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Hounsfield Units (HU)

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https://www.readbyqxmd.com/read/28817459/relation-between-epicardial-fat-and-subclinical-atherosclerosis-in-asymptomatic-individuals
#1
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-tumors
#2
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
#3
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
#4
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
#5
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
#6
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
#7
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
#8
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
#9
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
#10
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
https://www.readbyqxmd.com/read/28740930/functional-image-guided-radiation-therapy-planning-in-volumetric-modulated-arc-therapy-for-patients-with-malignant-pleural-mesothelioma
#11
Yoshiko Doi, Tomoki Kimura, Takeo Nakashima, Yuki Takeuchi, Ippei Takahashi, Ikuno Nishibuchi, Yuji Murakami, Yasushi Nagata
PURPOSE: To investigate the incorporation of functional lung image-derived low-attenuation area (LAA) based on 4-dimensional computed tomography (4D-CT) in volumetric modulated arc therapy (VMAT) planning for patients with malignant pleural mesothelioma (MPM) after extrapleural pneumonectomy. METHODS AND MATERIALS: Twelve patients with MPM after extrapleural pneumonectomy were included. The primarily affected side was the right in 6 patients and the left in 6 patients...
April 2017: Advances in Radiation Oncology
https://www.readbyqxmd.com/read/28728015/diagnostic-yield-of-percutaneous-biopsy-for-sclerotic-bone-lesions-influence-of-mean-hounsfield-units
#12
Jennifer Ní Mhuircheartaigh, Colm McMahon, Yu-Ching Lin, Jim Wu
PURPOSE: To identify whether there was an association between Hounsfield units of sclerotic bone lesions and diagnostic yield of biopsy. METHOD: All core needle biopsies of sclerotic bone lesion were identified from a database. Pathology reports were reviewed to determine whether the biopsy was diagnostic or non-diagnostic. RESULTS: 91 patients were included in the study group. The yield for lesions with mean HU≥500 was significantly lower than those with a mean HU≤500 (40% vs...
July 4, 2017: Clinical Imaging
https://www.readbyqxmd.com/read/28724406/iodine-concentration-calculated-by-dual-energy-computed-tomography-dect-as-a-functional-parameter-to-evaluate-thyroid-metabolism-in-patients-with-hyperthyroidism
#13
Duong Duc Binh, Takahito Nakajima, Hidenori Otake, Tetsuya Higuchi, Yoshito Tsushima
BACKGROUND: Thyroid function in patients with Grave's disease is usually evaluated by thyroid scintigraphy with radioactive iodine. Recently, dual-energy computed tomography (DECT) with two different energy X-rays can calculate iodine concentrations and can be applied for iodine measurements in thyroid glands. This study aimed to assess the potential use of DECT for the functional assessment of the thyroid gland. METHODS: Thirteen patients with Grave's disease treated at our hospital from May to September 2015 were included in this retrospective study...
July 19, 2017: BMC Medical Imaging
https://www.readbyqxmd.com/read/28720415/assessment-of-cirrhotic-liver-enhancement-with-multiphasic-computed-tomography-using-a-faster-injection-rate-late-arterial-phase-and-weight-based-contrast-dosing
#14
Kathleen Eddy, Andreu F Costa
PURPOSE: This study aimed to update our liver computed tomography (CT) protocol according to published guidelines, and to quantitatively evaluate the effect of these modifications. METHODS: The modified liver CT protocol employed a faster injection rate (5 vs 3 mL/s), later arterial phase (20-second vs 10-second postbolus trigger), and weight-based dosing of iodinated contrast (1.7 mL/kg vs 100 mL fixed dose). Liver and vascular attenuation values were measured on CTs of patients with cirrhosis from January to September 2015 (old protocol, n = 49) and from October to December 2015 (modified protocol, n = 31)...
July 15, 2017: Canadian Association of Radiologists Journal, Journal L'Association Canadienne des Radiologistes
https://www.readbyqxmd.com/read/28717539/single-session-vs-two-sessions-of-flexible-ureterosopy-furs-for-dusting-of-renal-pelvic-stones-2-3-cm-in-diameter-does-stone-size-or-hardness-play-a-role-in-number-of-sessions-to-be-applied
#15
Ahmed Mamdouh Abd El Hamed, Hazem Elmoghazy, Mohamed Aldahshoury, Ahmed Riad, Mohammed Mostafa, Fawzy Farag, Wael Gamal
OBJECTIVE: To evaluate the stone hardness in predicting the need for single or two sessions of retrograde intrarenal surgery (RIRS) for renal pelvis stones of 2-3 cm in size. MATERIAL AND METHODS: Ninety-six patients (64 male and 32 female) with only renal stones (2.5±0.3 cm) underwent RIRS using flexible 7.5 Fr ureteroscope (FURS). The stone hardness was evaluated by preoperative non-contrast computed tomography (NCCT). The patients were divided into two groups based on stone hardness: Group I (n=54) (hard stones - Hounsfield Unit (HU) >1000) and group II (n=42) (not hard stone - HU <1000)...
June 2017: Turkish Journal of Urology
https://www.readbyqxmd.com/read/28712697/hepatic-steatosis-in-participants-in-a-program-of-low-dose-ct-screening-for-lung-cancer
#16
Xiangmeng Chen, Kunwei Li, Rowena Yip, Ponni Perumalswami, Andrea D Branch, Sara Lewis, David Del Bello, Betsy J Becker, David F Yankelevitz, Claudia I Henschke
OBJECTIVE: Determine the frequency of moderate-to-severe hepatic steatosis (HS) in asymptomatic participants in a low-dose CT (LDCT) screening program for lung cancer, to identify risk factors, and develop recommendations. METHODS: Baseline LDCT scans of the chest of 170 participants in an IRB-approved study between August 2011 and April 2016 were reviewed. Demographic variables, comorbidities, and liver function tests were documented. Hepatic and splenic attenuation values hounsfield unit (HU) were measured...
June 27, 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28711443/regional-distribution-of-pulmonary-blood-volume-with-dual-energy-computed-tomography-results-in-42-subjects
#17
Paul Felloni, Alain Duhamel, Jean-Baptiste Faivre, Jessica Giordano, Suonita Khung, Valérie Deken, Jacques Remy, Martine Remy-Jardin
RATIONALE AND OBJECTIVES: The noninvasive approach of lung perfusion generated from dual-energy computed tomography acquisitions has entered clinical practice. The purpose of this study was to analyze the regional distribution of iodine within distal portions of the pulmonary arterial bed on dual-source, dual-energy computed tomography examinations in a cohort of subjects without cardiopulmonary pathologies. MATERIALS AND METHODS: The study population included 42 patients without cardiorespiratory disease, enabling quantitative and qualitative analysis of pulmonary blood volume after administration of a 40% contrast agent...
July 12, 2017: Academic Radiology
https://www.readbyqxmd.com/read/28708732/investigating-the-robustness-neighborhood-gray-tone-difference-matrix-and-gray-level-co-occurrence-matrix-radiomic-features-on-clinical-computed-tomography-systems-using-anthropomorphic-phantoms-evidence-from-a-multivendor-study
#18
Usman Mahmood, Aditya P Apte, Joseph O Deasy, C Ross Schmidtlein, Amita Shukla-Dave
OBJECTIVE: The aim of this study was to determine if optimized imaging protocols across multiple computed tomography (CT) vendors could result in reproducible radiomic features calculated from an anthropomorphic phantom. METHODS: Materials with varying degrees of heterogeneity were placed throughout the lungs of the phantom. Twenty scans of the phantom were acquired on 3 CT manufacturers with chest CT protocols that had optimized protocol parameters. Scans were reconstructed using vendor-specific standards and lung kernels...
July 13, 2017: Journal of Computer Assisted Tomography
https://www.readbyqxmd.com/read/28708725/dual-energy-computed-tomography-in-stroke-imaging-technical-and-clinical-considerations-of-virtual-noncontrast-images-for-detection-of-the-hyperdense-artery-sign
#19
Sebastian Winklhofer, Ilaria Vittoria De Martini, Chrisitian Nern, Iris Blume, Susanne Wegener, Athina Pangalu, Antonios Valavanis, Hatem Alkadhi, Roman Guggenberger
OBJECTIVE: The technical feasibility of virtual noncontrast (VNC) images from dual-energy computed tomography (DECT) for the detection of the hyperdense artery sign (HAS) in ischemic stroke patients was investigated. METHODS: True noncontrast (TNC) scans of 60 patients either with or without HAS (n = 30 each) were investigated. Clot presence and characteristics were assessed on VNC images from DECT angiography and compared with TNC images. Clot characterization included the level of confidence for diagnosing HAS, a qualitative clot burden score, and quantitative attenuation (Hounsfield unit [HU]) measurements...
July 13, 2017: Journal of Computer Assisted Tomography
https://www.readbyqxmd.com/read/28670160/assessment-of-myocardial-bridge-by-cardiac-ct-intracoronary-transluminal-attenuation-gradient-derived-from-diastolic-phase-predicts-systolic-compression
#20
Mengmeng Yu, Yang Zhang, Yuehua Li, Minghua Li, Wenbin Li, Jiayin Zhang
OBJECTIVE: To study the predictive value of transluminal attenuation gradient (TAG) derived from diastolic phase of coronary computed tomography angiography (CCTA) for identifying systolic compression of myocardial bridge (MB). MATERIALS AND METHODS: Consecutive patients diagnosed with MB based on CCTA findings and without obstructive coronary artery disease were retrospectively enrolled. In total, 143 patients with 144 MBs were included in the study. Patients were classified into three groups: without systolic compression, with systolic compression < 50%, and with systolic compression ≥ 50%...
July 2017: Korean Journal of Radiology: Official Journal of the Korean Radiological Society
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