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Virtual monoenergetic

Lianna D Di Maso, Jessie Huang, Michael F Bassetti, Larry A DeWerd, Jessica R Miller
PURPOSE: Tumor delineation using conventional CT images can be a challenge for pancreatic adenocarcinoma where contrast between the tumor and surrounding healthy tissue is low. This work investigates the ability of a split-filter dual-energy CT (DECT) system to improve pancreatic tumor contrast and contrast-to-noise ratio (CNR) for radiation therapy treatment planning. MATERIALS AND METHODS: Multiphasic scans of 20 pancreatic tumors were acquired using a split-filter DECT technique with iodinated contrast medium, OMNIPAQUETM ...
August 17, 2018: Journal of Applied Clinical Medical Physics
Khaled Y Elbanna, Mohammed F Mohammed, Tejbir Chahal, Faisal Khosa, Ismail Tawakol Ali, Ferco H Berger, Savvas Nicolaou
OBJECTIVE: The hypothesis of this study was that the use of dual-energy spectral techniques in CT can improve accuracy in the diagnosis of acute gangrenous appendicitis. MATERIALS AND METHODS: This retrospective study included 209 patients with a pathologic diagnosis of appendicitis. Two board-certified abdominal radiologists reviewed 120-kV simulated images, 40-keV virtual monoenergetic images, and color-coded iodine overlay images. Sensitivity, specificity, positive and negative predictive values (PPV and NPV), accuracy, and interobserver agreement were calculated for each set of images...
July 31, 2018: AJR. American Journal of Roentgenology
Wei Zhou, Dilbar Abdurakhimova, Michael Bruesewitz, Ahmed Halaweish, Cynthia H McCollough, Shuai Leng
The purpose of this study is to determine the optimal iodine contrast-to-noise ratio (CNR) achievable for different patient sizes using virtual-monoenergetic-images (VMIs) and a universal acquisition protocol on photon-counting-detector CT (PCD-CT), and to compare results to those from single-energy (SE) and dual-source-dual-energy (DSDE) CT. Vials containing 3 concentrations of iodine were placed in torso-shaped water phantoms of 5 sizes and scanned on a 2nd generation DSDE scanner with both SE and DE modes...
March 2018: Proceedings of SPIE
Wei Zhou, Rachel Schornak, Gregory Michalak, Jayse Weaver, Dilbar Abdurakhimova, Andrea Ferrero, Kenneth A Fetterly, Cynthia H McCollough, Shuai Leng
Photon counting detector (PCD) based multi-energy CT is able to generate different types of images such as virtual monoenergetic images (VMIs) and material specific images (e.g., iodine maps) in addition to the conventional single energy images. The purpose of this study is to determine the image type that has optimal iodine detection and to determine the lowest detectable iodine concentration using a PCD-CT system. A 35 cm body phantom with iodine inserts of 4 concentrations and 2 sizes was scanned on a research PCD-CT system...
March 2018: Proceedings of SPIE
David Zopfs, Simon Lennartz, Kai Laukamp, Nils Große Hokamp, Anastasios Mpotsaris, David Maintz, Jan Borggrefe, Victor Neuhaus
No abstract text is available yet for this article.
July 18, 2018: European Journal of Radiology
Julia Dangelmaier, Benedikt J Schwaiger, Alexandra S Gersing, Felix F Kopp, Andreas Sauter, Martin Renz, Isabelle Riederer, Rickmer Braren, Daniela Pfeiffer, Alexander Fingerle, Ernst J Rummeny, Peter B Noël
INTRODUCTION: To evaluate the clinical potential of dual layer computed tomography (DLCT) for posterior fusions of the thoracic and lumbar spine and determine the optimal keV-settings for an improved overall image quality and effective reduction of metal artefacts affecting the implant inheriting vertebral body, the spinal canal, the paravertebral muscle and aorta. METHODS AND MATERIALS: Twenty patients with posterior thoracic and lumbar spinal fusion, who underwent a 120kVp- DLCT scan were included in this study...
August 2018: European Journal of Radiology
Iman Khodarahmi, Reham R Haroun, Moses Lee, George S K Fung, Matthew K Fuld, Lew C Schon, Elliot K Fishman, Jan Fritz
OBJECTIVE: The aim of this study was to compare the effects of combined virtual monoenergetic extrapolation (VME) of dual-energy computed tomography data and iterative metal artifact reduction (iMAR) at higher photon energies on low- and high-density metal artifacts and overall image quality of the ankle arthroplasty implants with iMAR, weighted filtered back projection (WFBP), and WFBP-based VME. MATERIALS AND METHODS: Total ankle arthroplasty implants in 6 human cadaver ankles served as surrogates for arthroplasty implants...
July 14, 2018: Investigative Radiology
George Noid, An Tai, Diane Schott, Nilesh Mistry, Yu Liu, Taly Gilat-Schmidt, Jared R Robbins, X Allen Li
PURPOSE: The purpose of this work is to investigate the use of low-energy monoenergetic decompositions obtained from dual-energy CT (DECT) to enhance image contrast and the detection of radiation-induced changes of CT textures in pancreatic cancer. METHODS: The DECT data acquired for 10 consecutive pancreatic cancer patients during routine nongated CT-guided radiation therapy (RT) using an in-room CT (Definition AS Open, Siemens Healthcare, Malvern, PA) were analyzed...
July 4, 2018: Medical Physics
Cherry Kim, Ki Yeol Lee, Chol Shin, Eun-Young Kang, Yu-Whan Oh, Moin Ha, Chang Sub Ko, Jaehyung Cha
Objective: To evaluate the accuracy of emphysema volume (EV) and airway measurements (AMs) produced by various iterative reconstruction (IR) algorithms and virtual monoenergetic images (VME) at both low- and standard-dose settings. Materials and Methods: Computed tomography (CT) images were obtained on phantom at both low- (30 mAs at 120 kVp) and standard-doses (100 mAs at 120 kVp). Each CT scan was reconstructed using filtered back projection, hybrid IR (iDose4 ; Philips Healthcare), model-based IR (IMR-R1, IMR-ST1, IMR-SP1; Philips Healthcare), and VME at 70 keV (VME70)...
July 2018: Korean Journal of Radiology: Official Journal of the Korean Radiological Society
Lakshmi Ananthakrishnan, Xinhui Duan, Prabhakar Rajiah, Todd C Soesbe, Matthew A Lewis, Yin Xi, Julia R Fielding, Robert E Lenkinski, John R Leyendecker, Suhny Abbara
PURPOSE: Spectral detector computed tomography (SDCT) is a new CT technology that uses a dual-layer detector to perform energy separation. We aim to assess 3 clinical concepts using a phantom model: noise profile across the virtual monoenergetic (VME) spectrum, accuracy of iodine quantification, and virtual noncontrast (VNC) reconstructions' ability to remove iodine contribution to attenuation. METHODS: Six vials containing varying concentrations of iodinated contrast (0-6 mg/mL) diluted in water were placed in a water bath and scanned on an SDCT scanner...
June 12, 2018: Journal of Computer Assisted Tomography
Daisuke Sakabe, Yoshinori Funama, Katsuyuki Taguchi, Takeshi Nakaura, Daisuke Utsunomiya, Seitaro Oda, Masafumi Kidoh, Yasunori Nagayama, Yasuyuki Yamashita
PURPOSE: To investigate the image quality characteristics for virtual monoenergetic images compared with conventional tube-voltage image with dual-layer spectral CT (DLCT). METHODS: Helical scans were performed using a first-generation DLCT scanner, two different sizes of acrylic cylindrical phantoms, and a Catphan phantom. Three different iodine concentrations were inserted into the phantom center. The single-tube voltage for obtaining virtual monoenergetic images was set to 120 or 140 kVp...
May 2018: Physica Medica: PM
Nils Große Hokamp, K R Laukamp, S Lennartz, D Zopfs, N Abdullayev, V F Neuhaus, D Maintz, J Borggrefe
OBJECTIVES: Image quality in head and neck imaging is often severely hampered by artifacts arising from dental implants. This study evaluates metal artifact (MA) reduction using virtual monoenergetic images (VMI) compared to conventional CT images (CI) from spectral-detector computed tomography (SDCT). METHODS: 38 consecutive patients with dental implants were included in this retrospective study. All examinations were performed using a SDCT (IQon, Philips, Best, The Netherlands)...
July 2018: European Journal of Radiology
Fabian K Lohöfer, Georgios A Kaissis, Frances L Köster, Sebastian Ziegelmayer, Ingo Einspieler, Carlos Gerngross, Michael Rasper, Peter B Noel, Steffen Koerdt, Andreas Fichter, Ernst J Rummeny, Rickmer F Braren
PURPOSE: The aim of this study was to evaluate the advantages of dual-layer spectral CT (DLSCT) in detection and staging of head and neck cancer (HNC) as well as the imaging of tumour margins and infiltration depth compared to conventional contrast enhanced CT (CECT). MATERIALS AND METHODS: Thirty-nine patients with a proven diagnosis of HNC were examined with a DLSCT scanner and retrospectively analysed. An age-matched healthy control group of the same size was used...
May 28, 2018: European Radiology
Daniela Pfeiffer, Anushri Parakh, Manuel Patino, Avinash Kambadakone, Ernst J Rummeny, Dushyant V Sahani
PURPOSE: To determine the diagnostic potential of Material Density (MD) iodine images in dual-energy CT (DECT) for visualization and quantification of arterial phase hyperenhancement and washout in hepatocellular carcinomas compared to magnetic resonance imaging (MRI). MATERIALS AND METHODS: The study complied with HIPAA guidelines and was approved by the ethics committee of the institutional review board. Thirty-one patients (23 men, 8 women; age range, 36-87 years) with known or suspected Hepatocellular Carcinoma (HCC) were included...
May 17, 2018: Abdominal Radiology
Kai Roman Laukamp, Simon Lennartz, Victor-Frederic Neuhaus, Nils Große Hokamp, Robert Rau, Markus Le Blanc, Nuran Abdullayev, Anastasios Mpotsaris, David Maintz, Jan Borggrefe
OBJECTIVES: This study compares metal artifact (MA) reduction in imaging of total hip replacements (THR) using virtual monoenergetic images (VMI), for MA-reduction-specialized reconstructions (MAR) and conventional CT images (CI) from detector-based dual-energy computed tomography (SDCT). METHODS: Twenty-seven SDCT-datasets of patients carrying THR were included. CI, MAR and VMI with different energy-levels (60-200 keV) were reconstructed from the same scans. MA width was measured...
May 3, 2018: European Radiology
D Mera Fernández, E Santos Armentia, A Bustos Fiore, A M Villanueva Campos, E Utrera Pérez, M Souto Bayarri
OBJECTIVE: To assess the ability of dual-energy CT (DECT) to reduce metal-related artifacts in patients with clips and coils in head CT angiography, and to analyze the differences in this reduction between both type of devices. MATERIALS AND METHODS: Thirteen patients (6 clips, 7 coils) were selected and retrospectively analized. Virtual monoenergetic images (MEI) with photon energies from 40 to 150 keV were obtained. Noise was measured at the area of maximum artifact...
July 2018: Radiología
Nils Große Hokamp, Rivka Kessner, Steven Van Hedent, Frank Philipp Graner, Amit Gupta, Robert Gilkeson
OBJECTIVE: This study aimed to evaluate image quality (IQ) of virtual monoenergetic images (VMIs) from novel spectral detector computed tomography angiography of the pulmonary arteries and to identify appropriate window settings for each kiloelectron volt level. MATERIALS: Forty consecutive patients were included in this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant study.Signal- and contrast-to-noise ratios were calculated within the pulmonary trunk, and pulmonary/lobar/segmental arteries were calculated...
April 13, 2018: Journal of Computer Assisted Tomography
Abed Ghandour, Andrew Sher, Negin Rassouli, Amar Dhanantwari, Prabhakar Rajiah
OBJECTIVE: To evaluate the ability of retrospectively generated virtual monoenergetic images (VMIs) from the detector-based spectral computed tomography (SDCT) to augment pulmonary artery enhancement in CT and if iodine map can predict the optimal monoenergetic level. METHODS: The study included 79 patients with contrast-enhanced chest CT scans on an SDCT scanner. Conventional 120-kVp images and VMI from 40 to 80 keV were generated. Attenuation, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured at 7 different locations in the pulmonary arterial system...
April 13, 2018: Journal of Computer Assisted Tomography
Megumi Matsuda, Takaharu Tsuda, Teruhito Kido, Hiroaki Tanaka, Hikaru Nishiyama, Toshihide Itoh, Kenichi Nakao, Masashi Hirooka, Teruhito Mochizuki
PURPOSE: This study aimed to evaluate the utility of virtual monoenergetic images for detecting washout of small (≤2 cm) hepatocellular carcinoma (HCC) in the equilibrium phase. METHODS: We performed 120-kVp-equivalent linear-blended (M120) and monoenergetic reconstructions from 40 to 90 keV by standard (40, 50, 60, 70, 80, 90) and novel noise-reduced (nMERA: 40+, 50+, 60+, 70+, 80+, 90+) monoenergetic reconstruction algorithms. Image quality and tumor visibility of delayed washout of HCCs in the equilibrium phase were compared between standard monoenergetic reconstruction algorithm and nMERA by objective and subjective analyses...
April 13, 2018: Journal of Computer Assisted Tomography
Lakshmi Ananthakrishnan, Xinhui Duan, Yin Xi, Matthew A Lewis, Margaret S Pearle, Jodi A Antonelli, Harold Goerne, Elysha M Kolitz, Suhny Abbara, Robert E Lenkinski, Julia R Fielding, John R Leyendecker
PURPOSE: To assess the non-inferiority of dual-layer spectral detector CT (SDCT) compared to dual-source dual-energy CT (dsDECT) in discriminating uric acid (UA) from non-UA stones. METHODS: Fifty-seven extracted urinary calculi were placed in a cylindrical phantom in a water bath and scanned on a SDCT scanner (IQon, Philips Healthcare) and second- and third-generation dsDECT scanners (Somatom Flash and Force, Siemens Healthcare) under matched scan parameters. For SDCT data, conventional images and virtual monoenergetic reconstructions were created...
April 7, 2018: Abdominal Radiology
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