Article Abstract:
Sonography is a process by which internal structures of the body are visualized by computerized analysis of the differential patterns with which high-frequency sound waves are reflected by tissues of different density. Because of the safety of sonography (compared with X-ray and other imaging techniques), it is often the method of choice for diagnosis and evaluation of women of childbearing age, and patients requiring multiple exams. Conventional sonography involves the placement of an ultrasound probe over the abdomen, often with concomitant distension of the urinary bladder. In gynecological sonography, typically the uterus, ovaries, and occasionally the kidneys are imaged. Technological advances are allowing greater high-resolution imaging to be accomplished by means of transvaginal and transrectal transducers (ultrasound probes placed in the vagina and rectum, respectively). These higher-frequency probes allow more detailed imaging of structures in the vicinity of the probe tip, but the distance over which the imaging can be done is limited. Sonography can be used to detect and document normal gynecological events (early pregnancy, cyclical changes related to the menstrual cycle, localization of intrauterine devices, etc.) as well as pathological events (congenital abnormalities, pelvic inflammatory disease, ectopic pregnancy, ovarian cysts, tumors, and uterine cancer). Endometriosis, a painful condition resulting from the presence of ectopic endometrial (uterine) tissue outside of the uterus, can sometimes be diagnosed with sonography; however, the small quantities of tissue involved usually require surgical verification of the diagnosis. (Consumer Summary produced by Reliance Medical Information, Inc.)
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Article Abstract:
Ultrasonography is a diagnostic method in which sound waves are used to provide images of internal structures. It is the most inexpensive imaging technique for examining the abdomen. Ultrasonography is particularly useful in pregnant women because the equipment is easily transported and ionizing radiation is not used. This method can also be used to monitor bowel peristalsis, or intestinal muscle movements, and movements of the diaphragm, the muscular wall which contracts during breathing and separates the chest from the abdomen. Blood flow within the abdomen can be assessed using the Doppler and color form of ultrasonography. Diseases associated with the prostate, a gland that surrounds the neck of the bladder and urethra in men, can be monitored using transrectal sonography; this requires insertion of the transducer, which sends and receives the sound wave signal, into the rectum. The most important factor influencing the use of ultrasonography is the training and experience of the examiner and interpreter. In addition, the presence of gas and bony structures within the abdomen interferes with the sound beam, and wounds, bandages and sutures prevent appropriate skin contact. Ultrasonography is not very effective in the traumatized or wounded patient. The current indications, or uses, for ultrasonic examination of the abdomen are discussed, and certain aspects of ultrasonography are compared with those of other imaging techniques. (Consumer Summary produced by Reliance Medical Information, Inc.)
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Article Abstract:
Second-trimester ultrasound scans will not be sensitive enough to detect fetuses with Down syndrome unless the baby has anatomical malformations associated with the syndrome. This was the conclusion of researchers who analyzed 56 studies of prenatal ultrasound imaging.
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