Pediatric Radiology Practice Questions

Q: The time usually taken for air to reach the descending colon after birth in a normal infant is:

8-9 hours. **Explanation:** In a healthy newborn, the progression of air through the gastrointestinal tract follows a predictable chronological sequence, which is a critical diagnostic marker in pediatric radiology. Upon the first breath and subsequent swallowing, air enters the stomach immediately. **The Chronological Progression of Air:** * **Stomach:** Immediately after birth (within minutes). * **Small Bowel (Proximal):** 30 minutes to 1 hour. * **Distal Small Bowel (Ileum):** 3 to 4 hours. * **Proximal Colon (Cecum/Ascending):** 5 to 6 hours. * **Descending Colon/Rectum:** **8 to 9 hours** (reaching the rectum by 12 hours). **Analysis of Options:** * **Option A (1-2 hours):** At this stage, air has typically only reached the duodenum or proximal jejunum. * **Option B (3-4 hours):** This is the timeframe for air to reach the distal small intestine (ileum). * **Option C (5-6 hours):** At this point, air is usually entering the cecum and ascending colon. * **Option D (8-9 hours):** This is the standard physiological time for air to traverse the transverse colon and reach the **descending colon**. **Clinical Pearls for NEET-PG:** 1. **Diagnostic Significance:** If air does not reach the rectum by 24 hours, it is considered pathological, suggesting conditions like **Hirschsprung disease**, **imperforate anus**, or **meconium ileus**. 2. **Maternal Sedation:** The progression of bowel gas may be significantly delayed if the mother received heavy sedation or narcotics during labor. 3. **Gasless Abdomen:** In a newborn, a "gasless abdomen" on X-ray after 12–24 hours is an emergency, often indicating esophageal atresia (without fistula) or severe intestinal obstruction.

Q: The provided X-ray image depicts which of the following conditions?

Acute Epiglottitis. ***Acute Epiglottitis*** - The X-ray shows the classic **thumbprint sign** on lateral neck view, representing an enlarged and inflamed epiglottis that appears as a swollen thumb-like shadow. - This radiological finding is **pathognomonic** for acute epiglottitis, typically caused by **Haemophilus influenzae type b** in unvaccinated individuals. *Acute Laryngotracheobronchitis* - Would show the **steeple sign** on **anteroposterior (AP) neck X-ray**, not the thumbprint sign seen here. - Affects the **subglottic area** causing narrowing of the tracheal air column, unlike the supraglottic involvement in epiglottitis. *Foreign body aspiration* - Typically shows **unilateral hyperinflation** or **mediastinal shift** on chest X-ray, not epiglottic swelling. - May reveal a **radiopaque foreign body** if metallic, but the thumbprint sign is not a feature of aspiration. *Retropharyngeal abscess* - Shows **widened prevertebral soft tissue space** (>7mm at C2 level in children) on lateral neck X-ray. - The epiglottis remains **normal in size and shape**, unlike the enlarged thumbprint appearance seen in this case.

Q: A chest radiograph from an infant is provided. What is the probable diagnosis?

Respiratory Distress Syndrome. ***Respiratory Distress Syndrome*** - Classic **bilateral reticulogranular/ground-glass opacity** pattern with **air bronchograms** throughout both lung fields, characteristic of surfactant deficiency - **Low lung volumes** and diffuse uniform opacification are hallmarks of RDS, most commonly seen in **premature infants** *Congenital Diaphragmatic Hernia* - Would show **bowel loops** or **abdominal contents** in the chest cavity, typically on the left side - Associated with **mediastinal shift** away from the affected side and **reduced lung volume** on the herniated side only *Transient Tachypnea of Newborn* - Characterized by **perihilar streakiness** and **fluid in the fissures** rather than diffuse ground-glass appearance - Typically **resolves within 24-48 hours** and shows **preserved lung volumes** with clearer peripheral lung fields *Scimitar Syndrome* - Shows an **anomalous curved pulmonary vein** (scimitar sign) draining into the inferior vena cava - Associated with **right lung hypoplasia** and **dextroposition of the heart**, not bilateral diffuse opacification

Q: What is the most likely diagnosis based on a chest x-ray of a child presenting with acute breathlessness?

Pneumothorax. ***Pneumothorax*** - **Acute onset breathlessness** in a child with **visible pleural space** on chest X-ray strongly suggests pneumothorax, especially with **absent lung markings** in the affected area. - Chest X-ray typically shows **hyperlucent area** with **collapsed lung margin** and possible **mediastinal shift** away from the affected side. *Pneumatocele* - Appears as **thin-walled, air-filled cysts** within the lung parenchyma, typically following **pneumonia** or **trauma**. - Would not cause **acute breathlessness** unless very large, and appears as **round, air-filled spaces** rather than pleural air collection. *Normal* - A **normal chest X-ray** would not explain the **acute breathlessness** presentation in this clinical scenario. - Normal findings would show **clear lung fields**, **normal heart size**, and **no pleural abnormalities**. *None of the above* - Given the clinical presentation of **acute breathlessness** with abnormal chest X-ray findings, a specific diagnosis should be identifiable. - The radiological findings described are **consistent with pneumothorax**, making this option inappropriate.

Q: Scrotal calcifications in fetal sonography may be seen in which of the following conditions?

Meconium ileus. **Explanation:** The presence of scrotal calcifications in fetal sonography is a classic diagnostic marker for **Meconium Peritonitis**, which is frequently associated with **Meconium Ileus** (often secondary to Cystic Fibrosis). **1. Why Meconium Ileus is correct:** In cases of meconium ileus, bowel perforation can occur in utero. This leads to the leakage of sterile meconium into the peritoneal cavity, causing a chemical inflammatory response known as meconium peritonitis. Because the **tunica vaginalis** is an extension of the peritoneum (via the patent processus vaginalis), the meconium can migrate into the scrotal sac. Over time, these deposits undergo calcification, appearing as highly echogenic foci with or without shadowing on fetal ultrasound. **2. Why other options are incorrect:** * **Testicular Torsion:** While torsion can occur in utero (extravaginal torsion), it typically presents as an enlarged, heterogenous, or hydrocele-associated testis. Calcification is an extremely rare, late-stage finding and is not a characteristic prenatal sonographic feature. * **Hydrocele:** A simple fetal hydrocele is a common, benign finding representing fluid in the scrotum. It appears anechoic (black) and does not contain calcifications unless associated with underlying pathology like peritonitis. **High-Yield Clinical Pearls for NEET-PG:** * **Meconium Peritonitis Triad:** Ascites, peritoneal calcifications, and polyhydramnios. * **Scrotal Pearl:** A term used for benign, post-natal extratesticular calcifications, but in a **fetus**, scrotal calcification is a "red flag" for healed or active meconium peritonitis. * **Cystic Fibrosis Link:** Approximately 15-20% of infants with meconium ileus have Cystic Fibrosis; if fetal scrotal calcifications are seen, genetic screening is often recommended.

Q: Which one of the following is the earliest radiographic manifestation of childhood leukemia?

Radiolucent transverse metaphyseal band. ### Explanation **1. Why the Correct Answer is Right:** The **radiolucent transverse metaphyseal band** (also known as the "Leukemic line") is the **earliest** and most common radiographic sign of childhood leukemia (specifically ALL). These bands are typically found in areas of rapid bone growth, such as the knees, wrists, and ankles. * **Pathophysiology:** These bands do not represent leukemic infiltration itself. Instead, they result from a **disturbance in endochondral ossification** caused by the systemic stress of the disease, leading to deficient osteogenesis and a lack of calcified primary spongiosa at the metaphysis. **2. Analysis of Incorrect Options:** * **B. Diffuse demineralization of bones:** While common in leukemia due to marrow hyperplasia and pressure atrophy, it usually occurs later than the metaphyseal bands. It is a non-specific finding. * **C. Osteoblastic lesions in skull:** Leukemia is primarily an **osteolytic** process. Osteoblastic (sclerotic) lesions are rare in leukemia and are more characteristic of metastatic neuroblastoma or lymphoma. * **D. Parenchymal pulmonary lesions:** While leukemic infiltration or opportunistic infections can occur in the lungs, skeletal changes are far more frequent and typically precede pulmonary manifestations on imaging. **3. Clinical Pearls for NEET-PG:** * **Most common skeletal finding:** Generalized osteopenia (demineralization). * **Most characteristic/earliest finding:** Radiolucent metaphyseal bands. * **Differential Diagnosis for Metaphyseal Bands:** Remember the mnemonic **"CHIRP"** (Celiac disease/Chronic illness, Healing rickets, Infection (TORCH), Retinoids, Phosphorus/Lead poisoning). * **Other findings:** Subperiosteal new bone formation (periostitis) and "moth-eaten" osteolytic lesions are also seen in advanced cases.

Q: What is the investigation of choice for hydrocephalus in infants?

Cranial USG. **Explanation:** The investigation of choice for diagnosing and monitoring hydrocephalus in infants is **Cranial Ultrasonography (USG)**. **1. Why Cranial USG is the Correct Choice:** In infants (typically under 12–18 months), the **anterior fontanelle** remains open, serving as an ideal "acoustic window" for ultrasound waves. Cranial USG is the preferred first-line modality because it is non-invasive, bedside-portable, cost-effective, and involves **no ionizing radiation**. It accurately visualizes ventricular size, detects intraventricular hemorrhage (a common cause of hydrocephalus in preterms), and allows for serial monitoring of ventricular dilatation without the need for sedation. **2. Why Other Options are Incorrect:** * **CT Scan:** While excellent for bone and acute hemorrhage, it involves high doses of ionizing radiation. In infants, the developing brain is highly sensitive to radiation, making CT a secondary choice reserved for emergencies or trauma. * **MRI:** This is the "Gold Standard" for detailed anatomical evaluation (e.g., identifying Aqueductal Stenosis or Chiari malformations). However, it is not the *initial* investigation of choice because it requires prolonged immobilization, often necessitating sedation or anesthesia in infants. * **X-ray Skull:** This provides very limited information. While it may show "copper beaten appearance" or suture diastasis in chronic cases, it cannot visualize the brain parenchyma or ventricular system. **High-Yield Clinical Pearls for NEET-PG:** * **Acoustic Window:** The **Anterior Fontanelle** is the primary window; the Mastoid fontanelle is used to better visualize the cerebellum. * **Screening:** USG is the screening modality of choice for **Intraventricular Hemorrhage (IVH)** in premature neonates. * **Resistive Index (RI):** On Doppler USG, an increased RI in the anterior cerebral artery can suggest raised intracranial pressure in hydrocephalic infants.

Q: Intra-abdominal calcification in a plain X-ray of the abdomen is most often seen in which of the following conditions?

Meconium peritonitis. **Explanation:** **1. Why Meconium Peritonitis is Correct:** Meconium peritonitis is a sterile chemical peritonitis resulting from intrauterine bowel perforation. When meconium escapes into the peritoneal cavity, it triggers an intense inflammatory response. Because meconium contains high concentrations of enzymes and minerals, it undergoes **dystrophic calcification** rapidly (often within 24–48 hours). On a plain X-ray, this typically manifests as **scattered, irregular, or linear calcifications** across the abdomen or scrotum (via the processus vaginalis). It is the most common cause of neonatal intra-abdominal calcification. **2. Analysis of Incorrect Options:** * **Meconium Ileus:** This is a distal small bowel obstruction caused by inspissated meconium (highly associated with Cystic Fibrosis). While it shows a "soap-bubble" appearance (Neuhauser sign) due to air mixing with meconium, it **does not** typically show calcification unless a complication like perforation (leading to peritonitis) occurs. * **Meconium Plug Syndrome:** This is a functional colonic obstruction due to an immature colon. It presents with failure to pass meconium but lacks the inflammatory process required for calcification. * **Necrotizing Enterocolitis (NEC):** The hallmark radiological finding in NEC is **Pneumatosis Intestinalis** (air within the bowel wall) or portal venous gas. While it is a serious neonatal condition, intra-abdominal calcification is not a primary or frequent feature. **Clinical Pearls for NEET-PG:** * **Most common cause of neonatal bowel perforation:** Meconium peritonitis (often secondary to atresia or volvulus). * **Radiological Sign:** Look for "Snow-flake" or "Curvilinear" calcifications. * **Scrotal Calcification:** If you see calcification in the scrotum of a newborn, think of healed meconium peritonitis. * **Association:** Approximately 15-40% of cases are associated with **Cystic Fibrosis**.

Q: "Double bubble" sign is a feature of which of the following conditions?

All of the above. ### Explanation The **"Double Bubble" sign** is a classic radiographic finding seen on a plain abdominal X-ray. It represents the simultaneous dilatation of the **stomach** (first bubble) and the **proximal duodenum** (second bubble), with a lack of distal bowel gas. #### Why "All of the Above" is Correct: The sign occurs whenever there is a **complete or near-complete high intestinal obstruction** at the level of the duodenum. 1. **Duodenal Atresia:** The most common cause. There is a congenital failure of recanalization of the duodenum, leading to a complete blind end. 2. **Annular Pancreas:** A developmental anomaly where a ring of pancreatic tissue encircles the second part of the duodenum, causing extrinsic compression and obstruction. 3. **Duodenal Diaphragm (Web):** An intraluminal membrane with or without a small central aperture (fenestrated web) that obstructs the lumen. Since all three conditions cause obstruction at the same anatomical level (pre-vateric or post-vateric duodenum), they all manifest the "Double Bubble" sign. #### Clinical Pearls for NEET-PG: * **Associated Condition:** Duodenal atresia is strongly associated with **Down Syndrome (Trisomy 21)** in approximately 30% of cases. * **Antenatal Ultrasound:** The sign can be detected in utero, often accompanied by **polyhydramnios** (due to the fetus's inability to swallow and absorb amniotic fluid). * **Differential Diagnosis:** If distal gas is present along with a double bubble, consider **Malrotation with Midgut Volvulus**—a surgical emergency. * **Management:** Initial management involves nasogastric decompression and IV fluids, followed by surgical correction (e.g., Duodenoduodenostomy).

Question 1

Which contrast material is used in the diagnosis of esophageal atresia?

Accepted Answer

Dianosil

Answer

Gastrograffin

Answer

Conray 420

Answer

Myodii

Question 2

The time usually taken for air to reach the descending colon after birth in a normal infant is:

Accepted Answer

8-9 hours

Answer

1-2 hours

Answer

3-4 hours

Answer

5-6 hours

Question 3

The provided X-ray image depicts which of the following conditions?

Accepted Answer

Acute Epiglottitis

Answer

Acute Laryngotracheobronchitis

Answer

Foreign body aspiration

Answer

Retropharyngeal abscess

Question 4

A chest radiograph from an infant is provided. What is the probable diagnosis?

Accepted Answer

Respiratory Distress Syndrome

Answer

Congenital Diaphragmatic Hernia

Answer

Transient Tachypnea of Newborn

Answer

Scimitar Syndrome

Question 5

What is the most likely diagnosis based on a chest x-ray of a child presenting with acute breathlessness?

Accepted Answer

Pneumothorax

Answer

Pneumatocele

Answer

Normal

Answer

None of the above

Question 6

Scrotal calcifications in fetal sonography may be seen in which of the following conditions?

Accepted Answer

Meconium ileus

Answer

Testicular torsion

Answer

Hydrocele

Answer

All of the above

Question 7

Which one of the following is the earliest radiographic manifestation of childhood leukemia?

Accepted Answer

Radiolucent transverse metaphyseal band

Answer

Diffuse demineralization of bones

Answer

Osteoblastic lesions in skull

Answer

Parenchymal pulmonary lesions on chest films

Question 8

What is the investigation of choice for hydrocephalus in infants?

Accepted Answer

Cranial USG

Answer

CT Scan

Answer

MRI

Answer

X-ray skull

Question 9

Intra-abdominal calcification in a plain X-ray of the abdomen is most often seen in which of the following conditions?

Accepted Answer

Meconium peritonitis

Answer

Meconium ileus

Answer

Meconium plug syndrome

Answer

Necrotizing enterocolitis

Question 10

"Double bubble" sign is a feature of which of the following conditions?

Accepted Answer

All of the above

Answer

Annular pancreas

Answer

Duodenal atresia

Answer

Duodenal diaphragm

Pediatric Radiology — MCQs

Pediatric Radiology — MCQs

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