Neonatal X-Ray Interpretation Smeeta Sardesai, MD, MS Ed. Associate - PowerPoint PPT Presentation

Neonatal X-Ray Interpretation Smeeta Sardesai, MD, MS Ed. Associate Professor of Pediatrics Keck School of Medicine University of Southern California University of Southern California Los Angeles

Why X-Rays are Done? • X-rays are ordered: – To assess symptoms of conditions related to the heart or lungs – To check the position of – To check the position of internal devices such as central venous catheters or ETT – To correlate with physical findings

Assessment of the Quality of the Neonatal Chest X-Ray • Radiographs of the newborn chest must be of a high quality for accurate interpretation • The clinician evaluating the newborn chest film must be able to evaluate rotation, presence of artifacts, technique used, and be able to make an accurate diagnosis • Knowledgeable (Eyes cannot see what the mind doesn’t know)

Assessment of the Quality of the Neonatal Chest X-Ray: Normal Findings • Visualization of dorsal intervertebral spaces through the cardiac • Visualization of dorsal intervertebral spaces through the cardiac silhouette (film density) • Chest with trapezoid morphology • Ribs horizontally disposed and parallel to each other • Cardiophrenic sinuses well delineated • Anterior arch of the sixth rib is projected over the diaphragm • Caudal inclination of anterior costal arcs (adequate centralization) • Symmetry of bone structures on both sides of the thoracic cage (correct positioning of the neonate) • Supraclavicular fossas and superior hemiabdomen included

• Quality is essential for accurate evaluation – Position – Rotation – Artifact – Penetration/exposure – Penetration/exposure Poor Quality Good Quality

Position Normal Normal • There should be symmetry between the hemithoraces • The spine should lie in the middle of the chest, bisecting the lung fields – ability to make relative comparisons • Rotation causes skewed lung fields and possible misdiagnosis • Difficult to evaluate ETT and/or line position

Rotation Rotation to the right Normal Rotation to the Left • Rotation to the left • Rotation to the makes the heart look right makes the large and can make heart appear central the right heart border disappear

Artifacts Artifacts need to be recognized so that they are not mistaken for pathology Skin fold at left To differentiate “skin fold” from air leak, trace the outline of the lucency; if it crosses diaphragm or upwards into the neck, it is a skin fold. Artifact related to projection of neonatal incubator access port

Penetration/Exposure Exposure differences in chest x-rays for two different infants Underexposed Overexposed • The overall appearance is very • The details of the lung fields white are lost • The details of the lung fields are • The ribs and vertebral bodies exaggerated due to the exposure are very distinct • The vertebral bodies are not clearly • The soft tissue is not as defined apparent • The soft tissues very apparent

Assessment of Inspiratory Effort Supine inspiratory CXR Supine expiratory CXR Normal • Methods used by practitioners to assess the degree of inspiration: • Methods used by practitioners to assess the degree of inspiration: • Number of ribs above the diaphragm: • Diaphragm at or below the eighth rib- normal • Contour of the diaphragm: • Over inflation: overly flattened diaphragms • Under inflation: rounded diaphragms bulging into the lung fields • Position of the stomach bubble: • Should be located below the edge of the left diaphragm

Normal Findings • Radiographically, the thymus is characterized by widening of the upper mediastinum, above the cardiac image • On the frontal view, the normal width of the thymic image must be higher than the double width of the third thoracic vertebra, shorter dimensions representing a sign of thymic involution. involution.

X-Ray Characteristics of Thymus Thymic configuration may mimic disease and some signs are useful to identify its normal appearance In the Spinnaker sail sign , the lobes of the thymus are laterally displaced from mediastinum indicating pneumomediastinum Spinnaker sail sign Spinnaker sail sign

Assessment of Tubes Endotracheal Tube • The tip of Endotracheal tube should be in the trachea approximately midway between the interclavicular line and the carina. (with baby's head midline).

Endotracheal Tube Misplacement The most common malpositioning is Right mainstem bronchus intubation with in the right mainstem bronchus atelectasis of the entire left lung. atelectasis of the entire left lung. Complete collapse of left lung and Rt upper lobe with bronchus intermedius intubation Endotracheal tube is positioned in the esophagus

Assessment of Catheters Umbilical catheters Optimal levels Umbilical venous catheter: • At the level of D9 (ICV) • An intracardiac placement may cause arrhythmias • and even death in case of atrial wall perforation and cardiac tamponade. and cardiac tamponade. Umbilical arterial catheter: • At the level of D6 (D5-D9) or L3-L5 • It's important to avoid the origin of main arterial vessels: • • D12 (level of celiac trunk). • D12-L1 (level of the superior mesenteric artery, SMA). • L1-L2 (level of renal arteries). • L3 (inferior mesenteric artery, IMA). • L4 (aorto-iliac bifurcation)

Anomalous Position of UVC

Complications Associated With Catheters Catheters inside an artery or into the portal vein may cause thrombosis or portal cavernomatosis Other complications include hepatic necrosis, hepatic fluid collections, and hematoma, with the intraparenchymal liver lesions • Malpositioned catheter should be removed immediately

Anomalous Positions of UAC

Umbilical Catheter Complication

Chest Tube

Thoracostomy Tubes Complications Thirteen-year-old girl with bilateral breast deformity after multiple pneumothoraces as a neonate and treatment with chest tubes Pediatrics 2003;111;80-86

Orogastric Tube

Respiratory Distress Syndrome (RDS) Classic RDS: thorax is Bell-shaped due to • generalized under-aeration, lung parenchyma has a fine granular pattern, and air bronchograms that extend to the periphery Moderately severe RDS: reticulogranular Moderately severe RDS: reticulogranular • • pattern is more prominent and uniformly distributed than usual. The lungs are hypo- aerated with increased air bronchograms Severe RDS: beside the reticulogranular • opacities and air bronchograms there is total obscuration of the cardiac silhouette

Respiratory Problems in Neonates • TTN: hyperinflated lungs with retained fluid within the alveoli, interstitium and right fissure, as well as increased perihilar interstitial markings • Imaging findings of TTN typically improve within 24 hours MAS : pulmonary hyperinflation secondary to MAS : pulmonary hyperinflation secondary to TTN TTN the ball-valve mechanism of air trapping. Air trapping results in pneumothorax, pneumomediastinum & pulmonary interstitial emphysema. Other findings include perihilar ropey opacities and interspersed areas of atelectasis

Neonatal Pneumonia • Radiographic presentation of neonatal pneumonia is frequently nonspecific • Diffuse reticulonodular densities similar to RDS or patchy, asymmetric infiltrates with hyperaeration • Small pleural effusion will be present in 2/3 of pneumonia (uncommon in RDS) pneumonia (uncommon in RDS) X-rays should be interpreted with full reference to the clinical scenario