The immune system is a complex network of cells and organs which cooperate to protect individual against infectious microorganisms, as well as internally-derived threats such as cancers. The immune system specializes in identifying danger, containing and ultimately eradicating it. It is composed of highly specialized cells, proteins, tissues, and organs. B- and T- lymphocytes, phagocytic cells and soluble factors such as complement are some of the major components of the immune system, and have specific critical functions in immune defense. When part of the immune system is missing or does not work correctly, immunodeficiency occurs; it may be either congenital (primary) or acquired (secondary). Secondary immunodeficiency diseases are caused by environmental factors such as infection with HIV, chemotherapy, irradiation, malnutrition, and others; while primary immunodeficiency diseases (PIDs) are hereditary disorders, caused by mutations of specific genes. Primary immunodeficiency diseases are a heterogeneous group of inherited disorders with defects in one or more components of the immune system. These diseases have a wide spectrum of clinical manifestations and laboratory findings; however, in the vast majority of cases, they result in an unusually increased susceptibility to infections and a predisposition to autoimmune diseases and malignancies . Primary immunodeficiencies constitute a large group of diseases, including more than conservatively defined hereditary disorders affecting development of the immune system, its function, or both .

Osteoporosis is one of the most prevalent metabolic bone diseases in the world and is a major public health problem. Osteoporosis consists of a heterogeneous group of syndromes in which reduction of bone mass per unit volume results in bone fragility. The increment in bone porosity causes architectural instability of the bone and increases the likelihood of fracture. In osteoporosis, the mineral-to-matrix ratio is normal, but the bone quantity is reduced. In 2005, the direct and indirect costs ofosteoporosis in the United States alone were estimated to be $17 billion. In 2025, it is projected that the costs will be $25 billion, annually . Much of this expense relates to hip fractures. In 15%–20% of hip fracture cases, the outcome is fatal. In osteoporotic individuals, 50% of women and 25% of men older than 50 years could have a traumatic spine fracture during their life. Reports from Europe in 2003 indicate that variations of a gene on chromosome 20 may cause some postmenopausal women to have osteoporosis. Research studies are in progress to identify the gene in the carriers and implement preventive measures. Meanwhile, clinicians (through nonpharmacological intervention) can add quality to the years of life of osteoporotic patients with or without fractures. Nonpharmacologic intervention could be implemented alone or along with pharmacotherapy in cases of the need for pharmacotherapy. Clinical studies have shown that when pharmacotherapy is combined with the rehabilitative measures, the vertebral fracture rate is decreased.

Breast imaging plays a critical role in the detection, diagnosis, and management of women diagnosed with breast cancer. Although there are a multitude of risk factors associated with breast cancer, such as female gender, increasing age, and family history, the density of breast tissue as evident on mammography has more recently been identifed as an independent risk factor . Although some studies suggest that the lifetime risk increases by four to six times for women with dense breast tissue, this is misleading as this compares women with extremely dense tissue to women with predominantly fatty breasts, both of which represent a minority of the population . More realistically, the lifetime risk is only increased by 1.2–2.1 times in a woman with heterogeneously dense or extremely dense breasts, respectively, when compared to the average woman who has scattered fbroglandular tissue. However, as breast density is known to lower the sensitivity of mammography due to “masking” of cancers, the integration of newer modalities for the management of newly diagnosed breast cancer, such as digital breast tomosynthesis, ultrasound, and magnetic resonance imaging (MRI), continues to evolve. In addition, recent legislative efforts that mandate direct patient otifcation of breast density exist in nearly 50% of states in the USA. Consequently, there is a growing research on developing more sensitive and specifc tools to “see through” the dense tissue and therefore permit earlier cancer detection, which should translate into improved outcomes.