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Hounsfield Units (HU)

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https://www.readbyqxmd.com/read/27906743/vertebral-body-hounsfield-units-are-associated-with-cage-subsidence-after-transforaminal-lumbar-interbody-fusion-with-unilateral-pedicle-screw-fixation
#1
Jie Mi, Kang Li, Xin Zhao, Chang-Qing Zhao, Hua Li, Jie Zhao
OBJECTIVE: To assess the association between Hounsfield units (HU) measurement and cage subsidence after lumbar interbody fusion. BACKGROUND: Transforaminal lumbar interbody fusion (TLIF) with unilateral fixation becomes a popular treatment modality for lumbar degenerative disease. Cage subsidence is a potentially devastating complication after lumbar interbody fusion with unilateral fixation. Recently, a new technique for assessing bone mineral density using HU values from computed tomography has been proposed...
November 30, 2016: Clinical Spine Surgery
https://www.readbyqxmd.com/read/27903267/skeletal-muscle-quality-as-assessed-by-ct-derived-skeletal-muscle-density-is-associated-with-6-month-mortality-in-mechanically-ventilated-critically-ill-patients
#2
Wilhelmus G P M Looijaard, Ingeborg M Dekker, Sandra N Stapel, Armand R J Girbes, Jos W R Twisk, Heleen M Oudemans-van Straaten, Peter J M Weijs
BACKGROUND: Muscle quantity at intensive care unit (ICU) admission has been independently associated with mortality. In addition to quantity, muscle quality may be important for survival. Muscle quality is influenced by fatty infiltration or myosteatosis, which can be assessed on computed tomography (CT) scans by analysing skeletal muscle density (SMD) and the amount of intermuscular adipose tissue (IMAT). We investigated whether CT-derived low skeletal muscle quality at ICU admission is independently associated with 6-month mortality and other clinical outcomes...
December 1, 2016: Critical Care: the Official Journal of the Critical Care Forum
https://www.readbyqxmd.com/read/27895751/value-of-window-technique-in-diagnosis-of-the-ground-glass-opacities-in-patients-with-non-small-cell-pulmonary-cancer
#3
Gang Yao
The aim of the present study was to examine the value of window technique in qualitative diagnosis of the ground glass opacities (GGO) in patients with non-small cell pulmonary cancer. A total of 124 clinically suspected pulmonary cancer patients were analyzed retrospectively. The lesions were affirmed by puncture biopsy, and were GGO on pulmonary window while were invisible on mediastinal window. Sixty-four multi-detector spiral computed tomography with the window width and window level of 1,500 Hounsfield units (HU) and -450 HU on pulmonary window, while the window width and window level of 400 and 40 HU on mediastinal window, was used in the study...
November 2016: Oncology Letters
https://www.readbyqxmd.com/read/27893446/stability-of-radiomic-features-in-ct-perfusion-maps
#4
M Bogowicz, O Riesterer, R A Bundschuh, P Veit-Haibach, M Hüllner, G Studer, S Stieb, S Glatz, M Pruschy, M Guckenberger, S Tanadini-Lang
This study aimed to identify a set of stable radiomic parameters in CT perfusion (CTP) maps with respect to CTP calculation factors and image discretization, as an input for future prognostic models for local tumor response to chemo-radiotherapy. Pre-treatment CTP images of eleven patients with oropharyngeal carcinoma and eleven patients with non-small cell lung cancer (NSCLC) were analyzed. 315 radiomic parameters were studied per perfusion map (blood volume, blood flow and mean transit time). Radiomics robustness was investigated regarding the potentially standardizable (image discretization method, Hounsfield unit (HU) threshold, voxel size and temporal resolution) and non-standardizable (artery contouring and noise threshold) perfusion calculation factors using the intraclass correlation (ICC)...
December 21, 2016: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/27891826/ct-brain-perfusion-a-static-phantom-study-of-contrast-to-noise-ratio-and-radiation-dose
#5
Stewart M Midgley, Damien L Stella, Bruce Cv Campbell, Francesca Langenberg, Paul F Einsiedel
INTRODUCTION: Computed tomography perfusion (CTP) is increasingly employed in the diagnosis and management of ischaemic stroke but radiation dose can be significant and optimising contrast-to-noise ratio (CNR) is challenging. This study aimed to quantify and optimise the balance between CNR as a surrogate for image quality and radiation dose. METHODS: A perspex head phantom with vials of dilute contrast agent was scanned using a Siemens Definition Flash 128-slice scanner...
November 27, 2016: Journal of Medical Imaging and Radiation Oncology
https://www.readbyqxmd.com/read/27886084/intracranial-thrombus-morphology-and-composition-undergoes-time-dependent-changes-in-acute-ischemic-stroke-a-ct-densitometry-study
#6
Slaven Pikija, Jozef Magdic, Vladimir Trkulja, Peter Unterkreuter, Johannes Sebastian Mutzenbach, Helmut F Novak, Friedrich Weymayr, Larissa Hauer, Johann Sellner
The aim of our study was to assess whether cerebral artery clots undergo time-dependent morphological and compositional changes in acute ischemic stroke. We performed a retrospective chart review of patients admitted within 5 h from symptom onset to three European stroke centers and evaluated non-contrast-enhanced CT (NECT) for hyperdense artery signs (HAS) in 2565 scans. The occlusion site, density of HAS expressed in Hounsfield units (HU), area of HAS, and relative density (rHU) (HU clot/HU non-affected artery) were studied and related to time from symptom onset, clinical severity, stroke etiology, and laboratory parameters...
November 23, 2016: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/27876271/hiv-infection-is-independently-associated-with-increased-ct-scan-lung-density
#7
M Bradley Drummond, Allison A Lambert, Amira F Hussien, Cheng T Lin, Christian A Merlo, Robert A Wise, Gregory D Kirk, Robert H Brown
RATIONALE AND OBJECTIVES: Noninfectious pulmonary complications are common among HIV-infected individuals and may be detected early by quantitative computed tomography (CT) scanning. The association of HIV disease markers with CT lung density measurement remains poorly understood. MATERIALS AND METHODS: One hundred twenty-five participants free of spirometry-defined lung disease were recruited from a longitudinal cohort study of HIV-infected and HIV-uninfected individuals to undergo standardized CT scan of the chest...
November 18, 2016: Academic Radiology
https://www.readbyqxmd.com/read/27872327/relation-between-cardiovascular-disease-risk-factors-and-epicardial-adipose-tissue-density-on-cardiac-computed-tomography-in-patients-at-high-risk-of-cardiovascular-events
#8
Bas T Franssens, Hendrik M Nathoe, Tim Leiner, Yolanda van der Graaf, Frank Lj Visseren
BACKGROUND: The radiodensity of epicardial adipose tissue may provide information on cardiovascular risk in addition to epicardial adipose tissue volume. The aim of this study was to quantify the relation between cardiovascular risk factors and the radiodensity of epicardial adipose tissue in patients at high risk of cardiovascular disease. DESIGN: This was a cross-sectional study in 140 patients at high risk of cardiovascular disease. METHODS: Patients from the Secondary Manifestations of ARTerial disease (SMART) cohort study were invited to undergo cardiac computed tomography angiography...
November 21, 2016: European Journal of Preventive Cardiology
https://www.readbyqxmd.com/read/27862245/radiolucency-in-stemless-shoulder-arthroplasty-is-associated-with-an-imaging-phenomenons
#9
Robert Hudek, Birgit Werner, Ayman F Abdelkawi, Rainer Schmitt, Frank Gohlke
Stemless humeral implants show comparable midterm clinical results compared to stemmed components. Recently, radiolucencies around the metaphyseal seating of humeral stemless implants were reported on postoperative radiographs. It is controversial whether they are attributable to bone resorption. We hypothesized these radiolucencies result from imaging artifacts. Seven cadaveric specimens (3 male and 4 female) were first radiographed and then scanned with CT. A stemless humeral component of current design was implanted in each specimen...
November 10, 2016: Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society
https://www.readbyqxmd.com/read/27861382/single-injection-protocol-for-coronary-and-lower-extremity-ct-angiographies-in-patients-suspected-for-peripheral-arterial-disease
#10
Ashish Khandelwal, Takeshi Kondo, Makoto Amanuma, Akitsugu Oida, Tomonari Sano, Saboo S Sachin, Shinichi Takase, Frank J Rybicki, Kanako K Kumamaru
To evaluate the feasibility of a single injection protocol for coronary CT angiography (CTA) and lower extremity CTA in patients suspected for peripheral arterial disease (PAD).This prospective observational study included a total of 103 patients who showed an ankle brachial index ≤0.9 and underwent the single injection protocol for coronary and lower extremity CTA. All CTAs used iodinated contrast (weight × 0.06 mL/s × 20 seconds). A prospective Electrocardiogram (ECG)-gated coronary CTA was performed, followed by helical lower extremity CTA beginning 9 seconds after coronary CTA...
November 2016: Medicine (Baltimore)
https://www.readbyqxmd.com/read/27861205/improved-delineation-of-pulmonary-embolism-and-venous-thrombosis-through-frequency-selective-nonlinear-blending-in-computed-tomography
#11
Malte Niklas Bongers, Georg Bier, Christopher Kloth, Christoph Schabel, Jan Fritz, Konstantin Nikolaou, Marius Horger
OBJECTIVE: The aim of this study was to test the hypothesis that a novel frequency selective nonlinear blending (NLB) algorithm increases the delineation of pulmonary embolism and venous thrombosis in portal-venous phase whole-body staging computed tomography (CT). MATERIALS AND METHODS: A cohort of 67 patients with incidental pulmonary embolism and/or venous thrombosis in contrast-enhanced oncological staging CT were retrospectively selected. Computed tomography data sets were acquired 65 to 90 seconds after intravenous iodine contrast administration using state-of-the-art multi-detector CT scanners...
November 17, 2016: Investigative Radiology
https://www.readbyqxmd.com/read/27857919/multiple-intracranial-high-density-foci-after-brain-parenchymal-catheterization
#12
Tae-Min Choi, Kyu Yong Cho, Byung Chan Lim, Jun Seob Lim, Rae-Seop Lee
OBJECTIVE: To report an observational investigation of small high attenuated foci in computed tomography (CT) scan followed by brain parenchymal catheterization. METHODS: From January 2011 to March 2015, we retrospectively reviewed the 381 patients who had undergone brain catheterization in our clinic and enrolled the patients who had newly developed high attenuation foci in the postoperative CT scans. The brain CT scans were reviewed about the lesion location, Hounsfield Unit (HU) and the time of appearance...
October 2016: Korean Journal of Neurotrauma
https://www.readbyqxmd.com/read/27837185/quantitative-estimation-of-a-ratio-of-intracranial-cerebrospinal-fluid-volume-to-brain-volume-based-on-segmentation-of-ct-images-in-patients-with-extra-axial-hematoma
#13
Ha Son Nguyen, Mohit Patel, Luyuan Li, Shekar Kurpad, Wade Mueller
BACKGROUND: Diminishing volume of intracranial cerebrospinal fluid (CSF) in patients with space-occupying masses have been attributed to unfavorable outcome associated with reduction of cerebral perfusion pressure and subsequent brain ischemia. OBJECTIVE: The objective of this article is to employ a ratio of CSF volume to brain volume for longitudinal assessment of space-volume relationships in patients with extra-axial hematoma and to determine variability of the ratio among patients with different types and stages of hematoma...
November 11, 2016: Neuroradiology Journal
https://www.readbyqxmd.com/read/27812579/ultra-efficient-widely-tunable-gold-nanoparticle-based-fiducial-markers-for-x-ray-imaging
#14
G Maiorano, E Mele, M C Frassanito, E Restini, A Athanassiou, P P Pompa
We show the development of a new class of highly efficient, biocompatible fiducial markers for X-ray imaging and radiosurgery, based on polymer shells encapsulating engineered gold nanoparticle (AuNP) suspensions. Our smart fabrication strategy enables wide tunability of the fiducial size, shape, and X-ray attenuation performance, up to record values >20 000 Hounsfield units (HU), i.e. comparable to or even higher than bulk gold. We show that the NP fiducials allow for superior imaging both in vitro and in vivo (yet requiring 2 orders of magnitude less material), with strong stability over time and the absence of classical "streak artifacts" of standard bulk fiducials...
December 7, 2016: Nanoscale
https://www.readbyqxmd.com/read/27810702/low-muscle-attenuation-is-a-prognostic-factor-for-survival-in-metastatic-breast-cancer-patients-treated-with-first-line-palliative-chemotherapy
#15
Hánah N Rier, Agnes Jager, Stefan Sleijfer, Joost van Rosmalen, Marc C J M Kock, Mark-David Levin
BACKGROUND: Low muscle mass (LMM) and low muscle attenuation (LMA) reflect low muscle quantity and low muscle quality, respectively. Both are associated with a poor outcome in several types of solid malignancies. This study determined the association of skeletal muscle measures with overall survival (OS) and time to next treatment (TNT). PATIENTS AND METHODS: A skeletal muscle index (SMI) in cm(2)/m(2) and muscle attenuation (MA) in Hounsfield units (HU) were measured using abdominal CT-images of 166 patients before start of first-line chemotherapy for metastatic breast cancer...
October 27, 2016: Breast: Official Journal of the European Society of Mastology
https://www.readbyqxmd.com/read/27806611/accuracy-of-dose-calculations-on-kv-cone-beam-ct-images-of-lung-cancer-patients
#16
Mariska de Smet, Danny Schuring, Sebastiaan Nijsten, Frank Verhaegen
PURPOSE: To develop a clinically feasible method for dose calculations on cone beam CT (CBCT) images of two different vendors, and to determine the accuracy of these dose calculations for lung cancer patients. METHODS: Lung cancer patients with CBCT imaging (n = 10 for Elekta, n = 6 for Varian) and a repeated planning CT scan on the same day were selected. For CBCT dose calculations, an adapted Hounsfield units-to-mass density table (HU table) was used which was obtained by comparing CT values of corresponding points on the CBCT and the repeated planning CT scan...
November 2016: Medical Physics
https://www.readbyqxmd.com/read/27805563/computed-tomography-for-the-management-of%C3%A2-exit-site-and-tunnel-infections-in-peritoneal-dialysis-patients%C3%A2
#17
Keina Nozaki, Yuka Kamijo, Mineo Nakatsuka, Takeshi Azuma, Tohru Nakagawa, Hideyo Miyazaki, Tetsuya Fujimura, Hiroshi Fukuhara, Haruki Kume, Yoshitaka Ishibashi, Yukio Homma
PURPOSE: To evaluate the effectiveness of computed tomography (CT) for detection of exit-site and tunnel infections with a Tenckhoff catheter. MATERIALS AND METHODS: The study enrolled patients with exit-site or tunnel infections who underwent ultrasonography (US), CT scans, and subsequent catheter removal or partial catheter reimplantation from 2010 to 2014. Control cases on peritoneal dialysis who underwent abdominal CT scans for other reasons were randomly selected...
December 2016: Clinical Nephrology
https://www.readbyqxmd.com/read/27802255/diagnosing-the-undiagnosed-osteoporosis-in-patients-undergoing-lumbar-fusion
#18
Scott C Wagner, Peter M Formby, Melvin D Helgeson, Daniel G Kang
STUDY DESIGN: Retrospective analysis. OBJECTIVE: The aim of the study was to report the incidence of undiagnosed osteoporosis in patients undergoing lumbar spine fusion using computed tomography (CT) Hounsfield units (HU). SUMMARY OF BACKGROUND DATA: We used a recent technique utilizing HU to estimate bone mineral density (BMD) of the lumbar spine and hypothesized that this technique would reveal a high percentage of undiagnosed osteoporotic patients undergoing transforaminal lumbar interbody fusion (TLIF)...
November 1, 2016: Spine
https://www.readbyqxmd.com/read/27789788/successful-recanalization-in-acute-basilar-artery-occlusion-treated-with-endovascular-therapy-is-independent-of-thrombus-length
#19
Liang Shu, Christian Riedel, Johannes Meyne, Olav Jansen, Ulf Jensen-Kondering
BACKGROUND AND PURPOSE: As previously demonstrated, the recanalization rate and clinical outcome in patients with anterior circulation stroke treated with IV thrombolysis (IVT) depend on clot characteristics such as thrombus length and thrombus density. In patients with basilar artery occlusion (BAO) treated with IVT, the recanalization rate has also been shown to depend on thrombus length, although no cut-off value beyond which recanalization would seem impossible has been determined...
October 27, 2016: Journal of Neurointerventional Surgery
https://www.readbyqxmd.com/read/27782710/individually-optimized-contrast-enhanced-4d-ct-for-radiotherapy-simulation-in-pancreatic-ductal-adenocarcinoma
#20
Wookjin Choi, Ming Xue, Barton F Lane, Min Kyu Kang, Kruti Patel, William F Regine, Paul Klahr, Jiahui Wang, Shifeng Chen, Warren D'Souza, Wei Lu
PURPOSE: To develop an individually optimized contrast-enhanced (CE) 4D-computed tomography (CT) for radiotherapy simulation in pancreatic ductal adenocarcinomas (PDA). METHODS: Ten PDA patients were enrolled. Each underwent three CT scans: a 4D-CT immediately following a CE 3D-CT and an individually optimized CE 4D-CT using test injection. Three physicians contoured the tumor and pancreatic tissues. Image quality scores, tumor volume, motion, tumor-to-pancreas contrast, and contrast-to-noise ratio (CNR) were compared in the three CTs...
October 2016: Medical Physics
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