Pediatric Imaging

Clinical Findings

• • Fever

  • Dysphagia

  • Drooling

  • Sore throat

Radiographic Features ( Figs. 11.4 – 11.5 )

• • Thickened aryepiglottic folds (hallmark)

  • Key radiographic view: lateral neck

  • Thickened epiglottis

  • Subglottic narrowing because of edema, 25%: indistinguishable from croup on AP view

  • Distention of hypopharynx

Pearls

Other causes of enlarged epiglottis or aryepiglottic folds:

• • Caustic ingestion

  • Hereditary angioneurotic edema

  • Omega-shaped epiglottis (normal variant with normal aryepiglottic folds)

  • Stevens-Johnson syndrome

Clinical Findings

• • Barking cough

  • Upper respiratory tract infection

  • Self-limited

Radiographic Features ( Fig. 11.6 )

• • Subglottic narrowing (inverted “V” or “steeple sign”)

  • Key view: AP view

  • Lateral view should be obtained to exclude epiglottitis.

  • Steeple sign: loss of subglottic shoulders

Pearls

• • Membranous croup: uncommon infection of bacterial origin (Staphylococcus aureus). Purulent membranes in subglottic trachea.

  • Epiglottitis may mimic croup on AP view.

Clinical Findings

• • Fever

  • Stiff neck

  • Dysphagia

  • Stridor (uncommon)

  • Most cases present as cellulitis rather than true abscess.

Radiographic Features

• • Widened retropharyngeal space (most common finding)

  • Air in soft tissues is specific for abscess.

  • Straightened cervical lordosis

  • Computed tomography (CT) is helpful to define superior and inferior mediastinal extent.

  • Plain radiograph findings are usually nonspecific.

  • Main differential diagnosis (DDx):

    • Retropharyngeal hematoma

    • Neoplasm (i.e., rhabdomyosarcoma)

    • Lymphadenopathy

Radiographic Features ( Fig. 11.7 )

• • Mass in posterior nasopharynx (enlarged adenoids)

  • Mass near end of uvula (palatine tonsils)

  • CT is useful to determine the presence of a tonsillar abscess.

Radiographic Features ( Fig. 11.8 )

• • Bronchial foreign body

    • Unilateral air trapping causing hyperlucent lung, 90%

    • Expiratory radiograph or lateral decubitus makes air trapping more apparent.

    • Atelectasis is uncommon, 10%

    • Only 10% of foreign bodies are radiopaque.

    • Chest fluoroscopy or CT should be performed if plain radiograph findings are equivocal.

  • Tracheal foreign body

    • Foreign body usually lodges in sagittal plane.

    • Chest radiograph (CXR) is usually normal.

Clinical Findings

• • Recurrent infection

  • Lung abscess

  • Bronchiectasis

  • Hemoptysis during childhood

Pathology

• • Nonfunctioning pulmonary tissue (nearly always posteromedial segments of lower lobes [LLs])

  • Systemic arterial supply: anomalous arteries from the aorta (less common branch of the celiac artery)

  • No connection to bronchial tree

TYPES OF PULMONARY SEQUESTRATION ^a

Feature	Intralobar Sequestration	Extralobar Sequestration
Age	Older children, adults	Neonates
Pleura	Inside lung (intralobar)	Outside lung (extralobar, own pleura)
Forms	Airless (consolidation) and air-containing, cystic type	Always airless (pleural envelope) unless communication with GI tract
Venous return	Pulmonary vein	Systemic: IVC, azygos, portal
Arterial supply	Thoracic aorta > abdominal aorta	Thoracic aorta > abdominal aorta
Associations	In 10% of patients:	In 65% of patients:
	Skeletal anomalies, 5%	Diaphragmatic defect, 20%
	Foregut anomalies, 5%	Pulmonary hypoplasia, 25%
	Diaphragmatic anomalies	Bronchogenic cysts
	Other rare associations	Cardiac anomalies

GI , Gastrointestinal; IVC , inferior vena cava.

a Location of all sequestrations: posterobasal, L > R.

Radiographic Features

• • Large (>5 cm) mass near diaphragm

  • Air-fluid levels if infected

  • Surrounding pulmonary consolidation

  • Sequestration may communicate with GI tract.

Radiographic Features ( Fig. 11.9 )

• • Well-defined round mass in subcarinal/parahilar region

  • Pulmonary cysts commonly located in medial third of lung

  • Initially no communication with tracheobronchial tree

  • Cysts are thin walled.

  • Cysts can be fluid or air filled.

Types

• • Type 0: Rare and fatal

  • Type 1: Most common, large cysts (2–10 cm), unilateral

  • Type 2: Common, multiple small cysts (0.5–2 cm), associated with other congenital abnormalities

  • Type 3: Uncommon, large, often solid

  • Type 4: Uncommon, thin walled cysts, often multifocal, high association with malignancy, specifically pleuropulmonary blastoma

Pearls

• • Type 1 and type 4 are difficult to differentiate and carry risk of malignancy (especially type 4). Treatment is resection.

Radiographic Features ( Fig. 11.10 )

• • Multiple cystic pulmonary lesions of variable size

  • Air-fluid levels in cysts

  • Variable thickness of cyst wall

Causes

• • Idiopathic, 50%

  • Obstruction of airway with valve mechanism, 50%

    • Bronchial cartilage deficiency or immaturity

    • Mucus

    • Web, stenosis

    • Extrinsic compression

Radiographic Features ( Fig. 11.11 )

• • Hyperlucent lobe (hallmark)

  • First few days of life: alveolar opacification because there is no clearance of lung fluid through bronchi

  • May be asymptomatic in neonate but becomes symptomatic later in life

  • Use CT to differentiate from bronchial obstruction

  • Distribution

    • Left upper lobe (LUL), 40%

    • Right middle lobe (RML), 35%

    • Right upper lobe (RUL), 20%

    • Two lobes affected, 5%

Types of Pulmonary Underdevelopment

• • Agenesis: complete absence of one or both lungs (airways, alveoli, and vessels)

  • Aplasia: absence of lung except for a rudimentary bronchus that ends in a blind pouch

  • Hypoplasia: decrease in number and size of airways and alveoli; hypoplastic PA

Scimitar Syndrome (Hypogenetic Lung Syndrome, Pulmonary Venolobar Syndrome)

Special form of hypoplastic lung in which the hypoplastic lung is perfused from the aorta and drained by the inferior vena cava (IVC) or portal vein (PV). The anomalous vein has a resemblance to a Turkish scimitar (sword). Associations include:

• • Accessory diaphragm, diaphragmatic hernia

  • Bony abnormalities: hemivertebrae, rib notching, rib hypoplasia

  • CHD: atrial septal defect (ASD), VSD, PDA, tetralogy of Fallot

Radiographic Features ( Fig. 11.12 )

• • Small lung (most commonly the right lung)

  • Retrosternal soft tissue density (hypoplastic collapsed lung)

  • Anomalous vein resembles a scimitar

  • Systemic arterial supply from aorta

  • Dextroposition of the heart (shift because of hypoplastic lung)

Incidence

1 in 2000–3000 births. Mortality rate of isolated hernias is 60% (with postnatal surgery) and higher when other abnormalities are present. Most reliable predictor of postnatal survival is absence of liver herniation. Respiratory distress occurs in neonatal period. Associated abnormalities include:

• • Pulmonary hypoplasia (common)

  • Central nervous system (CNS) abnormalities

    • Neural tube defects (NTDs): spina bifida, encephalocele

    • Anencephaly

Types

• • Bochdalek hernia (90% of CDH): posterior

    • 75% are on the left, 25% on right

    • Right-sided hernias are more difficult to detect because of similar echogenicity of liver and lung.

    • Contents of hernia: stomach, 60%; colon, 55%; small intestine, 90%; spleen, 45%; liver, 50%; pancreas, 25%; kidney, 20%

    • Malrotation of herniated bowel is very common.

  • Morgagni hernia (10% of CDH): anterior

    • Most occur on right (heart prevents development on the left).

    • Most common hernia contents: omentum, colon

    • Accompanying anomalies common

  • Eventration

    • Caused by relative absence of muscle in dome of diaphragm

    • Associated with:

      • Trisomies 13, 18, congenital cytomegalovirus (CMV), rubella arthrogryposis multiplex, pulmonary hypoplasia

Radiographic Features ( Fig. 11.13 )

• • Hemidiaphragm not visualized

  • Multicystic mass in chest

  • Mass effect

Radiographic Features

• • Complete thoracic and abdominal situs inversus

  • Bronchiectasis

  • Sinus hypoplasia and mucosal thickening

Pearls

• • All types of bronchiolitis and bronchitis cause air trapping (overaeration) with flattening of hemidiaphragms (best seen on lateral radiograph).

  • RSV, Mycoplasma, and parainfluenza virus are the most common agents that cause radiographic abnormalities (in 10%–30% of infected children).

  • Any virus may result in any of the five different radiographic patterns.

Radiographic Features

• • Consolidation

    • Alveolar exudate

    • Segmental consolidation

    • Lobar consolidation

  • Other findings

    • Effusions

    • Pneumatocele

  • Complications

    • Pneumothorax

    • Bronchiectasis (reversible)

    • Swyer-James syndrome (acquired pulmonary hypoplasia/postinfectious bronchiolitis obliterans), radiographically characterized by small, hyperlucent lungs with diminished vessels (focal emphysema)

Round Pneumonia

• • Usually age <8 years

  • Pneumococcal pneumonia in early consolidative phase

  • Pneumonia appears round because of poorly developed collateral pathways (pores of Kohn and channels of Lambert).

  • With time, the initially round pneumonia develops into a more typical consolidation.

Recurrent Infections

• • Cystic fibrosis (CF)

  • Recurrent aspirations

  • Rare causes of recurrent infection:

    • Hypogammaglobulinemia (Bruton disease; DDx clue: no adenoids or hilar lymph nodes)

    • Hyperimmunoglobulinemia E (Buckley syn­drome)

    • Immotile cilia syndrome (Kartagener syndrome)

    • Other immunodeficiencies

    • BFM

Causes

• • Aspiration caused by swallowing dysfunction (most common cause)

    • Anoxic birth injury (common)

    • Coma, anesthesia

  • Aspiration caused by obstruction

    • Esophageal atresia (EA) or stenosis

    • Esophageal obstruction

    • Gastroesophageal (GE) reflux, hiatal hernia

    • Gastric or duodenal obstruction

  • Fistula

    • Tracheoesophageal fistula (TEF)

Radiographic Features

• • Recurrent pneumonias; distribution: aspiration in supine position: upper lobes (ULs), superior segments of LL; aspiration in upright position: both LLs

  • Segmental and subsegmental atelectasis

  • Interstitial fibrosis

  • Inflammatory thickening of bronchial walls

Radiographic Findings

• • Consolidation

  • Pleural effusion

  • Fine reticular opacities (pulmonary fibrosis)

  • Large heart in severe anemia

  • H-shaped vertebral bodies

  • Osteonecrosis, bone infarct in visualized humeri

Radiographic Features ( Fig. 11.16 )

• • Any opacity in a premature infant should be regarded as RDS until proven otherwise.

  • Lungs are opaque (ground-glass) or reticulogranular (hallmark).

  • Hypoaeration (atelectasis) leads to low lung volumes: bell-shaped thorax (if not intubated).

  • Bronchograms are often present.

  • Absence of consolidation or pleural effusions

  • In contrast to other causes of RDS in neonates, pleural effusions are uncommon.

  • Treatment with surfactant may result in asymmetric improvement.

  • CXR signs of premature infants:

    • No subcutaneous fat

    • No humeral ossification center

    • Endotracheal tube present

In most cases of RDS, the diagnosis is made clinically but may initially be made radiographically. The role of the radiologist is to assess serial CXRs.

Complications of RDS:

• • Persistent PDA (signs of congestive heart failure [CHF]); the ductus usually closes within 1–2 days after birth in response to the high P o ₂ content.

  • Barotrauma from treatment: pneumothorax, pneumomediastinum, PIE, and acquired lobar emphysema

  • Diffuse opacities (whiteout) may be due to a variety of causes:

    • Atelectasis

    • Progression of RDS

    • Aspiration

    • Pulmonary hemorrhage

    • CHF

    • Superimposed pneumonia

Radiographic Features

• • Tortuous linear lucencies radiate outward from the hilar regions.

  • The lucencies extend all the way to the periphery of the lung.

  • Lucencies do not change with respiration.

Radiographic Features

• • Patchy, bilateral opacities, may be “rope-like”

  • Atelectasis

  • Hyperinflated lungs

  • Pneumothorax, pneumomediastinum, 25%

Complication

• • Mortality (25%) from persistent fetal circulation

Pathogenesis

• • Transplacental infection

    • Toxoplasmosis, rubella, cytomegalovirus, herpes simplex virus (TORCH)

    • Pulmonary manifestation of TORCH is usually less severe than other manifestations.

  • Perineal flora (group B streptococci, enterococci, Escherichia coli )

    • Ascending infection

    • Premature rupture of membranes (PROM)

    • Infection while passing through birth canal

Radiographic Features

• • Patchy asymmetric opacities in a term infant represent NP until proven otherwise.

  • Hyperinflation

Causes

• • Cesarean section, premature delivery, maternal sedation (no thoracic squeezing)

  • Hypoproteinemia, hypervolemia, erythrocythemia

Radiographic Features

• • Fluid overload (similar appearance to noncardiogenic pulmonary edema)

    • Prominent vascular markings

    • Pleural effusion

    • Fluid in fissure

    • Alveolar edema

    • Lungs clear in 24–48 hours.

Complications

• • Late neurologic sequelae; developmental delay, 50%

  • Intracranial hemorrhage, 10%

  • Pneumothorax, pneumomediastinum

  • Pulmonary hemorrhage (common)

  • Pleural effusions (common)

  • Catheter complications

Pearls

• Any pediatric anterior mediastinal mass is considered thymus until proven otherwise.

• Posterior mediastinal masses are the most common abnormal chest masses in infants.

Causes

• • Airway obstruction (foreign body)

  • Mechanical ventilation

  • Obstructive lung disease—asthma (Macklin effect)

  • Trauma

  • Vomiting (e.g., in patients with bulimia)

  • Spontaneous

  • Infection (pneumonia, meconium aspiration)

Rotation

• • Duodenojejunal loop (first 270-degree loop) brings stomach into horizontal axis and puts liver into right and spleen into left abdomen. The common bile duct (CBD) is associated with the ventral pancreas and becomes located dorsally because of the rotation. Before the rotation, the first loop rotation results in the duodenojejunal junction being located to the left.

  • Cecocolic loop (second 270-degree loop). The small bowel (SB) develops from the dorsal mesentery and then rotates 270 degrees so that the cecum lies near the right upper quadrant (RUQ). It later descends to the right lower quadrant (RLQ).

Fixation

Fixation is incomplete at birth. Abnormal fixation of the colonic mesentery to the posterior abdominal wall results in potential spaces into which the bowel may herniate (paraduodenal hernias). Abnormalities of fixation include:

• • Increased mobility (cecal bascule)

  • Internal hernia (paraduodenal, paracecal)

Canalization

After forming a primitive tube, the bowel lumen solidifies and then recanalizes to form the viable lumen. Anomalies in this step may result in atresia or duplication.

• • Atresia

    • Duodenal atresia results from failure of recanalization of the foregut (10 weeks) and is frequently associated with other abnormalities (malrotation, 50%; Down syndrome, 30%; EA).

    • Jejunoileal atresia results from an ischemic insult, not a failure of recanalization; occurs later and is usually an isolated phenomenon.

  • Duplication

    • Abnormal recanalization: small intramural duplication cysts may develop.

    • Notochordal adhesion: a portion of bowel remains adherent to the notochord and a diverticulum may develop.

Types ( Fig. 11.20 )

• • TEF, N-type fistula, 85%

  • Pure EA without fistula, 10%

  • TEF, H-type fistula (no atresia), 1%

  • Other forms

Associations

• • VACTERL

    • V ertebral anomalies

    • A norectal anomalies

    • C ardiovascular anomalies

    • T racheal anomalies

    • E sophageal fistula

    • R enal anomalies: renal agenesis

    • L imb anomalies: radial ray cardiac anomalies

• VSD

• Ductus arteriosus

• Right aortic arch

• EA is associated with other atresias and/or stenosis

• Duodenal atresia

• Imperforate anus

Radiographic Features

• • Plain radiograph findings

    • Gas-filled dilated proximal esophageal segment (pouch)

    • Gasless abdomen (EA-type)

    • Excessive air in stomach (H-type)

    • Aspiration pneumonia

  • Procedures

    • Pass 8-Fr feeding tube through nose to the level of atresia; distal end of tube marks level of atresia; inject air if necessary

    • Definite diagnosis is established by injection of 1–2 mL of liquid barium; this, however, should be done only at a large referral institution.

    • Videotape the injection.

  • Main DDx

    • Traumatic perforation of posterior pharynx

    • Pharyngeal pseudodiverticulum

Causes

• • Immaturity of lower esophageal sphincter during first 3 months of life (usually resolves spontaneously)

  • Congenital short esophagus

  • Hiatal hernia

  • Chalasia (lower esophageal sphincter fails to contract in resting phase; differentiate from achalasia in adults)

  • Gastric outlet obstruction

Radiographic Features

• • Barium swallow

    • Determine presence of reflux

    • Exclude organic abnormalities

  • GE scintigraphy

    • Most sensitive technique to determine reflux and GE emptying

    • Semiquantitative method

    • Anatomy only poorly visualized

Radiographic Features

• • Foreign body lodges in coronal plane

  • Esophagogram may show inflammatory mass.

  • Fluoroscopic removal with Foley catheter in select instances (e.g., nonembedded)

Clinical Findings

• • Projectile nonbilious vomiting after each feeding

  • Peaks at 3–6 weeks after birth

  • Never occurs after 3 months

  • Palpable antral mass (olive-sized)

  • Weight loss

  • Dehydration

  • Jaundice

  • Alkalosis

Associations

• • EA, TEF, hiatal hernia

  • Renal abnormalities

  • Turner syndrome

  • Trisomy 18

  • Rubella

Radiographic Features

• • Plain radiograph ( Fig. 11.22 )

    • Gastric distention (>7 cm)

    • Peristaltic waves result in a “caterpillar” appearance to the distended stomach.

    • Decreased air in distal bowel

    • Thick antral folds

    

  • Ultrasound (US)

    • HPS appears as target lesion (anechoic mass in RUQ with central echoes because of gas).

    • Scan in right posterior oblique (RPO) projection (move fluid into antrum)

    • Size criteria are used to establish the diagnosis of HPS:

      • Pyloric muscle thickness >3.5–4 mm

      • Pyloric length >15–18 mm

    • Useful as first imaging modality

  • Upper gastrointestinal (UGI) technique ( Fig. 11.23 )

    • 1

      Insert an 8-Fr feeding tube to decompress the stomach and drain gastric contents before administration of contrast agent.

    • 2

      Use right anterior oblique (RAO) view (to visualize the pylorus)

    • 3

      Instill 10–20 mL of barium.

    • 4

      Wait for pylorus to open; obtain spot views

    • 5

      Get air contrast view by turning patient supine

    • 6

      If there is no pyloric stenosis, get lateral and AP views to exclude malrotation.

    • 7

      UGI findings of HPS:

      • Indented gastric antrum (shoulder sign)

      • Compression of duodenal bulb

      • Narrow and elongated pylorus: string sign

    

Associations

• • Adrenogenital syndrome

  • Dehydration

  • Sepsis

Radiographic Features

• • Pyloric musculature is of normal thickness.

  • Prominent mucosa (echogenic)

  • Exclude secondary causes of pylorospasm (e.g., ulcer).

Clinical Findings

• • Recurrent bacterial and fungal infections: Recurrent pneumonia (80%), osteomyelitis (30%, especially small bones of the feet and hand)

  • Lymphadenitis, abscess, and granuloma formation

  • Hepatosplenomegaly

  • GI manifestations from granuloma infiltration: esophageal strictures and antral narrowing (characteristic), which may lead to gastric outlet obstruction

Associations

• • 30% have Down syndrome.

  • 40% have polyhydramnios and are premature.

  • Malrotation, EA, biliary atresia, renal anomalies, imperforate anus with or without sacral anomalies, CHD

Radiographic Features

• • Enlarged duodenal bulb and stomach (double-bubble sign)

  • Small amount of air in distal SB does not exclude diagnosis of duodenal atresia (hepatopancreatic duct may bifurcate in “Y” shape and insert above and below atresia).

Types

• • Pancreatoblastoma (most common, young children <10 years old): heterogeneous large multilocular septated masses which enhance

  • Solid pseudopapillary tumor (adolescent girls): low malignant potential, cystic and solid, hemorrhagic, may have calcification.

  • Islet cell tumors (older children): insulinomas tend to be smaller compared with gastrinomas

Associations

• • Gastroschisis

  • Omphalocele

  • Diaphragmatic hernia

  • Duodenal or jejunal atresia

Radiographic Features

• • Plain radiograph

    • Suspect diagnosis in the setting of bowel obstruction and abnormally positioned bowel loops.

    • A normal position of the cecum does not exclude malrotation but makes it much less likely.

  • US

    • Reversal of SMA (right) and SMV (left) location may occasionally be diagnosed by color Doppler imaging.

    • Distended proximal duodenum

    • Usually not useful

  • UGI (gold standard)

    • Abnormal position of duodenojejunal junction because of absence of ligament of Treitz

    • Beaking at site of obstruction

    • Spiraling of SB as it twists around SMA (corkscrew) ( Fig. 11.26 )

      

    • Edema of bowel wall

    • Early diagnosis is essential to prevent bowel necrosis.

  • Barium enema (BE)

    • A normal BE will rule out 97% of malrotation.

    • Can determine if there is a concomitant cecal volvulus

  • CT

    • SMA to right of SMV

    • Gastric outlet obstruction

    • Spiraling of duodenum and jejunum around SMA axis

Radiographic Features

• • Dilated SB

  • Microcolon

Radiographic Features ( Fig. 11.28 )

• • Plain radiograph

    • Neuhauser sign: “soap bubble” appearance (air mixed with meconium)

    • SB obstruction

    • Calcification because of meconium peritonitis, 15%

  • Enema with water-soluble contrast medium

    • Microcolon is typical: small unused colon

    • Distal 10–30 cm of ileum is larger than colon.

    • Inspissated meconium in terminal ileum

    • Hyperosmolar contrast may stimulate passage of meconium.

Meconium Plug Syndrome

Neonatal intestinal obstruction as a result of colonic inertia (in contradistinction to meconium ileus where there is accumulation of meconium in SB). Because of the inertia, the colon usually requires an enema to stimulate peristalsis. Usually occurs in full-term babies and infants of diabetic mothers. In the spectrum with small left colon syndrome. No association with CF.

Meconium Peritonitis

As a result of prenatal perforation of bowel. The inflammatory response may cause peritoneal calcification as early as 12 hours after perforation. Can also observe calcifications in testes.

Meconium Ileus Equivalent

Occurs in older patients with CF, usually patients who do not excrete bile salts. The inspissated fecal material causes intestinal obstruction.

Types

• • Ileocolic

  • Ileoileocolic

  • Ileoileal

  • Colocolic

Ileocolic and ileoileocolic intussusception make up 90% of all intussusceptions. 90% of all pediatric intussusceptions have no pathologic lead point (hypertrophy of lymphoid tissue); in the remaining 10%, the lead point is due to:

• • Meckel diverticulum

  • Polyp or other tumors (lymphoma)

  • Intramural hematoma

  • Mesenteric adenitis

  • Henoch-Schönlein purpura

Clinical Findings

• • Usually in the first 2 years of life (40% from 3–6 months), rarely in neonates

  • Colicky crampy pain, 90%

  • Vomiting, 90%

  • Sausage-shaped mass, 60%

  • Blood per rectum (currant jelly stool), 60%

Complications

• • Bowel obstruction

  • Intestinal ischemia

  • Perforation

  • Sepsis

  • Dehydration

Radiographic Features

• • Plain radiograph

    • Frequently normal (50%)

    • Intraluminal convex filling defect in partially air-filled bowel loop (commonly at hepatic flexure)

  • US

    • Target or doughnut sign

Intussusception Reduction (80%+ Success)

• • 1

    Alert pediatric surgeon (in case of perforation).

  • 2

    Preliminary kidney, urethra, bladder (KUB) to rule out free air.

  • 3

    Insufflate air rapidly, maintaining air pressure below 120 mm Hg. Alternatively, use dilute contrast (e.g., Cysto-Conray 17%) in bag placed 3 feet above table top. Rectal tube may be taped to reduce air leak.

  • 4

    Maintain constant hydrostatic pressure but no longer than 3 min against the nonmoving intussusception mass. If patient evacuates around tube, repeat filling may be performed up to 3 tries before surgery is contemplated. (Rule of 3s: bag 3 feet high, 3 min per try, and 3 tries)

  • 5

    Successful reduction is marked by free flow of air/contrast into the terminal ileum. Fluoroscopy is used to evaluate for a pathologic lead point. A postevacuation and a 24-hour radiograph are obtained.

  • 6

    Contraindications to reduction:

    • Perforation

    • Peritonitis

    • Henoch-Schönlein purpura (predisposes to perforation)

  • 7

    Complications

    • Recurrence in 6%–10% (half within 48 hours after initial reduction)

    • Perforation during radiographic reduction is rare (incidence: 1 : 300 cases)

Radiographic Features

• • Intramural hemorrhage of SB

  • Intussusception, typically ileoileal

  • Gallbladder (GB) hydrops

  • Echogenic kidneys

Radiographic Features

• • Round fluid-filled mass displacing adjacent bowel

  • May contain ectopic gastric mucosa (hemorrhage)

  • Calcifications are rare.

  • Communicating vertebral anomalies (neurenteric cysts; most common in esophagus)

Meckel Diverticulum

Persistence of the omphalomesenteric duct at its junction with the ileum. Rule of 2s:

• • Occurs in 2% of population (most common congenital GI abnormality)

  • Complications usually occur before 2 years of age

  • The diverticulum is located within 2 feet of the ileocecal valve.

  • 20% of patients have complications.

    • Hemorrhage from peptic ulceration when gastric mucosa is present within lesion

    • Inflammation and ulcer

    • Obstruction

Radiographic Features

• • Difficult to detect because diverticula usually do not fill with barium.

  • Pertechnetate scan is the diagnostic imaging modality of choice to detect ectopic gastric mucosa (sensitivity 95%).

  • False-positive pertechnetate studies may occur in:

    • Crohn disease

    • Appendicitis

    • Intussusception

    • Abscess

Radiographic Features

• • Plain radiograph

    • Mass in RLQ

    • Obliterated properitoneal fat line

    • Sentinel loop

    • Fecalith

  • US

    • May be useful in children

    • Thickened appendiceal wall shadowing appendicolith, RLQ abscess

  • BE (rarely done)

    • A completely filled appendix excludes the diagnosis of appendicitis.

    • 15% of normal appendices do not fill with contrast.

    • Signs suggestive of appendicitis:

      • Beak of barium at base of appendix (mucosal edema)

      • Irregularity of barium near tip of cecum

      • Deformity of cecum (abscess, mass effect)

  • CT

    • Helical CT with opacification of the GI tract achieved through the oral or rectal administration of 3% diatrizoate meglumine solution is useful to diagnose or exclude appendicitis and to establish an alternative diagnosis.

Radiographic Features ( Fig. 11.30 )

• • SB dilatation: adynamic ileus (first finding), unchanging configuration over serial radiographs

  • Pneumatosis intestinalis, 80% (second most common sign)

  • Gas in portal vein may be seen transiently (US more sensitive than plain radiograph); this finding does not imply as poor an outcome as it does in adults.

  • Pneumoperitoneum (20%) indicates bowel perforation: football sign (floating air and ascites give the appearance of a large elliptical lucency in supine position).

  • Barium is contraindicated; use water-soluble contrast if a bowel obstruction or Hirschsprung disease needs to be ruled out.

Complications

• • Acute

    • Perforation

  • Later in life

    • Bowel stricture (commonly near splenic flexure)

    • Complications of surgery: short SB syndrome, dumping, malabsorption

    • Complications of associated diseases common in premature infants:

      • HMD

      • Germinal matrix hemorrhage

      • Periventricular leukomalacia

Complications

• • Intestinal obstruction (in neonates)

  • Perforation

  • Enterocolitis 15%, cause uncertain

Radiographic Features ( Fig. 11.31 )

• • Bowel gas pattern of distal colonic obstruction on plain radiograph

  • BE is normal in 30%

  • Transition zone between normal and stenotic colonic segment

  • Rectosigmoid ratio is abnormal (<1) because of the narrowed segment.

  • Sawtooth appearance of colon on contrast enema

  • Significant barium retention on the 24-hour BE radiograph may be helpful.

  • Transition zone in rectosigmoid, 80%

Radiographic Features

• • Plain radiograph

    • Low colonic obstruction

    • Gas bubbles in bladder or vagina

    • Determine location of the gas-filled rectal pouch to the M-line (line drawn through junction of upper two-thirds and lower one-third of ischia; line indicates level of levator sling).

    • Upside-down views can be obtained to distend distal rectal pouch.

  • Magnetic resonance imaging (MRI)

    • Determine location of rectal pouch with respect to levator and to determine if the malformation is supralevator or infralevator type.

    • Facilitates the detection of associated spinal anomalies

Types ( Fig. 11.33 )

• • Type I: Atresia restricted to CBD

  • Type II: Atresia including common hepatic duct

  • Type III: Atresia involves left and right hepatic ducts and porta hepatis, most common (>90%)

Kasai operation (hepatoportoenterostomy): bridge to liver transplant to help relieve jaundice and delay or stop liver fibrosis. Earlier age of surgery (before 60 days) and high volume surgical center are most important prognostic factors.

Main differential is neonatal hepatitis, which is often idiopathic (known causes include viral hepatitis, CMV, rubella, and other viruses). Neonatal hepatitis is a diagnosis of exclusion after other causes of cholestasis have been ruled out.

Radiographic Features

• • US

    • Normal GB in 20%

    • Failure to detect extrahepatic bile ducts

  • Hepatic iminodiacetic acid derivative (HIDA) scan

    • No visualization of bowel at 24 hours

    • Visualization of GB is not helpful and can be seen in 20%.

    • Good hepatic visualization within 5 minutes excludes diagnosis.

    • Preprocedural phenobarbital (5 mg/kg per day × 5 days) improves sensitivity of hepatobiliary scans. The finding of normal (≥1.5 cm) or enlarged (≥3 cm) GB is more supportive of diagnosis of hepatitis.

    • Main DDx is neonatal hepatitis. Findings of neonatal hepatitis include:

      • Bowel activity present at 24 hours

      • Decreased and slow hepatic accumulation of tracer

      • GB may not be seen

    • One must exclude the presence of CF in patients thought to have biliary atresia. Inspissated bile in CF can be indistinguishable from biliary atresia by US or nuclear scan.

Complications

• • CHF because of arteriovenous (AV) shunt, 15%

  • Intraperitoneal hemorrhage

  • Disseminated intravascular coagulopathy

  • Thrombocytopenia (Kasabach-Merritt syndrome)

Radiographic Features

• • Complex, hypoechoic mass by US

  • Similar signal intensity/contrast characteristics as adult hemangioma