Infectious and inflammatory disorders commonly involving the temporal bone; external, middle, and inner ear; and the facial nerve are discussed in this chapter. The auricle, the cartilaginous canal, and the external auditory canal (EAC) comprise the external ear, with the…
The discussion of congenital and neonatal temporal bone abnormalities in this chapter is approached from lateral to medial. External canal atresia and associated middle and inner ear anomalies are discussed initially. Isolated middle ear anomalies with associated branchial arch malformations…
Embryology A detailed study of the development of the ear is beyond the scope of this chapter; only the key embryologic events and their timing are discussed here. It is important to appreciate that the inner ear is derived from…
Development and Anatomy of the Nose and Sinonasal Cavities The craniofacial structures form from a complex sequence of events dictated by molecular changes during the third to 10th gestational weeks. The nose forms in the fourth gestational week from the…
A wide variety of primary and secondary neoplasms may affect the orbit. Most orbital masses are benign and slow growing, but approximately 20% are malignant. Making the correct diagnosis may be difficult for several reasons. In children, it may be…
A wide variety of disease processes can cause inflammatory changes in the orbit, including infection, idiopathic inflammation, granulomatous disease, thyroid-related disease, optic neuritis, and sickle cell disease. Additionally, metabolic diseases can also affect the optic nerves, leading to vision loss.…
Assessment of the orbits is part of a detailed fetal sonographic or magnetic resonance imaging (MRI) scan, particularly in the setting of suspected central nervous system malformation. When further assessment is performed by fetal MRI, obvious ocular pathologies can be…
Embryology of the Eye Development of the eye originates from neuroectoderm, surface ectoderm, and neural crest cells. The neuroectodermal layer gives rise to the retina, iris, and optic nerve; the surface ectoderm gives rise to the lens; the neural crest…
Allergic-Like Reactions Introduction Contrast media (CM) are an essential aid in diagnostic medical imaging. They are used primarily to enhance the visibility of blood vessels, organs, and pathology in the body. CM are considered pharmacologic agents, and, like any other…
Magnetic resonance imaging (MRI) has proved to be a powerful diagnostic imaging tool in children and adults. MRI uses low-energy nonionizing radio waves, and as such it is particularly well suited for pediatric and longitudinal imaging studies. MRI exploits a…