Neonatal Imaging

Neonatal CXR - Breathing Pixels

Key CXR Interpretations:

• RDS (HMD): Premature; surfactant deficiency. Fine granular (ground-glass) opacities, air bronchograms, low lung volumes (↓volumes).
• TTN: Term/late preterm; delayed fluid clearance. Perihilar streaking, fissural fluid, increased lung volumes (↑volumes). Clears 24-72h.
• MAS: Term/post-term; meconium aspiration. Coarse, patchy infiltrates, hyperinflation. High risk of air leaks.
• Neonatal Pneumonia: GBS/E.coli; infection. Asymmetric patchy infiltrates, consolidation, pleural effusion. Can mimic RDS.
• Pneumothorax: Air in pleural space. Lucency, absent markings, visceral pleural line. Deep sulcus sign (supine).

Line Positions (Verify!):

• ETT: Tip 1-2 cm above carina (T2-T3).
• UVC: IVC-RA junction (T8-T9).
• UAC: High (T6-T9) or Low (L3-L4).

⭐ Sail sign (normal thymus) in neonatal CXR, not consolidation.

Neonatal Abdomen - Gut Reactions

• Necrotizing Enterocolitis (NEC):
  • X-ray: Pneumatosis intestinalis (hallmark), portal venous gas (ominous), pneumoperitoneum (perforation: Rigler"s, football signs).
  • Bell"s Staging (I-III).
• Congenital Obstructions:
  • Duodenal Atresia: "Double bubble" sign (X-ray); no distal gas if complete.
  • Jejunal/Ileal Atresia: Multiple dilated loops; microcolon (contrast enema).
  • Malrotation ± Volvulus: UGI: abnormal DJ flexure, "corkscrew" duodenum. USG: "whirlpool" sign.
  • Hirschsprung Disease: Delayed meconium (>24-48h). Contrast enema: transition zone, rectosigmoid ratio <1.
  • Meconium Ileus: X-ray: "soap bubble" (Neuhauser), dilated loops. Enema: microcolon. Assoc. CF.

⭐ Portal venous gas in suspected NEC is ominous, indicating bowel necrosis and possible perforation.

Neonatal Neurosonography - Brainy Beams

• Role: First-line neuroimaging in neonates, especially preterm.
• Indications: Prematurity (<32 wks, <1500g), HIE, seizures, infection, hydrocephalus.
• Views: Standard coronal & sagittal via anterior fontanelle.
  • Optional: posterior fontanelle, mastoid.
• Pathologies Detected:
  • Intraventricular Hemorrhage (IVH): Papile Grading:
    • I: Germinal matrix (GMH).
    • II: IVH, no ventricular dilatation.
    • III: IVH + ventricular dilatation.
    • IV: IVH + intraparenchymal hemorrhage.
  • Periventricular Leukomalacia (PVL): Early echogenicity → cysts.
  • Hydrocephalus: ↑Ventricular size.
• Pros: Bedside, radiation-free, real-time, repeatable.

⭐ The germinal matrix, highly vascular and fragile, is the primary site of hemorrhage in preterm infants, typically before 32-34 weeks gestation.

Lines & Tubes - Placement Puzzles

• Endotracheal Tube (ETT):
  • Ideal: Tip 1-2 cm above carina; mid-trachea (T2-T4).
  • Malpositions: R main bronchus, esophagus.
  • Note: Neck flexion (↓ tip), extension (↑ tip).
• Umbilical Venous Catheter (UVC):
  • Ideal: Tip at cavo-atrial junction (T8-T9).
  • Path: Umbilical v. → L portal v. → ductus venosus → IVC.
  • Malpositions: Portal vein (liver damage), RA (arrhythmia).

  ⭐ UVC tip ideally at the junction of IVC and right atrium (T8-T9 vertebral level).

• Umbilical Arterial Catheter (UAC):
  • Ideal High: T6-T9 (avoids major branches). Low: L3-L4.
  • Path: Umbilical a. → internal iliac a. → aorta.
  • Malpositions: Too low/high, incorrect vessel.
• Nasogastric/Orogastric Tube (NGT/OGT):
  • Ideal: Tip in stomach, below GE junction.
  • Malpositions: Esophagus, coiled, tracheobronchial tree.
• Chest Tube (ICD):
  • Pneumothorax: Apical. Effusion: Basal.
  • All side holes within pleural space.
• PICC Line:
  • Ideal: Tip lower SVC / cavo-atrial junction.
  • Malpositions: Internal Jugular Vein (IJV), Right Atrium (RA).

High‑Yield Points - ⚡ Biggest Takeaways

• RDS: Characterized by diffuse ground-glass opacities, air bronchograms, and low lung volumes.
• TTN: Presents with perihilar streaking, fluid in fissures, and hyperaeration; resolves in 24-72 hours.
• MAS: Shows coarse, patchy infiltrates, hyperinflation, and increased risk of pneumothorax.
• NEC: Pneumatosis intestinalis is pathognomonic; look for portal venous gas or free air (perforation).
• CDH: Bowel loops in chest, mediastinal shift; Bochdalek hernia (left posterior) is most common.
• Duodenal Atresia: Exhibits the classic "double bubble" sign on X-ray; strongly associated with Trisomy 21.