feature of chronic hydrocephalus. Prolonged pressure leads to "beaten brass" or "copper beaten" appearance (digital impressions) and generalized thinning of the calvarium. **Clinical Pearls for NEET-PG:** * **Copper Beaten Skull:** Associated with chronic increased ICP, but can be a normal variant in children aged 4–10 years if seen only in the posterior skull. * **Macewen’s Sign (Cracked Pot Sign):** A clinical sign where percussion of the skull over the junction of the frontal, temporal, and parietal bones yields a resonant sound due to sutural diastasis. * **Setting Sun Sign:** Downward gaze palsy due to pressure on the midbrain tectum, a classic clinical sign of hydrocephalus.

Question 1

Which of the following is NOT a radiological feature of ileal atresia?

Accepted Answer

Double bubble sign

Answer

Obstruction on barium meal

Answer

Microcolon on barium enema

Answer

Apple-peel appearance

Question 2

Which of the following signs is associated with CHPS?

Accepted Answer

All of the above

Answer

Target sign

Answer

Antral nipple sign

Answer

Cervix sign

Question 3

Which of the following is NOT an X-ray finding of retinoblastoma?

Accepted Answer

Intracerebral calcification

Answer

Widening of the optic canal

Answer

Intraocular calcification

Answer

Secondaries in cranial bones

Question 4

What is the initial imaging of choice for suspected acute appendicitis in children?

Accepted Answer

Ultrasound (USG)

Answer

Magnetic Resonance Imaging (MRI)

Answer

Contrast-Enhanced Computed Tomography (CECT)

Answer

X-ray

Question 5

Snow storm ascites is seen in which of the following conditions?

Accepted Answer

Meconium ileus

Answer

Hirschsprung disease

Answer

Ileocaecal tuberculosis

Answer

Pseudomyxoma peritonei

Question 6

Which tumor is shown in the image?

Accepted Answer

Sacrococcygeal teratoma

Answer

Meningocele

Answer

Not recalled

Answer

Infantile fibrosarcoma

Question 7

What is the maximum limit of the cardiothoracic ratio in children below 2 years of age?

Accepted Answer

0.5

Answer

0.4

Answer

0.45

Answer

0.55

Question 8

A patient admitted with an abdominal mass underwent MRI, which revealed bilateral adrenal calcification. What is the most likely diagnosis?

Accepted Answer

Neuroblastoma

Answer

Pheochromocytoma

Answer

Adrenal incidentaloma

Answer

Medullary thyroid cancer

Question 9

An infantogram shows the presence of which of the following?

Accepted Answer

Sacrococcygeal teratoma

Answer

Hemangioma

Answer

Myelomeningocele

Answer

Arnold-Chiari malformation

Question 10

What is the first sign of hydrocephalus in children?

Accepted Answer

Sutural diastasis

Answer

Post clinoid erosion

Answer

Large head

Answer

Thinned out vault

Pediatric Radiology — MCQs

Pediatric Radiology — MCQs

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