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Hounsfield Units (HU)

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https://www.readbyqxmd.com/read/28914752/ct-attenuation-of-pericoronary-adipose-tissue-in-normal-versus-atherosclerotic-coronary-segments-as-defined-by-intravascular-ultrasound
#1
Mohamed Marwan, Michaela Hell, Annika Schuhbäck, Sören Gauss, Daniel Bittner, Tobias Pflederer, Stephan Achenbach
BACKGROUND: The factors influencing genesis of atherosclerosis at specific regions within the coronary arterial system are currently uncertain. Local mechanical factors such as shear stress as well as metabolic factors, including inflammatory mediators released from epicardial fat, have been proposed. We analyzed computed tomographic (CT) attenuation of pericoronary adipose tissue in normal versus atherosclerotic coronary segments as defined by intravascular ultrasound (IVUS). PATIENTS AND METHODS: We evaluated the data sets of 29 patients who were referred for invasive coronary angiography and in whom IVUS of 1 coronary vessel was performed for clinical reasons...
September 2017: Journal of Computer Assisted Tomography
https://www.readbyqxmd.com/read/28901659/using-gamma-index-to-flag-changes-in-anatomy-during-image-guided-radiation-therapy-of-head-and-neck-cancer
#2
Bryan Schaly, Jeff Kempe, Varagur Venkatesan, Sylvia Mitchell, Jerry J Battista
During radiation therapy of head and neck cancer, the decision to consider replanning a treatment because of anatomical changes has significant resource implications. We developed an algorithm that compares cone-beam computed tomography (CBCT) image pairs and provides an automatic alert as to when remedial action may be required. Retrospective CBCT data from ten head and neck cancer patients that were replanned during their treatment was used to train the algorithm on when to recommend a repeat CT simulation (re-CT)...
September 13, 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28894687/the-pedicles-are-not-the-densest-regions-of-the-lumbar-vertebrae-implications-for-bone-quality-assessment-and-surgical-treatment-strategy
#3
Eric A Hohn, Bryant Chu, Audrey Martin, Elizabeth Yu, Connor Telles, Jeremi Leasure, Tennyson L Lynch, Dimitriy Kondrashov
STUDY DESIGN: Cadaver study. OBJECTIVE: To determine the bone density of lumbar vertebral anatomic subregions. Bone mineral density (BMD) is a major factor in osseous fixation construct strength. The standard region for implant fixation of the spine is the pedicle; however, other regions may be more viable options with higher bone quality. METHODS: Using computed tomography images, the spine was digitally isolated by applying a filter for adult bone...
September 2017: Global Spine Journal
https://www.readbyqxmd.com/read/28893701/impact-of-vascular-calcifications-on-long-femoropopliteal-stenting-outcomes
#4
Adrien Kaladji, Pierre-Alexandre Vent, Aurore Danvin, Philippe Chaillou, Alain Costargent, Béatrice Guyomarch, Thibaut Quillard, Yann Gouëffic
OBJECTIVE: Vascular calcifications (VCs) may be a prognostic factor for outcome after endovascular treatment of peripheral arterial disease (PAD). Semi-quantitative analysis with X-ray imaging is the main limiting factor for assessing VCs. The aim of the present study was to find a correlation between the amount of VC with a CT scan quantification and mid-term results of endovascular treatment of TASC C/D femoropopliteal (FP) lesions. METHODS: Patients belonging to two previously published registries (STELLA and STELLA PTX) and who underwent a preoperative CT scan were retrospectively included in the study...
September 8, 2017: Annals of Vascular Surgery
https://www.readbyqxmd.com/read/28891903/the-effectiveness-of-oxidized-regenerated-cellulose-as-a-graft-material-in-transalveolar-osteotome-sinus-lift-procedure
#5
Laith A Hussein, Thair A L Hassan
The posterior maxilla is challenged with postextraction alveolar bone resorption and pneumatization drive of the Schneiderian membrane that reduces the subantral distance. To overcome such anatomic obstacle a sinus augmentation procedure was introduced either via lateral or crestal approach depending on residual ridge height. The current study evaluated oxidized regenerated cellulose (ORC) as a grafting material versus osteon II by measuring bone gain and graft density, 24 weeks postoperatively. Twenty consecutive patients (24 cases) aged from 20 to 65 years were considered eligible after clinical and radiographic evaluation...
September 7, 2017: Journal of Craniofacial Surgery
https://www.readbyqxmd.com/read/28891871/bone-density-development-of-the-temporal-bone-assessed-by-computed-tomography
#6
Kuniyuki Takahashi, Yuka Morita, Shinsuke Ohshima, Shuji Izumi, Yamato Kubota, Arata Horii
HYPOTHESIS: The temporal bone shows regional differences in bone development. BACKGROUND: The spreading pattern of acute mastoiditis shows age-related differences. In infants, it spreads laterally and causes retroauricular swelling, whereas in older children, it tends to spread medially and causes intracranial complications. We hypothesized that bone maturation may influence the spreading pattern of acute mastoiditis. METHODS: Eighty participants with normal hearing, aged 3 months to 42 years, participated in this study...
September 7, 2017: Otology & Neurotology
https://www.readbyqxmd.com/read/28870984/optimal-follow-up-strategies-for-adrenal-incidentalomas-reappraisal-of-the-2016-ese-ensat-guidelines-in-real-clinical-practice
#7
A Ram Hong, Jung Hee Kim, Kyeong Seon Park, Kyong Young Kim, Ji Hyun Lee, Sung Hye Kong, Seo Young Lee, Chan Soo Shin, Sang Wan Kim, Seong-Yeon Kim
OBJECTIVE: Recently, the European Society of Endocrinology (ESE), in collaboration with the European Network for the Study of Adrenal Tumors (ENSAT), asserted that adrenal incidentalomas (AIs) <4 cm and ≤10 Hounsfield units (HU) do not require further follow-up imaging. In order to validate the clinical application of the follow-up strategies suggested by the 2016 ESE-ENSAT guidelines, we explored the clinical characteristics and natural course of AIs in a single center over 13 years...
September 4, 2017: European Journal of Endocrinology
https://www.readbyqxmd.com/read/28860894/high-pitch-coronary-ct-angiography-at-70-kvp-adopting-a-protocol-of-low-injection-speed-and-low-volume-of-contrast-medium
#8
Ruiqi Feng, Jiajie Tong, Xiaofei Liu, Yu Zhao, Liang Zhang
OBJECTIVE: To evaluate the feasibility and image quality (IQ) of prospectively high-pitch coronary CT angiography (CCTA) with low contrast medium injection rate at 70 kVp. MATERIALS AND METHODS: One hundred and four patients with suspected coronary artery disease (body mass index < 26 kg/m(2), sinus rhythm and heart rate < 70 beats/min) were prospectively enrolled and randomly divided into two groups. In group A and group B, 28 mL and 40 mL of 370 mgI/mL iodinated contrast media was administrated at a flow rate of 3...
September 2017: Korean Journal of Radiology: Official Journal of the Korean Radiological Society
https://www.readbyqxmd.com/read/28837045/subject-specific-bone-attenuation-correction-for-brain-pet-mr-can-zte-mri-substitute-ct-scan-accurately
#9
Maya Khalifé, Brice Fernandez, Olivier Jaubert, Michael Soussan, Vincent Brulon, Irene Buvat, Claude Comtat
In brain PET/MR applications, accurate attenuation maps are required for accurate PET image quantification. An implemented attenuation correction (AC) method for brain imaging is the single-atlas approach which estimates an AC map from an averaged CT template. As an alternative, we propose to use a Zero Echo Time (ZTE) pulse sequence to segment bone, air and soft tissue. A linear relationship between histogram normalized ZTE intensity and measured CT density in Hounsfield Units (HU) in bone has been established thanks to a CT-MR database of 16 patients...
August 24, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28835993/metastatic-and-non-metastatic-lymph-nodes-quantification-and-different-distribution-of-iodine-uptake-assessed-by-dual-energy-ct
#10
Stefania Rizzo, Davide Radice, Marco Femia, Paolo De Marco, Daniela Origgi, Lorenzo Preda, Massimo Barberis, Raffaella Vigorito, Giovanni Mauri, Alberto Mauro, Massimo Bellomi
OBJECTIVES: To evaluate quantification of iodine uptake in metastatic and non-metastatic lymph nodes (LNs) by dual-energy CT (DECT) and to assess if the distribution of iodine within LNs at DECT correlates with the pathological structure. METHODS: Ninety LNs from 37 patients (23 with lung and 14 with gynaecological malignancies) were retrospectively selected. Information of LNs sent for statistical analysis included Hounsfield units (HU) at different energy levels; decomposition material densities fat-iodine, iodine-fat, iodine-water, water-iodine...
August 23, 2017: European Radiology
https://www.readbyqxmd.com/read/28817459/relation-between-epicardial-fat-and-subclinical-atherosclerosis-in-asymptomatic-individuals
#11
Rami M Abazid, Osama A Smettei, Mohammad Obadah Kattea, Sawsan Sayed, Hanaa Saqqah, Adel M Widyan, Maksymilian P Opolski
PURPOSE: Excessive quantity of epicardial adipose tissue (EAT) is considered a risk factor for coronary artery disease (CAD). There are limited data, however, on the relationship between the quality of EAT and CAD. We investigated the association between the density and volume of EAT and subclinical CAD defined by positive coronary artery calcification (CAC), using computed tomography (CT). MATERIALS AND METHODS: We reviewed 609 consecutive CT scans of patients with a mild to moderate risk for CAD to assess the EAT volume, which was measured manually by tracing the parietal pericardial sac on axial images...
August 16, 2017: Journal of Thoracic Imaging
https://www.readbyqxmd.com/read/28815667/diagnostic-performance-of-unenhanced-computed-tomography-and-18-f-fluorodeoxyglucose-positron-emission-tomography-in-indeterminate-adrenal-tumours
#12
Danae A Delivanis, Irina Bancos, Thomas D Atwell, Grant D Schmit, Patrick W Eiken, Neena Natt, Dana Erickson, Spyridoula Maraka, William F Young, Mark A Nathan
OBJECTIVE: Evidence on the diagnostic performance of adrenal imaging is limited. We aimed to assess the diagnostic performance of unenhanced computed tomography (CT) and (18) F-fluorodeoxyglucose ((18) FDG) positron emission tomography (PET)/CT imaging in a high-risk population for adrenal malignancy using an optimal reference standard. DESIGN: Retrospective cohort study. METHODS: Imaging studies of patients with adrenal nodules who underwent adrenal biopsy and/or adrenalectomy between 1994 and 2014 were reviewed and compared to the reference standard of histology...
August 17, 2017: Clinical Endocrinology
https://www.readbyqxmd.com/read/28811994/the-measurement-of-liver-fat-from-single-energy-quantitative-computed-tomography-scans
#13
Xiaoguang Cheng, Glen M Blake, J Keenan Brown, Zhe Guo, Jun Zhou, Fengzhe Wang, Liqiang Yang, Xiaohong Wang, Li Xu
BACKGROUND: Studies of soft tissue composition using computed tomography (CT) scans are often semi-quantitative and based on Hounsfield units (HU) measurements that have not been calibrated with a quantitative CT (QCT) phantom. We describe a study to establish the water (H2O) and dipotassium hydrogen phosphate (K2HPO4) basis set equivalent densities of fat and fat-free liver tissue. With this information liver fat can be accurately measured from any abdominal CT scan calibrated with a suitable phantom...
June 2017: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/28809759/independent-dose-verification-system-with-monte-carlo-simulations-using-topas-for-passive-scattering-proton-therapy-at-the-national-cancer-center-in-korea
#14
Wook-Geun Shin, Mauro Testa, Hak Soo Kim, Jong Hwi Jeong, Se Byeong Lee, Yeon-Joo Kim, Chul Hee Min
For the independent validation of treatment plans, we developed a Monte Carlo (MC)-based patient dose calculation system with the tool for particle simulation (TOPAS) to enable routine and automatic dose recalculation for each patient. The proton beam nozzle was modeled with TOPAS to simulate the therapeutic beam, and MC commissioning was performed by comparing percent depth dose with the measurement. The beam set-up based on the prescribed beam range and modulation width was automated by modifying the vendor-specific method...
August 15, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28797587/subcutaneous-adipose-tissue-characteristics-and-the-risk-of-biochemical-recurrence-in-men-with-high-risk-prostate-cancer
#15
Andrew M McDonald, John B Fiveash, Robert S Kirkland, Rex A Cardan, Rojymon Jacob, Robert Y Kim, Michael C Dobelbower, Eddy S Yang
PURPOSE/OBJECTIVE(S): To assess subcutaneous adipose tissue characteristics by computed tomography (CT) as potential imaging biomarkers predictive of biochemical recurrence in men with high-risk prostate cancer receiving radiotherapy (RT). MATERIALS AND METHODS: This retrospective study included men with high-risk prostate cancer (PSA>20ng/ml, Gleason score ≥8, or clinical extraprostatic extension) treated between 2001 and 2012. All patients received definitive, dose-escalated external beam RT along with a course of neoadjuvant, concurrent, and adjuvant androgen deprivation therapy (ADT)...
August 7, 2017: Urologic Oncology
https://www.readbyqxmd.com/read/28777462/generation-of-realistic-virtual-nodules-based-on-three-dimensional-spatial-resolution-in-lung-computed-tomography-a-pilot-phantom-study
#16
Akihiro Narita, Masaki Ohkubo, Kohei Murao, Toru Matsumoto, Shinichi Wada
PURPOSE: The aim of this feasibility study using phantoms was to propose a novel method for obtaining computer-generated realistic virtual nodules in lung computed tomography (CT). METHODS: In the proposed methodology, pulmonary nodule images obtained with a CT scanner are deconvolved with the point spread function (PSF) in the scan plane and slice sensitivity profile (SSP) measured for the scanner; the resultant images are referred to as nodule-like object functions...
August 4, 2017: Medical Physics
https://www.readbyqxmd.com/read/28760426/body-composition-measurement-using-computed-tomography-does-the-phase-of-the-scan-matter
#17
Katie E Rollins, Hannah Javanmard-Emamghissi, Amir Awwad, Ian A Macdonald, Kenneth C H Fearon, Dileep N Lobo
OBJECTIVES: The aim of this study was to determine, from the methodologic standpoint, the effect of the presence or absence of intravenous contrast on body composition variables obtained by analysis of computed tomography (CT) images. METHODS: Triphasic abdominal (noncontrast, arterial phase, and portovenous phase contrast) CT scans from 111 patients were analyzed by two independent assessors at the third lumbar vertebral level using SliceOmatic software (version 5...
September 2017: Nutrition
https://www.readbyqxmd.com/read/28759740/radiological-evaluation-of-maxillary-sinus-anatomy-a-cross-sectional-study-of-300-patients
#18
Naroa Lozano-Carrascal, Oscar Salomó-Coll, Sergio Alexandre Gehrke, José Luis Calvo-Guirado, Federico Hernández-Alfaro, Jordi Gargallo-Albiol
OBJECTIVE: The aim of the present study was to evaluate the principal anatomical characteristics of the maxillary sinus using Cone Beam Computed Tomography (CBCT) in order to facilitate prevention of intra- and post-operative complications. MATERIALS AND METHODS: Three hundred CBCT scans from patients undergoing implant surgery were analysed. The following anatomical structures were evaluated: (1) Residual ridge height (RRH) and width (RRW); (2) Ridge bone density (BD); (3) Maxillary sinus angle (MSA); (4) Maxillary sinus lateral wall thickness (LWT); (5) Schneiderian membrane thickness (MT); (6) Maxillary sinus septa (SS); (7) Posterior superior alveolar artery (PSAA)...
July 29, 2017: Annals of Anatomy, Anatomischer Anzeiger: Official Organ of the Anatomische Gesellschaft
https://www.readbyqxmd.com/read/28752151/intra-articular-lipoma-of-the-knee-joint-located-in-the-posterior-compartment-a-rare-location
#19
Mujdat Bankaoglu, Ozge Yapici Ugurlar, Meric Ugurlar, Mesut Mehmet Sonmez, Osman Tugrul Eren
This report presents the case of a 51-year-old woman with intermittent left knee pain, especially during full flexion of the knee, which had been ongoing for 1 year. Magnetic resonance imaging (MRI) showed mild effusion and round mass at the posterior compartment without synovial changes. Computerized tomography (CT) indicated mass had homogeneous low attenuation and density measurement of -99.4±62.3 Hounsfield units (HU), correlated with a lipomatous lesion.
2017: Northern Clinics of Istanbul
https://www.readbyqxmd.com/read/28743427/contrast-enhancement-influences-skeletal-muscle-density-but-not-skeletal-muscle-mass-measurements-on-computed-tomography
#20
Jeroen L A van Vugt, Robert R J Coebergh van den Braak, Henk J W Schippers, Kevin M Veen, Stef Levolger, Ron W F de Bruin, Marcel Koek, Wiro J Niessen, Jan N M IJzermans, François E J A Willemsen
BACKGROUND & AIMS: Low skeletal muscle mass and density have recently been discovered as prognostic and predictive parameters to guide interventions in various populations, including cancer patients. The gold standard for body composition analysis in cancer patients is computed tomography (CT). To date, the effect of contrast-enhancement on muscle composition measurements has not been established. The aim of this study was to determine the effect of contrast-enhancement on skeletal muscle mass and density measurements on four-phase CT studies...
July 14, 2017: Clinical Nutrition: Official Journal of the European Society of Parenteral and Enteral Nutrition
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