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Hounsfield Units (HU)

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https://www.readbyqxmd.com/read/28345547/contrast-dose-and-radiation-dose-reduction-in-abdominal-enhanced-computerized-tomography-scans-with-single-phase-dual-energy-spectral-computerized-tomography-mode-for-children-with-solid-tumors
#1
Tong Yu, Jun Gao, Zhi-Min Liu, Qi-Feng Zhang, Yong Liu, Ling Jiang, Yun Peng
BACKGROUND: Contrast dose and radiation dose reduction in computerized tomography (CT) scan for adult has been explored successfully, but there have been few studies on the application of low-concentration contrast in pediatric abdominal CT examinations. This was a feasibility study on the use of dual-energy spectral imaging and adaptive statistical iterative reconstruction (ASiR) for the reduction of radiation dose and iodine contrast dose in pediatric abdominal CT patients with solid tumors...
April 5, 2017: Chinese Medical Journal
https://www.readbyqxmd.com/read/28342121/can-comprehensive-imaging-analysis-with-analytic-morphomics-and-geriatric-assessment-predict-serious-complications-in-patients-undergoing-pancreatic-surgery
#2
Andrew J Benjamin, Mary M Buschmann, Andrew Schneider, Brian A Derstine, Jeffrey F Friedman, Stewart C Wang, William Dale, Kevin K Roggin
We aimed to determine whether comprehensive imaging analysis with analytic morphomics (AM) enhances or replaces geriatric assessment (GA) in risk-stratifying pancreatic surgery patients. One hundred thirty-four pancreatic surgery patients were identified from a prospective cohort. Sixty-three patients in the cohort had preoperative CT scans in addition to comprehensive geriatric assessments. CT scans were processed using AM. Associations with National Surgical Quality Improvement Program (NSQIP) serious complications were evaluated using univariate analysis and robust elastic net modeling to obtain AUROC curves by adding AM and GA measures to our previously defined clinical base risk model (age, body mass index, American Society of Anesthesiologists classification, and Charlson comorbidity index)...
March 24, 2017: Journal of Gastrointestinal Surgery: Official Journal of the Society for Surgery of the Alimentary Tract
https://www.readbyqxmd.com/read/28341412/dorsal-muscle-attenuation-may-predict-failure-to-respond-to-interleukin-2-therapy-in-metastatic-renal-cell-carcinoma
#3
Bamidele Otemuyiwa, Brian A Derstine, Peng Zhang, Sandra L Wong, Michael S Sabel, Bruce G Redman, Stewart C Wang, Ajjai S Alva, Matthew S Davenport
RATIONALE AND OBJECTIVES: To explore whether the sarcopenia body type can help predict response to interleukin-2 (IL-2) therapy in metastatic renal cell carcinoma (RCC). MATERIALS AND METHODS: Institutional review board approval was obtained for this Health Insurance Portability and Accountability Act-compliant retrospective cohort study of 75 subjects with metastatic RCC who underwent pretreatment contrast-enhanced computed tomography within 1 year of initiating IL-2 therapy...
March 21, 2017: Academic Radiology
https://www.readbyqxmd.com/read/28335088/further-characterization-of-computed-tomographic-and-clinical-features-for-staging-and-prognosis-of-idiopathic-pulmonary-fibrosis-in-west-highland-white-terriers
#4
Florence Thierry, Ian Handel, Gawain Hammond, Lesley G King, Brendan M Corcoran, Tobias Schwarz
Idiopathic pulmonary fibrosis is an interstitial lung disease of unknown etiology resulting in progressive interstitial fibrosis, with a known predilection in West Highland white terriers. In humans, computed tomography (CT) is a standard method for providing diagnostic and prognostic information, and plays a major role in the idiopathic pulmonary fibrosis staging process. Objectives of this retrospective, analytical, cross-sectional study were to establish descriptive criteria for reporting CT findings and test correlations among CT, clinical findings and survival time in West Highland white terriers with idiopathic pulmonary fibrosis...
March 23, 2017: Veterinary Radiology & Ultrasound
https://www.readbyqxmd.com/read/28317122/an-anthropomorphic-abdominal-phantom-for-deformable-image-registration-accuracy-validation-in-adaptive-radiation-therapy
#5
Yuliang Liao, Linjing Wang, Xiangdong Xu, Haibin Chen, Jiawei Chen, Guoqian Zhang, Huaiyu Lei, Ruihao Wang, Shuxu Zhang, Xuejun Gu, Xin Zhen, Linghong Zhou
PURPOSE: To design and construct a three-dimensional (3D) anthropomorphic abdominal phantom for geometric accuracy and dose summation accuracy evaluations of deformable image registration (DIR) algorithms for adaptive radiation therapy (ART). METHOD: Organ molds, including liver, kidney, spleen, stomach, vertebra and two metastasis tumors, were 3D printed using contours from an ovarian cancer patient. The organ molds were molded with deformable gels made of different mixtures of polyvinyl chloride (PVC) and the softener dioctyl terephthalate...
March 20, 2017: Medical Physics
https://www.readbyqxmd.com/read/28315063/the-effect-of-regadenoson-on-the-integrity-of-the-human-blood-brain-barrier-a-pilot-study
#6
Sadhana Jackson, Richard T George, Martin A Lodge, Anna Piotrowski, Richard L Wahl, Sachin K Gujar, Stuart A Grossman
Regadenoson is an FDA approved adenosine receptor agonist which increases blood-brain barrier (BBB) permeability in rodents. Regadenoson is used clinically for pharmacologic cardiac stress testing using SPECT or CT imaging agents that do not cross an intact BBB. This study was conducted to determine if standard doses of regadenoson transiently disrupt the human BBB allowing higher concentrations of systemically administered imaging agents to enter the brain. Patients without known intracranial disease undergoing clinically indicated pharmacologic cardiac stress tests were eligible for this study...
March 17, 2017: Journal of Neuro-oncology
https://www.readbyqxmd.com/read/28297355/mr-image-based-synthetic-ct-for-imrt-prostate-treatment-planning-and-cbct-image-guided-localization
#7
Shupeng Chen, Hong Quan, An Qin, Seonghwan Yee, Di Yan
The purpose of this study was to propose and evaluate a method of creating a synthetic CT (S-CT) from MRI simulation for dose calculation and daily CBCT localization. A pair of MR and CT images was obtained in the same day from each of 10 prostate patients. The pair of MR and CT images was preregistered using the deformable image registration (DIR). Using the corresponding displacement vector field (atlas-DVF), the CT image was deformed to the MR image to create an atlas MR-CT pair. Regions of interest (ROI) on the atlas MR-CT pair were delineated and used to create atlas-ROI masks...
May 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28296984/implant-stability-and-bone-characteristics-in-free-fibula-flaps-used-for-jaw-reconstruction-a-prospective-cohort-study
#8
Vinay V Kumar, Ullash Kumar, Vijay Pillai, Vinotha Ponnusamy, Bilal Al-Nawas, Moni A Kuriakose
PURPOSE: The primary objective of this prospective cohort study was to evaluate primary and secondary implant stability values of implants placed into healed free fibula-reconstructed mandibles. The secondary objective was to investigate whether a correlation existed between primary implant stability and the quantity of cortical bone-implant contact and of cortical fibular bone in contact with the implants. MATERIALS AND METHODS: The study participants are patients enrolled in a registered trial (No...
March 17, 2017: International Journal of Oral & Maxillofacial Implants
https://www.readbyqxmd.com/read/28296757/radiological-prediction-of-tumor-invasiveness-of-lung-adenocarcinoma-on-thin-section-ct
#9
Masahiro Yanagawa, Takeshi Johkoh, Masayuki Noguchi, Eiichi Morii, Yasushi Shintani, Meinoshin Okumura, Akinori Hata, Maki Fujiwara, Osamu Honda, Noriyuki Tomiyama
To evaluate thin-section computed tomography (CT) (TSCT) features that differentiate adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive adenocarcinoma (IVA), and to determine the size of solid portion on CT that correlates to pathological invasive components. Forty-eight patients were included. Nodules were classified into ground-glass nodule (GGN), part-solid, solid, and heterogeneous. Visual density of GGNs was subjectively evaluated using reference standard images: faint GGN (Ga), <-700 Hounsfield unit (HU); intermediate GGN (Gb), from -700 to -400 HU; dense GGN (Gc), >-400 HU; and mixed (Ga + Gb, Ga + Gc, and Gb + Gc)...
March 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28296333/automated-calculation-of-water-equivalent-diameter-dw-based-on-aapm-task-group-220
#10
Choirul Anam, Freddy Haryanto, Rena Widita, Idam Arif, Geoff Dougherty
The purpose of this study is to accurately and effectively automate the calculation of the water-equivalent diameter (DW) from 3D CT images for estimating the size-specific dose. DW is the metric that characterizes the patient size and attenuation. In this study, DW was calculated for standard CTDI phantoms and patient images. Two types of phantom were used, one representing the head with a diameter of 16 cm and the other representing the body with a diameter of 32 cm. Images of 63 patients were also taken, 32 who had undergone a CT head examination and 31 who had undergone a CT thorax examination...
July 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28290354/development-of-a-phantom-to-test-fully-automated-breast-density-software-a-work-in-progress
#11
G G Waade, S Hofvind, J D Thompson, R Highnam, P Hogg
OBJECTIVES: Mammographic density (MD) is an independent risk factor for breast cancer and may have a future role for stratified screening. Automated software can estimate MD but the relationship between breast thickness reduction and MD is not fully understood. Our aim is to develop a deformable breast phantom to assess automated density software and the impact of breast thickness reduction on MD. METHODS: Several different configurations of poly vinyl alcohol (PVAL) phantoms were created...
February 2017: Radiography
https://www.readbyqxmd.com/read/28289482/efficacy-of-computed-tomography-ct-attenuation-values-and-ct-findings-in-the-differentiation-of-pleural-effusion
#12
Kadihan Yalçin-Şafak, Neslihan Umarusman-Tanju, Muhammet Ayyıldız, Nihal Yücel, Tamer Baysal
BACKGROUND: The aim of this study was to investigate the efficacy of computed tomography (CT) findings for characterizing pleural effusions with the use of attenuation values. MATERIAL/METHODS: One hundred and twenty eight patients with pleural effusions on thoracic CT who underwent thoracentesisis within two weeks were studied. Pleural effusions were classified as exudates or transudates according to the Light's criteria. A region of interest was placed for the measurement of Hounsfield Unit (HU) values in the area of the greatest amount of effusion on each slice of the three slices used...
2017: Polish Journal of Radiology
https://www.readbyqxmd.com/read/28279438/relation-of-epicardial-adipose-tissue-radiodensity-to-coronary-artery-calcium-on-cardiac-computed-tomography-in-patients-at-high-risk-for-cardiovascular-disease
#13
Bas T Franssens, Hendrik M Nathoe, Frank L J Visseren, Yolanda van der Graaf, Tim Leiner
Adipose tissue radiodensity detected by computed tomography (CT) is hypothesized to be associated with differences in adipose tissue composition which may contribute to the development of coronary atherosclerosis independent of epicardial adipose tissue volume. The aim of the present study is to quantify the relation between epicardial adipose tissue radiodensity and presence, distribution, and density of coronary artery calcium (CAC) in patients at high risk for cardiovascular disease. A total of 140 patients of the Secondary Manifestations of ARTerial disease (SMART) study underwent cardiac-CT angiography...
February 11, 2017: American Journal of Cardiology
https://www.readbyqxmd.com/read/28273652/potential-of-gadolinium-as-contrast-material-in-second-generation-dual-energy-computed-tomography-an-ex-vivo-phantom-study
#14
Malte N Bongers, Christoph Schabel, Bernhard Krauss, Claus D Claussen, Konstantin Nikolaou, Christoph Thomas
PURPOSE: To evaluate the potential of gadolinium (Gd) as contrast material (CM) in second generation dual energy computed tomography (DECT). MATERIAL AND METHODS: In a phantom model, DECT post-processing was used to increase Gd attenuation using advanced monoenergetic extrapolation (MEI), to create virtual non-contrast images (Gd-VNC) and Gd maps and to quantify Gd content. Dilutions of Gd and iodinated CM (7-296 HU) were filled in syringes, placed in an attenuation phantom and scanned with standard DECT protocols (80 &100/Sn140 kV)...
February 22, 2017: Clinical Imaging
https://www.readbyqxmd.com/read/28267536/bone-density-loss-on-computed-tomography-at-3-year-follow-up-in-current-compared-to-former-male-smokers
#15
E Pompe, J Bartstra, H J Verhaar, H J de Koning, C M van der Aalst, M Oudkerk, R Vliegenthart, J-W J Lammers, P A de Jong, F A A Mohamed Hoesein
OBJECTIVES: Cigarette smoking negatively affects bone quality and increases fracture risk. Little is known on the effect of smoking cessation and computed tomography (CT)-derived bone mineral density (BMD) decline in the spine. We evaluated the association of current and former smoking with BMD decline after 3-year follow-up. METHODS: Male current and former smokers participating in a lung cancer screening trial who underwent baseline and 3-year follow-up CT were included...
April 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28267350/variation-in-ct-number-and-image-noise-uniformity-according-to-patient-positioning-in-mdct
#16
Timothy P Szczykutowicz, Andrew DuPlissis, Perry J Pickhardt
OBJECTIVE: Many algorithms for clinical decision making rely on assessment of the CT number (expressed as Hounsfield units); however, to our knowledge, few, if any, studies have addressed how CT numbers change as a function of patient positioning within the scanner. MATERIALS AND METHODS: An anthropomorphic phantom underwent imaging with varying amounts of vertical orientation misalignment with respect to isocenter. CT number and noise were measured using ROIs in the upper thorax, mid thorax, and abdomen...
March 7, 2017: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/28265799/optimizing-radiation-exposure-in-screening-of-body-packing-image-quality-and-diagnostic-acceptability-of-an-80-kvp-protocol-with-automated-tube-current-modulation
#17
Joel Aissa, Johannes Boos, Christian Rubbert, Julian Caspers, Christoph Schleich, Christoph Thomas, Patric Kröpil, Gerald Antoch, Falk Miese
The aim of this study was to evaluate the objective and subjective image quality of a novel computed tomography (CT) protocol with reduced radiation dose for body packing with 80 kVp and automated tube current modulation (ATCM) compared to a standard body packing CT protocol. 80 individuals who were examined between March 2012 and July 2015 in suspicion of ingested drug packets were retrospectively included in this study. Thirty-one CT examinations were performed using ATCM and a fixed tube voltage of 80 kVp (group A)...
March 7, 2017: Forensic Science, Medicine, and Pathology
https://www.readbyqxmd.com/read/28263129/profile-of-metabolic-and-infectious-stone-formers-in-a-contemporary-pcnl-cohort
#18
Benjamin J King, Caleb J Seufert, Zhamshid Okhunov, Nazih Khater, D Duane Baldwin, Peter W Callas, Kevan M Sternberg
INTRODUCTION: To identify factors associated with stone composition in patients undergoing percutaneous nephrolithotomy (PCNL). MATERIAL AND METHODS: A retrospective analysis of patients who underwent PCNL at two academic institutions between 2002 and 2014. Stone composition, stone characteristics based on non-contrast computer tomography (NCCT), patient demographics, and the S.T.O.N.E nephrolithometry scores were compared. Stones were characterized as either infection or metabolic...
February 2017: Canadian Journal of Urology
https://www.readbyqxmd.com/read/28260317/-association-between-epicardial-fat-volume-and-coronary-artery-calcification-in-patients-with-chronic-kidney-disease
#19
Y N Sheng, D M Zhao, Q L Ma, Y Gao
Objective: To evaluate whether epicardial fat volume (EFV) is related to coronary artery calcification in patients with chronic kidney disease(CKD). Method: Multi-slice computed tomography was performed in 30 healthy subjects and 120 patients with CKD. Cross-sectional tomographic cardiac slices from base to apex were traced semi-automatically using a Volume Viewer of AW4.3 off-line workstation, and EFV was measured by assigning Hounsfield units ranging from -250 to -30 HU to fat.The coronary artery calcification score was assessed by CaScoring software...
February 24, 2017: Zhonghua Xin Xue Guan Bing za Zhi
https://www.readbyqxmd.com/read/28260125/pull-out-strength-of-patient-specific-template-guided-vs-free-hand-fluoroscopically-controlled-thoracolumbar-pedicle-screws-a-biomechanical-analysis-of-a-randomized-cadaveric-study
#20
A Aichmair, M Moser, M R Bauer, E Bachmann, J G Snedeker, M Betz, M Farshad
PURPOSE: To assess the pull-out strength of thoracolumbar pedicle screws implanted via either a patient-specific template-guided or conventional free-hand fluoroscopically controlled technique in a randomized cadaveric study, and to evaluate the influence of local vertebral bone density, quantified by Hounsfield units (HU), on pedicle screw pull-out strength. METHODS: Thoracolumbar pedicles of three spine cadavers were instrumented using either a free-hand fluoroscopically controlled or a patient-specific template-guided technique...
March 4, 2017: European Spine Journal
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