Subdural collections in the neonatal ICU: Assessment using high frequency sonography.

Area of Science:

• Neonatal imaging
• Pediatric neurology
• Medical ultrasound technology

Background:

• Subdural collections (SDC) in neonates are often misdiagnosed as birth-related subdural hematomas on CT and MRI.
• High-frequency linear ultrasound (US) transducers have increased the detection frequency of SDC in neonatal intensive care unit (NICU) populations.

Purpose of the Study:

• To determine the prevalence of SDC detected by US in a NICU population.
• To assess the impact of US transducer frequency on SDC detection.

Main Methods:

• A retrospective review of head US exams in a NICU from August 2020 to March 2021.
• Scans were performed using the anterior fontanelle approach with specific cine clip criteria for full and superficial brain fields of view.
• Assessment included SDC presence and echogenicity relative to subarachnoid fluid, utilizing linear transducers of 2-9 MHz and 6-24 MHz.

Main Results:

• 142 US exams met inclusion criteria, identifying SDC in 10 patients (15 studies).
• SDC were exclusively detected on superficial field-of-view clips using the 6-24 MHz transducer; all identified SDC were anechoic.
• Lower gestational age (median 31.3 weeks) and thrombocytopenia were associated with SDC detection.

Conclusions:

• Small, anechoic subdural collections are visualized via head US in NICU patients.
• Detection of these SDC is critically dependent on using very high-frequency linear transducers with a small field of view.