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Virtual monoenergetic

Rolf Symons, Yves De Bruecker, John Roosen, Laurent Van Camp, Tyler E Cork, Steffen Kappler, Stefan Ulzheimer, Veit Sandfort, David A Bluemke, Amir Pourmorteza
PURPOSE: To evaluate the performance and clinical feasibility of 0.25 mm resolution mode of a dual-energy photon-counting detector (PCD) computed tomography (CT) system for coronary stent imaging and to compare the results to state-of-the-art dual-energy energy-integrating detector (EID) CT. MATERIALS AND METHODS: Coronary stents with different diameters (2.0-4.0 mm) were examined inside a coronary artery phantom consisting of plastic tubes filled with iodine-based and gadolinium-based contrast material diluted to approximate clinical concentrations (n = 18)...
November 2018: Journal of Cardiovascular Computed Tomography
Qin Zong Gao, Zhi Wei Wang, Ya Fei Qi, Zheng Yu Jin
Objective To evaluate the value of virtual monoenergetic(monoE)using dual-layer detector spectrum CT in detecting small lesions in rabbit VX2 liver cancer models.Methods Hepatic VX2 double tumor models were established in 24 New Zealand white rabbits by CT-guided puncture. All the rabbits underwent CT scans by using dual-layer detector CT to generate conventional 120-keV polychromatic images and monoE images with energy levels ranging from 40 to 100 keV during the arterial phase. The quantity of the lesion and measurement of the lesion length as well as the objective evaluations[signal noise ratio(SNR)and contrast noise ratio(CNR)] and the subjective evaluations(overall image quality score)of the image quality were independently measured by two radiologists...
October 30, 2018: Zhongguo Yi Xue Ke Xue Yuan Xue Bao. Acta Academiae Medicinae Sinicae
Eva Braig, Jessica Böhm, Martin Dierolf, Christoph Jud, Benedikt Günther, Korbinian Mechlem, Sebastian Allner, Thorsten Sellerer, Klaus Achterhold, Bernhard Gleich, Peter Noël, Daniela Pfeiffer, Ernst Rummeny, Julia Herzen, Franz Pfeiffer
Dual-energy CT has opened up a new level of quantitative X-ray imaging for many diagnostic applications. The energy dependence of the X-ray attenuation is the key to quantitative material decomposition of the volume under investigation. This material decomposition allows the calculation of virtual native images in contrast enhanced angiography, virtual monoenergetic images for beam-hardening artifact reduction and quantitative material maps, among others. These visualizations have been proven beneficial for various diagnostic questions...
November 6, 2018: Scientific Reports
Simon Lennartz, Kai Roman Laukamp, Victor Neuhaus, Nils Große Hokamp, Markus Le Blanc, Volker Maus, Christoph Kabbasch, Anastasios Mpotsaris, David Maintz, Jan Borggrefe
PURPOSE: Retrospective comparison of diagnostic quality of virtual monoenergetic images (VMI) and conventional images (CI) reconstructed from dual-layer detector CT (DLCT) regarding intraparenchymal hemorrhage (IPH) and hypodense parenchymal lesions (HPL) of the brain. METHODS: 58 patients underwent unenhanced DLCT of the head. CI and VMI ranging from 40 to 120 keV were reconstructed. Objective image quality was assessed using ROI-based measurements within IPH, HPL, grey matter, white matter and cerebrospinal fluid, from which contrast to noise ratio (CNR) was calculated...
November 2018: European Journal of Radiology
Steven Van Hedent, Nils Große Hokamp, Rivka Kessner, Robert Gilkeson, Pablo R Ros, Amit Gupta
OBJECTIVE: The aim of this study was to investigate the quantitative and qualitative effects of virtual monoenergetic images (VMI) by spectral detector computed tomography (SDCT) on calcium blooming in coronary computed tomography angiography. METHODS: Coronary computed tomography angiography using SDCT was performed on 42 patients with coronary artery calcifications. Stenosis grading by diameter and area of calcified plaques and free lumen using VMI from 70 to 140 keV was performed and compared with measurements by conventional images...
November 2018: Journal of Computer Assisted Tomography
Nils Große Hokamp, Verena C Obmann, Rivka Kessner, Robert C Gilkeson, Amit Gupta, Thorsten Persigehl, Stefan Haneder, Nikhil Ramaiya
OBJECTIVE: The aim of the study was to establish the reference window settings for display of virtual monoenergetic images (VMIs) from spectral detector computed tomography when assessing hypodense liver lesions. METHODS: In patients with cysts (n = 24) or metastases (n = 26), objective (HU, signal-to-noise ratio [SNR]) and subjective (overall image quality, lesion conspicuity and noise) were assessed. Furthermore, 2 readers determined optimal window center/width (C/W) for conventional images (CIs) and VMIs of 40 to 120 keV...
November 2018: Journal of Computer Assisted Tomography
Anish A Patel, Patrick D Sutphin, Yin Xi, Suhny Abbara, Sanjeeva P Kalva
OBJECTIVE: To assess the feasibility of creating virtual monoenergetic arterial images from venous phase CTA obtained on a detector-based spectral CT scanner and quantitatively compare the signal-to-noise (SNR) and contrast-to-noise (CNR) ratios of the major arteries to those on polyenergetic true arterial phase images. METHODS: In this retrospective study, 23 patients (15 men and 8 women, median age 68 years) who underwent triple-phase CTA on a spectral CT scanner for aortic endograft surveillance were included...
October 24, 2018: Cardiovascular and Interventional Radiology
Michael C Burke, Ankur Garg, Jonathan M Youngner, Swati D Deshmukh, Imran M Omar
OBJECTIVE: Our purpose was to determine whether dual-energy CT (DECT), specifically the bone marrow setting of the virtual noncalcium (VNCa) algorithm, could be used to identify and accurately biopsy suspected bone malignancies that were visible on magnetic resonance imaging (MRI), nuclear bone scintigraphy, or positron-emission tomography/computed tomography (PET/CT), but occult on monoenergetic computed tomography (CT) by virtue of being either isodense or nearly isodense to surrounding normal bone...
October 20, 2018: Skeletal Radiology
Matthias Stefan May, Marco Wiesmueller, Rafael Heiss, Michael Brand, Joscha Bruegel, Michael Uder, Wolfgang Wuest
OBJECTIVES: The aim of this study was to compare image quality of single-source dual-energy CT (SS-DECT) with third-generation dual-source dual-energy CT (DS-DECT) in head and neck cancer. MATERIALS AND METHODS: One hundred two patients with histologically proven head and neck cancer were prospectively randomized to undergo radiation dose-matched SS-DECT (n = 51, 120 kV, split-filter technique, 384 ref. mAs) or DS-DECT (n = 51, 80/Sn150 kV, tube A 100/tube B 67 ref...
October 18, 2018: European Radiology
Philippe Jagoda, Daniel Schmitz, Stefan Wagenpfeil, Arno Bücker, Peter Minko
OBJECTIVE: The objective of this study was to compare the capability of two algorithms for metal artifact reduction and virtual monoenergetic imaging (VME), a metal artifact reduction application for dual-source CT. MATERIALS AND METHODS: A bovine vertebra phantom with 16 artificial osteolyses and two 20 × 4.5 mm stainless steel screws was scanned on two single-source CT scanner and one dual-source CT scanner at a dose identical to the single-source acquisitions...
December 2018: AJR. American Journal of Roentgenology
Daisuke Sueta, Daisuke Utsunomiya, Yasuhiro Izumiya, Takeshi Nakaura, Seitaro Oda, Koichi Kaikita, Yasuyuki Yamashita, Kenichi Tsujita
Because the prognosis of pulmonary thromboembolism (PTE) will be often poor, early diagnosis and assessing severity at the first visit is important. A 76-year-old man with suspected venous thromboembolism and a contrast deficit in the pulmonary artery (PA) was revealed by contrast-enhanced computed tomography (CT) imaging by dual-layer spectral-detector CT (IQon Spectral CT® , Philips Healthcare, Best, The Netherlands). The lung perfusion image showed decreased perfusion in the culprit lesion. The dual-energy analysis of the virtual monoenergetic imaging showed clear visualization of deep vein thrombosis (DVT)...
September 2018: Journal of Cardiology Cases
Hye Jin Yoo, Sung Hwan Hong, Bo Mi Chung, Sun Jeong Moon, Ja-Young Choi, Hee Dong Chae, Min-Yung Chang
OBJECTIVE: The purpose of this study was to evaluate the image quality of virtual monoenergetic images obtained from dual-layer-detector spectral CT of patients with metallic orthopedic implants of the distal radius. MATERIALS AND METHODS: A retrospective analysis was performed between April 2016 and January 2017. Forty-three consecutively registered patients (33 women, 10 men; mean age, 50.7 ± 15.4 years) with metallic implants for distal radius fractures underwent dual-layer-detector spectral CT...
November 2018: AJR. American Journal of Roentgenology
Y Nagayama, T Nakaura, S Oda, N Taguchi, D Utsunomiya, Y Funama, M Kidoh, T Namimoto, D Sakabe, M Hatemura, Y Yamashita
AIM: To compare the image quality and radiation dose of reduced iodine dose dual-layer detector (DL) computed tomography (CT) with those of a conventional 120 kVp protocol for chest-abdomen-pelvis CT (CAP-CT). MATERIALS AND METHODS: Forty patients with renal dysfunction (estimated glomerular filtrating ratio <45 ml/min/1.73 m2 ) underwent reduced iodine dose CAP-CT (120 kVp, 200 mg iodine/kg) on DLCT. Virtual monochromatic images (VMI) at 40-70 keV (5 keV interval) were reconstructed retrospectively...
September 17, 2018: Clinical Radiology
Iulia Mocanu, Morgane Van Wettere, Julie Absil, Michaël Bruneau, Boris Lubicz, Niloufar Sadeghi
PURPOSE: To evaluate the ability of dual-energy CT angiography (DECTA) in metal artifact reduction in patients with treated intracranial aneurysms by comparing DECTA-based virtual monoenergetic extrapolations (VMEs) and mixed images (MI). METHODS: Thirty-five patients underwent prospectively a dual-source DECTA (Somatom Force, Siemens Medical Solutions, Forchheim, Germany) after aneurysm repair. A total number of 40 aneurysms (23 treated by coil embolization and 17 treated by surgical clipping) were analyzed...
December 2018: Neuroradiology
Hamid Chalian, Kevin Kalisz, Negin Rassouli, Amar Dhanantwari, Prabhakar Rajiah
OBJECTIVES: To evaluate the ability of the retrospectively generated virtual monoenergetic images (VMIs) from a dual-layer detector-based spectral computed tomography (SDCT) to augment aortic enhancement for the evaluation of aortic anatomy and pathology. METHODS: 98 patients with suboptimal aortic enhancement (≤200 HU) were retrospectively identified from SDCT scans. VMI from 40 to 80 keV were generated. Attenuation, noise, SNR, and CNR were measured at seven levels in the aorta...
August 11, 2018: Clinical Imaging
Haitao Yang, Xiong Wu, Bo Jiang, Kai Deng, Jianning Sun, Xilong Mei
To assess the value of noise-optimized virtual monoenergetic imaging (VMI+) reconstruction technique on objective and subjective image quality in patients with inflammatory bowel disease (IBD) undergoing abdominal dual-energy computed tomography (DECT).
 Methods: Datasets from 32 patients (22 men, 10 women) with IBD, who underwent abdominal DECT, were reconstructed by using the standard linearly blended (M_0.6), traditional monoenergetic (VMI) and VMI+ algorithms in 10-keV intervals from 40-100 keV. Attenuation in IBD lesions was measured to perform objective evaluation using signal-to-noise (SNR) and contrast-to-noise ratios (CNR)...
August 28, 2018: Zhong Nan da Xue Xue Bao. Yi Xue Ban, Journal of Central South University. Medical Sciences
Kai Mei, Sebastian Ehn, Markus Oechsner, Felix K Kopp, Daniela Pfeiffer, Alexander A Fingerle, Franz Pfeiffer, Stephanie E Combs, Jan J Wilkens, Ernst J Rummeny, Peter B Noël
Background: X-ray and particle radiation therapy planning requires accurate estimation of local electron density within the patient body to calculate dose delivery to tumour regions. We evaluate the feasibility and accuracy of electron density measurement using dual-layer computed tomography (DLCT), a recently introduced dual-energy CT technique. Methods: Two calibration phantoms were scanned with DLCT and virtual monoenergetic images (VMIs) at 50 keV and 200 keV were generated...
December 2018: European radiology experimental
Lukas Lenga, Rouben Czwikla, Julian L Wichmann, Doris Leithner, Moritz H Albrecht, Christian Booz, Christophe T Arendt, Ibrahim Yel, Tommaso D'Angelo, Thomas J Vogl, Simon S Martin
PURPOSE: To assess the value of the noise-optimized virtual monoenergetic imaging (VMI+) technique on quantitative and qualitative image parameters in patients with hypoattenuating liver metastases from colorectal cancer (CRC) at abdominal dual-energy CT (DECT). MATERIALS AND METHODS: Fifty-three consecutive patients (mean age, 70.3 ± 11.4 years; range, 44-86 years) with histologically proven, hypoattenuating liver metastases from CRC were retrospectively included in this IRB-approved study...
September 2018: European Journal of Radiology
Khalid W Shaqdan, Anushri Parakh, Avinash R Kambadakone, Dushyant V Sahani
Computed tomography angiography (CTA) is the modality of choice to evaluate abdominal vascular emergencies (AVE). CTA protocols are often complex and require acquisition of multiple phases to enable a variety of diagnosis such as acute bleeding, pseudoaneurysms, bowel ischemia, and dissection. With single energy CT (SECT), differentiating between calcium, coagulated blood, and contrast agents can be challenging based on their attenuation, especially when in small quantity or present as a mixture. With dual-energy CT (DECT), virtual monoenergetic (VM) and material decomposition (MD) image reconstructions enable more robust tissue characterization, improve contrast-enhancement, and reduce beam hardening artifacts...
August 24, 2018: Abdominal Radiology
Junghoan Park, Se Hyung Kim, Joon Koo Han
PURPOSE: To determine whether there is any additional metal artifact reduction when virtual monochromatic images (VMI) and metal artifact reduction for orthopedic implants (O-MAR) are applied together compared to their separate application in both phantom and clinical abdominopelvic CT studies. METHODS: An agar phantom containing a spinal prosthesis was scanned using a dual-layer, energy CT scanner (IQon, Philips Healthcare), and reconstructed with the filtered back-projection algorithm without O-MAR (FBP), filtered back-projection algorithm with O-MAR (O-MAR), VMI140 without O-MAR (VMI140 ), and VMI140 with O-MAR (VMI140  + O-MAR)...
August 22, 2018: Abdominal Radiology
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