Table 1 provides a comparison of ct scan characteristics and acquisition. Computed tomography ct was created in the early 1970s to overcome many of these limitations. Basic principles of computed tomography physics and technical. It also enabled the reconstruction of images at any position along the patients length axis as well as reconstructions of. This setup requires nearly twofold investments in hardware but offers important advantages for dect. Build the foundation necessary for the practice of ct scanning with computed tomography. The introduction of dual source computed tomography dsct in 2005 was an. 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. Recently, dual source ct scanners have been developed. The introduction of spiral ct in the early 1990s marked one of the important steps in the evolution of ct imaging techniques.
One detector a covers the entire scan fov 50 cm, while the other detector b is restricted to a smaller, central fov 26 cm due to. A dual source ct dsct scanner provides temporal resolution equivalent to a. Dualsource ct aiming for even higher performance levels xray computed tomography ct has shown an absolutely remarkable and impressive increase in its performance characteristics for many years remarkable because the modality was declared dead in the 1980s, impressive because these developments seemed impossible to many, for technical and for physics reasons. Dualsource technology gains acceptance in computed tomography. Basic principles of computed tomography physics and. This book focuses on principles of physics, effects of scan parameters on image quality, and optimum radiation dosage.
A dual source ct scan uses two xray sources at right angles to each other. This book provides an introduction to dsct technology and to the basics of contrast media administration followed by 25 indepth clinical scan and contrast media injection protocols. Electron beam tomography ebt machine patent illustration showing a cutaway view of an electron beam computerized tomography system. Because you always get the widest spectral separation possible, you can quantify even the subtlest changes such as bone marrow defects. 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. Material decomposition with dual and multienergy computed.
Macdougall ct medical a airs, canon medical systems usa, tustin, california 92780 charles. Apart from using dual source, using different energies could have the. Explains the physics behind multidetector ct technology. Unlike xray radiography, the detectors of the ct scanner do not produce an. Dualenergy ct clinical applications radiology reference.
Ct scanning in preclinical research and development provides the highest level of comparable and detailed imaging as used in a clinical setting. Currently, there are four different dect imaging methods available i. Dualsource ct a straightforward approach is dsct with two tubes running at different voltages and corresponding detectors mounted orthogonal ly in one gantry fig. Technical principles of dual source ct sciencedirect. Novel, energydiscriminating photon counting ct system. Dec 26, 2007 a ct system with a coverage of 40, 80, and 160 mm requires, and more dose in a single.
By acquiring multiple xray views of an object and performing mathematical operations on digital data, a full 2d section of the object can be reconstructed with exquisite detail of the anatomy present. This doubles the speed of the test so you receive less radiation, and it also creates sharper images. Dose performance relative to existing scan modes, rsna 2009. Deep learning ec can produce substantially fewer cleansing artifacts at dual energy than at singleenergy ct colonography, because the dual energy information can be used to identify relevant material in the colon more precisely than is possible with the single xray attenuation value. Physics based iterative reconstruction for dual source and flying focal spot computed tomography xiao wang computational radiology laboratory, department of radiology, boston childrens hospital, harvard medical school, boston, massachusetts 02115 robert d. Ever since dual energy ct dect technology has rapidly. With independent kv and mas options for each tube, coupled with the dosereducing tin. Dual energy ct or multispectral ct is becoming increasingly more common in clinical practice due to the rapid rise in computer technology and expanding literature exhibiting vast advantages over conventional single energy ct. Qualitative and quantitative evaluation of iq of dect data sets blended, iodine.
Dual energy ct in clinical practice thorsten johnson springer. The clinical practice, adaptation and techniques of dual energy ct is broken into individual articles. Dual source ct is equipped with two xray tubes and two corresponding detectors, mounted onto the rotating gantry with an angular offset of 90. During the past years, multidetector row ct mdct has evolved into clinical practice with a rapid increase of the number of detector slices. Jun 25, 2009 dual source computed tomography meets the most important demand placed on medical technology by cardiologists and radiologists.
Developing dual energy ct applications for pediatric imaging. These scanners have two xray tubes sources and two detectors within the gantry, spaced at a 90 degree angle. A ct scan or computed tomography scan formerly known as computed axial tomography or cat scan is a medical imaging technique used in radiology to get detailed images of the body noninvasively for diagnostic purposes. The introduction of dual source computed tomography dsct in 2005 was an evolutionary leap in the field of ct imaging. Of the above, hypodense dark structures can indicate edema and infarction, hyperdense bright structures indicate calcifications and haemorrhage and bone trauma can be seen as disjunction in bone windows.
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. Coronary ct angiography cta or ccta is the use of computed tomography ct angiography to assess the coronary arteries of the heart. Technical approaches to dual energy ct dual energy methods for ct were subsequently investigated by alvarez and macovski in 1976 2,3. The ability of dual and multi energy ct to differentiate materials of different effective. These spectra are generated using different tube potentials, partially also with additional filtration at 140 kvp. Multi slice computed tomography, dual source computed. Pdf flash imaging in dual source ct dsct researchgate. Dual layer detector superimposed energy sensitive layers detect different energy levels. This technology uses two xray tubes and two detectors arranged at 90 angles, allowing reconstruction of crosssectional images at one quarter of the gantry rotation time 330 milliseconds, thus improving temporal resolution to 82. Sep 14, 2016 publishing for text book on abdomen imaging. Dualenergy computed tomography ct allows for more specific material.
Dualsource dualenergy ct portal venous phase abdominal. The precise delivery of contrast media is a critical part of the contrastenhanced ct procedure. Physicsbased iterative reconstruction for dual source and. Thanks to precise table movements and two powerful tubes, it lets you achieve extremely wide coverage at exactly the right moment in time while keeping the dose in check all along. Tests carried out to date have shown that iodine z 53 can be readily differentiated from calcium z 20 1. While the concept of dual energy ct was introduced by siemens more than 30. The voltage, current, and filter can be chosen inde.
Search the worlds most comprehensive index of fulltext books. Dual source ct has recently become clinically available and can be used to further improve temporal resolution. Request pdf technical principles of dual source ct during the past years, multidetector row ct mdct has. Nearly 500,000 deaths caused by cad are reported every year in the us, over 600,000 in europe, 170,000 of these in germany alone. Two xray sources operated simultaneously enable heartrate independent temporal resolution and routine spiral dual energy imaging. Dualsource versus singlesource cardiac ct angiography. Dualsource dualenergy ct portal venous phase abdominal ct.
The latest highend ct scanner from siemensthe somatom definitionhas unmatched dual source technology making it the fastest scanner on the market. Ct scanning of the head is typically used to detect infarction, tumors, calcifications, haemorrhage, and bone trauma. Objective in dual energy ct dect, two ct datasets are acquired with different xray spectra. Dual source, ssm18, 8002178, willi kalender, computed tomography,general, physics and basic science. Image reconstruction and assessment of image quality. Dual energy ct or multispectral ct is becoming increasingly more common in clinical practice due to the rapid rise in computer technology and expanding literature exhibiting vast advantages over conventional single energy ct clinical applications. Dual source dual energy two xray tube with corresponding detectors operate at different kvp with an angular offset. The latter is a novel technique where a single beam is split using two filters. The clinical practice, adaptation and techniques of dual energy ct is broken into individual. Physical principles, clinical applications, and quality control, 4th edition. During the years since its invention, ct technology has undergone continual improvement in. Dual energy ct is a novel, rapidly emerging imaging technique which offers important new functional and specific information.
Dual source ct is ideally suited for dynamic imaging. Dualenergy computed tomography neuroimaging clinics. The subject receives an intravenous injection of radiocontrast and then the heart is scanned using a high speed ct scanner, allowing physicians to assess the extent of occlusion in the coronary arteries, usually in order to diagnose coronary artery disease. Introduction computed tomography is a well accepted imaging modality for evaluation of the entire body. In secondgeneration dual source dsct, a tin filter of 0. Ct computed tomography scans a level physics youtube. A basic description of the mechanism of ct computed tomography scans for medical use in remote sensing. Radiation dose considerations dual energy ct radiation dose depends on specific parameters such as tube current, pitch, and energy. 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. The term dual source ct refers to ct scanners that have two acquisition systems ie, two tubes and two corresponding detector arrays. Ct uses 2 xray sources and 2 detector arrays offset at 90 degrees. Sep 14, 2016 dual source ct scanner with 80 100 kvp and 140 kvp tubes siemens medical solutions dual layer multidetector scanner with acquisition at 120 or 140 kvp philips healthcare. Whereas conventional single energy ct produces a single image set, dual energy data attenuation values at two energy spectra can be used to reconstruct.
All were developed in consensus by selected physicians on the dual source ct expert panel. To generate the highest quality and most detailed images of quickly or irregularly beating hearts and to achieve this at only half the radiation dose in comparison to other systems currently available on the market. The concept of dualenergy computed tomography dect is almost as old as the. Its availability and usage have become increasingly widespread in recent years. Technical principles of dual source ct request pdf researchgate. About this book approximately one in five deaths is currently related to cardiac disease in europe and the us. The dual source ct scanner is composed of two xray tubes and two. Ct unit with one rapid kvp switching source and new detector based on gemstone scintillator materials ge healthcare. Dual source ct uses two rotating tubes to acquire both high and low voltage images. The personnel that performs ct scans are called radiographers or radiology technologists ct scanners use a rotating xray tube and a row of detectors placed in the gantry to. The images are obtained directly in the axial plane of varying tissue thickness with the. Advances in cardiac computed tomography intechopen. 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. Spectral information can also be resolved by layer detectors or quantumcounting detectors.
Dual source, dual energy computed tomography in pulmonary. Deep learning electronic cleansing for single and dual. Spectral computed tomography 2012 heismann publications. A dual xray source, tube a 140 kvp and tube b 80 kvp or 100 kvp with an angular offset of 90 degrees are preferred offsets for a dual source scanner in the current literature 15. A dual source ct dsct scanner provides temporal resolution equivalent to a quarter of the gantry. Dualenergy ct spectral ct or multienergy ct dualsource ct fast kvp switching. About this book the introduction of dual source computed tomography dsct in 2005 was an evolutionary leap in the field of ct imaging. Dual source ct dual source computed tomography non. Image quality and dose comparison of singleenergy ct sect. Several technical approachesthat is, sequential acquisition, rapid voltage switching, dual. A dual source ct scan can be used to guide a surgeon to the right area, to identify tumors, or to study blood vessels. Dual energy ct, also known as spectral ct, is a computed tomography technique.
Dual source ct imaging kindle edition by seidensticker, peter r. Dual source ct dual energy spectral imaging allows you to cover large anatomical volumes at high speeds and low doses. Computed tomography ct scan machines uses x rays, a powerful form of electromagnetic radiation. 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.
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