Physical Address

304 North Cardinal St.
Dorchester Center, MA 02124

Airway

Signs and symptoms referable to the airway are much more common in children than in adults. For practical purposes, abnormalities of the airway can be divided into acute upper airway obstruction, lower airway obstruction (extrinsic compression, intrinsic obstruction), obstructive sleep apnea (OSA), and congenital high airway obstruction syndrome (CHAOS). Clinically, children with acute upper airway obstruction (above the thoracic inlet) tend to present with inspiratory stridor,…

Special Considerations in Pediatric Imaging

Pediatric Radiology as a Potential Career A powerful and fulfilling aspect of becoming a pediatric healthcare provider is the satisfaction that comes from working with and for children. Few activities are more rewarding than helping children and their families. The sense of mission when working in a children's hospital is palpable and very different than what is often experienced in adult healthcare systems. In addition, there…

Spinal alignment

Key points Global spinal balance is equally important as it is a dynamic process that includes the spine along with compensatory mechanisms consisting of the hips, and ankles. Current commonly used spinal measurements include cervical lordosis, thoracic kyphosis, and lumbar lordosis, while the three most commonly used pelvic indices include the pelvic incidence, sacral slope, and pelvic tilt, where the pelvic incidence is constant in adults…

Paraspinal muscles

Key points Erector spinae, lumbar multifidus, quadratus lumborum, and psoas major are commonly investigated paraspinal muscles. Magnetic resonance imaging and computed tomography provide high-quality muscle images for the quantification of muscle morphometry, while ultrasonography is a low-cost noninvasive method capturing both static and dynamic muscle images. Decreased cross-sectional area and/or increased fatty infiltration of paraspinal muscles are likely to be associated with some spinal degenerative features…

Facet joints

Key Points Pathologic changes seen in facet joint degeneration include fibrillation, joint space narrowing, articular cartilage thinning, subchondral bone sclerosis, osteophytosis, and development of juxta-facet cysts. Risk factors for facet joint degeneration include lower spinal level, increasing age, sagittal orientation, and intervertebral disc degeneration. Facet tropism, gender, increasing body mass index, and ligamentum flavum abnormalities may also be risk factors for facet joint degeneration. Pathologic and…

Lumbar spinal stenosis

Key points Lumbar spinal stenosis is a complex disease with a plethora of clinical and imaging phenotypes. Developmental lumbar spinal stenosis is caused by mal-development of pedicles and posterior elements leading to narrowed bony spinal canals, and these patients are prone to developing symptoms at any spinal level and are at risk of reoperations. Degenerative lumbar spinal stenosis is an end result of the degenerative cascade…

Ossification of the posterior longitudinal ligament

Key points Ossification of the posterior longitudinal ligament (OPLL) is a hyperostotic condition of the spine associated with severe neurologic deficits. The incidence is higher in East Asians. OPLL is a multifactorial disease caused by a combination of environmental and genetic factors. Six susceptibility loci have been identified by a large-scale genome-wide association study among Japanese. Further study identified RSPO2 as a susceptibility gene for OPLL.…

Vertebral bone marrow (Modic) changes

Key points Modic changes are subchondral and vertebral bone marrow changes in conjunction with intervertebral disc degeneration, and they are classified into three categories (types 1, 2, and 3) based on magnetic resonance imaging appearance. Modic changes, especially Modic type 1 change, are associated with low back pain but they are also prevalent among people without low back pain. The precise pathology of Modic changes is…

Vertebral endplate abnormalities, defects, and changes

Key points The vertebral endplate is the key regulator of disc nutrient and oxygen transport. The endplate is composed of an inner bony and an outer cartilaginous layer in relation to the vertebra. Vertebral endplates are innervated so represent an important, yet often overlooked, potential source of pain. Endplate pathological change and damage may precede disc degeneration; however, endplate changes may also develop following disc changes…

High-intensity zones and annular tears

Key points High-intensity zones (HIZs) represent a hyperintense signal on T2-weighted MRI in the region of the annulus fibrosus and can be used to represent annular tears. HIZs have variable biomechanics, epidemiology, and risk factors and are associated with or without low back pain. HIZs were considered as a specific pain and degenerative marker; however, this remains a matter of contention due to a lack of…

Displacement of intervertebral discs

Key points Intervertebral disc displacement is not a “disease,” but is a component of many variations of disorders of the spine. The displaced disc material and the effects it creates must be carefully assessed and its origin sought by clinical examination and imaging. Coordination of clinical and imaging findings is a necessary prelude to treatment. Accurate conceptualization and communication require an understanding of terminology. Introduction Understanding…

Disc space narrowing and osteophytes

Key points Disc space narrowing and osteophyte formation are features of the general spine condition known as intervertebral disc (IVD) degeneration IVD degeneration is an age-related condition IVD degeneration is highly heritable The burden of IVD degeneration predicts the likelihood of low back pain episodes Introduction The outgrowth of small spicules of bone—osteophytes—from the endplate of the vertebral body is one of the hallmarks of the…

Intervertebral disc degeneration

Key points The process of intervertebral disc (IVD) degeneration consists of gradual structural and biochemical changes that may lead to pain and disability. IVD degeneration is multifaceted, mediated by biomechanical alterations, nutritional compromise, genetics, and environmental factors among others Various imaging modalities exist to assess the IVD and degenerative phenotypes, whereas magnetic resonance imaging is considered the gold standard. Various classification schemes of IVD degeneration have…

Imaging technologies of the spinal discs

Key points Various imaging modalities exist to assess the intervertebral disc. Classification grading schemes have been proposed to assess the morphological and structural changes of the disc. Novel or nontraditional imaging platforms have been developed to assess early disc changes, biochemical profiles of the disc and assist in identifying painful discs. Clinical studies are needed to assess the efficacy of all imaging technologies in relation to…

Animal models to study spinal intervertebral disc phenotypes

Key points Animal models are critical for understanding disease mechanisms and developing new therapies. Species differences in intervertebral disc size, tissue composition, and cellular content associate with distinct biomechanical and biological behaviors. Some features of human disc degeneration are mimicked in animal model systems, but the absence of standardized methods for assessing, reporting, and comparing histopathologies of human and animal discs limits our ability to generalize…

Biomechanical models to study spinal phenotypes

Key points Intervertebral disc (IVD) degeneration involves endplate-driven and annulus-driven phenotypes that accumulate and interact with progressive degeneration and eventual collapse of the IVD. IVD injuries result in organ-level changes that affect cellular level responses and organ level biomechanical behaviors, which can be measured and manipulated in model systems. IVD degeneration phenotypes can be represented by distinct injuries in biomechanical model systems including endplate-driven defects and…

Biomechanics of the spine

Key points The spine protects the spinal cord and provides mechanical strength to the trunk while allowing for a certain amount of flexibility. The intervertebral disc has a design and structure highly optimized to fulfill its mechanical requirements, that is, to sustain the compressive loads arising from the erect posture and distribute them to the vertebrae. Zygapophyseal joints, also known as facet joints, limit the spinal…

Anatomy of the spine

Key points Intimate relationships between osseous, nervous, vascular, and soft tissue structures of the spine are critical to normal function. A thorough understanding of these relationships is essential to the comprehension of spinal pathology and its surgical management as well as the avoidance of dire consequences. Distinct morphology along the spinal column allows for unique characteristics at diverse levels of the spine, defining normal function in…

Conclusions (multiparametric ultrasound for the work-up of chronic liver disease)

Overview Chronic liver disease (CLD) is a significant cause of morbidity and mortality worldwide, and in Chapter 1 the extent of the problem is fully discussed. There are now effective treatments for liver disease caused by hepatitis B or hepatitis C virus, and these causes are expected to continue to decrease in incidence over time. Nonalcoholic fatty liver disease (NAFLD) is a worldwide problem, and the…

Focal liver lesions in the setting of chronic liver disease

Introduction Any discussion of chronic liver disease (CLD) would be remiss if a detailed description of hepatocellular carcinoma (HCC) were not included. In 2018 primary liver cancer was projected to be the sixth most diagnosed and fourth most common cause of cancer death worldwide, with HCC making up 75%–85% of all primary liver cancers. CLD or cirrhosis is recognized as the most important precursor of HCC.…