What contribution did cormack make to the development of clinical computed tomography. Dual energy ct dect 2nd generation dual source system siemens somatom definition flash software collimation. In the context of metal implants, the actual ct number of the implant may be higher than the ct number scale used to store the data this is called overranging. Slice counts dual source, 320 slice, 256 slice, 128 slice, 64 slice, 16 slice, 4 slice, single detector. Reliable head bone removal courtesy of friedrichalexander university erlangennuremberg institute of medical physics erlangen, germany 100kvsn140kv c. The next two books in this series will be published in 2011 and 2012. Kelley and firesteins textbook of rheumatology tenth edition, 2017. In secondgeneration dual source dsct, a tin filter of 0. The iqon spectral ct adds spectral resolution to traditional ct scanning through a new dual layer spectral detector.
Farrs physics for medical imaging second edition book 2nd edition 2008. Ct scanner somatom force siemens healthineers global. There are increasing applications of dualenergy computed tomography ct, a type of. Schmidt 24 without any user interaction, bone can be subtracted, also in complicated anatomical. Dual source ct is ideally suited for dynamic imaging. Free radiology books download ebooks online textbooks. Ct is an essential imaging modality which utilises the latest and most advanced medical technology to detect and assist with the diagnosis of many conditions. Computed tomography ct is the workhorse of modern medical imaging, accounting for approximately 65 million adult scans in the united states each year. The present book will try to explain the physical principle behind each of these imaging modalities, together with a description of how these are implemented. All sections journal club lectures pearls protocols case studies medical illustrations search. Preliminary clinical work using a prototype multilayer detector system and a 64 detector row ct scanner brilliance64. In this study, we summarized the clinical applications of dect and included images that were acquired using the dual source ct and rapid kvp switching. Dual energy ct, also known as spectral ct, is a computed tomography technique that uses two separate xray photon energy spectra, allowing the interrogation of materials that have different attenuation properties at different energies. With this in mind, this book, the first in a series of three about pet ct, comes at a timely moment.
Basic principles of computed tomography physics and technical considerations kyongtae t. For reconstruction, you can choose a virtual noncontrast image, a noncontrast with iodine overlay in green, or a bone subtraction image. Two xray sources operated simultaneously enable heartrate independent temporal resolution and routine spiral dual energy imaging. Dual source ctdual source ct siemens introduced a ct model with dual xray tube and dual array of 64 slice detectors, at the 2005 radiological society of north america rsna medical meeting. Each chapter has a reference list, though we have tried to keep these lists to essential references only. A ct system with a coverage of 40, 80, and 160 mm requires, and more dose in a single. Crosssections are reconstructed from measurements of attenuation coefficients of xray beams in the volume of the object studied. Asian adaptation of the dual source ct dsct imaging protocol book compiles cases especially tailored for the asian population to fully utilize the potential of dsct technology in asia. Dual source ct dual energy spectral imaging allows you to cover large.
The introduction of dual source computed tomography dsct in 2005 was an evolutionary leap in the field of ct imaging. Understanding the differences in and the benefits of one ct scanner from another will help you to optimize the capabilities of the scanner, but requires a basic understanding of the mdct imaging physics. Technical approaches to dual energy ct dual energy methods for ct were subsequently investigated by alvarez and macovski in 1976 2,3. Medical imaging is a collection of technologies, all having the purpose of visualization of the interior of the intact, living human body for the purpose of diagnosis. With a yttriumbased scintillator, the nanopanel prism detector identifies photons of high energy and low energy simultaneously, allowing you to not only view anatomy, but also use color to characterize the material content of. Slice counts dual source, 320 slice, 256 slice, 128 slice, 64 slice, 16 slice, 4. Basic principles of computed tomography physics and. In ct imaging, you can now reach a higher level of clinical confidence in your images across these many different case types while still meeting your efficiency goals. This chapter details the physics of hybrid sys tems along with the typical imaging parameters, artifacts, and radiation doses. Our dual source ct scanner somatom force enables new levels of image quality. Whereas conventional single energy ct produces a single image set, dual energy data attenuation values at two energy spectra can be used to reconstruct. Ct has been applied to the study of internal log defects and egyptian mummies. Dual energy ct offers the potential to analyze material composition.
Identification using monoenergetic reconstructions from a novel duallayer. And, it is more than just imaging coronary arteries. The precise delivery of contrast media is a critical part of the contrastenhanced ct procedure. Computed tomography ct uses an xray machine and advanced computer programs to create two and three dimensional images of your body.
He developed the solutions to the mathematical problems in. Ct scanning ct protocols ct scan protocols imaging. Dual energy ct in clinical practice thorsten johnson springer. Dual energy ct can simulate a monochromatic xray beam. Dual energy ct in clinical practice thorsten johnson. While the concept of dual energy ct was introduced by siemens more than. An appreciation of the potential of ct and its limitations can be obtained with an understanding of basic. This barcode number lets you verify that youre getting exactly the right version or edition of a book. An exciting development that offers great promise to further increase the modalitys potential is. Dose performance relative to existing scan modes, rsna 2009. Dual energy computed tomography an overview sciencedirect. 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.
Spectral computed tomography 2012 heismann publications. Dualenergy ct dect is a new technological development whereby. The introduction of dual source computed tomography dsct in 2005 was an. These scanners have two xray tubes sources and two detectors within the gantry, spaced at a 90 degree angle. Thanks to precise table movements and two powerful tubes, it lets you achieve extremely wide. Principle of dual energy ct image based evaluation each material is characterized by its dual energy index x80 and x 140 are the hounsfield numbers at 80 kv and 140 kv, resp. Recently, dual source ct scanners have been developed. Whiting introduction slightly more than three decades old, computed tomography ct continues to advance rapidly in both imaging performance and widening clinical applications. Strategies for scatter correction in dual source ct. Typically, a combination of 80140 kvp is used for dect, but for some applications, 100140 kvp is preferred. In this book, physicists and specialists from different ct manufacturers provide an insight into the technological basis of, and the different approaches to, dualenergy.
Established and novel imaging biomarkers for assessing response to. It is highly applicable to clinical radiology, unlike many of the other rsna et. This book covers complex applications such as ct cardiac imaging and dualsource dualenergy ct scanning as well as the pitfalls and. Ct fluoroscopy computed tomographic fluoroscopy is a technical advance resulting from slipring technology, xray tubes with improved heat capacity, highspeed array processors, and partial reconstruction algorithms. Simulation of dual energy ct decomposition and reconstruction in the abdomen. Dualenergy ct is a novel, rapidly emerging imaging technique which offers important new functional and specific information. A dualsource ct scan uses two xray sources at right angles to each other. The epub file can be opened with an ebook reader, a reader app, a mac. They demonstrated that even with polyenergetic xray spectra, one could still separate the measured attenuation coefficients into their contributions from the photoelectric effect and compton scattering processes. Dual source ct dual energy spectral imaging allows you to cover large anatomical volumes at high speeds and low doses. A dualsource ct scan can be used to guide a surgeon to the right area, to identify tumors, or to study blood vessels. Chapter 10 describes the physics of the cuttingedge technologies of dual source ct and 320mdct with a discussion of special applications of ct fluoroscopy and perfusion ct. This doubles the speed of the test so you receive less radiation, and it also creates sharper images.
In computed tomography, it is recommended that the number of projections p must be in the same order as the number of rows of pixels in a single projection s 3. This means that the tube needs only rotate 90 degrees to obtain a full data set, instead of 180 degrees the two tubes contribute 90 degrees each to make 180 degrees of data from. Dual energy methods for ct were subsequently investigated by alvarez and macovski in 1976 2,3. Dual sources increase the temporal resolution by reducing the rotation angle required to acquire a complete image, thus permitting cardiac studies without. Image reconstruction and assessment of image quality.
Somatom drive with dual source technology boosts your performance, empowers your routines, and expands your capabilities. Ct scan protocols, ct protocols by manufacturer ge, siemens, phillips, toshiba. The book also includes chapters on the language of radiation dose and strategies for dose reduction that are essential for optimal ct imaging and patient. Preliminary clinical work using a prototype multilayer detector system and a 64detector row ct scanner brilliance64. Despite material differentiation through ct scans acquired with xray beams of different spectra had been conceived soon after the emergence of single energy ct in early 70 s, the clinical endorsement of the method and its widespread application was only initiated after the introduction of the first dual source ct systems in 2006. Tests carried out to date have shown that iodine z 53 can be readily differentiated from calcium z 20 1. A thicker filter further hardens the spectrum but absorbs so much of the output of quanta that the remainder gets too small even with a maximum tube current. Panknin, christoph, lengsfeld, philipp, verma, vivek eds.
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