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Pelvic floor disease

Anatomy, embryology, pathophysiology ◼ The pelvic floor consists of the levator ani, the pelvic sphincters, and fascia that support the rectum, bladder and urethra, as well as the vagina, cervix, and uterus in females and the prostate in males. ◼ These organs are divided into three compartments in females: anterior (bladder and urethra), middle (uterus, cervix, and vagina), and posterior (rectum and anus). In males, there…

Müllerian abnormalities

Anatomy, embryology, pathophysiology ◼ After the sixth week of gestation, in the absence of a Y chromosome, the paired Müllerian (paramesonephric) ducts begin to form in female neonates. ◼ Over the ensuing weeks, the two Müllerian ducts fuse with a resultant cervicouterine septum formed in between them. This septum is subsequently resorbed, creating a fully patent uterine cavity. ◼ Complete fusion of the Müllerian ducts results…

Solid adnexal lesions

Anatomy, embryology, pathophysiology Please see Chapter 33 . Imaging techniques and protocols Please see Chapter 33 . Specific disease processes A purely solid adnexal lesion is usually considered benign, with a few exceptions. This chapter provides a differential for benign and malignant solid adnexal lesions with emphasis on their imaging appearances. However, it is worth noting that the most common ovarian tumors are epithelial ovarian tumors,…

Cystic adnexal lesions

Anatomy, embryology, pathophysiology The term adnexa includes the fallopian tubes, the ovaries, and their ligamentous attachments in the female pelvis. The fallopian tubes ◼ The fallopian tubes are paired tubular structures, approximately 10 cm in length extending from the uterus to the ovaries. ◼ The fallopian tubes consist of four parts. From medial to lateral, these are the isthmus, ampulla, infundibulum, and fimbriae. The fimbrial segments…

Focal uterine lesions

Anatomy, embryology, pathophysiology The uterus is a thick-walled muscular organ of the female reproductive system that lies in the true pelvis posterior to the bladder and anterior to the rectosigmoid colon. It is divided into the body (corpus) and cervix at the internal os, and it consists of an inner mucosa (endometrium), a middle muscular layer (myometrium), and an outer serosa (perimetrium). The endometrium and the…

Endometrial/junctional zone thickening

Anatomy, embryology, pathophysiology The uterus is a hollow muscular organ of the female reproductive system with a shape and size similar to that of an upside-down pear in women of reproductive age ( Table 31.1 ). It is located within the pelvic cavity along the body’s midline, posterior to the urinary bladder and anterior to the rectum. The gross anatomy of the uterus is divided into…

Testicular lesions

Anatomy, embryology, pathophysiology ◼ The testes, the principal male reproductive organs, are located within the scrotal sac, and surrounded by a thick layer of fibrous capsule and the tunica albuginea ( Fig. 30.1 ). ◼ The tunica albuginea forms a capsule that covers the testis. The testis is then further covered by a reflected fold of the processes vaginalis that becomes the visceral layer of the…

Prostate imaging

Anatomy, embryology, and pathophysiology ◼ The prostate is a cone-shaped exocrine gland located inferior to the bladder and anterior to the rectum. It surrounds the uppermost segment of the urethra and is enveloped by an incomplete fibromuscular capsule. ◼ The gland contains a base superiorly, a mid-gland, and an apex inferiorly. ◼ Important neurovascular structures lie within the pericapsular fat anterior to the apex (anterior periprostatic…

Adrenal gland enlargement and nodules

Anatomy, embryology, pathophysiology ◼ The adrenal glands are multifunctioning, inverted Y-shaped, retroperitoneal endocrine glands normally located superior to the kidneys in the perirenal space ( Fig. 28.1 ). ◼ The adrenal glands mediate the stress response by releasing cortisol and are involved in secondary sex hormone synthesis and blood pressure regulation. ◼ Absence of the Y-shape indicates development in the absence of an orthotopic kidney (i.e.,…

Urothelial lesions

Anatomy, embryology, pathophysiology ◼ The urothelium is the mucosa composed of transitional epithelium that lines the renal calyces and pelvis, ureters, bladder, and much of the urethra. Further anatomic and clinical classification defines the upper tract as the renal collecting system and ureter, whereas the lower tract pertains to the bladder and urethra. ◼ The ureters connect the renal collecting system to the bladder. The average…

Urinary tract obstruction

Anatomy, embryology, pathophysiology ◼ Urinary tract obstruction (UTO) is a commonly encountered clinical scenario that can affect all age groups. In the pediatric population, the underlying pathology is often congenital in nature ( Box 26.1 ), whereas in adults, there is a variety of acquired conditions ( Table 26.1 ). The site of obstruction may range from the renal hilum, along the course of the ureter,…

Diffuse renal parenchymal disorders

Anatomy, embryology, pathophysiology ◼ The renal parenchyma can be divided into an outer region called the cortex and an inner region called the medulla. ◼ Parenchymal abnormalities can be divided by their involvement. ◼ Entire kidney (glomerulonephritides, amyloidosis, drugs, and rejection). ◼ Primarily cortical. ◼ Primarily medullary. ◼ Glomerulonephritis (GN) is a complex spectrum of disorders characterized by inflammation of the glomeruli. ◼ It is a…

Solid renal lesions

Anatomy, embryology, pathophysiology Please see Chapter 23 for discussion. Techniques and protocols Please see Chapter 23 for discussion. Specific disease processes Benign solid lesions Oncocytoma ◼ An oncocyte is a large transformed epithelial cell with fine granular eosinophilic cytoplasm. Oncocytomas arises from distal tubules or collecting ducts of the kidney. Epidemiology ◼ 3% to 7% of all renal neoplasms. ◼ Present in the sixth to seventh…

Cystic renal masses

Anatomy, embryology, and pathophysiology Anatomy ◼ The kidneys are paired, bean-shaped, retroperitoneal organs that primarily function in the excretion of metabolic waste. ◼ The concave medial surface is known as the renal hilum. ◼ Each collecting system consists of the minor calyces, major calyces (infundibula), and renal pelvis. There are 10 to 25 minor calyces in each kidney. ◼ The perirenal space is confined by the…

Urolithiasis

Anatomy, embryology, pathophysiology ◼ Renal calculi result from crystallization of supersaturated inorganic and organic compounds and proteins within renal tubular fluid, renal interstitial fluid, or in the urinary collecting system along the papillary surfaces. Supersaturation and crystallization of stone constituents may result from a combination of increased constituent excretion, reduced urinary fluid volume, abnormal urinary pH, urinary stasis from anatomic abnormality or obstruction, and chronic infection.…

Lymphadenopathy

Anatomy, embryology, pathophysiology ◼ Complex drainage system of lymphatic capillaries connected by ducts connected to central lymph node ‘stations’ following a similar course to the arterial system ( Figs. 21.1 and 21.2 ). ◼ Lymph nodes play an integral part in the immune system through both physical and immunological elimination of bacteria, neoplastic cells, and other foreign substances. ◼ Approximately 230 to 250 lymph nodes within…

Splenomegaly/splenic lesions

Anatomy, embryology, pathophysiology Embryology Splenogenesis initiates in the fifth week of embryological life. The dorsal mesogastrium anchors the stomach posteriorly; it is within the two leaves of this mesogastrium that the spleen forms from mesenchymal cells. Asymmetric stomach growth results in rotation of the spleen from the midline to its final position in the left upper quadrant. The mesogastric connection becomes the gastrosplenic ligament. Medial to…

Jaundice

Anatomy, embryology, pathophysiology ◼ Jaundice refers to the clinical sign of hyperbilirubinemia (>2.5 mg/dL), often manifesting with yellowing of the cutaneous surfaces, sclerae conjunctiva, and oral mucosa. ◼ Largely subdivided into nonobstructive (prehepatic and hepatic etiologies) and obstructive (posthepatic etiologies). ◼ Prehepatic causes: ◼ Hemolytic anemia. ◼ Hypersplenism. ◼ Artificial heart valves. ◼ Sepsis and low perfusional states. ◼ Hepatic causes: ◼ Hepatocellular injury (e.g., viral…

Cholecystitis

Anatomy, embryology, pathophysiology ◼ The gallbladder (GB) is a pear shaped musculomembranous structure, lying along the hepatic undersurface, functioning as a reservoir to accumulate bile (~30–50 mL). ◼ Embryologically, the GB develops from a diverticulum outpouching in the caudal portion of the hepatic duct, becoming part of a continuous lumen within 3 months of gestation. ◼ The adult GB spans 7 to 10 cm in length…

Benign focal liver lesions

Anatomy, embryology, pathophysiology ◼ Lesions in the liver are often characterized based upon underlying histology. The most common benign lesions include simple cysts, hemangiomas, hepatocellular adenoma (HCA), focal nodular hyperplasia (FNH), regenerative nodules, and hepatic abscess. ◼ Most benign hepatic lesions are asymptomatic and found incidentally ( Fig. 17.1 ). Symptoms, if present, are often related to mass effect including pain/discomfort, nausea, vomiting, or early satiety.…