2.2. Dual-Energy CT Imaging System. We constructed a micro-CT system, which employed a broad spectral x-ray source and a PCD, as shown in Figure 1.The x-ray tube (L10101, Hamamatsu Photonics, Japan) has a focal spot of 5μm, and the voltage ranges from 20kVp to 100kVp.The detector manufactured by X-Counter Corporate defines the finest spatial resolution and fastest imaging speed, and each. Bone density tests for osteoporosis, also known as Dual energy X-ray Absorption testing or DEXA, uses low-dose X-ray to measure bone density in the spine, hips and forearms. The test takes about 10 minutes, and the results determine whether a person is developing osteoporosis, which can lead to painful bone fractures Dual Energy CT By acquiring CT images at different photon energies, DECT allows medical physicists to deduce material properties which influence the linear attenuation coefficient. This has clear benefits for proton therapy, where the proton range in tissues is strongly correlated to the electron density, which is one of the quantities DECT. Dual-energy CT has recently been recognized as very sensitive and specific for identifying monosodium urate (MSU) crystal deposition. By using a specific display algorithm that assigns different colors to materials of different chemical composition, MSU can be color-coded and thereby distinguished from surrounding structures
Diagnostic imaging has been a widely used tool in the detection and treatment of various diseases. Dual-energy computed tomography (DECT) is an emerging imaging technique that combines information. Workflow for advanced examination procedures including CT Angiography, Neuro Perfusion, Intervention, Single Source and Dual Source Dual Energy, Cardiac CTA and TAVR will be reviewed and discussed. NOTE: Examinations will be performed on simulation consoles using anonymized patient data Ingrain's proprietary methodology CoreHD® service extracts the effects of chemical composition and density through Dual Energy Computed Tomography (DE CT). CT bulk density and PE are combined with spectral gamma ray logs to rapidly deliver a detailed analysis of lithology, porosity, rock facies and depositional sequences MATERIAL DECOMPOSITION UTILIZING DUAL ENERGY COMPUTED TOMOGRAPHY Centre of Excellence Telč Daniel Vavřík1,2, Jan Jakůbek 1, Martin Pichotka , Ivana Kumpová2 1 Institute of Experimental and Applied Physics, CTU in Prague, Czech Republic, email@example.com
Computed tomography (CT) is the workhorse of modern medical imaging, accounting for approximately 65 million adult scans in the United States each year.1 Technical advances such as faster scan times, thinner slices, multiplanar reformatting, and 3D rendering have revolutionized the scope of CT. An exciting development that offers great promise to further increase the modality’s potential is dual energy CT (DECT). Also known as “spectral imaging,” DECT was first conceptualized in the 1970s.2-5 However, the clinical application of DECT has only recently been realized as a result of robust improvements in performance and post-processing capabilities. This review article aims to summarize the available literature regarding the utility of Dual-Energy CT (DECT) in spine imaging. DECT using virtual non-calcium images, virtual monoenergetic images, and material decomposition techniques have shown promise in bone marrow edema visualization associated with vertebral fractures, metallic artifact reduction related to spinal hardware, axial. This issue of Neuroimaging Clinics of North America focuses on Dual Energy CT: Applications in Neurologic, Head and Neck Imaging, and is edited by Drs. Reza Forghani and Hillary R. Kelly. Articles will include: Dual Energy CT: Physical Principles and App
Evaluation of small liver lesions on conventional CT can be a diagnostic dilemma. Subcentimeter lesions are often “too small to characterize,” leading to further workup with MRI or biopsy. However, cysts can be differentiated from small hypodense masses (ie, metastases) on iodine images in a DECT acquisition because a metastasis will show iodine uptake while a cyst will not (Figure 3). Improved lesion detection and characterization by DECT could potentially reduce the need for short interval follow-up studies, decrease the number of unnecessary biopsies, and improve screening for hypervascular liver tumors in cirrhotic patients.The Dual Source CT scanner enables the simultaneous operation of the two X-ray sources at two different energy levels (dual energy mode). It therefore allows the acquisition of two data sets of diverse information. Because X-ray absorption is energy-dependent, changing the energy level of the X-ray source results in a material-specific change of attenuation. The material-specific difference in attenuation facilitates differentiation, characterization, isolation, and distinction of the imaged tissue and material. Furthermore, specific details of the scanned body part beyond morphology can be obtained.DECT has several applications in both initial and post-treatment oncologic imaging. By increasing lesion conspicuity, tumor margins are better delineated, allowing for more accurate size measurements (Figure 6). Accurate measurement on restaging examinations is important for guiding management, especially for patients in clinical trials in which tumor response is reliant on serial measurements according to Response Evaluation Criteria in Solid Tumors (RECIST) or World Health Organization (WHO) criteria, for example. DECT offers yet more potential for assessing treatment response due to the potential ability of quantitative iodine maps to evaluate and quantify tumor viability. Although this technique requires validation and standardization, it is an exciting development that may allow for characterization of tumor at a functional level that predates any change in size. 18-19 Dual-energy CT is still mainly only used for imaging of gout and kidney stones. All the new technologies described in this book are not clinically established and thus rarely encountered. If you want a visually appealing book for your nightstand to get an insight into the field, this might be it CT Scan Protocols, CT Protocols by Manufacturer- GE, Siemens, Phillips, Toshiba. Slice Counts- Dual Source, 320 slice, 256 slice, 128 slice, 64 slice, 16 slice, 4.
Conclusion: Dual Energy CT is feasible without additional dose. There is no significant difference in image noise, while CNR can be doubled with optimized dual energy CT reconstructions. A restriction in collimation is required for dose-neutrality at 140/80 kVp, whereas this is not necessary at 140 Sn/100 kVp Rationale: Iodine mapping of the lung using subtraction imaging in addition to standard computed tomography pulmonary angiography (CTPA) may improve the evaluation of pulmonary embolism (PE) in the same manner as the addition of dual energy computed tomography (DECT) to CTPA Dual-energy CT: radiation dose aspects. AJR Am J Roentgenol. 2012; 199(5 Suppl):S16-25 (ISSN: 1546-3141) Henzler T; Fink C; Schoenberg SO; Schoepf UJ. OBJECTIVE: Various applications for dual-energy CT (DECT) have been investigated and have shown substantial clinical benefits
The ability of current dual-energy CT systems to simultaneously (or near-simultaneously) acquire images at two different energies is the focus of this article, which discusses how dual-energy CT works, the kinds of information it provides, and scenarios in which it may be helpful for abdominopelvic imaging, particularly in the liver, kidneys. 2. Dual Source, Dual Detector (Siemens) This method uses two tubes and two detectors that are offset 90 degrees in the scanner. One tube scans at a low energy (80 or 100 kVp) and the other at high energy (120 or 140 kVp). 3. Single Source, Dual Detector (Philips) This method uses a single tube but two detectors stacked on top of each other CT angiography (CTA) typically involves a multiphasic protocol with potential for higher contrast loads and radiation doses. DECT can play an important role in vascular imaging by improving image quality with less contrast and lower radiation dose compared to conventional CTA (Figure 8). Since tissues will attenuate more of the X-ray beam at photon energies closer to their k-edge, low energy DECT with customized VMC images can increase the attenuation of intravascular iodine while decreasing the administered contrast bolus. In addition, radiation dose can be significantly decreased through the utilization of virtual unenhanced images, which may eliminate the need for multiphasic imaging. These advantages of DECT can enhance CTA protocols while obtaining exquisite image quality. Such images may even be further improved by implementing calcium subtraction techniques at post-processing.22 DUAL ENERGY. Dual energy helical scanning alternates between high and low kV with each gantry rotation. Also the mA is automatically adjusted for the two different energies to ensure a matched signal-to-noise ratio which increases the accuracy of dual energy analysis TwinBeam Dual Energy allows simultaneous acquisition of high and low kV datasets in a single CT scan. In order to create the two datasets necessary for Dual Energy CT processing, a movable split filter is positioned in front a 120 kV x-ray beam
. In this regard, dual-energy CT, introduced as a first-generation dual-source CT system in 2006, can improve material differentiation by using two different X-ray energy spectra (2). The concept of dual-energy CT was initially described in 1973 (3) and re-emerged in the field of clinical radiology with the recent technical developments. This issue of Radiologic Clinics of North America focuses on Multi-Energy CT: The New Frontier in Imaging, and is edited by Drs. Savvas Nicolaou and Mohammed F. Mohammed. Articles will include: Dual Energy CT: Image Acquisition, Processing and Workflow; In a standard computed tomography (CT) image, pixels having the same Hounsfield Units (HU) can correspond to different materials and it is, therefore, challenging to differentiate and quantify materials. Dual-energy CT (DECT) is desirable to differentiate multiple materials, but DECT scanners are not widely available as single-energy CT (SECT) scanners. Here we develop a deep learning approach. Dual-layer detector Superimposed energy sensitive layers detect different energy levels. Dual source dual energy Two X-ray tube with corresponding detectors operate at different kVp with an angular off-set. Dual-energy data are acquired simultaneously. J Fornaro et al. Insights Imaging (2011)2:149-15
A hospital seeking to replace CT technology that does not meet the XR-29 standard has a wide range of slice counts and capabilities to consider, all the way up to state-of-the-art—but pricey—dual energy CT (DECT). For hospitals in the community-provider category, however, dual-energy CT. Compare All Energy Plans in Your Area. Save on Your Bill Now
Overall, dual energy imaging with facilitated bone and plaque removal overcomes limitations of standard CT, improves diagnostic confidence of CT angiographic imaging of the entire vascular territory and is expected to improve patient care. November 22, 2019 — Carestream's Dual-Energy imaging technology and its Focus 35C digital radiography (DR) detector with Image Suite Software have received 510(k) clearance from the U.S. Food and Drug Administration (FDA). Both technologies will be showcased at Carestream's booth #7513 at the upcoming Radiological Society of North America annual conference CT imaging. New Approaches for Dual Energy CT Using Dual Source CT Systems Dual source CT is a CT system where two x-ray sources and two data acquisition systems are mounted on the same x-ray gantry, positioned orthogonally to one another on the gantry.4-6 A commercial dual source CT system was introduced in 2006 (SOMATOM Definition
.6 Bn in 2018, and is expected to expand at a CAGR of 8% during the forecast period of 2019-2029. Europe and North America are expected to hold a collective revenue share of 60% of the global dual and multi-energy computed tomography market by the end of 2029 DECTDec (Dual Energy Computed Tomography Decomposition) is a MATLAB-based tool for three-material decomposition based on dual energy microCT scanning. It is a supplement to the publication Microscopic dual-energy CT (microDECT): a flexible tool for multichannel ex vivo 3D imaging of biological specimens Dual Energy CT Image Reconstruction Algorithms and Performance Joseph A. O'Sullivan Samuel C. Sachs Professor Dean, UMSL/dd/WU Joint Undergraduate Engineering Program Professor of Electrical and Systems Engineering, Biomedical Engineering and RadiologyBiomedical Engineering, and Radiology firstname.lastname@example.org J. A. O'Sullivan, AAPM 07/28/0
Dual-energy CT is a novel, rapidly emerging imaging technique which offers important new functional and specific information. In this book, physicists and specialists from different CT manufacturers provide an insight into the technological basis of, and the different approaches to, dual-energy Of all the possible material-specific images, iodine and water (or virtual unenhanced) images offer the most practical datasets for everyday clinical imaging (Figure 1). Iodine images demonstrate the amount of iodine (mg/ml) within an image voxel and its distribution in tissues. Because iodine images are independent of inherent tissue attenuation, they are a more reliable measure of enhancement compared to conventional contrast-enhanced studies. Water (ssDECT) or virtual unenhanced (dsDECT) images can be used to simulate true unenhanced images, therefore, possibly eliminating the need for an unenhanced acquisition altogether. This would reduce both radiation dose and exam time. What is a dual-energy CT scan? Standard computed tomography (CT) scanners use normal X-rays to make cross-sectional 'slice-like' pictures or images of the body. A dual-energy CT scanner is new technology that uses both the normal X-ray and also a second less powerful X-ray to make the images Finally, DECT can help assess response to treatment related to locoregional targeted therapies, such as ablation (eg, radiofrequency, microwave, cryo), targeted radiation therapy (eg, protons), and intra-arterial therapy (eg, selective internal radiation therapy [SIRT] and transarterial chemoembolization [TACE]). Iodine maps obtained immediately after radiofrequency ablation have shown better lesion conspicuity and internal homogeneity of the ablation zone, providing an additional benefit for assessing the safety margin after radiofrequency ablation.21 In our practice, we have observed that iodine images are helpful not only immediately after the procedure but also for follow up of patients undergoing hepatic microwave/radiofrequency ablation and renal cryo/radiofrequency ablation (Figure 7). DUAL ENERGY. Dual-energy helical scanning alternates between high and low kV with each gantry rotation. Also the mA is automatically adjusted for the two different energies to ensure a matched signal-to- noise ratio which increases the accuracy of dual energy analysis
Dual energy CT, also known as spectral CT, is a computed tomography technique that uses two separate x-ray photon energy spectra, allowing the interrogation of materials that have different attenuation properties at different energies. Whereas conventional single energy CT produces a single image set, dual energy data (attenuation values at two energy spectra) can be used to reconstruct. 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. Dual Energy CT. The Abdominal Imaging Division has implemented the dual energy CT technique in their routine daily practice, performing over 600 studies in the last year. Dual energy CT is now typically used for liver, pancreas and renal imaging at Presbyterian hospital. We are working with GE to improve protocols and reduce radiation dose Conclusions Dual-energy CT ECV correlated well with CMR and histology. Dual-energy CT is useful for characterizing doxorubicin-induced cardiomyopathy by measuring ECV fraction; however, further technical improvements are desirable to lower motion artifact and improve image quality of the iodine map
In addition to symptoms, size, and location, the composition of renal stones is critical for appropriate clinical management. It is important for the urologist to differentiate uric acid stones (treated medically) from non-uric acid stones (treated with invasive methods like extracorporeal shockwave lithotripsy or percutaneous nephrolithotripsy). Although uric acid stones tend to have lower attenuation values than non-uric acid stones (ie, struvite, cystine, and calcium) on SECT, they may be difficult to distinguish due to overlap in attenuation values.17 Dual-energy cone-beam CT scanning . United States Patent 9414790 . Abstract: A CT scanning apparatus includes a control apparatus arranged to cause a first rotation of a gantry and trigger an x-ray source to emit x-radiation at a first x-ray energy when an angular encoder reports that the gantry is at each of multiple predetermined angular. The aim of this study was to assess the feasibility of a differentiation of iodine from other materials and of different body tissues using dual energy CT. Ten patients were scanned on a SOMATOM Definition Dual Source CT (DSCT; Siemens, Forchheim, Germany) system in dual energy mode at tube voltages of 140 and 80 kVp and a ratio of 1:3 between tube currents Physics of Dual Energy CT (DECT) CTisus. Loading... Unsubscribe from CTisus? Computed Tomography: Dual Source CT - Dual Energy - Duration: 2:12. Siemens Healthineers 9,653 views
Dual energy CT offers exciting applications and possibilities previously unavailable with conventional single energy CT. The potential benefits of DECT include increased lesion detection and characterization, improved oncologic staging and evaluation of treatment response, and reduced artifacts, all at comparable or even reduced radiation doses DIW14: Dual energy CT Date & Time: February, 24, 2016, Wed 13:15-17:15 Venue: CT Services section, Department of Radiology, and GE light speed CT room #1, King Faisal Specialist Hospital &Research Centr Active joint inflammation is a key feature in rheumatoid arthritis (RA). Treatment guidelines for RA,1 including 'Treat-to-Target' strategies,2 stress the importance of abrogation of inflammation. MRI clearly demonstrates bone marrow oedema lesions (BMEL) as a sign of inflammation.3 Dual-energy CT (DECT) scanners could provide a new approach to visualise BME.4-7 We investigated if DECT. Dual energy and 4D computed tomography (CT) seek to address some of the limitations in traditional CT imaging. Dual energy CT, among other purposes, allows for the quantification and improved visualization of contrast materials, and 4D CT is often used in radiation therapy applications as it allows for the visualization and quantification of object motion In addition, based on a newly developed software algorithms, the dual energy technique allows the automated removal of calcified plaque from the vessel. This permits to readily detect and display narrowed segments of the arterial tree otherwise obscured by overlying calcifications without time-consuming manual post-processing. This technique is particularly helpful in patients with advanced atherosclerosis, when conventional CT angiograms are difficult to interpret.
. The ability to enhance the contrast resolution of CT images using different x-ray spectra was shown in the 1970s but was clinically implemented only for the purpose of emission tomography .Early diagnostic CT approaches exploring multiple energy applications involved two subsequent. Abstract Dual-energy CT offers several new applications and opportunities for routine clinical practice. Increasing utilization in the context of both routine practice and clinical research raises questions about expected radiation dose when compared with conventional single-energy exams. Despite initial concerns, advanced iterative. Dual-Energy CT: Basic Principles, Technical Approaches,andApplicationsinMusculoskeletal Imaging (Part 2) Patrick Omoumi, MD, MSc, PhD1 Francis R. Verdun, PhD2 Roman.
DECT scanners can process both routine diagnostic images and material decomposition (also known as material-specific or material density) images. Routine diagnostic images are intended to mirror the standard images produced by SECT. Blended images (Siemens) are created through a combination of the acquired low-energy (80 kVp) and high-energy (140 kVp) data to simulate a standard 120 kVp dataset. Virtual monochromatic (VMC) or monoenergetic (VME) [GE/Siemens] images are generated to simulate a scan obtained at a single energy level. VMC/VME images with specific energies (40 to 140 keV) provide more reliable attenuation measurements compared to polychromatic SECT. VMC images can be customized to a specific energy level for various clinical applications. Low-energy VMC images are suggested for studies with high contrast between lesions and adjacent tissues (eg, CT angiography; 45-55 keV). Intermediate-energy VMC images (60-75keV) are ideal for evaluation of soft tissues due to the balance between adequate contrast and reduced image noise. High-energy VMC images (95-140keV) reduce artifacts from metal implants. In dual-energy CT, an additional attenuation measurement is obtained at a second energy, allowing the differentiation of the two materials (Fig 1).Assuming the use of monoenergetic x-rays, at approximately 100 keV the same linear attenuation coefficients can be measured for bone and iodine There are currently three DECT platforms marketed by three of the major CT vendors. Dual source DECT (dsDECT) [Somatom Definition Flash, Siemens Medical Solutions, Forchheim, Germany] utilizes two X-ray tubes and two detectors to obtain simultaneous dual energy acquisition and data processing. Single source DECT (ssDECT) [Discovery 750HD, GE Healthcare, Milwaukee, WI] uses a single X-ray tube that rapidly alternates between low and high energies (fast-switching) and a single detector that quickly registers information from both energies. In detector based spectral CT [IQon spectral CT, Philips Healthcare, Eindhoven, The Netherlands], a single X-ray tube with full dose modulation capabilities is paired with a detector made of two layers (sandwich detector) that simultaneously detects two energy levels. AbstractID: 11941 Title: Dual Energy CT Image Reconstruction Algorithms and Performance Dual energy X-ray computed tomography (CT) is becoming more important, in part due to the availability of multi-row scanners that collect data using two source energy spectra. An X-ray source emits a spectrum of energies for each setting of the source . (866) 281-7545; Contact Us; Separate soft tissue and bone structures. Make one acquisition with two exposures at different energy levels in less than 200 milliseconds in chest or abdominal studies
. Yeh directs the Contrast and CT Research lab at UCSF which explores novel contrast-enhanced imaging techniques for CT, dual energy CT, and MR imaging. Ongoing projects include the development and testing of novel contrast materials, bowel imaging, fibrosis imaging, assessment of contrast material distribution in healthy and diseased tissues. Dual-energy CT empowers us to re-assess imaging protocols in a new light and optimize patient care. REFERENCES 1. Grajo JR, Sahani DV. Dual-energy CT of the abdomen and pelvis: radiation dose considerations. J Am Coll Radiol 2018;15: 1128-32. 2. Weidman EK, Plodkowski AJ, Halpenny DF, et al. Dual-energy CT angi-ography for detection of. Dual Energy CT Daisy Uppal, M.D. 2017-04-25T17:04:02-04:00 Dual Energy CT examinations provide answers for a wide range of diagnostic challenges. At Charter Radiology our Siemens SOMATOM CT scanners will provide you with excellent dual energy images at equal, or often lower radiation dose levels compared to conventional CT examinations
The Definition Dual Source CT scanner makes non-invasive cardiovascular CT imaging routinely accessible for even the most challenging patients. With a temporal resolution of just 83 milliseconds it can freeze cardiac motion and permits diagnostic imaging of the coronary arteries, pulmonary arteries and aorta at the same time within a single breath-hold. Dual Source CT is not only an excellent diagnostic tool, which improves patient care by making cardiovascular imaging available to even the most critically ill patients, but is also an interesting imaging modality to discover completely new clinical applications. Dual Energy CT • Two x-ray sources (80 and 140 kVp) • Simultaneously acquires two data sets • X-ray absorption is energy dependent • Materials act differently at different energies depending on their chemical composition • Creates a difference in attenuation (DEI) • Each unique DEI makes classification of chemical composition of. Dual-energy CT Aortography with 50% Reduced Iodine Dose Versus Single-energy CT Aortography with Standard Iodine Dose William P. Shuman, MD, Keith T. Chan, MD, Janet M. Busey, MS, Lee M. Mitsumori, MD, Kent M. Koprowicz,MD Rationale and Objectives: Because many patients with aortic pathology also have compromised renal function, we wished to inves Dual-energy computerized tomography (DECT) has high accuracy in detecting in established gout, but low diagnostic sensitivity for recent-onset gout, according to a recent meta-analysis published in Rheumatology. Investigators conducted a systematic search of PubMed, EMBASE, and Cochrane Library for research on the diagnostic utility of DECT for gout
Dual-energy CT (DECT) perfusion imaging can not only obtain the features found on conventional CT but also several quantitative and semiquantitative spectral parameters (water concentration, WC. The IQon Spectral CT adds spectral resolution to traditional CT scanning through a new dual-layer spectral detector. With a Yttrium-based 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. Dual energy computed tomography (DECT) is an exciting development in CT technology and has multiple clinical benefits [1-4].Applications include characterization of renal stones [5-7], visualization of lung perfused blood volume and ventilation [8-11] as well as assessment of myocardial perfused blood volume [12-14].In oncological imaging, DECT has proven potential for detection and.
Ct urography: With the ability to generate virtual unenhanced images from contrast enhanced dual energy CT image datasets, dual energy CT urography can lessen the need for an unenhanced scanning phase. But small stones may be less well depicted on virtual images than on actual unenhanced images. 55 55 • Dual-Energy CT: Vascular Applications. Ioannis Vlahos, Raymond Chung, Arjun Nair, and Robert Morgan. American Journal of Roentgenology 2012 199:5_supplement, S87- S97. • Dual-Energy Spectral CT: Various Clinical Vascular Applications. Haruhiko Machida, Isao Tanaka, Rika Fukui, Yun Shen, Takuya Ishikawa, Etsuko Tate, and EikoUeno CT of the kidney, ureter and bladder (CT KUB). Dual energy CT KUB scans can reliably distinguish urate from non-urate calculi. CT imaging around metal implants. Dual energy CT can significantly reduce the streak artefact normally associated with metal implants and allow better visualisation; for example, around spinal rods or hip replacements Dual Energy CT: A New Method for Better Dose Calculation in Proton Beam Therapy ((DUAL)) The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government Vitrea CT Dual Energy enables users to review and report CT Dual Energy images which are acquired using different tube voltages and/or tube currents. The application has multiple functions which enable users to evaluate and characterize body material composition using the attenuation coefficient energy dependence of different materials
Author: Dr John Coucher* What is a dual energy CT scan? Standard computed tomography (CT) scanners use normal X-rays to make cross-sectional 'slice-like' pictures or images of the body (see InsideRadiology: Computed Tomography). A dual energy CT scanner is fairly new technology that uses both the normal X-ray and also a second less powerful X-ray to make the images Dual Energy CT was initially explored and described by Godfreyhoundfiled, who stated in 1973,two pictures are taken in same slice, one at 100 kV and other at 140kV..so that areas of high atomic numbers can be enhanced. Test carried out date have shown that iodine(z=53)n can be readily differentiated from calcium (z=20)'(Hounsfield, 1973) AbstractID: 11940 Title: A Double-Layer Detector, Dual-Energy CT - Principles, Advantages and Applications The emerging of fast-rotating MDCT scanners, and the recent approach of the, so called, Slice War to its saturation, opened new opportunities for CT evolution. New routes to extend CT applications beyond anatomical imaging have been. Dual-energy CT has recently evolved as a promising tool with multiple clinical applications such as improved lesion detection, lesion characterisation, material quantification as well as metal artefact reduction, lower radiation dose and contrast volumes. The workshop includes a series of lectures followed by a hands-on workshop conducted in small groups with experienced faculty members Conventional or single energy CT (SECT) utilizes a single polychromatic X-ray beam (ranging from 70 to 140 kVp with a standard of 120 kVp) emitted from a single source and received by a single detector. The inherent contrast of the image dataset generated by this process depends on differences in photon attenuation of the various materials that constitute the human body (ie, soft tissue, air, calcium, fat). The degree that a material will attenuate the X-ray beam is dependent on (1) tissue composition and (2) photon energy level and how closely it exceeds the k-edge (ie, inner electron shell binding energy) of the material. Therefore, tissue attenuation can be manipulated by changing photon energy levels. In DECT, two energy levels (typically 80 and 140 kVp) are used to acquire images that can be processed to generate additional datasets.
Dual energy computed tomography (DECT) usually scans the object twice using different energy spectrum, and then DECT is able to get two unprecedented material decompositions by directly performing signal decomposition. In general, one is the water equivalent fraction and other is the bone equivalent fraction Early attempts at CT imaging Limited by experimental nature Limited by dedicated acquisition protocols Hybrid Imaging (e.g. SPECT and CT) Dual‐energy CT for myocardial perfusion defects Delayed enhancement dual‐energy CT Adenosine stress dual‐energy CT Integrative CHD Imaging with CT The algorithms for material decomposition are unique for each CT manufacturer. ssDECT algorithms mathematically transform material attenuation information into the amount (or concentration) of two-material pairs that would be necessary to produce the measured attenuation level within each image voxel based on the difference of atomic numbers of the materials present within the voxel. The two-material decomposition algorithm creates material-specific image pairs, such as water and iodine images. dsDECT utilizes a three material decomposition algorithm to create soft tissue, fat, and iodine material-specific images.
The role of dual energy CT in differentiating between brain haemorrhage and contrast medium after mechanical revascularization in acute ischaemic stroke. EurRadiol . 2014 ; 24 ( 4 ): 834 - 840 of different body tissues using dual energy CT. Ten patients were scanned on a SOMATOM Definition Dual Source CT (DSCT; Siemens, For-chheim, Germany) system in dual energy mode at tube voltages of 14 Using the two-material (basis pair) decomposition approach on ssDECT, water and iodine image datasets are generated. Stone visualization on water images only suggests uric acid calculi, whereas visualization on both water and iodine images implies non-uric acid stones (Figure 4). Effective Z (Zeff) images are an alternative approach for renal stone characterization and can be generated in an offline workstation. Zeff weights both the attenuation and atomic number of certain materials, thereby facilitating the identification of predominant materials within mixed stones. Low Zeff is commonly seen in uric acid stones, whereas high Zeff is seen in non-uric acid stones.
Dual-energy computed tomography (CT) is a sensitive and specific way to detect early changes in gout Purpose Accurate liver tumor delineation is crucial for radiation therapy, but liver tumor volumes are difficult to visualize with conventional single‐energy CT. This work investigates the use of sp.. PURE ViSION Optics provides significantly improved imaging efficiency from photon generation to detection. An optimized beam spectrum combined with a more efficient detector result in a better balance between image quality and dose. PURE ViSION Optics transforms routine CT imaging to new levels of image detail and low contrast detectability with up to 31% less dose. Dual-energy CT (DECT) is not new, in fact, says Benjamin Yeh, MD, it has been around just as long as computed tomography (CT) has. What is new is that CT scanners can capture DECT quickly and with good image quality.The benefits are mostly that it improves confidence and specificity for diagnoses. Like regular CT imaging, DECT provides 3-dimensional information about the size and shape of. Dual energy CT offers exciting applications and possibilities previously unavailable with conventional single energy CT. The potential benefits of DECT include increased lesion detection and characterization, improved oncologic staging and evaluation of treatment response, and reduced artifacts, all at comparable or even reduced radiation doses.
Dual Energy CT reduces this artifact both by using a higher energy beam as well as by applying special reconstruction software that minimizes the propagation of the artifact into the adjacent soft tissues. Diagnosing gout - Gout is a common inflammatory arthritis (in fact, it is the most common inflammatory arthritis in males).. Dual-energy scanners. There are several different systems currently that are able to create dual-energy CT acquisitions. Some scanners will do two separate scans at different energies. Newer dual-source scanners are able to scan at both energies simultaneously - one x-ray tube scans at the higher energy while the other scans at the lower energy. ¹1.5mm @ 0.3%, 22.6 mGy for Genesis. 1.5mm@ 0.3%, 21.8 mGy for Prime SP ²Aquilion Precision, Dose neutral between Ultra-high resolution mode with AiCE and normal resolution mode with hybrid iterative reconstructio
For diagnosis of adenomas, dual-energy material density analysis showed a sensitivity of 96% (23 of 24 lesions) at a specificity of 100% (23 of 23 lesions), yielding significantly improved diagnostic performance compared with nonenhanced multidetector CT attenuation (sensitivity of 67% [16 of 24 lesions] at a specificity of 100% [23 of 23. projection-domain dual-energy processing of dual-source CT data, but have not yet been implemented in clinical practice.4 In this educational exhibit, we summarize how virtual monochromatic images are synthesized from dual-energy CT, using either projection-domain or image-domain methods. We compare the iodine contrast, image noise As a Level 1 Trauma Center, ECMC offers state-of-the-art diagnostic imaging technology, including: American College of Radiology (ACR) accredited 128 slice- Dual Energy Computed Tomography (CT) Unit MATERIALS AND METHODS: Using a dual-source CT scanner, we obtained TNC single-energy and postcontrast DECT scans for 56 patients with unknown-origin spontaneous ICH. From the 2 sets of postcontrast DECT images obtained with different tube energy, EA (equivalent to conventional postcontrast CT), VNC, color-coded iodine overlay, fusion images of iodine overlay and VNC images were produced
Dual-energy X-ray absorptiometry (DXA, previously DEXA) is a means of measuring bone mineral density (BMD) using spectral imaging.Two X-ray beams, with different energy levels, are aimed at the patient's bones.When soft tissue absorption is subtracted out, the bone mineral density (BMD) can be determined from the absorption of each beam by bone. Dual-energy X-ray absorptiometry is the most. DECT can help differentiation via analysis of underlying material composition, as uric acid stones are composed of lighter elements (hydrogen, carbon, oxygen, and nitrogen) while non-uric acid stones are composed of heavier elements (calcium, phosphorus, and sulfur). Uric acids stones demonstrate increased photon attenuation at 140 kVp because the attenuation is driven primarily by Compton scatter (due to lighter element chemical composition). Conversely, non-uric acid stones demonstrate increased attenuation at 80 kVp due to increased photoelectric effect contribution from the heavier elements nearing the k-edge of calcium (Z=20).
Computed tomography (CT) has undergone several transformations throughout its history of 40-plus years, from the introduction of the helical (spiral) CT to the development of the multi-detector row, to today's emerging dual energy, or spectral, CT. While different manufacturers use different names—dual-energy, spectral CT and spectral. Dual- energy CT- by whatever technology - can be configured to employ less radiation than single energy CT. But for some specific applications, it produces more diagnostic and specific information. Dual- energy CT currently may be the best radiology technique for characterizing urinary tract stones to their chemical composition (which. Background/Purpose: Advanced imaging modalities such as ultrasound (US) and dual-energy CT (DECT) can help diagnose crystalline arthritis. DECT is a highly sensitive and specific modality to detect gout and has not been well studied in pseudogout. We compared the sensitivity of DECT, US, and x-ray (XR) in pseudogout. Methods: We prospectively enrolled patients with crystal-proven [ Dual Energy Computed Tomography. Dual-energy CT (DECT) is a new technological development whereby images can be reconstructed based on a two-material decomposition algorithm that can separate calcium from monosodium urate (Figure 58-12).59 DECT has been used to show that monosodium urate crystals are frequently present in joints affected by radiographic damage in gout, which supports the. 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. The clinical practice, adaptation and techniques of dual-energy CT is broken into individual articles:.
Dual-energy CT analysis Dual-energy analysis was conducted on originally developed dual-energy imaging analysis software performed in the Matlab environment (Matlab, version 7.10; Math-Works, Natick, Mass). Prior to the analysis a three-dimensional noise reduction filter was applied to each set of images for continuous slices Dual Energy. Dual Energy uses two energies during one CT scan, providing clinicians with more data to help quantify and characterize anatomy and lesions. As a result, exam times and radiation dose are both reduced. Volume Dual Energy Revolution HD has best-in-class cardiac CT spatial resolution. At 18.2 lp/cm 4, the system provides up to 66% greater spatial resolution than comparable systems. Offered as an option, SnapShot™ Freeze is designed to reduce blurring artifacts due to motion in coronary vessels that cannot be addressed by gantry speed alone. Providing up to 6x.
Grajo JR, Patino M, Prochowski A, Sahani DV. Dual energy CT in practice: Basic principles and applications. Appl Radiol. 2016;45(7):6-12. In addition to increasing lesion conspicuity, low keV and material density images can also provide accurate delineation of locoregional extent of disease and relationships to adjacent vasculature that is useful to guide treatment planning. 18, 20 Of particular interest, iodine maps can help differentiate tumor from bland thrombus through qualitative and quantitative demonstration of iodine within the clot. This differentiation is critical in hepatocellular and renal cell carcinoma staging. Background Dual-energy CT (DECT) has been shown to be a useful modality in neuroradiology. Objective To assess failure modes and limitations of DECT in different neuroimaging applications. Patients and methods Dual-source DECT scans were performed in 72 patients over 30 months to differentiate contrast agent staining or extravasation from intracranial hemorrhage (ICH) (n=40); to differentiate. The algorithm for kidney stones in dsDECT assumes that all voxels are a mixture of calcium, uric acid, and water. Stones with X-ray attenuation profiles similar to calcium appear blue while stones with profiles similar to uric acid appear red (Figure 5).
Dual Energy CT Angiography Enhances Diagnostic Capabilities. The dual energy imaging with facilitated bone and plaque removal significantly improves diagnostic confidence of CT angiographic imaging of the entire vascular territory. This technique is particularly helpful in patients with advanced atherosclerosis, when conventional CT angiograms. Why Dual Energy CT ? Challenges with Single energy CT Better material differentiation enhancing tissue characterization Advantages of DECT Tissue composition HU value reliability More consistent HU values on Monochromatic images Beam hardening and metal artifact Protocol complexity Reduction of Beam hardening and metal artifac The two dual‐source scanners, with well‐separated spectra, present a noticeable distinction in CT numbers between the low and high energy scans for the iodine and calcium scans. The FORCE scanner with the third‐generation detectors and the smaller spectral overlap (of only 10.5% of the area overlapping) shows scatter plots further away.
Iodine images play a critical role in DECT’s ability to improve lesion conspicuity. They can be displayed as quantitative gray-scale images or color overlay maps, both of which improve lesion conspicuity due to differences in iodine content between lesions and normal parenchyma (Figure 2). Iodine images detect and quantify iodine within each image voxel, allowing for detection of even a small amount of enhancement within a lesion. To illustrate improved tissue characterization, liver lesion, renal mass, and renal stone characterization will be briefly discussed. The role of DECT in oncologic imaging will also be outlined. Objective:New generation Dual Source computed tomography (CT) scanners offer different x-ray spectra for Dual Energy imaging. Yet, an objective, manufacturer independent verification of the dose required for the different spectral combinations is lacking. The aim of this study was to assess dose an Dual energy radiography can therefore save cost and radiation exposure by preventing unnecessary CT examination. Peripherally Inserted Central Catheter (PICC or PIC line) - Superimposed structures such as the heart, SVC, and other soft tissues can obscure the precise location a PICC following insertion