Computed+tomography

toc =Definition= Also called a CT scan, computed tomography uses high-tech X-ray equipment to give an improved image of the patient's internal organs. The CT machine rotates around a person's body, shooting beams from every direction to produce thin slices of the image of the organ. Compared to a typical X-ray, the CT scan is more beneficial to the patient because it produces cross-sectional views of the interior of the body.

This photo of a CT scanner is from Flickr.com. The photo was taken by thesmokingsection (username).

Xenon CT
The Xenon CT scan assesses the brain. The patient inhales a radioactive gas, called Xenon. The gas then traces blood flow within the body. A patient’s blood flow plays an important role in diagnosing certain brain disorders. For example, when a lack of blood flow through the brain occurs, a stroke arises.

Dynamic Spacial Reconstruction
Dynamic Spatial Reconstruction (DSR) CT scans perform with more accuracy and precision than standard CT scans. DSR scans can detect changes of speed and movement in internal organs. These changes of the blood flow reveal themselves in three-dimensional images. A DSR scan serves its purpose well while evaluating the heart. It can detect defects, clogged blood vessels, and blood flow. =Diagnostic Uses= Doctors use CT scans to diagnose multiple abnormalities. These include broken bones, cancers, blood clots, heart disease, and internal bleeding. [|Http://www.nlm.nih.gov/medlineplus/ctscans.html], also known as the Medline Plus Health Information site, not only offers the diagnostic uses of CT scans, but provides all sorts of various health information in the form of encyclopedias, dictionaries, directories for doctors, and a search engine for virtually any health-related questions. The scan also assesses problems concerning the brain and the abdomen. The different kinds of scans are broken up into four different categories: cardiac, chest, cranial and abdominal and pelvic. A CT scan of the brain provided by Flickr.com and taken by ClintJCL.
 * During the cardiac CT scan, the heart is imaged numerous amounts of times. The ability for a CT scan to rotate, produce "slices" of the heart in the imaging, and its high speed and resolution make for a well-defined scan of the heart, especially the coronary arteries. However, the radiation exposure in a single scan is equivalent to hundreds of chest x-rays, thus increasing the risk of potential cancer. Yet, due to the machine's strong sensitivity, the scan has the ability to diagnose coronary heart disease by producing negative results (meaning the patient tested negative for coronary heart disease).
 * To detect irregular issues in the chest, the CT scan can be conducted in a variety of methods. For chronic diseases, such as emphysema and fibrosis, the scan goes uses high resolution computed tomography, also known as HRCT. In this process, the machine develops thin slices of pictures of the chest. Computed tomography may also spot airspace diseases, including pneumonia, and even cancer, by taking thicker slices to develop pictures from.
 * CT, being more sensitive than an MRI, is often chosen to detect acute hemorrhages in the brain; however, MRIs are often chosen over CT to detect brain tumors. In the case of a traumatic accident, CT helps sense any kind of skull or facial fracture. Besides detecting injury or disease, CT can aid in the planning of a surgical procedure around the head, neck, or mouth area to correct any dental or cranial defects.


 * Computed tomography's sensitivity assists in finding any abdominal problems such as the initial stage of cancer or some sort of organ injury after an accident. CT is also used for examining minor abdominal pain. Abdominal conditions diagnosed through CT include appendicitis, renal or urinary stones, pancreatitis, and much more. Even though the scan could be very useful for the stomach, it has restricted access into the pelvic area, which makes ultrasounds (for females) and MRIs the choice medical imaging processes. Wikipedia.org contains useful information on CT scans and its components.

A CT scan of the abdomen/stomach area provided by Flickr.com, taken by Crucially. The site http://en.wikipedia.org/wiki/computed_tomography#diagnostic_use not only gives an in-depth analysis of the four different forms of CT scanning, but it gives the benefits of each type of scan along with helpful pictures. =History= The word Tomography in Computed Tomography originated from the Greek word //Tomos,// which means "slice". The second part of the word, graphy, stems from //graphein,// which means "to write". Sir Godfrey Hounsfield and Dr. Alan Cormack developed the CT scan. The two won the Nobel Prize in medicine in 1979 for their accomplishments. In the early days, to get the CT scanner's images was a long and tedious process. It would take the founders hours or even days to construct one image from the raw data acquired. Fortunately, modern technology improved the process. Now a patient can be scanned and images can be created within minutes. The website //Imaginis// reiterates the positive improvements made on the CT scan. The CT scan now can be considered a generally comfortable experience by the patient. Http://www.imaginis.com/ct-scan gives a brief history on CT scanning and a page of links for what to expect, professionsls who perform the scanning, frequently asked questions, and more. [|Http://www.emedicinehealth.com/ct_scan/article_em.htm], or the eMedicine health site, gives a deep analysis of all differnt topics of cT scanning, such as the procedure itself, any risks involved, and during and after the procedure directions. =Process= To begin the CT scan, a technologist places the patient in the correct position, usually lying flat on their back or on their side on a table. Occasionally, pillows and straps are used in order to keep the patient in the correct position. A certain form of contrast material may be used to aid in the scanning process to get a better quality image. Once the patient and technologist are readily prepared, the table which the patient is placed upon moves forward into the opening of the doughnut-shaped CT scanning machine. When the patient is in the machine, it is rotating around the body as the table moves the patient slowly through, and it sends beams to certain areas of the afflicted person. When the machine has completed scanning the afflected body part the patient will until the images have been looked at. If the image quality is good, the patient may leave the table. The whole CT scan usually does not last very long. According to the **UCL Institute of Child Health** website the scan lasts between five and twenty minutes.

A man lying in the typical position preparing to undergo the CT scanning procedure. The picture was provided by Flickr.com and taken by ohthebill.

The UCL Institute of Child Health http://www.ich.ucl.ac.uk/factsheets/families/F030059/index.html gives a short introduction explaining the process of a CT scan and the procedures taken if a person is to have their child undergo computed tomography. The machine produces exceptionally advanced images. The images are two-dimensional and cross-sectional. The website, radiologyinfo.org, compares the images to slices of bread, "[its like] looking into a loaf of bread by cutting the loaf into thin slices. When the image slices are reassembled by computer software, the result is a very detailed multidimensional view of the body's interior." This comparison of bread makes the images easier to visualize and understand. H[|ttp://www.radiologyinfo.org/en/info.cfm?pg=bodyct&bhcp=1] allows a patient to gain some background knowledge of the machine they are put through as well as some of the common uses of the CT scanner.

=Advantages=

= = =Citations= http://www.nlm.nih.gov/medlineplus/ctscans.html http://en.wikipedia.org/wiki/computed_tomography#diagnostic_use http://www.emedicinehealth.com/ct_scan/article_em.htm http://www.ich.ucl.ac.uk/factsheets/families/F030059/index.html http://www.radiologyinfo.org/en/info.cfm?pg=bodyct&bhcp=1.
 * CT eliminates the imposition of the images of all structures outside the area of interest. This makes it so that it is easier to study said area without unnecessary images getting in one's way.
 * It can also distinguish the difference between tissues with densities differing by less than 1% as a result of the inherent high-contrast resolution it bears.
 * Data from a single CT scan can be viewed as images in the axial, sagittal, or coronal planes depending on the diagnostic task. This is known as multiplanar reformatted imaging.
 * The scanning time is relatively low, and internal structures such as the lungs can be viewed within less than a minute.
 * The operator can leave the examination room after they have set the various parameters for the examination.
 * Although there is of course some radiation exposure, it is relatively minimal compared to some other methods.