The passage of radiation, such as x-rays and gamma rays, through a given material leads to ionizations and excitations that can be used to quantify the amount of energy deposited. This property allows measurement of the level of intensity of…
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In nuclear medicine, radiopharmaceuticals given to the patient emit the radiation used to create images or perform therapy. In order to understand how these agents perform and what safety considerations are involved in their use, it is necessary to be…
Introduction Paget's disease, or osteitis deformans, is a chronic metabolic disorder characterized by increased bone turnover and breakdown secondary to excessive and disorganized osteoclastic and osteoblastic activity ( Fig. 48.1 ). The precise etiology is still unclear. The excessive breakdown…
Introduction Otospongiosis, also known as otosclerosis, is a progressive primary bone disorder of abnormal bone resorption and deposition. The majority of cases result in a progressive conductive hearing loss with severe cases evolving to a combination of conductive and sensorineural…
Introduction Injection laryngoplasty is performed for treatment of vocal cord paralysis, which may have a variety of causes ( Box 46.1 ). Imaging during a Valsalva maneuver demonstrates the mechanical and physiologic barriers that patients with unilateral vocal cord paralysis…
Introduction Esthesioneuroblastoma (olfactory neuroblastoma) is an uncommon malignancy of the nasal cavity. Esthesioneuroblastoma represents 3% to 6% of sinonasal malignancies and has an estimated incidence of 0.4 cases per 1 million people. This tumor has been reported across a wide…
Introduction Paragangliomas of the head and neck are rare neoplasms of neural crest cell origin. The four most common sites for paragangliomas within the head and neck are at the carotid body, the jugular foramen, in the middle ear, and…
Introduction Labyrinthitis, also known as otitis interna, is an inflammatory disorder of the inner ear. Inflammation of the perilymphatic spaces results in secondary changes within the membranous labyrinth, the most common symptoms of which are sensorineural hearing loss and vertigo.…
Introduction A cholesteatoma is a cystic mass filled with keratin and lined by stratified squamous epithelium. Cholesteatoma is not a neoplasm and can be thought of most simply as skin in the wrong place. Although a cholesteatoma is histologically identical…