Pediatric Radiology Practice Questions

Q: A child presents with respiratory distress. A vascular ring is suspected. Investigation of choice is -

MRI. ***MRI/MRA*** - **Magnetic Resonance Imaging (MRI) with MR Angiography** provides excellent visualization of the **aortic arch** and its branches without ionizing radiation, making it ideal for pediatric patients with suspected **vascular rings**. - MRI clearly delineates **vascular anatomy, tracheal and esophageal compression**, confirming the diagnosis and guiding surgical planning. - Particularly preferred when **radiation-free imaging** is prioritized in children. *CT Angiography* - **CT Angiography (CTA) with 3D reconstruction** provides excellent vascular imaging and is widely used for vascular ring diagnosis in many centers. - **Advantage**: Faster acquisition time, less need for sedation, excellent anatomical detail with 3D reconstruction. - **Disadvantage**: Involves **ionizing radiation** exposure, which is a concern in pediatric patients when equally diagnostic radiation-free alternatives exist. - Both MRI and CTA are considered appropriate first-line investigations; choice depends on institutional expertise and clinical context. *Conventional Angiography* - **Catheter angiography** is invasive, involves radiation, and has been largely replaced by non-invasive cross-sectional imaging (MRI/CT). - May be reserved for cases requiring intervention or when non-invasive imaging is inconclusive. *PET* - **Positron Emission Tomography (PET)** detects metabolic activity and is used for cancer or inflammation, not for **anatomical vascular anomalies**. - Not indicated for vascular ring diagnosis.

Q: All correlates with USG findings of congenital pyloric stenosis except:

High gastric residues. ***High gastric residues*** - **High gastric residues** are a **clinical finding** in pyloric stenosis (due to impaired gastric emptying), NOT a direct **ultrasound measurement** of the pyloric muscle. - Ultrasound directly visualizes the **pyloric muscle dimensions and morphology**, not the volume of stomach contents. - While you may observe gastric contents on ultrasound, "high gastric residues" refers to the clinical assessment of retained stomach contents, typically assessed through aspiration or clinical examination. *Thickness >4mm* - A pyloric muscle wall **thickness greater than 4mm** is a **key diagnostic USG criterion** for congenital pyloric stenosis. - This measurement directly reflects the **hypertrophy** of the pyloric muscle visualized on ultrasound. *> 95% accuracy* - This refers to the **diagnostic accuracy of ultrasound** as the imaging modality for pyloric stenosis. - While this is a **test performance characteristic** rather than an anatomical finding, it describes how reliably USG **correlates with** the diagnosis of pyloric stenosis. - Ultrasound is the **imaging modality of choice** with very high sensitivity and specificity. *Segment length >16mm* - A pyloric channel **length greater than 16mm** is another **critical USG diagnostic criterion** for congenital pyloric stenosis. - This reflects the **elongation of the pyloric canal** due to muscle hypertrophy, directly measured on ultrasound.

Q: Which among the following is not an ultrasound feature of Congenital Hypertrophic Pyloric Stenosis?

95% sensitivity by ultrasound. ***95% sensitivity by ultrasound*** - This statement describes the **diagnostic accuracy** of ultrasound for pyloric stenosis, not a specific ultrasound feature of the condition itself - While relevant to diagnosing the condition, it doesn't represent **anatomical or functional findings** observed on an ultrasound image - Sensitivity refers to the test's ability to correctly identify disease when present *Thickness of pylorus > 4mm* - A **pyloric muscle wall thickness greater than 3-4 mm** is a key diagnostic criterion for hypertrophic pyloric stenosis on ultrasound - This increased thickness is due to the **hypertrophy of the muscular layer** of the pylorus - Normal pyloric wall thickness is typically 16mm* - A **pyloric canal length greater than 16 mm** is another major diagnostic feature for hypertrophic pyloric stenosis - The thickened muscle causes the **elongation of the pyloric channel** - Normal pyloric canal length is typically <15mm in infants *High gastric residue* - **Increased gastric residue** or a dilated, fluid-filled stomach is often observed on ultrasound in infants with pyloric stenosis - This is a consequence of the **pyloric obstruction**, preventing stomach contents from passing into the duodenum - This is a **secondary finding** rather than a primary morphological feature

Q: Investigation of choice to diagnose hypertrophic pyloric stenosis in infants is

Ultrasound abdomen. ***Ultrasound abdomen*** - **Abdominal ultrasound** is the diagnostic procedure of choice due to its **non-invasive nature**, **lack of radiation exposure**, and high accuracy in visualizing the pylorus. - It allows for direct measurement of the **pyloric muscle wall thickness** (typically >3-4 mm) and **pyloric channel length** (typically >14-17 mm), which are characteristic findings of hypertrophic pyloric stenosis. *Gastroscopy* - While gastroscopy can visualize the gastric outlet, it is an **invasive procedure** and not the primary diagnostic tool due to the risk associated with endoscopy in infants. - It is often reserved for cases where the diagnosis is unclear or other upper gastrointestinal pathologies are suspected. *CT scan abdomen* - **CT scans** expose infants to **ionizing radiation**, making it an unsuitable primary diagnostic investigation, especially when a highly accurate non-irradiating alternative exists. - Although it can show pyloric thickening, its disadvantages outweigh its benefits for this diagnosis. *Contrast radiology* - **Barium studies** are less sensitive and specific than ultrasound for diagnosing pyloric stenosis, especially for distinguishing muscle thickening from spasm. - This method also involves **radiation exposure** and poses a risk of aspiration, making it a secondary choice.

Q: Contrast material used in the diagnosis of esophageal atresia is:

Gastrograffin. ***Gastrograffin*** - **Gastrograffin** (diatrizoate meglumine) is the **traditional standard** water-soluble iodinated contrast agent for diagnosing **esophageal atresia**. - Historically preferred because if aspirated, it is absorbed from the lungs, unlike barium which causes severe pneumonitis. - **Note**: Modern practice increasingly favors **non-ionic, low-osmolar agents** (like Iohexol) due to Gastrograffin's hyperosmolarity, but **Gastrograffin remains the textbook answer** for most competitive exams. *Conray* - **Conray** (iothalamate meglumine) is an ionic iodinated contrast agent, primarily used for angiography and excretory urography. - Not typically recommended for esophageal studies in neonates with suspected **atresia**, due to its higher osmolality and potential complications if aspirated. *Barium swallow* - **Barium sulfate** is **absolutely contraindicated** in cases of suspected **esophageal atresia** or perforation. - If aspirated into the lungs, **barium** causes severe **chemical pneumonitis**, granuloma formation, and potentially **ARDS**, with significant morbidity and mortality. - Barium is not absorbed and remains in lung tissue, causing chronic inflammation. *Iohexol (Omnipaque)* - **Iohexol (Omnipaque)** is a **non-ionic, low-osmolar contrast agent** that is actually **safer than Gastrograffin** if aspirated. - In modern practice, non-ionic agents like Iohexol are increasingly preferred for esophageal studies due to lower osmolality and reduced risk of pulmonary edema. - However, for **exam purposes**, **Gastrograffin** remains the standard answer based on traditional teaching and most Indian textbooks.

Q: X-ray feature of pyloric stenosis is –

Single bubble appearance. ***Single bubble appearance*** - Pyloric stenosis is characterized by an **enlarged stomach** due to the obstruction at the pylorus, which appears as a **single large air-filled bubble** on an X-ray. - The obstruction prevents gastric contents, including air, from passing into the duodenum, leading to gastric distension. *Multiple air fluid levels* - This finding is more typical of a **distal bowel obstruction**, where multiple loops of bowel are dilated and contain fluid. - Pyloric stenosis typically affects only the stomach, so multiple fluid levels in the small or large intestine would not be expected. *Triple bubble appearance* - This pattern is seen in **jejunal atresia** or other obstructions involving the duodenum and proximal jejunum. - It indicates air in the stomach, duodenum, and a third dilated loop of bowel. *Double bubble appearance* - This classic sign is indicative of **duodenal atresia** or an **annular pancreas**, where air is seen in the stomach and the dilated first part of the duodenum. - The obstruction is **distal to the pylorus** in the duodenum, allowing gastric contents to pass through the pylorus into the duodenum up to the point of obstruction, but no further.

Q: A 3-year-old child presents with recurrent urinary tract infections. An intravenous pyelogram (IVP) shows a characteristic "Cobra head appearance" at the distal end of the ureter. What is the most likely diagnosis?

Ureterocele. ***Ureterocele*** - A **ureterocele** is a congenital dilatation of the **distal ureter** as it enters the bladder, characterized by a **cystic bulge** in the bladder wall. - The "Cobra head appearance" on IVP is a classic radiological sign of a ureterocele, where the dilated ureter projects into the bladder with a clear halo around it. *Polycystic kidney* - This condition involves multiple **cysts** forming in the kidneys, leading to kidney enlargement and impaired function, which does not present with a "Cobra head appearance". - It would typically be diagnosed by **ultrasound or CT scan** showing numerous renal cysts, rather than a specific ureteral finding. *Horse shoe kidney* - A **horseshoe kidney** is a congenital anomaly where the two kidneys are fused at their lower poles, forming a **U-shape** across the midline. - This condition involves a fusion anomaly of the kidneys themselves and does not result in a "Cobra head appearance" on IVP relating to the ureter. *Hydronephrosis* - **Hydronephrosis** refers to the swelling of the kidney due to a backup of urine, often caused by obstruction. - While recurrent UTIs and obstruction can occur with a ureterocele due to its obstructive nature, hydronephrosis itself describes dilation of the renal pelvis and calyces, not a "Cobra head" sign at the distal ureter.

Q: X-ray chest in a neonate may show 'ground glass' haziness in all the following conditions EXCEPT:

Left-to-right shunt. ***Left-to-right shunt*** - A **left-to-right shunt** in a neonate typically causes an increase in pulmonary blood flow, leading to vascular congestion and possibly **cardiomegaly**, not ground-glass haziness. - While prolonged significant shunting can lead to pulmonary edema, classic "ground glass" haziness is more characteristic of diffuse lung pathology. *Obstructed TAPVC* - **Obstructed total anomalous pulmonary venous connection (TAPVC)** leads to severe pulmonary venous congestion, resulting in **pulmonary edema** and a classic **ground-glass appearance** on chest X-ray. - This condition is a surgical emergency due to severe respiratory distress and lung opacification. *Staphylococcal pneumonia* - **Staphylococcal pneumonia** in neonates can cause extensive **pulmonary inflammation** and **exudate formation**, leading to a diffuse alveolar filling pattern that appears as ground-glass opacities. - This is a severe form of pneumonia that can rapidly progress. *Hyaline membrane disease* - **Hyaline membrane disease (respiratory distress syndrome)** is characterized by surfactant deficiency, leading to diffuse **atelectasis** and **pulmonary edema**, which manifests as a **ground-glass appearance** on chest X-ray. - This condition commonly affects premature infants and is associated with air bronchograms.

Q: Which statement(s) is/are true about neuroblastoma with respect to Wilms tumor?

All of these.. ***Correct: All of these*** - All three statements accurately describe distinguishing features of neuroblastoma compared to Wilms tumor - These imaging characteristics help differentiate these two common pediatric abdominal masses **Key Differentiating Features:** **Statement 1: Neuroblastoma encases major vessels without invasion** - Neuroblastoma characteristically grows around and encases major vessels (aorta, IVC, renal vessels) without invading vessel walls - Vessels appear "trapped" within tumor mass on CT/MRI but remain patent - In contrast, Wilms tumor typically displaces or compresses vessels rather than encasing them - This is one of the most reliable imaging features to differentiate the two tumors **Statement 2: Neuroblastoma causes inferolateral kidney displacement without collecting system distortion** - Neuroblastoma arises from adrenal medulla or sympathetic chain (extrinsic to kidney) - Displaces kidney downward and outward as an extrinsic mass - Collecting system and renal architecture remain intact (no claw sign) - Wilms tumor originates from renal parenchyma (intrarenal), causing internal distortion of calyces and collecting system with characteristic "claw sign" **Statement 3: Neuroblastoma crosses midline** - Neuroblastoma frequently crosses midline (60-70% of cases) due to origin from paraspinal sympathetic chain - Can involve bilateral paravertebral regions - Wilms tumor is typically unilateral and confined to one kidney, rarely crossing midline - Midline crossing strongly favors neuroblastoma over Wilms tumor *Why not individual statements alone?* - Since all three statements are correct, selecting any single statement would be incomplete - The question asks "which statement(s)" (plural), indicating multiple or all may be correct

Q: Posterior urethral valve is diagnosed on micturating cystourethrogram by-

Dilatation of posterior urethra. ***Dilatation of posterior urethra*** - **Posterior urethral valves (PUV)** create an obstruction in the **posterior urethra**, leading to its characteristic dilatation during micturition due to increased pressure. - This **dilatation** is a direct radiographic sign of the anatomical obstruction caused by the valves. *Bladder wall hypertrophy* - **Bladder wall hypertrophy** is a secondary change that occurs over time due to the bladder working harder against the obstruction caused by PUV, but it is not the primary diagnostic feature on a micturating cystourethrogram (MCU). - While present in many cases of PUV, it indicates chronic obstruction rather than directly imaging the valves themselves. *Bladder neck contracture* - **Bladder neck contracture** is a narrowing at the exit of the bladder, which is a different anatomical obstruction than PUV. - The primary pathology in PUV is within the **posterior urethra**, distal to the bladder neck. *Vesico-Ureteric reflux* - **Vesico-ureteric reflux (VUR)** is the retrograde flow of urine from the bladder into the ureters and kidneys, which is a common associated finding with PUV due to the high bladder pressures. - While often seen in PUV, VUR is a complication or associated condition, not the direct diagnostic indicator of the valves themselves.

Question 1

A child presents with respiratory distress. A vascular ring is suspected. Investigation of choice is -

Accepted Answer

MRI

Answer

Angiography

Answer

CT

Answer

PET

Question 2

All correlates with USG findings of congenital pyloric stenosis except:

Accepted Answer

High gastric residues

Answer

Thickness >4mm

Answer

> 95% accuracy

Answer

Segment length >16mm

Question 3

Which among the following is not an ultrasound feature of Congenital Hypertrophic Pyloric Stenosis?

Accepted Answer

95% sensitivity by ultrasound

Answer

Thickness of pylorus > 4mm

Answer

Canal length > 16mm

Answer

High gastric residue

Question 4

Investigation of choice to diagnose hypertrophic pyloric stenosis in infants is

Accepted Answer

Ultrasound abdomen

Answer

Gastroscopy

Answer

CT scan abdomen

Answer

Contrast radiology

Question 5

Contrast material used in the diagnosis of esophageal atresia is:

Accepted Answer

Gastrograffin

Answer

Conray

Answer

Barium swallow

Answer

Iohexol (Omnipaque)

Question 6

X-ray feature of pyloric stenosis is –

Accepted Answer

Single bubble appearance

Answer

Multiple air fluid levels

Answer

Triple bubble appearance

Answer

Double bubble appearance

Question 7

A 3-year-old child presents with recurrent urinary tract infections. An intravenous pyelogram (IVP) shows a characteristic "Cobra head appearance" at the distal end of the ureter. What is the most likely diagnosis?

Accepted Answer

Ureterocele

Answer

Polycystic kidney

Answer

Horse shoe kidney

Answer

Hydronephrosis

Question 8

X-ray chest in a neonate may show 'ground glass' haziness in all the following conditions EXCEPT:

Accepted Answer

Left-to-right shunt

Answer

Obstructed TAPVC

Answer

Staphylococcal pneumonia

Answer

Hyaline membrane disease

Question 9

Which statement(s) is/are true about neuroblastoma with respect to Wilms tumor?

Accepted Answer

All of these.

Answer

Neuroblastoma encases major vessels without invasion.

Answer

Neuroblastoma causes displacement of kidney inferolaterally without distortion of collecting system.

Answer

Neuroblastoma crossing midline.

Question 10

Posterior urethral valve is diagnosed on micturating cystourethrogram by-

Accepted Answer

Dilatation of posterior urethra

Answer

Bladder wall hypertrophy

Answer

Bladder neck contracture

Answer

Vesico-Ureteric reflux

Pediatric Radiology — MCQs

Pediatric Radiology — MCQs

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