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virtual noncontrast

Yuan-Mao Lin, Yi-You Chiou, Mei-Han Wu, Shan-Su Huang, Shu-Huei Shen
OBJECTIVES: To compare the renal parenchyma attenuation of virtual noncontrast (VNC) images derived from multiphase renal dual-energy computed tomography (DECT) with standard noncontrast (SNC) images, and to determine the optimum phase for VNC images. MATERIALS AND METHODS: Twenty-nine men and 16 women (mean age, 61 ± 13 years; range, 37-89 years) underwent dynamic renal DECT (100/Sn140 kVp) were included in this institutional review board-approved retrospective study...
April 2018: European Journal of Radiology
Jeremy R Wortman, Jennifer W Uyeda, Urvi P Fulwadhva, Aaron D Sodickson
Computed tomography (CT) is key to the assessment of hemodynamically stable patients with blunt or penetrating trauma to the abdomen and pelvis. Dual-energy (DE) CT is a technology that allows acquisition of data at both high and low kilovolt peaks, allowing materials that have different x-ray absorption behaviors as a function of kilovolt peak (such as iodine) to be differentiated and quantified. DE CT has a variety of postprocessing applications that may be helpful in abdominal and pelvic trauma, including iodine-selective imaging, virtual monenergetic imaging, and virtual noncalcium imaging...
March 2018: Radiographics: a Review Publication of the Radiological Society of North America, Inc
Xinhui Duan, Gary Arbique, Jeffrey Guild, Yin Xi, Jon Anderson
PURPOSE: The purpose of this study was to evaluate the quantitative accuracy of spectral images from a detector-based spectral CT scanner using a phantom with iodine-loaded inserts. METHODS: A 40-cm long-body phantom with seven iodine inserts (2-20 mg/ml of iodine) was used in the study. The inserts could be placed at 5.5 or 10.5 cm from the phantom axis. The phantom was scanned five times for each insert configuration using 120 kVp tube voltage. A set of iodine, virtual noncontrast, effective atomic number, and virtual monoenergetic spectral CT images were generated and measurements were made for all the iodine rods...
May 2018: Medical Physics
Soo Buem Cho, Hye Jin Baek, Kyeong Hwa Ryu, Jin Il Moon, Bo Hwa Choi, Sung Eun Park, Kyungsoo Bae, Kyung Nyeo Jeon, Dong Wook Kim
PURPOSE: The purpose of this study was to investigate the clinical feasibility of spectral analyses using dual-layer detector spectral computed tomography (CT) in acute intracerebral haemorrhage (ICH). MATERIAL AND METHODS: We retrospectively reviewed patients with acute ICH who underwent CT angiography on a dual-layer detector spectral CT scanner. A spectral data analysis was performed to detect contrast enhancement in or adjacent to acute ICH by using spectral image reconstructions including monoenergetic (MonoE), virtual noncontrast (VNC), and iodine overlay fusion images...
2017: PloS One
U K Bodanapally, D Dreizin, G Issa, K L Archer-Arroyo, K Sudini, T R Fleiter
BACKGROUND AND PURPOSE: Extravasation of iodinated contrast into subdural space following contrast-enhanced radiographic studies results in hyperdense subdural effusions, which can be mistaken as acute subdural hematomas on follow-up noncontrast head CTs. Our aim was to identify the factors associated with contrast-enhancing subdural effusion, characterize diffusion and washout kinetics of iodine in enhancing subdural effusion, and assess the utility of dual-energy CT in differentiating enhancing subdural effusion from subdural hematoma...
August 10, 2017: AJNR. American Journal of Neuroradiology
Ahmed M Tawfik, Andreas Michael Bucher, Thomas J Vogl
There is recent interest in the use of dual-energy computed tomography (CT) in head and neck imaging, and the results are encouraging. This article reviews dual-energy CT applications as complementary tools to conventional CT scanning in the evaluation of cervical lymphadenopathy. The article cites the most relevant studies and highlights their results. Single-source and dual-source dual-energy applications including virtual noncontrast images, linear and nonlinear image blending, monochromatic images, iodine quantification, and spectral Hounsfield unit attenuation curve analysis are reviewed...
August 2017: Neuroimaging Clinics of North America
Sebastian Winklhofer, Ilaria Vittoria De Martini, Chrisitian Nern, Iris Blume, Susanne Wegener, Athina Pangalu, Antonios Valavanis, Hatem Alkadhi, Roman Guggenberger
OBJECTIVE: The technical feasibility of virtual noncontrast (VNC) images from dual-energy computed tomography (DECT) for the detection of the hyperdense artery sign (HAS) in ischemic stroke patients was investigated. METHODS: True noncontrast (TNC) scans of 60 patients either with or without HAS (n = 30 each) were investigated. Clot presence and characteristics were assessed on VNC images from DECT angiography and compared with TNC images. Clot characterization included the level of confidence for diagnosing HAS, a qualitative clot burden score, and quantitative attenuation (Hounsfield unit [HU]) measurements...
November 2017: Journal of Computer Assisted Tomography
Jan Borggrefe, Jonathan Kottlors, Mahmood Mirza, Victor-Frederic Neuhaus, Nuran Abdullayev, Volker Maus, Christoph Kabbasch, David Maintz, Anastasios Mpotsaris
BACKGROUND AND PURPOSE: In unenhanced computed tomography (CT) of acute ischemic stroke, the density of occluding clots is associated with the content of red blood cells and successful recanalization with stent thrombectomy. However, no CT marker for fibrin content is established. In order to improve clot diagnostics, we conducted an in vitro study to investigate thrombus composition of histologically defined ovine blood clots with unenhanced and contrast-enhanced CT using spectral detector CT (SDCT)...
May 23, 2017: Clinical Neuroradiology
İlknur Özdeniz, İlkay S İdilman, Seyfettin Köklü, Erhan Hamaloğlu, Mustafa Özmen, Deniz Akata, Muşturay Karçaaltıncaba
PURPOSE: We aimed to determine dual-energy computed tomography (DECT) characteristics of colorectal cancer and investigate effectiveness of DECT method in differentiating tumor from stool in patients with colorectal cancer. METHODS: Fifty consecutive patients with colorectal tumors were enrolled. Staging was performed by DECT (80-140 kV) using dual-source CT after rectal air insufflation and without bowel preparation. Both visual and quantitative analyses were performed at 80 kV and 140 kV, on iodine map and virtual noncontrast (VNC) images...
July 2017: Diagnostic and Interventional Radiology: Official Journal of the Turkish Society of Radiology
Adeline Schwein, Ponraj Chinnadurai, Dipan J Shah, Alan B Lumsden, Carlos F Bechara, Jean Bismuth
OBJECTIVE: Three-dimensional image fusion of preoperative computed tomography (CT) angiography with fluoroscopy using intraoperative noncontrast cone-beam CT (CBCT) has been shown to improve endovascular procedures by reducing procedure length, radiation dose, and contrast media volume. However, patients with a contraindication to CT angiography (renal insufficiency, iodinated contrast allergy) may not benefit from this image fusion technique. The primary objective of this study was to evaluate the feasibility of magnetic resonance angiography (MRA) and fluoroscopy image fusion using noncontrast CBCT as a guidance tool during complex endovascular aortic procedures, especially in patients with renal insufficiency...
May 2017: Journal of Vascular Surgery
Yao Yu, Wen-Bo Zhang, Xiao-Jing Liu, Chuan-Bin Guo, Guang-Yan Yu, Xin Peng
PURPOSE: To describe a new procedure assisted by digital techniques for secondary mandibular reconstruction with free fibula flap. METHODS: The 3-dimensional (3D) reconstruction images for vessels were used to demonstrate the vascular diameter and location, which help select the most suitable vein and artery for anastomosis. Maxillary and mandibular stone models of the patient were fabricated and a stable occlusal relationship was determined on an articulator. The 3D tooth model data were scanned using a 3D-optical measuring system, and the obtained stereolithographic (STL) data were imported to Geomagic software...
November 2016: Journal of Craniofacial Surgery
Karin Slebocki, Bastian Kraus, De-Hua Chang, Martin Hellmich, David Maintz, Christopher Bangard
PURPOSE: To assess correlation between attenuation measurements of incidental findings in abdominal second generation dual-energy computed tomography (CT) on true noncontrast (TNC) and virtual noncontrast (VNC) images. MATERIALS AND METHODS: Sixty-three patients underwent arterial dual-energy CT (Somatom Definition Flash, Siemens; pitch factor, 0.75-1.0; gantry rotation time, 0.28 seconds) after endovascular aneurysm repair, consisting of a TNC single energy CT scan (collimation, 128 × 0...
March 2017: Journal of Computer Assisted Tomography
Charlie Chia-Tsong Hsu, Gigi Nga Chi Kwan, Dalveer Singh, Jit Pratap, Trevor William Watkins
Dual-energy computed tomography (DECT) simultaneously acquires images at two X-ray energy levels, at both high- and low-peak voltages (kVp). The material attenuation difference obtained from the two X-ray energies can be processed by software to analyze material decomposition and to create additional image datasets, namely, virtual noncontrast, virtual contrast also known as iodine overlay, and bone/calcium subtraction images. DECT has a vast array of clinical applications in imaging cerebrovascular diseases, which includes: (1) Identification of active extravasation of iodinated contrast in various types of intracranial hemorrhage; (2) differentiation between hemorrhagic transformation and iodine staining in acute ischemic stroke following diagnostic and/or therapeutic catheter angiography; (3) identification of culprit lesions in intra-axial hemorrhage; (4) calcium subtraction from atheromatous plaque for the assessment of plaque morphology and improved quantification of luminal stenosis; (5) bone subtraction to improve the depiction of vascular anatomy with more clarity, especially at the skull base; (6) metal artifact reduction utilizing virtual monoenergetic reconstructions for improved luminal assessment postaneurysm coiling or clipping...
2016: Journal of Clinical Imaging Science
Haruhiko Machida, Isao Tanaka, Rika Fukui, Yun Shen, Takuya Ishikawa, Etsuko Tate, Eiko Ueno
Single-source dual-energy (DE) computed tomography (CT) with fast switching of tube voltage allows projection-based image reconstruction, substantial reduction of beam-hardening effects, reconstruction of accurate monochromatic images and material decomposition images (MDIs), and detailing of material composition by using x-ray spectral information. In vascular applications, DE CT is expected to overcome limitations of standard single-energy CT angiography, including patient exposure to nephrotoxic contrast medium and carcinogenic radiation, insufficient contrast vascular enhancement, interference from metallic and beam-hardening artifacts and severe vessel calcification, and limited tissue characterization and perfusion assessment...
July 2016: Radiographics: a Review Publication of the Radiological Society of North America, Inc
Manuel Patino, Andrea Prochowski, Mukta D Agrawal, Frank J Simeone, Rajiv Gupta, Peter F Hahn, Dushyant V Sahani
Dual-energy (DE) computed tomography (CT) offers the opportunity to generate material-specific images on the basis of the atomic number Z and the unique mass attenuation coefficient of a particular material at different x-ray energies. Material-specific images provide qualitative and quantitative information about tissue composition and contrast media distribution. The most significant contribution of DE CT-based material characterization comes from the capability to assess iodine distribution through the creation of an image that exclusively shows iodine...
July 2016: Radiographics: a Review Publication of the Radiological Society of North America, Inc
Inyoung Song, Jeong Geun Yi, Jeong Hee Park, Sung Mok Kim, Kyung Soo Lee, Myung Jin Chung
OBJECTIVE: To evaluate the feasibility of coronary artery calcium scoring based on three virtual noncontrast-enhanced (VNC) images derived from single-source spectral dual-energy CT (DECT) as compared with true noncontrast-enhanced (TNC) images. MATERIALS AND METHODS: This prospective study was conducted with the approval of our Institutional Review Board. Ninety-seven patients underwent noncontrast CT followed by contrast-enhanced chest CT using single-source spectral DECT...
May 2016: Korean Journal of Radiology: Official Journal of the Korean Radiological Society
Dongik Cha, Chan Kyo Kim, Jung Jae Park, Byung Kwan Park
OBJECTIVE: To investigate the utility of dual-energy CT (DECT) for differentiating between solid and benign cystic lesions presenting as hyperdense renal lesions incidentally detected on single-phase post-contrast CT. METHODS: 90 hyperdense renal lesions incidentally detected on single-phase post-contrast CT were evaluated with follow-up DECT. DECT protocols included true non-contrast (TNC), DE corticomedullary and DE late nephrographic phase imaging. The CT numbers of hyperdense renal lesions were calculated on linearly blended and iodine overlay (IO) images, and the results were compared...
June 2016: British Journal of Radiology
Brian P Flemming, Carlo N De Cecco, Andrew D Hardie
The authors describe a case of a patient with a solitary hepatocellular carcinoma status post transarterial chemoembolization. Follow-up imaging was performed using dual-energy computed tomography. The study was performed with and without contrast and a virtual noncontrast data set was constructed from the postcontrast images. The evaluation of this patient status post transarterial chemoembolization with virtual noncontrast alone erroneously suggested enhancement and viable tumor. However, examination of true noncontrast images revealed these findings to be due to the subtraction of iodine in Ethiodol within the treated lesion...
July 2016: Journal of Computer Assisted Tomography
André Euler, Anushri Parakh, Anna L Falkowski, Sebastian Manneck, David Dashti, Bernhard Krauss, Zsolt Szucs-Farkas, Sebastian T Schindera
OBJECTIVE: The aim of this study was to investigate the image quality, radiation dose, and accuracy of virtual noncontrast images and iodine quantification of split-filter dual-energy computed tomography (CT) using a single x-ray source in a phantom and patient study. MATERIALS AND METHODS: In a phantom study, objective image quality and accuracy of iodine quantification were evaluated for the split-filter dual-energy mode using a tin and gold filter. In a patient study, objective image quality and radiation dose were compared in thoracoabdominal CT of 50 patients between the standard single-energy and split-filter dual-energy mode...
August 2016: Investigative Radiology
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