Category Archives: PEDIATRICS

NEONATAL RESPIRATORY DISEASES IMAGING

NEONATAL DISEASES IMAGING is very important

Neonatal Respiratory Distress (NRD):

  • RD in the newborn is usually due to one of 4 disease entities:
1.     Respiratory distress syndrome (RDS; hyaline membrane disease, HMD)

2.     Transient tachypnea of the newborn (TTN)

3.     Meconium aspiration

4.     Neonatal pneumonia

The most common complications of RDS are:

  • Pulmonary interstitial emphysema (PIE)
  • Persistent PDA
  • Bronchopulmonary dysplasia (BPD)

Neonatal Respiratory Distress:

Disease Lung Volume Opacities Time Course Complication
RDS:  Low Granular 4-6 days PIE, BPD, PDA
Transient tachypnea: High or normal Linear, streaky* < 48 hours None
Meconium aspiration:  Hyperinflation Coarse, patchy At birth PFC, ECMO
Neonatal pneumonia:  Anything Granular Variable  

*Ground-glass opacity at birth.

ECMO: extracorporeal membrane oxygenation; PFC : persistent fetal circulation;

RDS/ hyaline membrane disease (HMD):

Evolving Terminology:

  • The term hyaline membrane disease is now less commonly used in clinical practice to describe pulmonary surfactant insufficiency in infants.
  • Hyaline membranes are considered a byproduct, not the cause, of respiratory failure in neonates with immature lungs.
  • The term respiratory distress syndrome is currently used to denote surfactant deficiency and should not be used for other causes of respiratory distress.
  • In recognition of the underlying pathogenesis of the disease process, the alternative term surfactant deficiency disorder has been proposed.

Pathogenesis:

  • RDS is caused by surfactant deficiency. Surfactant diminishes surface tension of expanding alveoli. As a result, acinar atelectasis and interstitial edema occur.
  • Hyaline membranes are formed by proteinaceous exudate.
  • Symptoms occur within 2 hours of life.

The incidence of RDS depends on the gestational age at birth:

Birth at Gestational Age (wk) Incidence (%)
27 50
31 16
34 5
36 1

Radiographic Features:

  • 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 chest films.

CXR signs of premature infants:

  • No subcutaneous fat
  • No humeral ossification center
  • Endotracheal tube present

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

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

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

o   Bronchograms are often present.

o   Absence of consolidation or pleural effusions

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

o   Treatment with surfactant may result in asymmetric improvement

Treatment complication of RDS:

  • Persistent PDA : signs of congestive heart failure (CHF):
  • The ductus usually closes within 1 to 2 days after birth in response to the high Po2 content.
  • Air-trapping : PIE & acquired lobar emphysema
  • Diffuse opacities (whiteout) may be due to a variety of causes:
  • Atelectasis
  • Progression of RDS
  • Aspiration
  • Pulmonary hemorrhage
  • CHF
  • Superimposed pneumonia

Pulmonary interstitial emphysema (PIE):

  • PIE refers to àaccumulation of interstitial air in peribronchial & perivascular spaces.
  • Most common cause à +ve-pressure ventilation.

Complications:

  • Pneumothorax
  • Pneumomediastinum
  • Pneumopericardium

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.

Bronchopulmonary dysplasia (BPD)

  • Caused by oxygen toxicity & barotrauma of respiratory therapy.
  • BPD is now uncommon in larger & more mature infants (gestational age > 30 weeks or weighing >1200 g at birth).

Definition of BPD & Diagnostic Criteria:

Diagnostic Criterion Gestational Age < 32 wk Gestational Age > 32 wk
Time point of assessment o   36 wk PMA* or

o   discharge to home, whichever comes first;

o   treatment with >21% oxygen for at least 28 days plus

o   >28 days but <56 days postnatal age or

o   Discharge to home, whichever comes first;

o   Treatment with >21% oxygen for at least 28 days plus

Mild BPD o   Breathing room air at 36 wk PMA or

o   discharge, whichever comes first

o   Breathing room air by 56 days postnatal age or

o   discharge, whichever comes first

Moderate BPD o   Need* for <30% oxygen at 36 wk PMA or

o   discharge, whichever comes first

o   Need* for <30% oxygen at 56 days postnatal age or

o   discharge, whichever comes first

Severe BPD o   Need* for ≥30% oxygen and/or positive pressure (PPV* or nasal CPAP) at 36 wk PMA or

o   discharge, whichever comes first

o   Need* for ≥30% oxygen and/or positive pressure (PPV or nasal CPAP) at 56 days postnatal age or

o   discharge, whichever comes first

*Using a physiologic test (pulse oximetry saturation range) to confirm the oxygen requirement.

  • BPD : bronchopulmonary dysplasia.
  • CPAP: continuous positive airway pressure.
  • PMA : postmenstrual age (gestational age at birth plus chronologic age).
  • PPV : positive-pressure ventilation.
  • There are 4 stages in the development; the progression of BPD àthrough all 4 stages is now rarely seen because of the awareness of this disease entity.
  • Stages of Bronchopulmonary Dysplasia:
Stage Time Pathology Imaging
1 o   < 4 days o   Mucosal necrosis o   Similar to RDS
2 o   1 week o   Necrosis, edema, exudate o   Diffuse opacities
3 o   2 weeks o   Bronchial metaplasia o   Bubbly lungs*
4 o   1 month o   Fibrosis o   Bubbly lungs*

*Bubbly lungs (honeycombing): rounded lucencies surrounded by linear densities; hyperaeration.

Prognosis of Stage 4:

  • Mortality, 40%
  • Minor handicaps, 30%
  • Abnormal pulmonary function tests in almost all in later life
  • Clinically normal by 3 years, 30%

Meconium aspiration syndrome:

  • Meconium (mucus, epithelial cells, bile, debris) à the 1.st stool that is evacuated within 12 hours after delivery.
  • In fetal distress, evacuation may occur into the amniotic fluid (up to 10% of deliveries).
  • However, in only 1% does this aspiration cause respiratory symptoms.
  • Only meconium aspirated to below the vocal cords is clinically significant.
  • Meconium aspiration sometimes clears in 3 to 5 days.
  • CXR nearly always returns to normal by 1 year of age.

Radiographic Features:

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

o   Atelectasis

o   Hyperinflated lungs

o   Pneumothorax, pneumomediastinum, 25%

Complication:

  • Mortality (25%) from persistent fetal circulation

Neonatal pneumonia (NP):

  • Pathogenesis:

Trans-placental infection: ·        TORCH:

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

Perineal flora: ·        Group B streptococci, enterococci, Escherichia coli:

ü Ascending infection

ü Premature rupture of membranes

ü Infection while passing through birth canal

Radiographic Features:

  • Patchy asymmetrical opacities in a term infant represent neonatal pneumonia until proven otherwise.
  • Hyperinflation

Transient tachypnea of the newborn (TTN):

  • TTN (wet lung syndrome) is a clinical diagnosis.
  • It is caused by a delayed resorption of intrauterine pulmonary liquids.
  • Normally, pulmonary fluids are cleared by:

Bronchial squeezing during delivery, 30%

Absorption, 30%: lymphatics, capillaries

Suction, 30%

Causes:

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

Radiographic Features:

o   Fluid over-load àsimilar appearance as non-cardiogenic pulmonary edema.

o   Prominent vascular markings

o   Pleural effusion

o   Fluid in fissure

o   Alveolar edema

o   Lungs clear in 24 48 hours.

Extracorporeal membrane oxygenation (ECMO):

  • Technique of providing prolonged extracorporeal gas exchange.

Indications:

  • Any severe respiratory failure with predicted mortality rates of > 80%.

Exclusion criteria for ECMO include:

  • < 34 weeks of age
  • >10 days of age
  • Serious intracranial hemorrhage
  • Patients who require epinephrine

Complications:

  • Late neurologic sequelae; developmental delay, 50%
  • Intracranial hemorrhage, 10%
  • Pneumothorax, pneumomediastinum
  • Pulmonary hemorrhage (common)
  • Pleural effusions (common)
  • Catheter complications

IMAGING OF PNEUMONIA IN CHILDREN

IMAGING OF PNEUMONIA IN CHILDREN is very important for very doctor to know .

  • Childhood pneumonias are commonly caused by:

– Mycoplasma, 30% àlower in age group < 3 years.

– Viral, 65% àhigher in age group < 3 years)

– Bacterial, 5%

Viral pneumonia:

Causes

  • respiratory syncytial virus (RSV), parainfluenza

Radiographic Patterns of Viral Pneumonia:

Pattern Frequency Description
Bronchiolitis:

Common o   Normal CXR

o   Overaeration is only diagnostic clue

o   Commonly due to RSV

Bronchiolitis+parahilar, peribronchial opacities:

Most Common o   Dirty parahilar regions caused by:

–         Peribronchial cuffing (inflammation)

–         Hilar adenopathy

Bronchiolitis+atelectasis:

Common o   Disordered pattern with:

–         Atelectasis

–         Areas of hyperaeration

–         Parahilar+peribronchial opacities

Reticulonodular interstitial:

Rare o   Interstitial pattern
Hazy lungs:

Rare o   Diffuse increase in density

Pearls:

  • All types of bronchiolitis & bronchitis cause air trapping (over-aeration) with flattening of hemi-diaphragms.
  • RSV, Mycoplasma, & parainfluenza virus : the most common agents that cause radiographic abnormalities (in 10 30% of infected children).
  • Any virus may result in any of the 5 different radiographic patterns.

Bacterial pneumonia:

  • The following 3 pathogens are the most common:

– Pneumococcus (ages 1 to 3)

– Staphylococcus aureus (infancy)

– Haemophilus influenzae (late infancy)

Radiographic Features:

Consolidation: o   Alveolar exudate

o   Segmental consolidation

o   Lobar consolidation

Other findings: o   Effusions

o   Pneumatocele

Complications: o   Pneumothorax

o   Bronchiectasis (reversible)

o   Swyer-James syndrome:

– Acquired pulmonary hypoplasia.

-Radiographically ch.ch by small, hyperlucent lungs + diminished vessels (focal emphysema).

o   Bronchiolitis obliterans

Round Pneumonia:

  • Usually age < 8 years
  • Pneumococcal pneumonia in early consolidative phase
  • Pneumonia appears round because of poorly developed collateral pathways (pores of Kohn & channels of Lambert).
  • With time the initially round pneumonia develops into a more typical consolidation.

Causes of recurrent Infections:

1-    Cystic fibrosis

2-    Recurrent aspirations

3-    Rare causes of recurrent infection:

o   Hypogammaglobulinemia (Bruton disease):  DDx clue : no adenoids or hilar LNs.

o   Hyperimmunoglobulinemia E (Buckley syndrome)

o   Kartagener syndrome.

o   Other immune-deficiencies

o   Bronchopulmonary foregut malformation

 

Aspiration pneumonia:

  • Results from inhalation of swallowed materials or gastric content.
  • Gastric acid damages capillaries causing acute pulmonary edema.
  • 2ry infection or acute respiratory distress syndrome (ARDS) may ensue.

Causes:

aspiration due to :

Swallowing dysfunction:

(most common cause)

o   Anoxic birth injury (common)

o   Coma,

o   Anesthesia.

Obstruction: o   Esophageal atresia or stenosis.

o   Esophageal obstruction.

o   Gastroesophageal reflux (GER),

o   Hiatus hernia.

o   Gastric or duodenal obstruction.

Fistula: o   Tracheoesophageal fistula (TEF)

Radiographic Features:

o   Recurrent pneumonias : distribution:

– Aspiration in supine position: upper lobes, superior segments of lower lobes.

– Aspiration in upright position : both lower lobes

o   Segmental and subsegmental atelectasis

o   Interstitial fibrosis

o   Inflammatory thickening of bronchial walls

Sickle cell anemia:

  • Pulmonary manifestations : are the leading cause of death:
  • Pneumonia, acute chest syndrome, & pulmonary fibrosis.
  • Children with acute chest syndrome may present with one or multiple foci of consolidation, fever, chest pain, or cough.

Causes:

  • Infection (higher incidence).
  • Fat emboli originating from infracting bone.
  • Pulmonary thrombosis.

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

 

Congenital Pulmonary Abnormalities IMAGING

Congenital cystic adenoid malformation IMAGING IS VERY ESSENTIAL

Bronchopulmonary foregut malformation:

  • Arise from a supernumerary lung bud that develops below the normal lung bud.
  • Location and communication with GIT depend on when in embryonic life the bud develops.
  • Most malformations present clinically when they become infected (communication with GIT).

Overview of Bronchopulmonary Malformations:

Malformation Location
Sequestration:

·        Intralobar

Sequestration

 

60% basilar, left

80% left or below diaphragm

Bronchogenic cyst Mediastinum, 85%; lung, 15%
CCAM All lobes
Congenital lobar emphysema LUL, 40%; RML, 35%; RUL, 20%

Pulmonary sequestration:

Clinical Findings:

  • Recurrent infection
  • Lung abscess
  • Bronchiectasis
  • Hemoptysis during childhood.

Pathology:

  • Non-functioning pulmonary tissue ànearly always posteromedial segments of lower lobes.
  • Systemic arterial supply à anomalous arteries from the aorta (less common branch of the celiac artery)
  • No connection to bronchial tree

Types of Pulmonary Sequestration:

                                                          

Feature Intralobar Sequestration Extralobar Sequestration
Age ·        Older children, adults ·        Neonates
Pleura ·        Inside lung (intralobar) ·        Outside lung àextralobar, own pleura)
Forms ·        Airless (consolidation) and air-containing, cystic type ·        Always airless (pleural envelope) unless à communication with GIT
Venous return: ·        Pulmonary vein ·        Systemic: IVC, azygos, portal
Arterial supply: ·        Thoracic aorta > abdominal aorta
Associations: ·        In 10% of patients:

o   Skeletal anomalies, 5%

o   Foregut anomalies, 5%

o   Diaphragmatic anomalies

o   Other rare associations

·        In 65% of patients:

o   Diaphragmatic defect, 20%

o   Pulmonary hypoplasia, 25%

o   Bronchogenic cysts

o   Cardiac anomalies

     

Radiographic Features:

  • Large (>5 cm) mass near diaphragm
  • Air-fluid levels if infected
  • Surrounding pulmonary consolidation
  • Sequestration may communicate with GIT.

Bronchogenic cyst:

  • It Results from the abnormal budding of the tracheobronchial tree. Cysts contain respiratory epithelium.

Location:

  • Mediastinum, 85% àposterior > middle > anterior mediastinum)
  • Lung, 15%

Radiographic Features:

o   Well-defined round mass in subcarinal / parahilar region

o   Pulmonary cysts commonly located in medial 1/3 of lung

o   Initially no communication with tracheobronchial tree

o   Cysts are thin walled.

o   Cysts can be fluid or air filled.

 

 

 

Congenital cystic adenoid malformation (CCAM):

  • CCAM refers to a proliferation of polypoid glandular lung tissue without normal alveolar differentiation.
  • Respiratory distress occurs during first days of life.

Treatment:

surgical resection (sarcomatous degeneration has been described).

Types:

Macrocystic:

(Stocker types 1 & 2)

o   single cyst or multiple cysts > 5 mm confined to one hemi-thorax.

o    Better prognosis.

o    Common.

Microcystic:

(Stocker type 3)

o   Homogeneous echogenic mass without discernible individual cysts.

o   Closely resembles pulmonary sequestration or intrathoracic bowel from a diaphragmatic hernia.

o   Less common.

Radiographic Features:

o   Multiple cystic pulmonary lesions of variable size

o   Air-fluid levels in cysts

o   Variable thickness of cyst wall

 

 

Congenital lobar emphysema:

  • Progressive overdistention of one or more pulmonary lobes but usually not the entire lung.
  • 10% of patients have congenital heart disease àpatent ductus arteriosus [PDA] & ventricular septal defect [VSD].

Causes:

  • Idiopathicà 50%
  • Obstruction of airway with valve mechanismà 50%:
  • Bronchial cartilage deficiency or immaturity
  • Mucus
  • Web, stenosis
  • Extrinsic compression

 

Radiographic Features:

o   Hyperlucent lobe (hallmark)

o   1.st few days of life à alveolar opacification because there is no clearance of lung fluid through bronchi

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

o   Use CT to àdifferentiate from bronchial obstruction

o   Distribution

§  LUL, 40%

§  RML, 35%

§  RUL, 20%

§  2 lobes affected, 5%

 

Pulmonary hypoplasia:

Types of Pulmonary Underdevelopment:

  • Agenesis: Complete absence of one or both lungs (airways, alveoli, & 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)

– A special form of a hypoplastic lung.

– The hypoplastic lung is àperfused from the aorta & drained by the IVC or portal vein.

– The anomalous vein has a resemblance to a Turkish scimitar (sword).

– Associations include:

   1) Accessory diaphragm, diaphragmatic hernia

   2) Bony abnormalitiesà hemivertebrae, rib notching, rib hypoplasia

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

 

 

  • Radiographic Features:
o   Small lung àmost commonly the right lung.

o   Retrosternal soft tissue density à hypoplastic collapsed lung.

o   Anomalous vein resembles a scimitar

o   Systemic arterial supply from aorta

o   Dextroposition of the heart àshift because of hypoplastic lung)

 

Congenital diaphragmatic hernia (CDH):

Incidence:

  • 1 in 2000 to 3000 births.
  • The mortality rate of isolated hernias is 60% (with postnatal surgery) and higher when other abnormalities are present.
  • Respiratory distress occurs in the neonatal period.
  • Associated abnormalities include:

Pulmonary hypoplasia (common)

CNS abnormalities:

Neural tube defects : spina bifida, encephalocele Anencephaly

Types:

Bochdalek’s hernias: Ø 90% of CDH à posterior:

o   75% are on the left, 25% on right

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

o   Contents of hernia:

ü Stomach, 60%.

ü Colon, 55%.

ü Small intestine, 90%.

ü Spleen, 45%.

ü Liver, 50%.

ü Pancreas, 25%.

ü Kidney, 20%.

o   Malrotation of herniated bowel is very common.

Morgagni hernias: Ø 10% of CDH à anterior:

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

o   Most common hernia contents: omentum, colon

o   Accompanying anomalies common

Eventration: o   Due to relative absence of muscle in dome of diaphragm

o   Associated with:

ü Trisomies 13, 18, congenital CMV, rubella arthrogryposis multiplex, pulmonary hypoplasia

  • Radiographic Features:
o   Hemi-diaphragm not visualized

o   Multi-cystic mass in chest

o   Mass effect

 

Kartagener syndrome (immotile cilia syndrome):

  • Due to the deficiency of the dynein arms of cilia causing immotility of respiratory, auditory, & sperm cilia.

Radiographic Features:

o   Complete thoracic & abdominal situs inversus

o   Bronchiectasis

o   Sinus hypoplasia & mucosal thickening

YOU CAN SEE REAL CASE IMAGES AT THIS LINK:

https://radiopaedia.org/articles/congenital-pulmonary-airway-malformation

PEDIATRIC RESPIRATORY TRACT IMAGING

PEDIATRIC RESPIRATORY TRACT IMAGING IS VERY ESSENTIAL AND VERY EASY, IN THE FOLLOWING, WE WILL EXPLAIN IT IN VERY SIMPLE WORDS:

Upper Airway:

Approach:

  • Inspiratory stridor : is the most common indication for radiographic upper airway evaluation.
  • The main role of imaging is to identify conditions that need to be treated emergently & /or surgically (e.g., epiglottitis, foreign bodies).
  • Technique:
  1. Physician capable of emergency airway intervention should accompany child
  2. Obtain 3 films:

– Lateral neck: full inspiration, neck extended

– Anteroposterior (AP) and lateral chest: full inspiration, include upper airway.

 

  1. Fluoroscope the neck if radiographs are suboptimal or equivocal
  2. Primary diagnostic considerations:
  • Infection : epiglottitis, croup, abscess.
  • Foreign body : airway or pharyngo-esophageal.
  • Masses : lymphadenopathy, neoplasms.
  • Congenital abnormalities : webs, malacia
  1. If upper airway is normal, consider:
  • Pulmonary causes : foreign body, bronchiolitis.
  • Mediastinal causes: vascular rings, slings.
  • Congenital heart disease (CHD)

 

Normal appearance:

  • 3 anatomic regions:

– Supra-glottic region

– Glottic region : ventricle & true cords

– Sub-glottic region

  • Epiglottis & aryepiglottic folds are thin structures.
  • Glottic shoulders are seen on AP view.
  • Adenoids are visible at 3 to 6 months after birth.
  • Normal retropharyngeal soft tissue thickness (C1 C4) = three-fourths vertebral body width.

Laryngomalacia:

  • A common cause of stridor in the 1st year of life.
  • Immature laryngeal cartilage leads to supra-glottic collapse during inspiration.
  • Stridor improves with activity & is relieved by prone positioning or neck extension.
  • Self-limited course.
  • Diagnosis is established by fluoroscopy àlaryngeal collapse with inspiration.

Tracheomalacia:

  • Collapse of trachea with expiration.
  • May be focal or diffuse.
  • Focal type is usually Secondary to congenital anomalies that impress on the trachea, such as a vascular ring.

 

Webs:

  • Most common in the larynx.

Tracheal stenosis:

  • Diffuse hypoplasia, 30%
  • Focal ring-like stenosis, 50%
  • Funnel-like stenosis, 20%

Subglottic stenosis:

  • Fixed narrowing at level of cricoid. Failure of laryngeal recanalization in utero.

Epiglottitis:

  • Life-threatening bacterial infection of the upper airway.
  • Most commonly caused by Haemophilus influenzae.
  • Age: 3 to 6 years (older age group than with croup).
  • ttt is with àprophylactic intubation for 24 48 hours & antibiotics.
  • Clinical Findings

Fever

Dysphagia

Drooling

Sore throat

  • Radiographic Features:

Thickened aryepiglottic folds (hallmark)

Key radiographic view: lateral neck

Thickened epiglottis

Subglottic narrowing due to edema, 25%: indistinguishable from croup on AP view

Distention of hypopharynx

  

  • Pearls:
  • Other causes of enlarged epiglottis or aryepiglottic folds:

o   Caustic ingestion

o   Hereditary angioneurotic edema

o   Omega-shaped epiglottis : normal variant with normal aryepiglottic folds.

o   Stevens-Johnson syndrome

Croup:

  • Sub-glottic laryngotracheobronchitis.
  • Most commonly caused by parainfluenza virus.
  • Age: 6 months to 3 years (younger age group than epiglottitis).
  • Clinical Findings:

Barking cough

Upper respiratory tract infection

Self-limited

  • Radiographic Features:

Subglottic narrowing: inverted “V” or “steeple sign”.

Key view: AP view

Lateral view should be obtained to exclude à

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.

 

Retropharyngeal abscess:

  • Typically due to the extension of a suppurative bacterial lymphadenitis, most commonly S. aureus, group B streptococci, oral flora.
  • Age  < 1 year.
  • Other causes include foreign body perforation and trauma.
  • Clinical Findings

Fever

Stiff neck

Dysphagia

Stridor (uncommon)

Most cases present as àcellulitis rather than a true abscess.

  • Radiographic Features:
o   Plain film findings : usually nonspecific.

o   Widened retropharyngeal space : most common finding

o   Air in soft tissues is specific for abscess.

o   Straightened cervical lordosis

o   CT is helpful to define superior & inferior mediastinal extent.

  • Main DDs:

Retropharyngeal hematoma

Neoplasm àe., rhabdomyosarcoma.

Lymphadenopathy

Tonsillar hypertrophy:

  • The tonsils consist of lymphoid tissue that encircles the pharynx.
  • 3 groups:

Pharyngeal tonsil (adenoids).

Palatine tonsil.

Lingual tonsil.

  • Tonsils enlarge secondary to infection and may obstruct nasopharynx & /or eustachian tubes.
  • Rarely, bacterial pharyngitis can lead to àa tonsillar abscess (quinsy abscess), which requires drainage.
  • Specific causes include:

                                      

o   Mononucleosis (Epstein-Barr virus)

o   Coxsackievirus (herpangina, hand-foot-mouth disease)

o   Adenovirus (pharyngoconjunctival fever)

o   Measles prodrome (rubeola)

o   Beta-Hemolytic Streptococcus (quinsy abscess)

  • Radiographic Features:
o   Mass in posterior nasopharynx (enlarged adenoids)

o   Mass near end of uvula (palatine tonsils)

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

 

Airway foreign body (FB):

  • Common cause of respiratory distress.
  • Age à 6 months to 4 years.
  • Acute aspiration results in cough, stridor, wheezing; chronic FB causes à hemoptysis or recurrent pneumonia.
  • Location à right bronchi > left bronchi > larynx, trachea.
  • Radiographic Features:
Bronchial FB: o   Unilateral air tapping causing hyperlucent lung à 90%

o   Expiratory film or lateral decubitus àmakes air trapping more apparent.

o   Atelectasis is uncommon, 10%

o   Only 10% of FBs are radio-opaque.

o   Chest fluoroscopy or CT should be performed if plain film findings are equivocal.

Tracheal FB:

 

o   FB usually àlodges in sagittal plane

o   CXR is usually ànormal.

     

Mediastinum:

Thymus:

  • The ratio of thymus to body weight â with age.
  • Thymus is routinely identified on CXR from birth to 2 years of age.
  • Size & shape of the thymus are highly variable from person to person.

Common mediastinal tumors:

Anterior: o   Thymic hyperplasia & thymic variations in shape & size (most common)

o   Teratoma

o   T-cell lymphoma

o   Cystic hygroma

o   Thymomas are extremely rare.

Middle: o   Adenopathy (leukemia, lymphoma, TB)

o   Bronchopulmonary foregut malformation

Posterior: o   Neuroblastoma

o   Ganglioneuroma

o   Neurofibromatosis

o   Neurenteric cysts

o   Meningoceles

Pearls:

  • Any pediatric anterior mediastinal mass is considered thymus until proven otherwise.
  • Posterior mediastinal masses are the most common abnormal chest masses in infants

If you want to view Real Case Imaging of each disease , this link will be very helpful :

https://radiopaedia.org/playlists/6642

 

 

PEDIATRIC PERTH’S DISEASE

Introduction.

Legg-Calvé Perth’s Disease or in another word Avascular necrosis of epiphysis of the proximal femoral head, Osteochondritis coxae juveniles coxa plana is osteochondrosis due to AVN of the capital femoral epiphysis.

Also called idiopathic osteonecrosis of the capital femoral epiphysis, is a famous form of epiphyseal osteonecrosis. Children are often susceptible to the disease due to the improper calcification rate that occurs in the skeletal tissue. It is fundamental to mention that the condition may result in the manifestation of symptoms such as lower limb pain, immobility, and swelling (1).

It is, hence, the role of the radiographer and medical practitioner to ensure the proper management of the disease as a way of reducing future onset complications. there are peculiarities that distinguish Perth disease that happens in skeletons that get growing from avascular necrosis that occurs in the adult femoral head.

LCP is a classic an illustrative example of the clinical course and prognosis related to epiphyseal osteonecrosis at the femoral head (2). This illustration necessitates the need for the utilization of supportive management as an adjunct for treatment of the disease.

Pathophysiology:

Pathology occurs through four distinct stages. The first stage incorporates the process of ischemia which occurs at the femoral caput. Injury or disease may provoke ischemia in the femoral region. Often, trauma may cause the occlusion of the vessels nourishing the region around the femoral caput.

Ischemia abolishes the blood supply running to the femoral caput. The tissue cells lack nutrients for survival. Alternatively, accumulation of metabolic wastes occurs at the region of the affected bone. It is relevant to point out that ischemia precedes the process of osteonecrosis occurring at the femoral caput.

Additionally, the first component of the pathology includes the process of tissue death occurring at the bone region next to the femoral caput. It is relevant to mention that the osteonecrosis activity commences at this region resulting in the advancement of the disease condition (3). The second part of the pathological process involves the resorption and repair of the bone at the affected anatomical region.

It is crucial to mention that the diseased tissue incites a pathological process which results in the resorption of damaged cells. The process of resorption coincides with the fragmentation activity occurring at the skeletal bone of the femur caput. Accordingly, the fragmentation aids the tissue to undergo a new process of vascularization. As mentioned earlier, ischemia usually precedes the entire process of necrosis.

Thus, the activity of re-vascularization usually results in the development of vessels on the repaired tissue. It is worth noting that revascularization coincides with the activity of repair. The bone tissue starts undergoing a process of repair which results in the build-up and formation of new cells and tissues (4).

The bone undergoes a whole reformation and transition activity which leads to the development of repaired bone and tissue after osteonecrosis. The third stage of the pathological process incorporates the entire activity of re-ossification. This stage principally involves the overactivity of osteoblasts and the inhibition of the osteoclasts. Based on this principle, the epiphyseal plate undergoes a major re-ossification process resulting in the formation of a bony prominence around the femoral neck.

This activity may result in the obstruction of the vascular supply at the femoral bony region (5). It is worth mentioning that the fourth stage of the pathological process incorporates the remodeling phase of the femoral bone. At this stage, the femoral head may undergo the process of flattening and collapse. It is thus, critical for the radiographer to make proper adjustments to avoid this complication.

The last stage of LCPD start after the head is fully re-ossified and so remodeling still happening till the child reaches maturity and the disease damage the epiphysis of the head of the femur and cause increase size of the trochanter and shortening of the neck what’s called coxa breva. short neck 6

Incidence and Associations:

Perth disease has a Male and White prominence, it’s the Age of four to eight years that is preferable for that disease. Its bilateral incidence is low (2). and when it occurs bilaterally it’s usually asynchronous (7). The incongruity of joint cause premature degeneration in 2nd or 3rd decades of life (7).

Aetiology:

The main cause of Perth’s disease is the decrease of blood reaching to the epiphysis of the capital and the physics play a role as an avascular barrier Infarction which causes fracture of the trabecula and results in reducing the epiphyseal height (7).

     There is no definite known cause of that avascular necrosis even the genetic proved to not have a direct relation to it. Although few studies have referred to some sort of relation between Perth’s disease and some other disease like ADHD (Attention Deficit Hyperactivity Disorder) and some congenital anomalies like Undescended Testis (8).

Clinical Features and Examinations:

Clinical presentation of the child varies according to his Age, but usually, the child comes with joint pain and Limb that are increased by doing physical activity, on examination, we notice that the abduction is limited abduction as well as the hip internal rotation (9). and referred knee pain which leads to Limb (7). Muscle spasm, thigh & buttocks Atrophy, otherwise the child has no abnormality (2).

Important of Early Diagnosis:

When we talk about the prognosis of this disease. there’s a role (The younger Age is the better Prognosis and the smaller necrosis, the better prognosis) (7).  That’s Why Early Diagnosis is important as Children < 6 years have a good course and prognosis, while children > 8 years have a worse prognosis and may require surgery (10).

 

Differential Diagnosis:

Perth’s Disease is a disease of differential diagnosis, in the following, we are going to the numerate differential diagnosis of Perth’s disease and what characterizes it.

First, we will talk about Septic Arthritis that characterized by acute onset of fever, increase WBCs. We can differentiate it from Perth’s as in septic Arthritis the Hips are held in flexion, abduction, and external rotation, while in Perth’s the hip is adducted. there is also Joint effusion and joint debris and may be marrow edema. (7).

Secondly, we will talk about Juvenile Osteonecrosis, which is Avascular necrosis due to known cause as Sickle cell anemia, steroids, Gaucher, after hip dislocation. (7).

Epiphyseal Dysplasia is another important disease that can be divided into multifocal which have Spondylo-epiphyseal and multiple epiphyseal dysplasia. And Limited to hips in Meyer dysplasia. (7).

Toxic Synovitis is another important disease which is Self-limiting acute synovitis. while steroid Osteoma characterizes by local nigh pain which decreases by NSAID (7).

Investigations: (modalities):

Due to this assertion, radiographers have been at the forefront of the management of Perth’s disease. The principal imaging methods include the utilization of the plain radiograph, MRI, and arthrography as imaging interventions of the disease.

CT scans are good another method critical in the assessment of Perth’s disease, MR is helpful for early changes of acute infarction or revascularization late MR better delineates the extent of involvement (7). in the following part, we will talk about the imaging modalities.

1- Plain Radiograph.

A plain radiograph of the pelvis is the most common procedure involved as part of the diagnosis of the disease condition and the imaging technique of choice among many radiographers.

The radiograph is, moreover, capable of identifying the various stages involved in the disease development of Perth’s disease.

Positions that used to diagnose LCPD involve the following: First Ant-Post position erect (weight bearing) in which the child stands with its pelvis lie posterior to the cassette as shown in the figure(4) below12, the other important position is Lateral both hips with frog projection in which the child lies supine on the table and a cassette is put under him, the medial sagittal plane of the child trunk is at rt angle to cassette midline as shown below in figure (5) .12  .

Perth’s disease typically involves the necrosis of the epiphyseal plate of the femur bone. Based on this concept, the early stages may incorporate the restriction of the epiphyseal plate and progressive accumulation of inflammatory fluid between the joints.

The radiographer is able to use the plain radiograph to detect these changes and stage the Perth’s disease as an early onset condition.

The late onset usually manifests through the remodeling and reshaping of the femur head. The plain radiograph is very critical in the late onset stages of the disease due to its ability to portray the various anatomical changes (13). This illustration is critical during the radiographic analysis because of its role in the identification of late-onset Perth’s disease.

The patient usually lies in a supine position during imaging of the pelvis remove it. For instance, the Caterall classification method is an illustration of a method that portrays the various changes in the bone (14).

Stage 1 usually indicates the diverse histological changes at the bone while stage 4 indicates the loss of structural bonds in the comprehensive acetabulum bone. One of the weaknesses of this method incorporates its lack of sensitivity during the early stages of the disease

Figure 1: show Radiographs of right hip show decrease the height of epiphysis of the femoral head and its sclerosis, and subchondral fracture 7

Figure 2:  Showing a plain radiograph of Perth’s Disease, Early Stage- Widening of the Joint of Hip, note the sclerosis of the head of Femur  (2).

 

 

 

Figure 3: Right-sided images is lateral Frog leg position view of 6-years old child with rt hip pain show the rt femoral head is seen sclerosed and flattened with some fragments, indicate avascular necrosis. the left side image of the same lateral frog leg position but only of rt hip which has a subcortical fracture of head of the femur.15

 

Figure 4: show A-P erect weight-bearing position adjustment of a child with Perth's disease, not the Ant.Sup iliac spine is at the same distance from the cassette and median sagittal plane. Gonadal protection must be done .12

Figure 5: show Child adjusted to take lateral both hip with frog projection x-ray view, note that the cassette must include both hips and centered at level of femoral pulse, window protection is applied 12

 

2- MRI

Fundamentally, MRI is a procedure preferred by certain radiographers due to its defined merits over the utilization of plain radiographs. It is fundamental to mention that MRIs utilize electromagnetic waves to depict images of the inner soft tissues.

Hence, it is capable of producing high-quality images that portray how Perth’s disease has resulted in the damage of femoral caput and adjacent bone (16). MRI images have more precision and clarity. In fact, in many cases, radiographers are capable of visualizing the abnormalities around the caput region using the MRI technique that isn’t visible on the plain radiographs.

Alternatively, the radiographers are able to choose between the T1 and T2 images so as to visualize the affected bone more precisely and visible. MRI imaging techniques are more elemental in Perth’s disease when it comes to the early diagnosis of Perth’s disease. The technique has a higher sensitivity rating compared to the plain radiograph (17).

MRI imaging is highly safe compared to other technique because it lacks radiation effects. Arthroscopy is another adjunct for the diagnosis and examination of Perth’s disease in the pediatric patient.

Critically, arthroscopy is an invasive technique that uses the idea of contrast media to visualize the affected anatomical regions (18).

This illustration elaborates why the procedure is very important when identifying the abnormalities brought about by the disease condition. Congruence, for instance, refers to the abnormality caused by the disease on the femoral head.

figure 6: T1-WI, post-contrast fat saturation show; the ossific nucleus of the Lt proximal head is not enhanced ( the white arrowheads), which indicate its necrosis.on the other side the hyper-enhanced region that surrounds the Lt femoral neck and head (black arrowheads) and the lateral portion of femoral head (arrow) indicate synovitis (10).

Figure 7: This Sagittal 2D T1-WI post-contrast fat saturated image shows the ossific nucleus of Rt proximal femoral head has centra necrosis, while the post and Ant femoral head is spared. This image of seven years old child complaining of rt hip pain (10).

Figure 8: Rt Image is Coronal STIR MR sequence show hyper-intense signal of Rt hip joint (white arrowheads) and rt sub-chondral epiphyses of the right proximal femoral head(black arrowhead).The Left Image is T1 WI coronal spin-echo MR sequence show hypo-intense signal of same rt femoral head (black arrowhead).. these findings of thirteen years old male child indicate Rt hip sub-chondral fracture (10)

3- Fluoroscopy (Arthrography).

The use of arthrography is an illustration of another imaging method which is fundamental in the assessment of Perth’s disease (19).

Arthrography of the pelvis, often, incorporates the utilization of fluoroscopy as an adjunct towards proper imaging. It is essential to note that arthrography involves the use of a contrast media that create distinct zones of the tissues, hence, increasing the rate of visibility (20).

But nowadays he loses his role to conventional MR as it makes a good job in the good assessment of congruity and contamination and assessment of prognosis with the need to get the risk of irradiation and intra-articular injection and risks of anesthesia.21Arthrography of the pelvis is capable of eliciting the congruence of the acetabulum in relation with the femoral caput.

This feature makes it a critical imaging technique for radiographers when assessing the impact of Perth’s disease on the mobility component of the patient.

4- CT Scan.

The CT scan is another fundamental imaging technique that visualizes the sclerosis patterns in the affected bone tissues. It is capable of detecting the earliest pathologic signs of Perth’s disease in patients. It utilizes multiple rays to visualize the changes occurring in the bone tissue. However, one significant limitation of the utilization of the CT scan is its radiation effect (22).

CT scans are capable of causing radiation damage to pediatric patients. Therefore, many radiographers avoid this method due to its potentially harmful effects on the internal organs.

Figure 9: these CT images which are oblique reformatted with the reconstruction of sixty-two years-old patient which have a late phase of Rt LCPD. The femoral head has lost its spherical shape,  give appearance of “mushroom”, there is also shortening and  broadening of neck of femur .there are also 2ndrys osteoarthritis and Acetabular remodeling 7

Staging:

There are multiple ways to do staging of Perth’s disease, one important is Catterall classification: Based on the extent of epiphyseal involvement while Salter-Thompson scheme: Based on extent and location of the subchondral fracture. Herring system: Based on lateral pillar (LP, lateral 1/3 of the femoral head) involvement (7).

 The Most reliable, reproducible that based on X-ray Imaging as following:

stage I: the early one, it’s asymmetric size of femoral epiphysis. and increase the density of epiphysis of the femoral head. And medial joint space Widening with the blurring of the physical plate. radiolucency of the proximal metaphysis (23).

stage II: fragmentation. subchondral lucency (crescent sign) with fragments of the femoral epiphysis with thickened trabeculae (23).

stage III: it’s called reparative in which begins the re-ossification and the femoral head shape become better. And enhance bone density (23).

stage IV: is the healed stage in which femoral head changes occur according to the severity. Some changes may occur like superior articular surface flattening femur head and neck widening (23).

 

Treatment:

Radiographers and orthopedic surgeons both agree to the fact that the goals of treatment of the disease condition include the elimination of hip irritability and the gaining of proper hip mobility.

Other goals include the attainment of a spherical femoral head and the prevention of epiphyseal collapse. This fact makes it critical for the health practitioner to make proper adjustments to the affected limb (24).

The use of the broomstick plaster is an illustration of an essential medical equipment that keeps the femur abducted and internally rotated. Moreover, other practitioners use the Scottish Rite brace to ensure that the limb is in the proper position.

Surgical therapy normally involves the use of femoral osteotomy as a form of therapy to ensure that the femoral head is in a proper position. Surgical techniques have indicated higher rates of prognosis compared to the non-surgical techniques.

To achieve these goals, most physicians say that contamination principles must be applied which based on that if the femoral head is fragmented and so not in hard condition, so the best is that it remains in the acetabulum in which it protects it, till it regenerates. 6

To begin contamination, the first step is to limit movement and protect weight-bearing. then nonsurgical options by Petria cast to make the head of the femur abducted and directed deep in the acetabulum. 6 the Surgical option of containment is as proximal femur osteotomy .6 After finishing the healing process, surgery is done to adjust the residual deformity.6

 

Complications:

Perth’s disease children have a risk of hip arthritis after being an adult, this occurs especially if healing occurs in an abnormal shape and the bones of the hip are not a perfect fit. So, the joint is liable to early wear and tear and surgery of replacement surgery is needed.25

 

Rehabilitation:

After Perth’s Surgery the physiotherapy is helpful in returning the patient previous healthy state as quickly as possible. As it assists in avoiding lower limb or back compensatory problems so he/she can restore the motion and strength as soon as possible.26

 

Conclusion:

Conclusively, radiographers utilize various methods to indicate the severity and progression of the condition in the pediatric child. Accordingly, radiographers are capable of assessing the stages of the Perth’s disease in the patient. Medical knowledge indicates that imaging usually serves an important step towards the process of diagnosis and disease assessment. Additionally, it provides an incentive to the radiographer regarding the management of the condition.

 

 

 

 

References:

 

  1. Saran N, Varghese R, Mulpuri K. Do femoral or salter innominate osteotomies improve femoral head sphericity in Legg-Calvé-Perthes disease? A meta-analysis. Clinical Orthopaedics and Related Research®. 2012;470(9):2383-93.
  2. Coley BD. Caffey’s Pediatric Diagnostic Imaging E-Book: Elsevier Health Sciences; 2013.
  3. Freeman CR, Jones K, Byrd JT. Hip arthroscopy for Legg-Calve-Perthes disease: minimum 2-year follow-up. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2013;29(4):666-74.
  4. Albers CE, Steppacher SD, Ganz R, Siebenrock KA, Tannast M. Joint-preserving surgery improves pain, the range of motion, and abductor strength after Legg-Calvé-Perthes disease. Clinical Orthopaedics and Related Research®. 2012;470(9):2450-61.
  5. Larson AN, Sucato DJ, Herring JA, Adolfsen SE, Kelly DM, Martus JE, et al. A prospective multicenter study of Legg-Calvé-Perthes disease: functional and radiographic outcomes of nonoperative treatment at a mean follow-up of twenty years. JBJS. 2012;94(7):584-92.
  6. Kliegman, R. and Nelson, W. (2016). Nelson textbook of pediatrics. Philadelphia: Elsevier Saunders.Volume II. Neuromuscular Disorders.
  7. Donnelly LF. Diagnostic imaging: pediatrics: Amirsys Incorporated; 2005.
  8. What causes it? About Perthes Disease, published by The official site of Perth study group available at http://www.perthesdisease.org/perthes-disease-about.
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  13. Maranho DAC, Nogueira-Barbosa MH, Zamarioli A, Volpon JB. MRI abnormalities of the acetabular labrum and articular cartilage are common in healed Legg-Calvé-Perthes disease with residual deformities of the hip. JBJS. 2013;95(3):256-65.
  14. Hosalkar H, Da Cunha ALM, Baldwin K, Ziebarth K, Wenger DR. Triple innominate osteotomy for Legg-Calve-Perthes disease in children: does the lateral coverage change with time? Clinical Orthopaedics and Related Research®. 2012;470(9):2402-10.
  15. Daldrup-Link, H. and Gooding, C. (2010). Essentials of pediatric radiology. Cambridge: Cambridge University Press. 2010 ISBN-13 978-0-511-78965-6.Chapter 5.
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  17. Millis MB, Lewis CL, Schoenecker PL, Clohisy JC. Legg‐Calvé‐Perthes Disease and Slipped Capital Femoral Epiphysis: Major Developmental Causes of Femoroacetabular Impingement. Journal of the American Academy of Orthopaedic Surgeons. 2013;21: S59-S63.
  18. Cook PC. Transient synovitis, septic hip, and Legg-Calvé-Perthes disease: an approach to the correct diagnosis. Pediatric Clinics of North America. 2014;61(6):1109-18.
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  20. Shah H, Siddesh N, Pai H, Tercier S, Joseph B. Quantitative measures for evaluating the radiographic outcome of Legg-Calvé-Perthes disease. JBJS. 2013;95(4):354-61.
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  25. Kim, H. (2009). Legg–Calve–Perthes disease and AVN. Bone, 45, pp.S47-S48.
  26. Felicio RL, Barros ARSB, Volpon JB (2005) Physiotherapy approach in children with Legg- Calve of disease – Perthes undergoing installation of artrodistrator : a case study. Rev FisioterPesq 12:37-42.