Transcranial ultrasound tomography for neonatal brain imaging: A feasibility study

Early and reliable detection of brain injury in premature neonates remains a clinical challenge because routine cranial ultrasound is limited by operator dependence and restricted acoustic access through the fontanelles. Magnetic resonance imaging is often impractical during the early stages of neonatal intensive care, and X-ray computed tomography is generally avoided due to limitations in imaging detail and ionizing radiation exposure. An ideal neuroimaging platform should be safe, operator independent, and capable of bedside volumetric assessment without requiring transport of fragile infants. In this work, we evaluate the feasibility of Transcranial Ultrasound Tomography (TcUST) as an operator independent approach for structural and functional neonatal brain imaging through the skull. Simulation studies identified a favorable frequency operating range below 3 MHz that provides sufficient penetration through the thin neonatal skull while preserving clinically meaningful contrast. Point spread function analysis at multiple spatial positions revealed that skull-induced aberrations primarily affect tangential resolution, whereas radial resolution and overall anatomical visibility remain largely preserved. Phantom experiments further demonstrated that TcUST can detect millimeter-scale hemorrhagic inclusions, show essential anatomical features, and reconstruct vascular flow through a skull mimic. Although a fully operational clinical prototype has not yet been evaluated in more clinically relevant models, these results provide strong evidence supporting the feasibility of TcUST for transcranial whole brain imaging in neonates and motivate its further development as a platform for longitudinal bedside neuromonitoring.