Computed Tomography Term Paper

Download this Term Paper in word format (.doc)

Note: Sample below may appear distorted but all corresponding word document files contain proper formatting

Excerpt from Term Paper:

Computed tomography, more commonly know as a CT or CT scan, is an X-ray technique that is used to produce very detailed images of internal organs located in various parts of the body, such as the head, chest, and abdomen. Doctors use the images produced through this procedure to help diagnose and treat diseases. Other terms for the technique are also called computerized tomography or computerized axial tomography (CAT). While conventional X-ray exams produce two-dimensional images, CT scans uses an X-ray-sensing unit that rotates around your body and a large computer to create cross-sectional images of the inside of your body. This paper will address vital educational information including a brief history, uses for computed tomography, and the effects that it may have on the patient.

Computed Tomography

Brief History

British engineer, Godfrey Hounsfield of EMI Laboratories, England and Allan Cormack of Tufts University in Massachusetts invented computed tomography. Their work led to the installation of the first clinical CT scanners between the years 1974-1976. The original systems were limited to only taking images of the head, but soon "whole body" systems with larger patient openings became offered. The use of Cat Scans was in wide use beginning in 1980. There are now about 6,000 CT scanners installed in the United States and about 30,000 installed worldwide.

The first CT scanner developed by Hounsfield in his lab took several hours to acquire the raw data for a single scan or "slice" and took days to reconstruct a single image from this raw data. This is a far cry from the efficient imaging of the latest multi-slice CT systems that now have the capability to collect up to four "slices of data" in about 350 milliseconds and then reconstruct a matrix image from millions of data points in less than a second. For example, an entire chest image can be scanned in five to ten seconds using the most advanced multi-slice CT system.

During its brief history, advancements for computerized tomography have made great improvements in speed, patient comfort, and resolution. As scan times have gotten faster, more anatomy can be scanned more quickly and more efficiently. The extreme speed of scanning allows the elimination of artifacts from patient motion such as normal breathing. Faster scanning helps to eliminate artifacts from patient motion such as breathing or peristalsis. CT exams are even now quicker and more patient friendly than ever before. Tremendous research and development has been made to provide exceptional image quality for a diagnostic guarantee of the lowest possible x-ray dose.

Benefits for Computed Tomography

Computed tomography has been a powerful tool for more than thirty years and the benefits of a CaT scan include many. It is also a noninvasive way to "see" one's internal organs and tissues. "Advances with helical and subsequent multidetector technology have offered expanding and diverse opportunities" (Frush, 2003) where doctors use CaT scans to diagnose many conditions, such as tumors, infections, blood clots, and broken bones. (, 2003). A CaT scan also helps in diagnosing some diseases that might otherwise require surgery. For example, doctors can use a CaT scan to guide catheters to an abscess in the body and then drain pus from the infected area.

Computed tomograpy is used for various reasons and include:

Diagnose muscle and bone disorders, such as osteoporosis

Bone disorders are easier to detect than with traditional x-ray technology. Many hairline fractures may now be detected that previously were overlooked, thus possibly causing loss of bone area since it remained untreated.

Pinpoint the location of a tumor, infection or blood clot

Guide procedures such as surgery, biopsy and radiation therapy

Detect and monitor diseases such as cancer or heart disease, and monitor the progression of a disease

Detect internal injuries and internal bleeding

Revolutionized the surgical approaches to the posterior-ethmoid sinuses since the introduction of computed tomography

There are many revolutionary advances in the field of sinus surgical procedures. When the introduction of computer-aided image guidance in 1993, the endoscopic view and the CT view have been united to provide a three-dimensional triplanar perspective to the surgical anatomy, thus allowing computer-aided imaging to become an invaluable aspect of crucial anatomic regions such as the sphenoid sinus (Wagner & Conti, 1991).

They state, "that the sphenoid sinus, located in the recessed position in the skull base and surrounded by a host of vital neurologic structures, may be amenable to image-guided surgery in both primary and revision surgical cases. Laterally, the sphenoid sinus is flanked by the cavernous sinus, which houses the oculomotor nerve, the trochlear nerve, the ophthalmic division of the cranial nerve, and the internal carotid artery."

Usually, the sphenoid sinus was accessed by two principal methods being bicoronal craniotomy or a through the nose entry also known as transnasal entry. Both approaches may produce many risks and there are usually expected post-operative problems such as brain retraction and possibly permanent anosmia. However, with the use of computer tomography, "the anatomy of the paranasal sinuses constitutes a complex three-dimensional structure that deserves the accurate spatial representation afforded by computer-aided image-guided endoscopic sinus surgery to avoid surgical pitfalls" (Wagner & Conti, 1991).

Computed tomography exams can be done even if the patient already has a pacemaker or cardioverter defibrillator that has been implanted in the chest to help regulate the heartbeat. Also, if the patient is pregnant or thinks that they might be, their doctor should be informed because it might become suggested to postpone the procedure or choose an alternative exam that doesn't involve radiation. A variety of procedures are also used on healthy people. Many people who are healthy will undergo whole-body CaT scans to detect cancer and other medical conditions in the earliest stages, before any symptoms develop. Early detection is the key to a healthy life.

Cancer screening has also benefited from the use of CaT scans. Wagner and Conti (1991) state that lesions may not appear on traditional scans such as an MRI, and lesions of disparate pathology may also appear similar. The superior image quality, however, ensures that the experience will be sought and that MRI will find increasing use." The data produced by the CaT scan is more accurate thus showing that the biochemical function of the brain can be provided by positron emission tomography and single photon emission tomography. Emissions from radioactive tracers can be utilized to construct an image of where the tracers are concentrated in living tissue. Through the appropriate tracer, detailed information about the location of key biochemical processes may be obtained. These imaging technologies, used to complement one another, will yield information about cancer in its living, dynamic state, and complement the pathological analysis of processed tissue specimens (Wagner and Conti, 1991).

How Does Computer Tomography Work? (2000) explains that "computed tomography is based on the x-ray principal: as x-rays pass through the body they are absorbed or weakened at differing levels creating a matrix or profile of x-ray beams of different strength. This x-ray profile is registered on film, thus creating an image. In the case of CaT, the film is replaced by a banana shaped detector which measures the x-ray profile."

The CaT scan is performed in a hospital or an outpatient clinic. The duration of the X-ray imaging may last about 45 minutes to an hour. There are various levels of preparation that must be made in order to prepare for the scan, depending upon the patient's needs. The scan itself may only last up to several minutes. The patient may not have any metal zippers, snaps, and buttons on their clothing that would interfere with the CaT scan. A hospital gown will be worn if the patient's clothing does not comply with the CaT equipment. The patient will lie on a narrow table that moves in or out of the opening of the gantry or front area. The patient is not to move during this time and should become as comfortable as possible for the duration of the procedure; however, the table can be raised, lowered or tilted without any concern. Straps and pillows are provided to help the patient stay in position. During a head CaT, the table may be fitted with a special cradle that holds the head when imaging occurs (Mayo Clinic, 2000).

The table is positioned so that the organ to be scanned lies in the center of the gantry. A tube on the entrance beams X-rays through the patient's body and into special detectors that analyze the image produced. The gantry then rotates around the patient to obtain many images from different angles. The X-ray tube rotates around the body, while the table slowly moves through the opening. While the table is moving, there is a variety of motion taking place. The patient may realize that they might need to hold your breath to avoid blurring the images. The patient will begin to hear clicking and whirring noises and with each rotation, there are many images of thin slices of your body being conducted. The technologist…[continue]

Cite This Term Paper:

"Computed Tomography" (2004, April 02) Retrieved October 27, 2016, from

"Computed Tomography" 02 April 2004. Web.27 October. 2016. <>

"Computed Tomography", 02 April 2004, Accessed.27 October. 2016,

Other Documents Pertaining To This Topic

  • Computed Tomography CT Scans Are

    The recent two reported cases also suggest that there may be many more similar incidences happening around unnoticed. The two contrasting examples of overdoses of radiation at hospitals confirms that if the hospitals accept their responsibilities properly and try to serve the patient's in professional manner, such types of accidental over exposure can be avoided. Instead of creating a medical terror, the reporter managed to provide relevant information in a

  • CT Computed Tomography and Radiation

    However, the increased use of CT scans in more of less careless and ill-advised practices will raise the concern of the effects it has on the health of the general public. It is therefore critical that the public is made aware of the associated risks and necessary education is conducted. The voice of all radiologists, clinicians, and technicians should advocate for the safe use of CT scans for both

  • Conventional Tomography

    Conventional Tomography outlining the various aspects, issues and methods used. It has 10 sources. The field of medical imaging has been in existence for over one hundred years but new research and scientific breakthroughs have changed both its image and its role. Radiology is not only diagnostic but is expanding to encompass curative techniques as well. The most common radiological investigation remains the conventional X-ray but a wide range of

  • Positron Emission Tomography

    Positron Emission Tomography (PET) PET represents a new step forward in the way scientists and doctors look at the brain and how it functions. An X-ray or a CT scan shows only structural details within the brain. The PET scanner gives us a picture of the brain at work. - What is PET? The epigraph above is reflective of the enthusiasm being generated among clinicians concerning the advent of positron emission tomography

  • Kai Hung Fung Artwork Instrument of Expression

    Kai Hung Fung Artwork Instrument of Expression and Communication Kai Hung Fung and his Artwork Kai Hung Fung is a radiologist known for his 3D creative work on human body. He gained attention in 2003 when he started using computed tomography (CT) to visualize human body parts. His creative work is based on a complete background research for example he researched about color usage in 3D image of computed tomography. He is also

  • Extant Literature Has Been Dedicated to the

    Extant literature has been dedicated to the evaluation of closed head injuries using the Canadian Scale and New Orleans criteria for Adult patients in rural areas.The work of Stielle et al. (2005) explored the comparison of the Canadian CT head rule and the New Orleans Criteria in various Patients suffering from minor head injuries. Their work indicated that the current application of computed tomography (CT) for cases of minor head

  • Radiology Reducing Patient Exposure and

    Under conventional radiology, excessive exposure outputs a "black" film. In case of digital systems, good images are got from a large range of doses. With the help of digital fluoroscopy systems, it is extremely simple to get as well as delete images. There might be an inclination to get more images than what is required. In case of digital radiology, higher patient dosage implies improved image quality and therefore

Read Full Term Paper
Copyright 2016 . All Rights Reserved