Read by QxMD icon Read

virtual noncontrast

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...
October 18, 2016: 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
Hye Jeon Hwang, Joon Beom Seo, Sang Min Lee, Namkug Kim, Sang Young Oh, Jae Seung Lee, Sei Won Lee, Yeon-Mok Oh
OBJECTIVES: The aim of this study was to assess the feasibility of combined xenon-enhanced ventilation (V) and iodine-enhanced perfusion (Q) dual-energy computed tomography (DECT) to evaluate regional V and Q status in patients with chronic obstructive pulmonary disease (COPD). MATERIALS AND METHODS: Combined V and Q DECT imaging was performed in 52 prospectively enrolled male COPD patients. Virtual noncontrast images, V maps, and Q maps were anatomically coregistered with deformable registration and evaluated using in-house software...
May 2016: Investigative Radiology
Fei Fu, Anwei He, Yue Zhang, Baojiu Li, Yeda Wan
OBJECTIVE: The aim of this study was to evaluate the clinical value of dua-energy virtual noncontrast imaging (DVNCT) in the diagnosis of cervical metastasis lymph nodes. MATERIALS AND METHODS: From February 2014 to January 2015, 41 patients with 98 enlarged cervical lymph nodes were recruited in this study. All the enlarged lymph nodes were pathology confirmed. The patients received DVNCT and conventional noncontrast scan. The difference of average computed tomography (CT) value, signal to noise ratio, a contrast to noise ratio, image subjective assessment, and lesion detectability between virtual noncontrast imaging and conventional noncontrast scan were compared...
October 2015: Journal of Cancer Research and Therapeutics
A E Grams, M Knoflach, R Rehwald, J Willeit, M Sojer, E R Gizewski, B Glodny
BACKGROUND AND PURPOSE: Dual-energy CT features the opportunity to differentiate among up to 3 different materials because the absorption of x-rays depends on the applied tube voltage and the atomic number of the material. For example, it is possible to distinguish between blood-brain barrier disruption and an intracerebral hemorrhage following treatment for a stroke. The aim of this study was to evaluate whether dual-energy CT is capable of distinguishing intra-arterial contrast agent from residually clotted vessels immediately after endovascular stroke therapy...
August 2015: AJNR. American Journal of Neuroradiology
Ananya Panda, Atin Kumar, Shivanand Gamanagatti, Biplab Mishra
Virtopsy or virtual autopsy is an emerging technique, developed to supplement traditional forensic autopsy. Virtopsy can be done by using imaging techniques such as computed tomography (CT) and magnetic resonance imaging. Virtopsy CT comprises a pan-body noncontrast CT scan obtained after death. Virtopsy CT is useful in trauma cases as it can provide an overview of injuries sustained by the victim; detect craniofacial, cerebral, thoracic, and osseous injuries; and suggest putative causes of death. This can reduce the time taken for forensic autopsy and sometimes obviate the need for a forensic autopsy...
September 2015: Current Problems in Diagnostic Radiology
Shi-Feng Tian, Ai-Lian Liu, Jing-Hong Liu, Mei-Yu Sun, He-Qing Wang, Yi-Jun Liu
OBJECTIVE: The objective was to qualitatively and quantitatively evaluate hepatic metastases using computed tomography (CT) virtual noncontrast (VNC) spectral imaging in a retrospective analysis. METHODS: Forty hepatic metastases patients underwent CT scans including the conventional true noncontrast (TNC) and the tri-phasic contrast-enhanced dual energy spectral scans in the hepatic arterial, portal venous, and equilibrium phases. The tri-phasic spectral CT images were used to obtain three groups of VNC images including in the arterial (VNCa), venous (VNCv), and equilibrium (VNCe) phase by the material decomposition process using water and iodine as a base material pair...
March 5, 2015: Chinese Medical Journal
X Y Jiang, S H Zhang, Q Z Xie, Z J Yin, Q Y Liu, M D Zhao, X L Li, X J Mao
BACKGROUND AND PURPOSE: The virtual noncontrast images generated with iodine subtraction from dual-energy CTA images are expected to replace the true noncontrast images for radiation-dose reduction. This study assessed the feasibility of virtual noncontrast images for diagnosing SAH. MATERIALS AND METHODS: Eighty-four patients with or without SAH underwent true noncontrast brain CT (the criterion standard for diagnosing SAH). Among them, 37 patients underwent an additional head dual-energy angiography, and the other patients underwent head and neck dual-energy angiography...
May 2015: AJNR. American Journal of Neuroradiology
Bernhard Krauss, Katharine L Grant, Bernhard T Schmidt, Thomas G Flohr
INTRODUCTION: One method to acquire dual-energy (DE) computed tomography (CT) data is to perform CT scans at 2 different x-ray tube voltages, typically 80 and 140 kV, either as 2 separate scans, by means of rapid kV switching, or with the use of 2 x-ray sources as in dual-source CT (DSCT) systems. In DSCT, it is possible to improve spectral separation with tin prefiltration (Sn) of the high-kV beam. Recently, x-ray tube voltages beyond the established range of 80 to 140 kV were commercially introduced, which enable additional voltage combinations for DE acquisitions, such as 80/150 Sn or 90/150 Sn kV...
February 2015: Investigative Radiology
Yoshitake Yamada, Masahiro Jinzaki, Teppei Okamura, Minoru Yamada, Yutaka Tanami, Takayuki Abe, Sachio Kuribayashi
BACKGROUND: Dual-energy CT technology enables acquisition of virtual unenhanced (VUE) images from contrast-enhanced scans. OBJECTIVE: To assess the feasibility of coronary artery calcium (CAC) scoring on VUE images derived from fast kVp-switching dual-energy coronary CT angiography. METHODS: Twenty-seven patients underwent true noncontrast CAC-scoring CT followed by routine single-energy (120-kVp) and fast kVp-switching dual-energy coronary CT angiography, in a random acquisition order on the same day...
September 2014: Journal of Cardiovascular Computed Tomography
Yu Jin Yeo, See Hyung Kim, Mi Jeong Kim, Young Hwan Kim, Seung Hyun Cho, Eun Joo Lee
OBJECTIVE: The objective of this study was to evaluate the efficiency of virtual noncontrast image (VNCI) generated from dual-energy split-bolus computed tomographic urography (DE-SBCTU) for urinary stones detection. METHODS: Three hundred fifty-six patients underwent true noncontrast image (TNCI) and DE-SBCTU. Two radiologists evaluated opacification scores of DE-SBCTU as well as iodine subtractions and image noise on VNCI. Diagnostic performance of the VNCI was evaluated using TNCI as a reference standard, according to diameter and image quality...
January 2015: Journal of Computer Assisted Tomography
Vitaliano Buffa, Antonio Solazzo, Valeria D'Auria, Alessandra Del Prete, Andrea Vallone, Monica Luzietti, Manuela Madau, Roberto Grassi, Vittorio Miele
PURPOSE: This study was done to evaluate the possibility of reducing the dose of ionising radiation by using dual-source dual-energy computed tomography (CT) in patients undergoing CT angiography of the aorta to search for endoleaks after endovascular aneurysm repair (EVAR). MATERIALS AND METHODS: One hundred and forty-eight patients (117 M, 31 F; mean age 75 ± 6.5) underwent 171 CT angiography scans for follow-up after EVAR. For each patient we performed a triple-phase acquisition protocol consisting of a nonenhanced phase, an arterial phase and a delayed phase; the latter acquired in dual energy...
December 2014: La Radiologia Medica
Anna Chrabaszcz, Matthew Winn, Candise Y Lin, William J Idsardi
PURPOSE: This study investigated how listeners' native language affects their weighting of acoustic cues (such as vowel quality, pitch, duration, and intensity) in the perception of contrastive word stress. METHOD: Native speakers (N = 45) of typologically diverse languages (English, Russian, and Mandarin) performed a stress identification task on nonce disyllabic words with fully crossed combinations of each of the 4 cues in both syllables. RESULTS: The results revealed that although the vowel quality cue was the strongest cue for all groups of listeners, pitch was the second strongest cue for the English and the Mandarin listeners but was virtually disregarded by the Russian listeners...
August 2014: Journal of Speech, Language, and Hearing Research: JSLHR
Lucia Flors, Carlos Leiva-Salinas, Patrick T Norton, James T Patrie, Klaus D Hagspiel
PURPOSE: To evaluate the diagnostic performance of dual-energy (DE) computed tomography (CT) after thoracic endovascular aortic repair (TEVAR) of type B dissection, and to investigate the value of late delayed (LD) acquisition in endoleak detection and false lumen patency assessment. MATERIALS AND METHODS: Twenty-four patients with TEVAR for type B dissection underwent 53 tripe-phase CT examinations. Single-source unenhanced acquisition was followed by single-source arterial-phase and DE LD phase (300-s delay) imaging...
March 2014: Journal of Vascular and Interventional Radiology: JVIR
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"