This article needs more reliable medical references for verification or relies too heavily on primary sources .(August 2018) |
A-scan ultrasound biometry | |
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Purpose | diagnostic test used in optometry |
A-scan ultrasound biometry, commonly referred to as an A-scan (short for Amplitude scan), uses an ultrasound instrument for diagnostic testing. [1] A-scan biometry measures the axial length (AL) of the eye prior to cataract surgery in order to assess the refractive power of the intraocular lens that will be implanted. [2]
Medical ultrasound includes diagnostic techniques using ultrasound, as well as therapeutic applications of ultrasound. In diagnosis, it is used to create an image of internal body structures such as tendons, muscles, joints, blood vessels, and internal organs, to measure some characteristics or to generate an informative audible sound. The usage of ultrasound to produce visual images for medicine is called medical ultrasonography or simply sonography, or echography. The practice of examining pregnant women using ultrasound is called obstetric ultrasonography, and was an early development of clinical ultrasonography. The machine used is called an ultrasound machine, a sonograph or an echograph. The visual image formed using this technique is called an ultrasonogram, a sonogram or an echogram.
Radiology is the medical specialty that uses medical imaging to diagnose diseases and guide their treatment, within the bodies of humans and other animals. It began with radiography, but today it includes all imaging modalities, including those that use no ionizing electromagnetic radiation, as well as others that do, such as computed tomography (CT), fluoroscopy, and nuclear medicine including positron emission tomography (PET). Interventional radiology is the performance of usually minimally invasive medical procedures with the guidance of imaging technologies such as those mentioned above.
Obstetric ultrasonography, or prenatal ultrasound, is the use of medical ultrasonography in pregnancy, in which sound waves are used to create real-time visual images of the developing embryo or fetus in the uterus (womb). The procedure is a standard part of prenatal care in many countries, as it can provide a variety of information about the health of the mother, the timing and progress of the pregnancy, and the health and development of the embryo or fetus.
Gynecologic ultrasonography or gynecologic sonography refers to the application of medical ultrasonography to the female pelvic organs as well as the bladder, the adnexa, and the recto-uterine pouch. The procedure may lead to other medically relevant findings in the pelvis.This technique is useful to detect myomas or mullerian malformations.
Endoscopic ultrasound (EUS) or echo-endoscopy is a medical procedure in which endoscopy is combined with ultrasound to obtain images of the internal organs in the chest, abdomen and colon. It can be used to visualize the walls of these organs, or to look at adjacent structures. Combined with Doppler imaging, nearby blood vessels can also be evaluated.
Focused assessment with sonography in trauma is a rapid bedside ultrasound examination performed by surgeons, emergency physicians, and paramedics as a screening test for blood around the heart or abdominal organs (hemoperitoneum) after trauma. There is also the extended FAST (eFAST) which includes some additional ultrasound views to assess for pneumothorax.
3D ultrasound is a medical ultrasound technique, often used in fetal, cardiac, trans-rectal and intra-vascular applications. 3D ultrasound refers specifically to the volume rendering of ultrasound data. When involving a series of 3D volumes collected over time, it can also be referred to as 4D ultrasound or real-time 3D ultrasound.
D. Jackson Coleman is a professor of clinical ophthalmology at NewYork-Presbyterian Hospital at The Edward S. Harkness Eye Institute of Columbia University. He is the former John Milton McLean Professor of Ophthalmology and chairman emeritus at Weill Cornell Medical Center where he served as chairman from 1979 to 2006. His specialties are retinal diseases and ultrasound, working with patients at Columbia University Medical Center. Coleman is also engaged in research involving ultrasound, which he has pursued throughout his career with colleague Ronald Silverman in the Department of Ophthalmology at the Columbia University Medical Center.
Abdominal ultrasonography is a form of medical ultrasonography to visualise abdominal anatomical structures. It uses transmission and reflection of ultrasound waves to visualise internal organs through the abdominal wall. For this reason, the procedure is also called a transabdominal ultrasound, in contrast to endoscopic ultrasound, the latter combining ultrasound with endoscopy through visualize internal structures from within hollow organs.
Emergency ultrasound employing point-of-care ultrasound (POCUS) is the application of ultrasound at the point of care to make immediate patient-care decisions. It is performed by the health care professional caring for the injured or ill persons. This point-of-care use of ultrasound is often to evaluate an emergency medical condition, in settings such as an emergency department, critical care unit, ambulance, or combat zone.
Carotid ultrasonography is an ultrasound-based diagnostic imaging technique to evaluate structural details of the carotid arteries. Carotid ultrasound is used to diagnose carotid artery stenosis (CAS) and can assess atherosclerotic plaque morphology and characteristics. Carotid duplex and contrast-enhanced ultrasound are two of the most common imaging techniques used to evaluate carotid artery disease.
Pelvic congestion syndrome, also known as pelvic vein incompetence, is a long-term condition believed to be due to enlarged veins in the lower abdomen. The condition may cause chronic pain, such as a constant dull ache, which can be worsened by standing or sex. Pain in the legs or lower back may also occur.
The aim of an accurate intraocular lens power calculation is to provide an intraocular lens (IOL) that fits the specific needs and desires of the individual patient. The development of better instrumentation for measuring the eye's axial length (AL) and the use of more precise mathematical formulas to perform the appropriate calculations have significantly improved the accuracy with which the surgeon determines the IOL power.
Donald Eugene Strandness was an American physician, university professor, and research scientist. Dr. Strandness, known as Gene, was influential in the development of Doppler ultrasound as a diagnostic tool in vascular medicine, and did research that established much of the clinical grading criteria in the field of vascular ultrasound.
Vaginal ultrasonography is a medical ultrasonography that applies an ultrasound transducer in the vagina to visualize organs within the pelvic cavity. It is also called transvaginal ultrasonography because the ultrasound waves go across the vaginal wall to study tissues beyond it.
Doppler ultrasonography is medical ultrasonography that employs the Doppler effect to perform imaging of the movement of tissues and body fluids, and their relative velocity to the probe. By calculating the frequency shift of a particular sample volume, for example, flow in an artery or a jet of blood flow over a heart valve, its speed and direction can be determined and visualized.
Cranial ultrasound is a technique for scanning the brain using high-frequency sound waves. It is used almost exclusively in babies because their fontanelle provides an "acoustic window". A different form of ultrasound-based brain scanning, transcranial Doppler, can be used in any age group. This uses Doppler ultrasound to assess blood flow through the major arteries in the brain, and can scan through bone. It is not usual for this technique to be referred to simply as "cranial ultrasound". Additionally, cranial ultrasound can be used for intra-operative imaging in adults undergoing neurosurgery once the skull has been opened, for example to help identify the margins of a tumour.
Renal ultrasonography is the examination of one or both kidneys using medical ultrasound.
Ultrasonography in suspected deep vein thrombosis focuses primarily on the femoral vein and the popliteal vein, because thrombi in these veins are associated with the greatest risk of harmful pulmonary embolism.
The Pregnancy Outcome Prediction (POP) Study is a prospective cohort study of 4,512 women who have never given birth, recruited at the Rosie Hospital between January 2008 and July 2012.