Xray computed tomography ct has experienced tremendous growth in recent years, in terms of both basic technology and new clinical applications. Basic principles of computed tomography physics and. Pdf advances in computed tomography imaging technology. This book provides an overview of the evolution of ct, the mathematical and physical aspects of the technology, and the fundamentals of image reconstruction using algorithms.
Whiting introduction slightly more than three decades old, computed tomography ct continues to advance rapidly in both imaging performance and widening clinical applications. Ct scans can be used to identify disease or injury within various regions of the body. This first article covers the fundamental principles of ct, including the basic geometry of the ct scan process, the nature of the measurements made by ct. Basic principles of ct ct imaging system moves around the body part at a fixed location attenuation.
Principles of ct diagnosis precontrast study postcontrast study change in adjacent structures clinical information. Clinicians need to be aware of the potentially harmful radiation that patients are exposed to, with each individual ct scan that is performed. For example, ct has become a useful screening tool for detecting possible tumors or lesions within the abdomen. Kak and malcolm slaney, principles of computerized tomographic imaging, ieee press, 1988. Ct uses xrays to generate crosssectional, twodimensional images of the body. Computed tomography ct and magnetic resonance imaging mri are the most wide ly used crosssectional imaging methods used in medicine. Introduction to magnetic resonance imaging techniques. Definition facts about ctdefinition facts about ct computer tomography ct, originally known as computed axial tomography cat or ct scan and body section rentenography.
Pet imaging is now combined with ct, as the pet camera provides high sensitivity for the distribution of the tracer, and the ct provided precise anatomic localization and attenuation correction. A ct scan of the heart may be ordered when various types of heart disease or abnormalities are suspected. Imaging before ct entire body areas were inaccessible to radiography brain, mediastinum, retroperitoneum diagnostic procedures showing better detail in these areas were potentially harmful and or poorly tolerated by the patient pneumoencephalography, diagnostic pneumomediastinum, diagnostic laparotomy. Ct uses multiple pencil or fan beams of kilovoltage photons that pass through a desired volume from multiple angles usually over 180 degrees. This video presentation explains the basic principle of ct scan. Choose from used and new textbooks or get instant access with etextbooks and digital materials. Ct scans are created using a series of xrays, which are a form of radiation on the electromagnetic spectrum. Computed tomography ct school of veterinary medicine. A physicist and an engineer, allan cormack and godfrey. Computed tomography ct computed tomography ct uses xrays to produce multiple images of the inside of the body, and provides thin, crosssectional slices for viewing. In this article, we will outline the basic science behind ct scans, describe the principles of interpretation, and highlight their advantages and drawbacks compared to other imaging techniques. Please use one of the following formats to cite this article in your essay, paper or report. Basic principles of ct scanners and image reconstruction ct scanning and imaging parameters dr slavik tabakov slavik.
Basic principles of ct scanners and image reconstruction indico. Magnetic resonance imaging mri is arguably the most sophisticated imaging method used in clinical medicine. Computerised tomography, ct, is an ideal form of tomography yielding sequence images of thin consecutive slices of the patient and providing the opportunity to localise in three dimensions. It is quite possible to acquire images with an mr scanner without understanding the principles behind it, but choosing the best parameters and methods, and interpreting images and artifacts, requires understanding. On the opposite side of the volume is a dosimeter which measures the amount of ionising radiation reaching it. Ct instrumentation and principles of ct protocol optimisation. Basic ct scanner components gantry xray tube detector control.
In addition to the difficulty in differentiating and classifying tissue. This text serves as an introduction to magnetic resonance imaging techniques. Basic principles of ct ct neuroanatomy disease processes evaluated with ct. In recent years, mri scans have become increasingly common, as costs decrease. Multisection computed tomography ct was introduced in 1992 with the advent of dualsectioncapable scanners and was improved in 1998 following the development of quadsection technology. The scanner emits xrays towards the patient from a variety of angles and the detectors in the scanner measure the difference between the xrays that are absorbed by the body, and xrays that are transmitted through the body. Physical principles, clinical applications, and quality control, 4th edition. In 2010, the technologist committee decided that the next three guides would be dedicated to the topic of hybrid petct imaging. Basic principles of computed tomography flashcards quizlet. Computed tomography ct scanning is an extremely common imaging modality in modern medicine.
This presentation gives an information about basic principles of ct scanning covering the. With a recent increase in gantry speed from one to two revolutions per second, multisection ct scanners are now up to eight times faster than conventional. Tissue density differences as low as 1% or less can be detected with ct. An appreciation of the potential of ct and its limitations can be obtained with an understanding of basic.
With advancements in technology, it is rapidly replacing many diagnostic radiographic procedures. Introduced in the early 1970s, ct scanning gained rapid acceptance in clinics and hospitals. Click to view this presentation from the impact course. Pdf computed tomography download full pdf book download. Make sure each scan is justified even a lowdose ct is too much dose when inappropriately ordered check with physician if. Here is a description about image acquisition and the image formation processes. Since the ct scan requires so many xray exposures, the amount of radiation used to make a ct scan is typically greater that used to make a traditional xray. Background and terminology the main advantages of ct over conventional radiography are in the elimination of superimposed structures, the ability to differentiate small differences in density of anatomic structures and abnormalities, and the superior quality of the images. Basic interpretation of ct scans most of the ct pictures are nonspecific ct pictures are depending on the density of the structures. This course is based on the textbook, computed tomography physical principles, clinical applications, and quality control 4 th edition, authored by euclid seeram, phd, msc, bsc, fcamrt. Basic principles of ct scanners and image reconstruction.
Computed tomography ct scans can detect pathology that may be missed on a conventional chest radiograph. The basic principles of computed tomography and magnetic. Computed tomography ct is a technique that uses an xray beam to generate images. It examines image display from traditional methods through the most recent. Much ct development occurred via a series of scanner generations, especially spiral helical scanning and multidetector row designs. Basic principles of computed tomography physics and technical considerations kyongtae t. If the address matches an existing account you will receive an email with instructions to reset your password. Kak and malcolm slaney, principles of computerized tomographic imaging, society of industrial and applied mathematics, 2001 electronic copy each chapter of this book is available as an adobe pdf. Written to meet the varied requirements of radiography students and practitioners, this twocolor text provides comprehensive coverage of the physical principles of ct and its clinical applications. In this article, we will outline the basic principles behind mri scans, how to orientate and interpret a scan, and address some of their advantages and disadvantages compared to other imaging modalities. Crosssections are reconstructed from measurements of attenuation coefficients of xray beams in the volume of the object studied. Computed tomography available for download and read online in other formats. The basics of ct ct imaging chain system components acquisition methods image quality applications 632014 hareesha n g, dept of aero engg, dsce 2 3.
Petct medical imaging technique both systems in one gantry aquired image combined into a coregistered image functional imaging by pet anatomical imaging by ctscanner by eng. In modern 3rdgeneration ct systems with fanbeam geometry, the minimum amount of scan data. Tabakov, 1999 planar xray sinogram rotate around object reconstructed image advantages. Unlike conventional, classical tomography, computerised tomography does not. Basic principles of ct each ct slice represents a specific plane in the patients body, referred to as the z axis. Computed tomography ct is an essential tool in diagnostic imaging for evaluating many clinical conditions. In recent years, there have been several notable advances in ct technology that already. Principles and practice of petct part 1 a technologists guide publications brochures. If you are in a group, let us know the number of people that are watching. Ct can detect tissue density differences as low as what.
The z axis determines the thickness of the crosssectional slice. Here, only the xray tube rotates around the patient. History 1924 mathematical theory of tomographic image. The basic principles of fdgpetct imaging request pdf. In singlephoton emission computed tomography spect photons emitted from the radiotracer in the body are detected by the system as. Ct scans of internal organs, bone, soft tissue and blood vessels provide much more detail than conventional xrays. Magnetic resonance imaging mri scanning principles. Computed tomography ct and magnetic resonance imaging mri are the most widely used crosssectional imaging methods used in medicine. Part 1 of the petct series focussed on the principles and practice of petct and included topics ranging from practical radiation protection, quality assurance and quality control to pa tient care. Computed tomography ct scanning, also known as, especially in the older literature and textbooks, computerized axial tomography cat scanning, is a diagnostic imaging procedure that uses xrays to build crosssectional images slices of the body.26 1394 149 1264 1071 812 207 417 802 1482 340 390 1048 1228 386 1444 1527 1145 198 1264 381 364 1197 958 1103 349 797 747 180