Pediatric Radiology Practice Questions

Q: A 3-day-old child presents with the below CXR. What is the diagnosis?

Congenital diaphragmatic hernia. ***Congenital diaphragmatic hernia*** - Classic presentation in a **3-day-old neonate** with **bowel loops visible in the hemithorax** on CXR, causing **mediastinal shift** to the contralateral side. - Associated with **respiratory distress** and **scaphoid abdomen** due to abdominal contents herniating into the thoracic cavity through a **diaphragmatic defect**. *Pneumothorax left side* - Would show **hyperlucent lung field** with **absent lung markings** and **pleural line**, not bowel loops in the thorax. - Typically presents with **sudden onset respiratory distress** and **asymmetric chest expansion**. *Consolidation* - Appears as **dense opacification** with **air bronchograms** on CXR, not the characteristic bowel loop pattern. - Usually associated with **pneumonia** or **respiratory distress syndrome**, showing homogeneous density rather than tubular structures. *Congenital lobar emphysema* - Shows **hyperinflated lobe** with **hyperlucent appearance** and **compressed adjacent lung tissue**. - Presents with **progressive respiratory distress** but lacks the characteristic **bowel loops** and **mediastinal shift** pattern seen in diaphragmatic hernia.

Q: What is the initial imaging of choice for intussusception?

USG. **Explanation:** **1. Why USG is the Correct Answer:** Ultrasonography (USG) is the **initial imaging modality of choice** and the gold standard for diagnosing intussusception due to its high sensitivity (98-100%) and specificity. It is non-invasive, avoids ionizing radiation (crucial in the pediatric population), and can identify lead points. * **Classic USG signs:** The **"Target sign"** or **"Donut sign"** (seen on transverse view) and the **"Pseudokidney sign"** or **"Hayfork sign"** (seen on longitudinal view). **2. Why Other Options are Incorrect:** * **A. X-ray:** Often the first test performed in an emergency to rule out perforation (pneumoperitoneum) or bowel obstruction, but it has low sensitivity for diagnosing intussusception itself. * **C. Barium Enema:** Historically the "Gold Standard" for both diagnosis and treatment. However, it has been replaced by USG for diagnosis because it involves radiation and carries a risk of barium peritonitis if perforation is present. It is now primarily used for **therapeutic reduction** (Hydrostatic reduction). * **D. CT Scan:** Highly accurate but not the initial choice in children due to high radiation doses. It is more commonly used in **adult intussusception**, where the cause is frequently a primary malignancy. **3. NEET-PG High-Yield Pearls:** * **Most common site:** Ileocolic. * **Most common cause:** Idiopathic (often following a viral URTI leading to Peyer’s patch hypertrophy). * **Clinical Triad:** Intermittent abdominal pain, palpable "sausage-shaped" mass, and **"red currant jelly" stools**. * **Treatment:** Non-surgical reduction (hydrostatic/pneumatic enema) is the first line if there are no signs of peritonitis or perforation. If these are present, immediate surgery is required.

Q: What is the investigation of choice for studying vesico-ureteric reflux?

Micturition cystourethrogram. **Explanation:** **Micturition Cystourethrogram (MCU/VCUG)** is the gold standard investigation for diagnosing and grading **Vesico-ureteric Reflux (VUR)**. The underlying medical concept relies on the fact that VUR is a dynamic process where urine flows retrograde from the bladder into the ureters. This is most likely to occur during the **voiding (micturition) phase** when intra-vesical pressure is at its highest. MCU allows real-time fluoroscopic visualization of the bladder filling and emptying, enabling the identification of the reflux and its severity (Grades I-V). **Why other options are incorrect:** * **Ascending Pyelogram (Retrograde Pyelogram):** This involves injecting contrast directly into the ureters via cystoscopy. It is used to visualize the ureteric anatomy and site of obstruction, not to assess functional reflux from the bladder. * **Cystogram (Static):** A static cystogram only visualizes the bladder. While it may show gross reflux during the filling phase, it often misses reflux that occurs only during the high-pressure voiding phase. * **Intravenous Urogram (IVU):** This is a functional study of the kidneys and excretion. While it may show secondary signs of chronic reflux (like hydroureteronephrosis or renal scarring), it cannot definitively diagnose or grade active VUR. **Clinical Pearls for NEET-PG:** * **Grading:** VUR is graded using the International System of Radiographic Grading (Grade I: ureter only; Grade V: gross dilatation and tortuosity with loss of papillary impressions). * **Radionuclide Cystogram (RNC):** This is more sensitive than MCU and involves less radiation; it is preferred for **follow-up** of known VUR, though MCU remains the initial choice for anatomical detail. * **Initial Screening:** In a child with the first episode of febrile UTI, **Ultrasound** is the initial screening tool, but MCU is the definitive test for VUR.

Q: Gasless abdomen on X-ray is found in all except:

Meckel's diverticulum. ### Explanation A **"gasless abdomen"** on a plain X-ray refers to a paucity or complete absence of bowel gas distal to the stomach or duodenum. This occurs when there is a high-grade proximal obstruction or when the stomach contents cannot pass into the distal intestines. **1. Why Meckel’s Diverticulum is the Correct Answer:** Meckel’s diverticulum is a vestigial remnant of the vitellointestinal duct located in the distal ileum. In its uncomplicated state, it does not cause obstruction and has no effect on the distribution of bowel gas. Even if it causes complications like intussusception or volvulus, it typically results in **dilated bowel loops** (distal obstruction) rather than a gasless abdomen. Therefore, it is the "except" in this list. **2. Analysis of Incorrect Options:** * **Annular Pancreas & Duodenal Atresia:** Both conditions cause high intestinal obstruction at the level of the duodenum. If the obstruction is complete and occurs early (or if the infant has vomited all swallowed air), the distal bowel will contain no gas. These typically present with the classic **"Double Bubble" sign**, with a gasless distal abdomen. * **Pyloric Stenosis:** While the classic description is a "distended stomach," severe cases with persistent vomiting can lead to a gasless appearance of the distal intestines because air is unable to pass through the stenosed pyloric canal. **Clinical Pearls for NEET-PG:** * **Double Bubble Sign:** Diagnostic of Duodenal Atresia, Annular Pancreas, or Midgut Volvulus. * **Single Bubble Sign:** Seen in Pyloric Stenosis. * **Triple Bubble Sign:** Seen in Jejunal Atresia. * **Other causes of Gasless Abdomen:** Acute pancreatitis (due to vomiting/ileus), high-grade esophageal atresia (without fistula), and midgut volvulus (early stage).

Q: The diagnostic feature of congenital diaphragmatic hernia on prenatal ultrasonography is:

Peristalsis in the thoracic cavity. **Explanation:** **Congenital Diaphragmatic Hernia (CDH)** occurs due to the failure of the pleuroperitoneal membranes to fuse, most commonly on the left side (Bochdalek hernia). **Why Option C is Correct:** The definitive diagnostic feature on prenatal ultrasonography is the visualization of abdominal viscera within the thoracic cavity. Observing **peristalsis in the thoracic cavity** (bowel loops) is a pathognomonic sign that confirms the presence of herniated intestine. Other common findings include a fluid-filled stomach at the level of the four-chamber view of the heart. **Analysis of Incorrect Options:** * **Option A:** While a fluid-filled stomach may appear as a "cyst" in the chest, it is typically located **lateral** to the heart, not specifically behind the left atrium (which is more characteristic of a hiatal hernia or neurenteric cyst). * **Option B:** CDH causes a significant mediastinal shift, but it is almost always associated with an **abnormal cardiac axis** (levocardia or dextroposition) because the herniated mass displaces the heart. * **Option D:** In utero, the bowel does not contain air; therefore, the "gas bubble" sign is a postnatal radiographic finding, not a prenatal ultrasound feature. **High-Yield Clinical Pearls for NEET-PG:** * **Most Common Type:** Bochdalek (Posterolateral, 85-90%), usually on the **Left side**. * **Morgagni Hernia:** Anterior and retrosternal; less common. * **Key Ultrasound Findings:** Polyhydramnios, mediastinal shift, and herniated stomach/bowel. * **Prognostic Marker:** **Lung-to-Head Ratio (LHR)** is used to predict pulmonary hypoplasia and survival. * **Management:** The primary cause of mortality is **pulmonary hypoplasia** and persistent pulmonary hypertension, not the hernia itself. Stabilization is required before surgical repair.

Q: Neuroblastoma differs from Wilm's tumor radiologically by all EXCEPT?

Same location. ### Educational Explanation **1. Why "Same location" is the correct answer:** Neuroblastoma and Wilms’ tumor do **not** share the same anatomical location. **Neuroblastoma** is an extra-renal tumor, most commonly arising from the adrenal medulla (though it can occur anywhere along the sympathetic chain). In contrast, **Wilms’ tumor (Nephroblastoma)** is an intra-renal tumor arising from the kidney parenchyma itself. This is a fundamental radiological distinction: Wilms’ tumor displaces the pelvicalyceal system (claw sign), whereas Neuroblastoma displaces the entire kidney (usually downward and laterally). **2. Analysis of Incorrect Options:** * **A. Calcification:** This is a major differentiator. Calcification is very common in Neuroblastoma (80–90% of cases, often stippled) but rare in Wilms’ tumor (only 10–15%). * **B. Aorta and IVC displacement:** Neuroblastoma is notorious for **encasing and displacing** major vessels (Aorta/IVC) without invading them. Wilms’ tumor, however, is more likely to **invade** the renal vein and IVC rather than just pushing them aside. * **D. Intraspinal extension:** Neuroblastoma frequently extends through the neural foramina into the spinal canal (dumbbell-shaped tumor). This feature is virtually never seen in Wilms’ tumor. **3. Clinical Pearls for NEET-PG:** * **Age Factor:** Neuroblastoma typically presents earlier (median age 2 years) than Wilms’ tumor (median age 3–4 years). * **Midline Crossing:** Neuroblastoma frequently crosses the midline; Wilms’ tumor usually remains confined to one side. * **The "Claw Sign":** Present in Wilms’ tumor (indicates the tumor originates from the kidney). * **Metastasis:** Neuroblastoma often spreads to bones (Orbit - Proptosis/Raccoon eyes); Wilms’ tumor primarily spreads to the lungs (Cannonball secondaries).

Q: A 4-year-old child presents with findings on a chest X-ray. What is the probable location of the foreign body visible on the skiagram?

Esophagus. ***Esophagus*** - Foreign bodies in the **esophagus** appear **face-on** (en face) on **anteroposterior (AP) chest X-ray**, showing the full circular outline of objects like coins. - The esophagus is the **most common location** for foreign body impaction in children, especially at anatomical narrowings like the **cricopharyngeal area**. *Trachea* - Foreign bodies in the **trachea** appear **edge-on** (sagittal view) on **AP chest X-ray**, showing only the thin edge of circular objects. - Tracheal foreign bodies typically cause **immediate respiratory distress** and **stridor**, which would be the predominant clinical presentation. *Vallecula* - The **vallecula** is located in the **oropharynx** and would not be visible on a **chest X-ray**. - Foreign bodies here typically cause **drooling**, **difficulty swallowing**, and would require **lateral neck X-ray** for visualization. *Right main bronchus* - While the **right main bronchus** is indeed the most common site for **aspirated foreign bodies** due to its **wider diameter** and **more vertical orientation**. - Bronchial foreign bodies often appear as **radiolucent objects** and may cause **unilateral hyperinflation** or **atelectasis** rather than being directly visible.

Q: The 'keyhole sign' is a radiological finding typically associated with which of the following conditions?

Bladder outlet obstruction. ### Explanation The **'Keyhole Sign'** is a classic sonographic finding seen in male fetuses, representing a dilated posterior urethra and a thick-walled, distended urinary bladder. **1. Why the Correct Answer is Right:** The sign is most commonly associated with **Posterior Urethral Valves (PUV)**, the most frequent cause of **Bladder Outlet Obstruction** in male infants. The "keyhole" appearance is formed by the combination of: * The **round, distended bladder** (the head of the keyhole). * The **dilated posterior urethra** proximal to the obstruction (the neck of the keyhole). This finding is often accompanied by bilateral hydroureteronephrosis and oligohydramnios. **2. Why the Incorrect Options are Wrong:** * **Polycystic Kidney Disease:** Characterized by bilateral enlarged, echogenic kidneys with multiple cysts (Autosomal Dominant) or microcysts (Autosomal Recessive). It does not involve urethral dilation. * **Renal Agenesis:** This is the congenital absence of one or both kidneys. In bilateral cases, the bladder is typically absent or non-visualized due to a lack of urine production. * **Ureteropelvic Junction (UPJ) Obstruction:** This is the most common cause of neonatal hydronephrosis. However, the obstruction is at the level of the kidney; therefore, the ureters and bladder remain normal in caliber. **3. Clinical Pearls for NEET-PG:** * **PUV** is the most common cause of bladder outlet obstruction in male newborns. * **Gold Standard Investigation:** Voiding Cystourethrogram (VCUG) is the definitive test to diagnose PUV postnatally. * **Associated Finding:** Look for "thickening of the bladder wall" (>2mm) on ultrasound. * **Differential:** Prune Belly Syndrome can also present with a dilated bladder, but it lacks the mechanical obstruction seen in PUV.

Q: Interpret the plain X-ray of the abdomen:

Duodenal atresia. ***Duodenal atresia*** - Classic **double bubble sign** on plain abdominal X-ray - one bubble represents the **distended stomach** and the second represents the **distended proximal duodenum**. - Presents in **neonates** with **bilious vomiting** within the first day of life due to complete obstruction of the duodenum. *Annular pancreas* - While it can cause duodenal obstruction and mimic the double bubble sign, it is a **causative factor** rather than the radiological interpretation itself. - **Pancreatic tissue** encircles the duodenum, but the X-ray appearance would still be interpreted as duodenal obstruction/atresia. *Ladd's band* - Causes **external compression** of the duodenum in **malrotation** cases, typically presenting with **intermittent bilious vomiting**. - X-ray may show **duodenal obstruction** but often with **abnormal bowel gas pattern** throughout the abdomen, not the classic isolated double bubble. *All of the above* - Incorrect as the question asks for **X-ray interpretation**, which specifically identifies the **radiological sign** (double bubble) diagnostic of duodenal atresia. - While annular pancreas and Ladd's bands can cause similar clinical presentations, the **plain X-ray interpretation** points specifically to duodenal atresia.

Question 1

A 3-day-old child presents with the below CXR. What is the diagnosis?

Accepted Answer

Congenital diaphragmatic hernia

Answer

Pneumothorax left side

Answer

Consolidation

Answer

Congenital lobar emphysema

Question 2

What is the initial imaging of choice for intussusception?

Accepted Answer

USG

Answer

X-ray

Answer

Barium enema

Answer

CT scan

Question 3

What is the investigation of choice for studying vesico-ureteric reflux?

Accepted Answer

Micturition cystourethrogram

Answer

Ascending pyelogram

Answer

Cystogram

Answer

Intravenous urogram

Question 4

Gasless abdomen on X-ray is found in all except:

Accepted Answer

Meckel's diverticulum

Answer

Annular pancreas

Answer

Duodenal atresia

Answer

Pyloric stenosis

Question 5

The diagnostic feature of congenital diaphragmatic hernia on prenatal ultrasonography is:

Accepted Answer

Peristalsis in the thoracic cavity

Answer

A cyst behind the left atrium

Answer

Mediastinal shift with normal cardiac axis

Answer

Absence of gas bubble under the diaphragm

Question 6

Neuroblastoma differs from Wilm's tumor radiologically by all EXCEPT?

Accepted Answer

Same location

Answer

Calcification

Answer

Aorta and IVC are not eroded but pushed aside

Answer

Intraspinal extension of tumor

Question 7

The double bubble sign is typically seen in which of the following conditions?

Accepted Answer

Diaphragmatic hernia

Answer

Lad's band

Answer

Annular pancreas

Answer

Pancreatic pseudocyst

Question 8

A 4-year-old child presents with findings on a chest X-ray. What is the probable location of the foreign body visible on the skiagram?

Accepted Answer

Esophagus

Answer

Trachea

Answer

Vallecula

Answer

Right main bronchus

Question 9

The 'keyhole sign' is a radiological finding typically associated with which of the following conditions?

Accepted Answer

Bladder outlet obstruction

Answer

Polycystic kidney disease

Answer

Renal agenesis

Answer

Ureteropelvic junction obstruction

Question 10

Interpret the plain X-ray of the abdomen:

Accepted Answer

Duodenal atresia

Answer

Annular pancreas

Answer

Ladd's band

Answer

All of the above

Pediatric Radiology — MCQs

Pediatric Radiology — MCQs

On this page

Practice by Chapter

Want unlimited practice?