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Virtual Colonoscopy
Virtual colonoscopy (VC, also called CT colonography or CT pneumocolon) is the use of CT scanning or magnetic resonance imaging (MRI) to produce two- and three-dimensional images of the colon (large intestine), from the lowest part, the rectum, to the lower end of the small intestine, and to display the images on an electronic display device. The procedure is used to screen for colon cancer and polyps, and may detect diverticulosis. A virtual colonoscopy can provide 3D reconstructed endoluminal views of the bowel. VC provides a secondary benefit of revealing diseases or abnormalities outside the colon. Procedure While preparations for VC vary, the patient will usually be asked to take laxatives or other oral agents at home the day before the procedure to clear stool from the colon. A suppository is also used to cleanse the rectum of any remaining fecal matter. The patient may also be given a solution designed to coat any residual faeces which may not have been cleared by th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volume Rendering
In scientific visualization and computer graphics, volume rendering is a set of techniques used to display a 2D projection of a 3D discretely sampled data set, typically a 3D scalar field. A typical 3D data set is a group of 2D slice images acquired by a CT, MRI, or MicroCT scanner. Usually these are acquired in a regular pattern (e.g., one slice for each millimeter of depth) and usually have a regular number of image pixels in a regular pattern. This is an example of a regular volumetric grid, with each volume element, or voxel represented by a single value that is obtained by sampling the immediate area surrounding the voxel. To render a 2D projection of the 3D data set, one first needs to define a camera in space relative to the volume. Also, one needs to define the opacity and color of every voxel. This is usually defined using an RGBA (for red, green, blue, alpha) transfer function that defines the RGBA value for every possible voxel value. For example, a volu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supine Position
The supine position () means lying horizontally, with the face and torso facing up, as opposed to the prone position, which is face down. When used in surgical procedures, it grants access to the peritoneal, thoracic, and pericardium, pericardial regions; as well as the head, neck, and extremities. Using anatomical terms of location, the dorsal side is down, and the ventral side is up, when supine. Semi-supine In scientific literature "semi-supine" commonly refers to positions where the upper body is tilted (at 45° or variations) and not completely horizontal. Relation to sudden infant death syndrome The decline in death due to sudden infant death syndrome (SIDS) is said to be attributable to having babies sleep in the supine position. The realization that infants sleeping face down, or in a prone position, had an increased mortality rate re-emerged into medical awareness at the end of the 1980s when two researchers, Susan Beal in Australia and Gus De Jonge in the Nether ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cancer Screening
The objective of cancer screening is to detect cancer before symptoms appear, involving various methods such as blood tests, urine tests, DNA tests, and medical imaging. The purpose of screening is early cancer detection, to make the cancer easier to treat and extending life expectancy. In 2019, cancer was the second leading cause of death globally; more recent data is pending due to the COVID-19 pandemic. Universal screening, also known as mass screening or population screening, involves the screening of individuals within certain age and gender groups, aiming to screen the population for particular cancers or cancer risk factors. Selective screening, also known as targeted screening, identifies individuals with a higher risk of developing cancer, including individuals with a family history (genetic risk) of cancer or individuals engaging in high-risk behaviors such as smoking. The act of cancer screening plays a pivotal role in both preventing cancer and providing early diagn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold Standard (test)
In medicine and medical statistics, the gold standard, criterion standard, or reference standard is the diagnostic test or benchmark that is the best available under ''reasonable'' conditions. It is the test against which new tests are compared to gauge their validity, and it is used to evaluate the efficacy of treatments. The meaning of "gold standard" may differ between practical medicine and the statistical ideal. With some medical conditions, only an autopsy can guarantee diagnostic certainty. In these cases, the gold standard test is the best test that keeps the patient alive, and even gold standard tests can require follow-up to confirm or refute the diagnosis. History The term 'gold standard' in its current sense in medical research was coined by Rudd in 1979, in reference to the monetary gold standard. In medicine "Gold standard" can refer to popular clinical endpoints by which scientific evidence is evaluated. For example, in resuscitation research, the "gold standar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gray (unit)
The gray (symbol: Gy) is the unit of ionizing radiation dose in the International System of Units (SI), defined as the absorption of one joule of radiation energy per kilogram of matter. It is used as a unit of the radiation quantity absorbed dose that measures the energy deposited by ionizing radiation in a unit mass of absorbing material, and is used for measuring the delivered dose in radiotherapy, food irradiation and radiation sterilization. It is important in predicting likely acute health effects, such as acute radiation syndrome and is used to calculate equivalent dose using the sievert, which is a measure of the stochastic health effect on the human body. The gray is also used in radiation metrology as a unit of the radiation quantity kerma (physics), kerma; defined as the sum of the initial kinetic energy , kinetic energies of all the charged particles liberated by uncharged ionizing radiation in a sample of matter per unit mass. The unit was named after British phys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionizing Radiation
Ionizing (ionising) radiation, including Radioactive decay, nuclear radiation, consists of subatomic particles or electromagnetic waves that have enough energy per individual photon or particle to ionization, ionize atoms or molecules by detaching electrons from them. Some particles can travel up to 99% of the speed of light, and the electromagnetic waves are on the high-energy portion of the electromagnetic spectrum. Gamma rays, X-rays, and the higher energy vacuum ultraviolet, ultraviolet part of the electromagnetic spectrum are ionizing radiation; whereas the lower energy ultraviolet, visible light, infrared, microwaves, and radio waves are non-ionizing radiation. Nearly all types of laser light are non-ionizing radiation. The boundary between ionizing and non-ionizing radiation in the ultraviolet area cannot be sharply defined, as different molecules and atoms ionize at Ionization energies of the elements (data page), different energies. The energy of ionizing radiation starts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biopsy
A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, an interventional radiologist, or an interventional cardiology, interventional cardiologist. The process involves the extraction of sampling (medicine), sample Cell (biology), cells or Biological tissue, tissues for examination to determine the presence or extent of a disease. The tissue is then Histopathology, fixed, dehydrated, embedded, sectioned, stained and mounted before it is generally examined under a microscope by a pathologist; it may also be analyzed chemically. When an entire lump or suspicious area is removed, the procedure is called an excisional biopsy. An incisional biopsy or core biopsy samples a portion of the abnormal tissue without attempting to remove the entire lesion or tumor. When a sample of tissue or fluid is removed with a needle in such a way that cells are removed without preserving the histological architecture of the tissue cells, the procedure is called a needle as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Renal Cell Carcinoma
Renal cell carcinoma (RCC) is a kidney cancer that originates in the lining of the Proximal tubule, proximal convoluted tubule, a part of the very small tubes in the kidney that transport primary urine. RCC is the most common type of kidney cancer in adults, responsible for approximately 90–95% of cases. It is more common in men (with a male-to-female ratio of up to 2:1). It is most commonly diagnosed in the elderly (especially in people over 75 years of age). Initial treatment is most commonly either partial or complete removal of the affected kidney(s). Where the cancer has not metastasised (spread to other organs) or burrowed deeper into the tissues of the kidney, the five-year survival rate is 65–90%, but this is lowered considerably when the cancer has spread. The body is remarkably good at hiding the symptoms and as a result people with RCC often have advanced disease by the time it is discovered. The initial symptoms of RCC often include haematuria, blood in the urine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mayo Clinic
Mayo Clinic () is a Nonprofit organization, private American Academic health science centre, academic Medical centers in the United States, medical center focused on integrated health care, healthcare, Mayo Clinic College of Medicine and Science, education, and research. It maintains three major campuses in Rochester, Minnesota; Jacksonville, Florida; and Phoenix, Arizona, Phoenix/Scottsdale, Arizona. Mayo Clinic employs over 7,300 physicians and scientists, along with another 66,000 administrative and allied health staff. The practice specializes in treating difficult cases through Health care#Tertiary care, tertiary care and Medical tourism#United States, destination medicine. It is home to the top-15 ranked Mayo Clinic Alix School of Medicine in addition to many of the highest regarded residency education programs in the United States. It spends over $660 million a year on research and has more than 3,000 full-time research personnel. William Worrall Mayo settled his family i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barium Enema
A lower gastrointestinal series is a medical procedure used to examine and diagnose problems with the human colon of the large intestine. Radiographs (X-ray pictures) are taken while barium sulfate, a radiocontrast agent, fills the colon via an enema through the rectum. The term barium enema usually refers to a lower gastrointestinal series, although enteroclysis (an upper gastrointestinal series) is often called a small bowel barium enema. Purpose For any suspected large bowel disease, colonoscopy is the investigation of choice because tissue sample can be taken for investigation. Virtual colonoscopy (also known as CT colonography) is another preferred investigation, provided that facilities and expertise are available. Virtual colonoscopy also avoids the risk of total blockage of any stricture in the large bowel due to barium impaction. Some conditions are absolutely contraindicated for barium enema namely: toxic megacolon, pseudomembranous colitis, and recent history rigid e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colonoscopy
Colonoscopy () or coloscopy () is a medical procedure involving the Endoscopy, endoscopic examination of the large bowel (colon) and the distal portion of the small bowel. This examination is performed using either a Charge-coupled device, CCD camera or a fiber optic camera, which is mounted on a flexible tube and passed through the anus. The purpose of a colonoscopy is to provide a visual diagnosis via inspection of the internal lining of the colon wall, which may include identifying issues such as ulceration or Precancerous condition, precancerous polyps, and to enable the opportunity for biopsy or the removal of suspected colorectal cancer lesions. Colonoscopy is similar to sigmoidoscopy, but surveys the entire colon rather than only the sigmoid colon. A colonoscopy permits a comprehensive examination of the entire colon, which is typically around 1,200 to 1,500 millimeters in length. In contrast, a sigmoidoscopy allows for the examination of only the distal portion of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prone Position
Prone position () is a body position in which the person lies flat with the chest down and the back up. In anatomical terms of location, the dorsal side is up, and the ventral side is down. The supine position is the 180° contrast. Etymology The word ', meaning "naturally inclined to something, apt, liable," has been recorded in English since 1382; the meaning "lying face-down" was first recorded in 1578, but is also referred to as "lying down" or "going prone." ''Prone'' derives from the Latin ', meaning "bent forward, inclined to," from the adverbial form of the prefix ''pro-'' "forward." Both the original, literal, and the derived figurative sense were used in Latin, but the figurative is older in English. Anatomy In anatomy, the prone position is a position of the human body lying face down. It is opposed to the supine position which is face up. Using the terms defined in the anatomical position, the ventral side is down, and the dorsal side is up. Concerning the forea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
