Introduced in the early 1970s, ct scanning gained rapid acceptance in clinics and hospitals. A physicist and an engineer, allan cormack and godfrey. 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.
Computed tomography ct scanning is an extremely common imaging modality in modern medicine. This video presentation explains the basic principle of ct scan. 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. In recent years, there have been several notable advances in ct technology that already. Magnetic resonance imaging mri scanning principles. Basic principles of computed tomography flashcards quizlet. Basic principles of ct each ct slice represents a specific plane in the patients body, referred to as the z axis. Introduction to magnetic resonance imaging techniques. Basic interpretation of ct scans most of the ct pictures are nonspecific ct pictures are depending on the density of the structures.
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. 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. 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. Choose from used and new textbooks or get instant access with etextbooks and digital materials. Basic principles of computed tomography physics and technical considerations kyongtae t. 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. In singlephoton emission computed tomography spect photons emitted from the radiotracer in the body are detected by the system as. In addition to the difficulty in differentiating and classifying tissue. Much ct development occurred via a series of scanner generations, especially spiral helical scanning and multidetector row designs. 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. 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. On the opposite side of the volume is a dosimeter which measures the amount of ionising radiation reaching it. 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. 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.
In 2010, the technologist committee decided that the next three guides would be dedicated to the topic of hybrid petct imaging. 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. 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. The basic principles of computed tomography and magnetic. Here, only the xray tube rotates around the patient. In modern 3rdgeneration ct systems with fanbeam geometry, the minimum amount of scan data.
Computed tomography ct scans can detect pathology that may be missed on a conventional chest radiograph. If the address matches an existing account you will receive an email with instructions to reset your password. This text serves as an introduction to magnetic resonance imaging techniques. Ct instrumentation and principles of ct protocol optimisation. Computed tomography ct and magnetic resonance imaging mri are the most widely used crosssectional imaging methods used in medicine. Here is a description about image acquisition and the image formation processes. Basic principles of ct scanners and image reconstruction ct scanning and imaging parameters dr slavik tabakov slavik. Xray computed tomography ct has experienced tremendous growth in recent years, in terms of both basic technology and new clinical applications. Computed tomography ct is an essential tool in diagnostic imaging for evaluating many clinical conditions. Principles and practice of petct part 1 a technologists guide publications brochures. 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. 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. Ct uses multiple pencil or fan beams of kilovoltage photons that pass through a desired volume from multiple angles usually over 180 degrees.
A ct scan of the heart may be ordered when various types of heart disease or abnormalities are suspected. Magnetic resonance imaging mri is arguably the most sophisticated imaging method used in clinical medicine. Physical principles, clinical applications, and quality control, 4th edition. Make sure each scan is justified even a lowdose ct is too much dose when inappropriately ordered check with physician if. 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. 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 recent years, mri scans have become increasingly common, as costs decrease. 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. Computed tomography available for download and read online in other formats. Ct can detect tissue density differences as low as what. Basic principles of ct ct neuroanatomy disease processes evaluated with ct. Computed tomography ct school of veterinary medicine. 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.
Ct scans can be used to identify disease or injury within various regions of the body. Basic ct scanner components gantry xray tube detector control. Clinicians need to be aware of the potentially harmful radiation that patients are exposed to, with each individual ct scan that is performed. 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. Pdf computed tomography download full pdf book download. If you are in a group, let us know the number of people that are watching. Pdf advances in computed tomography imaging technology. 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. It examines image display from traditional methods through the most recent. Please use one of the following formats to cite this article in your essay, paper or report. Computed tomography ct is a technique that uses an xray beam to generate images. Definition facts about ctdefinition facts about ct computer tomography ct, originally known as computed axial tomography cat or ct scan and body section rentenography.
Ct scans are created using a series of xrays, which are a form of radiation on the electromagnetic spectrum. Basic principles of computed tomography physics and. Ct scans of internal organs, bone, soft tissue and blood vessels provide much more detail than conventional xrays. 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. 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. An appreciation of the potential of ct and its limitations can be obtained with an understanding of basic. Basic principles of ct scanners and image reconstruction. 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.
Principles of ct diagnosis precontrast study postcontrast study change in adjacent structures clinical information. With advancements in technology, it is rapidly replacing many diagnostic radiographic procedures. Basic principles of ct scanners and image reconstruction indico. Basic principles of ct ct imaging system moves around the body part at a fixed location attenuation. Click to view this presentation from the impact course. Tissue density differences as low as 1% or less can be detected with ct. Unlike conventional, classical tomography, computerised tomography does not. Crosssections are reconstructed from measurements of attenuation coefficients of xray beams in the volume of the object studied. The basic principles of fdgpetct imaging request pdf. Whiting introduction slightly more than three decades old, computed tomography ct continues to advance rapidly in both imaging performance and widening clinical applications. History 1924 mathematical theory of tomographic image. This presentation gives an information about basic principles of ct scanning covering the. Build the foundation necessary for the practice of ct scanning with computed tomography.