Introduction
In this updated review, current and advanced neuroimaging technologies are discussed, along with the basic principles of imaging diagnosis and guidelines for utilization in fetal, perinatal, and neonatal brain abnormalities. This includes pattern of injury and timing issues, with special emphasis on neurovascular disease and the differential diagnosis. In the causative differentiation of static encephalopathies (e.g., cerebral palsy, CP) from progressive encephalopathies, specific categories and timing are addressed. These include developmental abnormalities, trauma, neurovascular disease, infections and inflammatory processes, and metabolic disorders. Although a rare but important cause of progressive perinatal encephalopathy, neoplastic processes are not considered in detail here. Molecular and genetic technologies continue to advance toward eventual clinical application.
Neuroimaging technologies and general utilization
Imaging modalities may be classified as structural or functional. Structural imaging modalities provide spatial resolution based primarily on anatomic or morphologic data. Functional imaging modalities provide spatial resolution based upon physiologic, chemical, or metabolic data. Some modalities may actually be considered to provide both structural and functional information.
Ultrasonography (US) is primarily a structural imaging modality with some functional capabilities (e.g., Doppler: Fig. 18.1a,b) [1–8,13–26]. It is readily accessible, portable, fast, real-time and multiplanar. It is less expensive than other cross-sectional modalities and relatively non-invasive (non-ionizing radiation). It requires no contrast agent and infrequently needs patient sedation.