Ultrasound in Pediatric Emergencies

Gaurav Saigal, MD, Jennifer Runco Therrien, MD, and Frank Kuo, BS


Appl Radiol. 2014;43(8) 

In This Article

Cranial Pathology

In a young infant (with an open anterior fontanelle), presenting to the ER with an enlarging head circumference, cranial US can be used not only to rule out a parenchymal abnormality (hemorrhage, hydrocephalus, tumor, etc.) but also to differentiate benign enlargement of subarachnoid spaces (BESS) from subdural collections, particularly hematomas. BESS refers to excessive CSF accumulation in the subarachnoid spaces (particularly in the frontal regions) in infants.[34] The exact cause is unknown, but arachnoid villi immaturity has been hypothesized as one of the probable causes.[35] Identifying subdural hematomas as the cause of extra-axial collections is particularly important in the setting of non-accidental trauma. Doppler imaging is extremely useful in differentiating BESS from subdural hematoma (Figure 16).[36] In BESS, multiple vessels can be seen traversing the extra-axial collections, which helps in localizing collections to the subarachnoid space. Collections in the subdural space, on the other hand, displace vessels towards the surface of the brain.

Figure 16.

Child presenting with enlarging head circumference. Coronal US image (A) demonstrates isoechoic prominence of the extra-axial spaces bilaterally (short white arrows). Oblique color Doppler images towards the prominent spaces (B, C) demonstrate the vessels (long white arrows) displaced towards the cortical surface bilaterally, suggesting that the collections are not benign extra-axial fluid (subarachnoid spaces), but are subdural in location. A CT scan (not shown) demonstrated chronic subdural hematomas bilaterally. Coronal image (D) in a different patient with prominent CSF spaces demonstrates vessels traversing the spaces (black arrows), suggesting subarachnoid CSF accumulation as a cause of the widening of the CSF spaces.