Computed Tomography
Computed Tomography
By: Ashley Casella
July 20, 2010
The department of radiology produces hundreds of thousands of examinations each year using various modalities such as breast imaging, computed tomography (CT), general diagnostic imaging, nuclear medicine, magnetic resonance imaging (MRI), Ultrasound, and Neurovascular/ Interventional Imaging. I 'm going to inform you of the fundamentals, capabilities, and advancements of computed tomography, also known as CAT scan.
This imaging modality requires the technologist to look at anatomy of a CT image in a totally different way than they are used to with general radiographs. Like MRI and Sonography, CT technologies create a cross-sectional imaging plane that visualizes a slice through the body and has the advantage of eliminating structures that superimpose other anatomic parts. During a CT procedure, the patient 's body part of interest is scanned by an x-ray tube rotating around the gantry, which is the entry-way of the CT machine. A tightly collimated x-ray beam is directed through the anatomy from many different angles. The radiation exiting the patient is measured by the detector assembly, which sends information from the detectors to the host computer where data is then assembled into an image to be displayed on the monitor. CT takes images along three imaging planes, axial, coronal, and sagittal. Axial planes, also referred to as transverse planes, slice through the body from anterior to posterior and from side to side. In effect, this type of horizontal imaging plane also divides the body into superior and inferior portions. Most images generated by CT are examples of an axial plane. That is the reason CT is also referred to as CAT scan, or computed axial tomography. When looking at an axial image, it is helpful to imagine standing at the patient 's feet and looking up toward the head. In addition, the patient 's right side is to the viewer 's left and left side to the viewer
By: Ashley Casella
July 20, 2010
The department of radiology produces hundreds of thousands of examinations each year using various modalities such as breast imaging, computed tomography (CT), general diagnostic imaging, nuclear medicine, magnetic resonance imaging (MRI), Ultrasound, and Neurovascular/ Interventional Imaging. I 'm going to inform you of the fundamentals, capabilities, and advancements of computed tomography, also known as CAT scan.
This imaging modality requires the technologist to look at anatomy of a CT image in a totally different way than they are used to with general radiographs. Like MRI and Sonography, CT technologies create a cross-sectional imaging plane that visualizes a slice through the body and has the advantage of eliminating structures that superimpose other anatomic parts. During a CT procedure, the patient 's body part of interest is scanned by an x-ray tube rotating around the gantry, which is the entry-way of the CT machine. A tightly collimated x-ray beam is directed through the anatomy from many different angles. The radiation exiting the patient is measured by the detector assembly, which sends information from the detectors to the host computer where data is then assembled into an image to be displayed on the monitor. CT takes images along three imaging planes, axial, coronal, and sagittal. Axial planes, also referred to as transverse planes, slice through the body from anterior to posterior and from side to side. In effect, this type of horizontal imaging plane also divides the body into superior and inferior portions. Most images generated by CT are examples of an axial plane. That is the reason CT is also referred to as CAT scan, or computed axial tomography. When looking at an axial image, it is helpful to imagine standing at the patient 's feet and looking up toward the head. In addition, the patient 's right side is to the viewer 's left and left side to the viewer
Cited: Frank Long Smith. Merrill 's Atlas of Radiographic Positioning & Procedures. 11. 3. 2007. 304-319. Print. Ph.D., Smith, Steven D. "The Scientist and Engineer." Ch. 25. Special Imaging Techniques/ Computed Tomography. N.p., n.d. Web. 20 Jul 2010. http://www.dspguide.com/ch25/5.htm Mahesh, Mahadevappa. “Search for Isotropic Resolution in CT from Conventional through Multi-Row Detector.” The AAPM/RSNA Physics Tutorial for Residents. Web. http://radiographics.rsna.org/content/22/4/949.full "Systsem Operation & Components." The CT Registry Review Program. 4. Medical Imaging Consultants, Inc., Print.