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Cervical Spine Injuries

The exclusion of cervical spine injuries in patients with blunt trauma is one of the major challenges facing traumatologists and emergency department physicians. This is especially daunting in unresponsive or comatose patients. “Clearing” the cervical spine is a complex interdisciplinary process and has two major components. The first is the imaging evaluation for exclusion of fracture and to determine normal vertebral alignment. Second, even with a…

Imaging of Facial and Skull Trauma

The craniofacial structures have the formidable task of protecting the brain, the soft tissues that form the upper aerodigestive tracts, and the tissues vital to the special senses of vision, smell, taste, and hearing. Injury to the craniofacial region may therefore have devastating implications to the traumatized patient. Prompt and accurate diagnosis of craniofacial injuries is necessary for appropriate treatment to minimize both functional and aesthetic…

General Principles of Osseous Injury

In this chapter, concepts are identified and described that are intrinsic to musculoskeletal trauma, such as the purpose of the imaging report, vector forces causing musculoskeletal injury, musculoskeletal injury terminology, and fractures and dislocations in which the associated soft tissue component—not routinely delineated by conventional radiography—is the principal element of the injury. Because most of the musculoskeletal injuries described in this chapter are discussed and illustrated…

General Imaging Principles

Conventional Radiography The most frequently used modality for evaluation of bone and joint disorders is radiography. Radiography is the initial modality used in the setting of trauma, infection, and arthritis. It is useful for characterizing benign and malignant bone lesions and bony changes seen in metabolic conditions; it can also be used to locate foreign objects and guide intervention. Understanding the principles of proper radiographic technique…

Three-Dimensional Ultrasound: Techniques and Clinical Applications

Introduction Fetal anatomy is three-dimensional (3D). Cross-sections obtained during real-time ultrasound (US) examination are an artificial reduction of anatomy to produce one still image, created to capture a standard view or the essence of a particular pathology. Acquisition of a good US volume is not trivial, but a comprehensive volume may enable examination at a greater level of detail than is possible from a single cross-section;…

Magnetic Resonance Imaging in Obstetrics

Introduction Assessment of fetal development and screening for congenital anomalies are essential elements of prenatal care. Ultrasound (US) imaging remains the first-line modality because of its convenience, low cost, and wide availability, but it can be limited by several factors, sometimes making US incompatible with women's expectations, or subject to misdiagnosis-related legal issues. Compared to US, magnetic resonance imaging (MRI) is less limited by fetal lie,…

Doppler Ultrasound Evaluation of the Fetus and Placenta

Introduction Doppler ultrasound (US) can be used to assess waveform patterns of blood flow in various vascular beds in the maternal, fetal, and placental circulation. The information gained from the analysis of waveforms in combination with clinical factors provides insight into maternal adaptation to pregnancy, placental resistance, and fetal cardiovascular status, and thus can guide pregnancy management in many conditions. Doppler evaluation can be roughly divided…

Elasticity Imaging in Obstetrics

Introduction Palpation, the technique by which clinicians evaluate a patient by touch, has been fundamental to medical practice for thousands of years. Information about tissue stiffness can provide diagnostic information about the presence or status of disease, or about structural or microstructural changes in tissue because of physiologic and pathologic processes. Quantification of this type of information, however, did not emerge until the past two decades,…

Ultrasound Physics for the Clinician

Introduction Since its introduction to the medical community in the 1950s, ultrasound (US) has become a widespread imaging modality because of its portability, nonionizing energy, and relatively low cost. This chapter reviews basic physics concepts behind the formation of an US image, emphasizing conventional B-mode imaging. Other approaches, including US-based elasticity assessment, Doppler, and three-dimensional imaging, as well as magnetic resonance imaging, are discussed in other…

Congenital Syphilis

Introduction A number of maternal perinatal infections result in congenital malformations. Traditionally these diseases were delineated by the acronym TORCH ( t oxoplasmosis, o ther, r ubella, c ytomegalovirus, and h erpes simplex virus). Syphilis has dominated the “other” category, although several other infections have increased over time, including coxsackievirus, human immunodeficiency virus (HIV), parvovirus B19, and varicella zoster virus. Syphilis is the quintessential bacterial infection…

Parvovirus B19 Infection During Pregnancy

Introduction Parvovirus B19 infection during pregnancy is rare, but potentially dangerous. In susceptible mothers, transplacental transmission of parvovirus B19 is possible. If acquired in utero , parvovirus B19 infection can lead to severe fetal anemia and myocarditis. In some instances, the infection may result in fetal death in the second or third trimester. Although in utero fetal infection is usually self-limited, severe cases are treated with…

Congenital Zika Virus Syndrome

Introduction Every few years the threat of a “new” infectious disease becomes the center of world attention, producing waves of fear and even mass panic. Until now, at least in the beginning, these diseases affected only adult populations. Although, since the Yap island epidemic in 2007, Zika virus (ZIKAV) was known to be able to produce epidemics, it remained unknown for the general population at large…

Cytomegalovirus, Rubella, Toxoplasmosis, Herpes Simplex Virus, and Varicella

Cytomegalovirus Sonya S. Abdel-Razeq Introduction The acronym TORCH refers to a group of organisms associated with congenital infections: t oxoplasmosis, o ther (congenital syphilis and viruses), r ubella, c ytomegalovirus (CMV), and h erpes simplex virus (HSV). The approximate number of cases per year in the United States of these infections is listed in Table 165.1 . In the United States, CMV is the most common fetal…

Diagnostic Procedures in Multiples

Introduction The number of multiple pregnancies has exponentially increased in the last several decades mainly as a result of women delaying childbearing until they are of advanced maternal age and the expanded use of assisted reproductive techniques. The risk of chromosomal abnormalities increases with advancing maternal age; however, it has also been reported that there is an increased risk of structural and genetic abnormalities in twins…

Twin Reversed Arterial Perfusion Sequence

Introduction Twin reversed arterial perfusion (TRAP) sequence is a rare complication specific to monochorionic twin pregnancies. As a result of early vascular disruption occurring during embryogenesis, a dysmorphic acardiac twin receives circulatory support from a pump twin via aberrant placental arterioarterial anastomoses. Because the acardiac twin is entirely dependent on perfusion from the pump twin, the pump twin is at risk of hemodynamic compromise. Originally described…

Twin-Twin Transfusion Syndrome

Introduction Twin-twin transfusion syndrome (TTTS) is a serious condition that can complicate twin pregnancies with monochorionic diamniotic (MCDA) placentation. MCDA twin pregnancies should be monitored for TTTS with serial ultrasound (US) scans beginning in the second trimester. Early-stage TTTS can be managed conservatively, but because of the unpredictable risks of disease progression and intrauterine fetal demise, prenatal testing and delivery before term should be considered. Limited…

Dichorionic Diamniotic Twin Gestations

Introduction Twin pregnancies account for more than 3% of live births in the United States. Determination of chorionicity and amnionicity is essential in the clinical management of multiple gestations. Although dichorionic twin gestations are not associated with as many fetal complications as monochorionic gestations, all twin pregnancies, whether dichorionic or monochorionic, have an increased risk of adverse pregnancy outcomes compared with singletons. Ultrasound (US) plays a…

Monochorionic Diamniotic Twin Gestations

Introduction Compared with dichorionic twin gestations, monochorionic twin gestations, whether diamniotic or monoamniotic, have an increased risk of adverse pregnancy outcomes. Ultrasound (US) plays a vital role in prenatal determination of chorionicity and in the management of monochorionic diamniotic twin pregnancies. Disease Definition The term monochorionic refers to a multiple gestation with one placental disk (or chorion), and the term diamniotic describes the presence of two…

Monochorionic Monoamniotic Twin Gestations

Introduction In addition to the general risks associated with twin pregnancies and with specific risks of monochorionic gestations, monoamniotic twin gestations face the unique risk of cord entanglement and are at increased risk of fetal demise. Ultrasound (US) plays a vital role in prenatal determination of chorionicity and amnionicity and in the prenatal management of monochorionic monoamniotic twin pregnancies. Disease Definition The term monochorionic refers to…

Chorionicity of Multiple Gestations

Introduction In 2014, the twin birth rate in the United States rose to an all-time high of 33.9 per 1000 live births. Multiple gestations result from either the fertilization of multiple ova or the division of a single fertilized ovum into more than one fetus. The terms monozygotic and dizygotic refer to the number of ova leading to a multifetal gestation. A monozygotic pregnancy results from…