Added Value of Microvascular Imaging for the Diagnosis and Monitoring of Strokes in Newborns and Infants

Background: Neonatal/infantile stroke is a catastrophic condition associated with significant mortality and morbidity. Magnetic resonance imaging (MRI) remains the preferred modality for detecting ischemic stroke but has procedural limitations. Microvascular imaging (MVI) ultrasound (US) allows accurate visualization of the microvasculature. We assessed the added value of MVI to improve the detection of stroke diagnosis in neonates and infants. Methods: We retrospectively identified patients younger than one year who underwent brain US with MVI for suspected or confirmed stroke between January 2020 and June 2023. All patients had confirmed strokes on US and/or subsequent computed tomography or MRI. A pediatric radiologist (reader 1), a neuroradiologist (reader 2), and a pediatric radiology fellow (reader 3), unaware of the results, individually evaluated the US images to detect strokes. We used the McNemar test to determine the difference in responses before and after MVI. Results: Our cohort had 11 infants, nine boys and two girls (median age 61 days [13.5 to 145.5]). The three readers performed significantly better at stroke diagnosis with MVI (29 correct of 33) compared with grayscale US alone (13 of 33) (P < 0.001). Reader 1 improved from seven of 11 correct diagnoses to 11 of 11 (P = 0.045), reader 2 improved from five of 11 to 10 of 11 (P = 0.025), and reader 3 improved from one of 11 to eight of 11 (P < 0.001). Conclusions: Our preliminary findings suggest that MVI has potential as a complementary tool to standard brain US protocols for neonatal and infant stroke assessment.