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Virtual monoenergetic

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...
October 9, 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...
September 21, 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...
September 15, 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
Iman Khodarahmi, Elliot K Fishman, Jan Fritz
Advances in surgical techniques, orthopaedic implant design, and higher demands for improved functionality of the aging population have resulted in a high prevalence of patients with metallic implants about the knee. Total knee arthroplasty, knee-replacing tumor prostheses, and osteosynthesis implants create various imaging artifacts and pose special challenges for the imaging evaluation with computed tomography (CT) and magnetic resonance imaging (MRI). CT artifacts can be effectively mitigated with metal artifact reduction reconstruction algorithms, dual-energy data acquisition with virtual monoenergetic extrapolation, and three-dimensional postprocessing techniques, such as volume and cinematic rendering...
September 2018: Seminars in Musculoskeletal Radiology
Kathryn E Darras, Sheldon J Clark, Heejun Kang, Mohammed F Mohammed, Sarah Barrett, Silvia D Chang, Alison C Harris, Savvas Nicolaou, Patrick D McLaughlin
PURPOSE: To evaluate the role of virtual monoenergetic imaging (VMI) in the detection of peritoneal metastatic disease in contrast-enhanced computed tomography (CT) of the abdomen and pelvis and to compare this technique to the conventional 120 kV mixed dataset. MATERIALS AND METHODS: Institutional review board approval was obtained with no informed consent required for this retrospective analysis. 43 consecutive patients with histopathologically confirmed peritoneal disease were scanned using a standard protocol on a 128-section dual-source, dual-energy CT system (100/140 keV)...
August 17, 2018: Abdominal Radiology
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 ...
September 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...
October 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.
September 2018: European Journal of Radiology
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