Physical Address

304 North Cardinal St.
Dorchester Center, MA 02124

Imaging of the Head and Neck in the Pediatric Patient

Introduction The old adage that “children are not young adults” is certainly true when evaluating pediatric head and neck lesions. The differential diagnosis of neck masses differs compared to masses that arise in adults. The most common pediatric head and neck lesions are congenital or developmental in origin, followed by inflammatory processes and tumors. This chapter will focus on the congenital/developmental and neoplastic processes; inflammatory lesions…

Larynx

Imaging of the larynx is a challenge. Motion is a constant problem because breathing and swallowing are very difficult to control, particularly in patients with lesions that impinge on the airway. The patient's larynx moves slightly with each breath. Despite the difficulties, imaging can still provide important information regarding potential involvement of deeper soft tissues and cartilage. Imaging must be considered in view of the capabilities…

Cervical Adenopathy and Neck Masses

Classification Cancer of the head and neck, which includes cancers of the larynx, nasal passages and nose, oral cavity, pharynx, salivary glands, buccal regions, and thyroid, is the sixth most frequent cancer worldwide. Neck masses can be grouped into two major types: nodal masses and nonnodal masses. Both types can appear as benign or malignant lesions. Most malignant nonnodal masses are epithelial malignancies of the mucous…

Paranasal Sinuses

Imaging Options and Protocols Computed tomography (CT) and magnetic resonance imaging (MRI) are the primary imaging modalities for assessment of the paranasal sinuses. Both these imaging techniques are far superior to plain radiographs in the evaluation of the sinonasal cavities. Plain radiographs of the paranasal sinuses are limited in their ability to delineate the complex bony anatomy or to characterize sinonasal disease and hence are almost…

Pharynx

Introduction The pharynx is a fibromuscular tube situated directly anterior to the vertebral column. It extends from the skull base to the lower border of the cricoid cartilage. It comprises a group of six muscles that are predominantly responsible for the voluntary act of swallowing: three pharyngeal constrictor muscles (superior, middle, and inferior constrictor muscles) and three vertically oriented muscles (stylo­pharyngeus, salpingopharyngeus, and palatopharyngeus). They are…

Temporal Bone

Embryology and Development of Temporal Bone The ear consists of three major components, the external, middle, and internal ear. Embryologically the ear has a dual development with development of the inner ear structures (internal auditory canal [IAC], cochlea, vestibule, and semicircular canals [SCC]) independent of the middle and external ear structures (ossicles, middle ear air spaces, mastoid antrum, tympanic membrane [TM], external auditory canal [EAC], and…

Orbit

Anatomy The soft tissue structures of the orbit are contained within a bony cavity and include the globe, extraocular muscles, optic nerve–sheath complex, lacrimal apparatus, and various vascular and nerve structures ( Figs. 20-1 to 20-4 ). Bony Anatomy The bony orbit is a conical structure with the apex pointing posteriorly. The orbital roof is composed of the frontal bone and is thinner anteriorly. The medial…

Demyelinating Disease and Leukoencephalopathies

Introduction The white matter of the central nervous system (CNS) is made up of myelinated neuronal axons. Myelin is a dielectric material composed in large part of lipids; it allows for rapid propagation of nerve impulses and is critical for normal development and functioning of the nervous system. Myelination begins early in the second trimester of fetal development and is largely complete by the end of…

Meningeal Processes

Anatomy and Embryology Meninges The meninges, which form the coverings of the brain and spinal cord, develop from the meninx primitiva. The neural tube is surrounded by this dense cellular layer shortly after the neural tube closes. As early as 32 days and as late as 44 days of gestation, the meninx primitiva begins to cavitate to form the cerebral cisterns by gradually decreasing its cellular…

Brain Proton Magnetic Resonance Spectroscopy

Introduction The first reported in vivo localized proton ( 1 H) magnetic resonance spectroscopy (H1-MRS) studies of the human brain were first reported over 20 years ago. Since these early studies, in vivo H1-MRS brain studies have been shown to be a powerful technique to noninvasively investigate the biochemistry of the human brain and to assess in situ the neurochemical profile of brain tissue. Thus they…

Functional Magnetic Resonance Imaging

Introduction Magnetic resonance imaging (MRI) is very adept at displaying structural anatomy of the brain in great detail. However, the correlation between anatomy and function is not always clear or apparent, and this becomes particularly difficult in situations where the anatomy deviates from the expected owing to developmental anatomic variation or if there is structural distortion by disease. A few short years after the clinical use…

Neurodegenerative Disorders

It is often clinically difficult to differentiate among the various neurodegenerative disorders such as dementias, hydrocephalus, and movement disorders, and even between pathologic and normal aging. In recent years, more specific and sensitive neuroimaging criteria have evolved to more accurately establish the correct diagnosis in these disorders. Magnetic resonance imaging (MRI), with its ability to image both the structure and function of the living brain, is…

Spinal Cord Injury

Introduction More than 10,000 spinal cord injuries are diagnosed each year in the United States, with over half involving the cervical spinal cord. Multidetector computed tomography (CT) is recommended by the American College of Radiology as the first-line screening exam for any patient for whom spine injury cannot be excluded on clinical grounds alone. Coronal and sagittal spine reformats are also commonly incorporated into whole-body CT…

Traumatic Brain Injury

Introduction Nearly 2 million cases of traumatic brain injury (TBI) occur each year. Worldwide, trauma is the leading cause of death and disability in those younger than 45 years, with nearly half of fatalities resulting from TBI. In younger patients, traffic accidents are the leading cause of TBI, and in the elderly, falls are the principal cause. TBI is a heterogeneous disorder with different forms of…

Cerebral Aneurysms and Cerebrovascular Malformations

Cerebral Aneurysms Incidence and Natural History The incidence of a cerebral aneurysm in the general population is 0.5% to 5%. Women more commonly harbor a cerebral aneurysm than men, and aneurysm development increases with advancing age. Some families demonstrate a genetic predisposition to develop cerebral aneurysms, with a prevalence of 4% when a first-degree relative has a confirmed aneurysm, increasing to 8% if two first-degree relatives…

Stroke

Introduction Stroke is the second leading cause of death worldwide. Globally an estimated 16.9 million cases of new stroke occurred in 2010, resulting in 5.9 million stroke deaths. In the United States, a stroke occurs every 40 seconds, with a stroke death every 4 minutes. Although stroke mortality rates have reduced over the last 2 decades, the number of stroke survivors and disability-adjusted life-years lost from…

Cerebral Infections and Inflammation

Computed tomography (CT) and magnetic resonance imaging (MRI) have become indispensable for diagnosis, evaluation, and treatment of intracranial infectious disease, contributing to significant decline in morbidity and mortality of these patients. CT is useful as a rapid screening tool to detect complications of intracranial infections such as hydrocephalus, extraaxial collections, and mass effect. MRI is superior for assessment of intracranial infections and allows for a more…

Intracranial Neoplasms

Introduction Based on data collected from several central cancer registries during the years 2007-2011, the Central Brain Tumor Registry of the United States (CBTRUS) estimates that 67,900 new cases of primary brain and central nervous system (CNS) tumors will be reported in 2014—one third of which will be malignant. The brain and CNS are also common sites of secondary tumor implantation; metastases may occur up to…

Normal Anatomy

Anatomy of the Brain The advent of high-resolution computed tomography (CT) and magnetic resonance imaging (MRI) scanners has allowed the fine anatomic structure to be seen in detail. In this chapter the gross surface anatomy of the brain is briefly reviewed, followed by discussion of CT and MRI techniques, followed by the illustration of sectional anatomy in multiplanar axes in these two modalities. Overview of Brain…

Tissue Characterization in Liver Imaging Using Advanced Magnetic Resonance Techniques

Introduction In the evaluation of diffuse and focal liver disorders, magnetic resonance imaging (MRI) has been proven to provide superior characterization of disease processes and therapy outcomes compared to other modalities in the imaging armamentarium. The particular strength of hepatic MRI is based on its unique ability to synergistically extract information on various soft tissue components in combination with assessment of functional liver status. To achieve…