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Hounsfield Units (HU)

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https://www.readbyqxmd.com/read/28646939/hounsfield-units-for-nephrolithiasis-predictive-power-for-the-clinical-urologist
#1
Andrew Cohen, Blake Anderson, Glenn Gerber
INTRODUCTION: We aim to determine the optimal method for measuring Hounsfield Units (HU) of calculi for the clinical urologist. MATERIALS AND METHODS: We present a single institution prospective study from 2014-2015 for 125 consecutive patients. Demographics, baseline characteristics, imaging, and stone analysis were collected. CT scanners and settings were heterogeneous. Hounsfield units were measured by use of ellipsoid tool and free hand outline by two independent urology graders using Philips iSite PACs...
June 2017: Canadian Journal of Urology
https://www.readbyqxmd.com/read/28629453/three-dimensional-substructure-measurements-for-the-differential-diagnosis-of-ground-glass-nodules
#2
Mingzheng Peng, Gang Yu, Chengzhong Zhang, Cuidi Li, Jinwu Wang
BACKGROUND: We analyzed the differences between maximum and peak computed tomography (CT) numbers (M-P), respectively representing the densities of the solid center and the main periphery of ground-glass nodules (GGNs), and the average change in M-P velocity (V(M-P)) during follow-up to differentiate between pre-invasive (PIA) and invasive adenocarcinoma (IAC). METHODS: Data of 102 patients were retrospectively collected and analyzed in our study including 43 PIAs and 59 IACs...
June 19, 2017: BMC Pulmonary Medicine
https://www.readbyqxmd.com/read/28624923/a-comparison-of-enhancement-patterns-on-dynamic-enhanced-ct-and-survival-between-patients-with-pancreatic-neuroendocrine-tumors-with-and-without-intratumoral-fibrosis
#3
Cherry Kim, Jae Ho Byun, Seung-Mo Hong, Soyeon An, Jin Hee Kim, Seung Soo Lee, Hyoung Jung Kim
PURPOSE: To compare CT findings and survival between patients with pancreatic neuroendocrine tumors (pNETs) with and without fibrosis. METHODS: Forty-five pNET patients with intratumoral fibrosis (group A) were matched for age, gender, and tumor size and grade with 45 pNET patients without (group B), and CT images were retrospectively reviewed. Hounsfield units (HUs) of tumors in unenhanced, arterial and portal phases, HU ratio (tumor to normal parenchyma) in each phase, enhancement patterns, visible enhancement pattern changes, and survival were compared...
June 17, 2017: Abdominal Radiology
https://www.readbyqxmd.com/read/28621468/the-characteristics-of-regional-bone-quality-in-cervical-vertebrae-considering-bmd-determining-a-safe-trajectory-for-cervical-pedicle-screw-fixation
#4
Moon-Kyu Kim, Ho-Jung Cho, Dai-Soon Kwak, Seung-Hoon You
This study aimed to report the mechanical strength and characteristics of the lateral mass and pedicle considering BMD for the safe insertion of pedicle screws in the subaxial cervical level. We evaluated BMD and Hounsfield unit (HU) values of cortical bones at the lateral mass and pedicle of C3-7 from CT images in 99 patients. Patients were divided into three groups (Group A, T-score ≥-1; Group B, -2.5 < T-score < -1.0; Group C, T-score≤-2.5). The HU numbers of cortical bone in the vertebral canal (medial wall of the lateral mass; cHU), posterior wall of the transverse foramen (fHU), and medial wall, lateral wall, and trabecular area of the pedicle (mHU, lHU, and pHU, respectively) were measured on the CT images in the middle of the pedicle...
June 16, 2017: Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society
https://www.readbyqxmd.com/read/28604188/correlation-between-clot-density-and-recanalization-success-or-stroke-etiology-in-acute-ischemic-stroke-patients
#5
Manoj Jagani, David F Kallmes, Waleed Brinjikji
Background Predicting recanalization success for patients undergoing endovascular treatment for acute ischemic stroke is of significant interest. Studies have previously correlated the success of recanalization with the density of the clot. We evaluated clot density and its relationship to revascularization success and stroke etiology. Methods We conducted a retrospective review of 118 patients undergoing intra-arterial therapy for acute ischemic stroke. Mean and maximum thrombus density was measured by drawing a circular region of interest on an axial slice of a non-contrast computed tomography scan...
June 2017: Interventional Neuroradiology
https://www.readbyqxmd.com/read/28601233/computed-tomography-findings-predicting-the-success-of-silodosin-for-medical-expulsive-therapy-of-ureteral-stones
#6
Serdar Celik, Firat Akdeniz, Muge Afsar Yildirim, Ozan Bozkurt, Merve Gursoy Bulut, Mehmet Levent Hacihasanoglu, Omer Demir
Aim of the study is to investigate the relationship between non-contrast computed tomography (NCCT) findings and stone expulsion rate with medical expulsive therapy (MET) using silodosin for ureteral stones in male adults. Between January 2014 and June 2015, we retrospectively reviewed the patient charts with uncomplicated ureteral stones on NCCT images, who were treated with silodosin for MET. Stone diameter, volume and hounsfield units (HU) measured by NCCT and treatment findings were noted at the end of treatment...
June 2017: Kaohsiung Journal of Medical Sciences
https://www.readbyqxmd.com/read/28597229/couch-modelling-for-volumetric-modulated-arc-therapy-vmat
#7
Te-Yu Chyou, Friedlieb Lorenz
The aim of this work was to investigate the impact of the accuracy of a certain couch model on the overall accuracy of the dose calculation. For this purpose two models of the Varian Exact Couch (Varian Medical Systems, Palo Alto, CA, USA) for use in the planning of volumetric modulated arc therapy (VMAT) were created in Monaco 5.1 (Elekta, Stockholm, Sweden). The first was a simplistic model, with the relative electron densities (ED) of structures based entirely on CT Hounsfield units (HU). The second couch model was obtained by assigning the appropriate EDs to the relevant couch structures...
June 2017: Australasian Physical & Engineering Sciences in Medicine
https://www.readbyqxmd.com/read/28589076/non-contrast-computed-tomography-scan-based-parameters-of-ureteric-stones-affecting-the-outcome-of-extracorporeal-shock-wave-lithotripsy
#8
Muhammad Waqas, Mohammad Ayaz Khan, Muhammad Waqas Iqbal, Mian Khalid Akbar, Imad-Ud-Din Saqib, Saeed Akhter
OBJECTIVE : To compare the non-contrast computed tomography (NCCT) scan-based parameters of ureteric stones affecting the outcome of extracorporeal shock wave lithotripsy (ESWL). MATERIALS AND METHODS: We retrospectively evaluated the pre-procedure NCCT of 74 patients who had ESWL for solitary ureteric calculi of 5-20 mm in diameter. We assessed the age, sex, basal metabolic index (BMI), laterality, location, presence of double 'J' (DJ) stent, skin to stone distance (SSD), stone maximum diameter, Hounsfield unit (HU), Hounsfield density (HD), area, and volume...
May 5, 2017: Curēus
https://www.readbyqxmd.com/read/28587918/ct-based-diagnosis-of-visceral-obesity-and-hepatic-steatosis-is-associated-with-low-urine-ph
#9
Nishant D Patel, Ryan D Ward, Juan Calle, Erick M Remer, Manoj Monga
PURPOSE: Uric acid nephrolithiasis is associated with elevated visceral fat area (VFA) in kidney stone formers (KSF). Hepatic steatosis has also been linked to visceral obesity and nephrolithiasis. We evaluated the association of NCCT-based diagnosis of visceral obesity and hepatic steatosis with 24-hour urine parameters and stone composition in KSF. MATERIAL AND METHODS: 98 KSF were included who had CT imaging and 24-hour urine studies. For each patient, a single CT axial area measurement was obtained for visceral fat area (VFA)...
June 3, 2017: Journal of Urology
https://www.readbyqxmd.com/read/28578374/in-vitro-comparison-of-primary-stability-of-two-implant-designs-in-d3-bone
#10
J González-Serrano, R Ortega-Aranegui, J López-Quiles
BACKGROUND: Primary stability (PS) is a key factor for implant survival rate and depends on implant design or bone quality. The aim of this study was to compare different thread designs implants, evaluating PS with periotest values (PV) and implant stability quotient (ISQ) values through resonance frequency analysis (RFA). MATERIAL AND METHODS: A total of 60 implants (Radhex®, Inmet-Garnick S.A., Guadalajara, Spain) were placed in freshly bovine ribs in vitro. Two designs were used: 30 tapered body with single thread design (PHI) and 30 tapered body with double thread design implants (PHIA)...
June 4, 2017: Medicina Oral, Patología Oral y Cirugía Bucal
https://www.readbyqxmd.com/read/28562622/suv-quantification-of-physiological-lung-tissue-in-an-integrated-pet-mr-system-impact-of-lung-density-and-bone-tissue
#11
Ferdinand Seith, Holger Schmidt, Sergios Gatidis, Ilja Bezrukov, Christina Schraml, Christina Pfannenberg, Christian la Fougère, Konstantin Nikolaou, Nina Schwenzer
PURPOSE: The aim of the study was to investigate the influence of lung density changes as well as bone proximity on the attenuation correction of lung standardized uptake values (SUVs). METHODS AND MATERIALS: 15 patients with mostly oncologic diseases were examined in 18F-FDG-PET/CT and subsequently in a fully integrated PET/MR scanner. From each PET dataset acquired in PET/MR, four different PET reconstructions were computed using different attenuation maps (μ-maps): i) CT-based μ-map (gold standard); ii) CT-based μ-map in which the linear attenuation coefficients (LAC) of the lung tissue was replaced by the lung LAC from the MR-based segmentation method; iii) based on reconstruction ii), the LAC of bone structures was additionally replaced with the LAC from the MR-based segmentation method; iv) the vendor-provided MR-based μ-map (segmentation-based method)...
2017: PloS One
https://www.readbyqxmd.com/read/28556204/optimal-combination-of-anti-scatter-grids-and-software-correction-for-cbct-imaging
#12
Uros Stankovic, Lennert S Ploeger, Marcel van Herk, Jan-Jakob Sonke
PURPOSE: CBCT has been widely adopted in clinical practice for image-guided radiotherapy. Soft tissue contrast and Hounsfield units are impaired to presence of scattered radiation. In our previous work we proposed a high selectivity anti-scatter grid (ASG) as a possible solution to the problem. An alternative approach is the application of iterative scatter correction using deconvolution with scatter point spread function (PSF). The purpose of this work was to compare the performance of ASGs with different selectivity with and without the iterative and uniform scatter corrections in terms of CBCT image quality...
May 29, 2017: Medical Physics
https://www.readbyqxmd.com/read/28552547/spirometry-assisted-high-resolution-chest-computed-tomography-in-children-is-it-worth-the-effort
#13
Jeffrey Parke Otjen, Jonathan Ogden Swanson, Assaf Oron, Robert M DiBlasi, Tim Swortzel, Jade Adriana Marie van Well, Eva Anna Elisabeth Gommers, Margaret Rosenfeld
BACKGROUND: Image quality of high resolution chest computed tomographies (HRCTs) depends on adequate breath holds at end inspiration and end expiration. We hypothesized that implementation of spirometry-assisted breath holds in children undergoing HRCTs would improve image quality over that obtained with voluntary breath holds by decreasing motion artifact and atelectasis. METHODS: This is a retrospective case-control study of HRCTs obtained at a tertiary care children's hospital before and after implementation of a spirometry-assisted CT protocol, in which children ≥8 years of age are first trained in supine slow vital capacity maneuvers and then repeat the maneuvers in the CT scanner, coached by a respiratory therapist...
April 7, 2017: Current Problems in Diagnostic Radiology
https://www.readbyqxmd.com/read/28540783/role-of-dual-energy-computed-tomography-in-detecting-early-recurrences-of-lung-tumours-treated-with-radiofrequency-ablation
#14
Jean Izaaryene, Vincent Vidal, Jean-Michel Bartoli, Anderson Loundou, Jean-Yves Gaubert
PURPOSE: Detecting a recurrence after lung radiofrequency ablation (RFA) is based on a group of arguments that include CT, positron emission tomography (PET-CT) at 3 months and clinical patient follow-up. There is no one examination that is absolutely reliable. Recurrences are diagnosed tardily, when the cancers are locally extended, or when the patients are metastatic. The purpose of this article is to investigate the utility of dual-energy computed tomography (DECT) in order to assess therapeutic responses to RFA for lung neoplasia...
March 23, 2017: International Journal of Hyperthermia
https://www.readbyqxmd.com/read/28536753/differentiation-of-clot-composition-using-conventional-and-dual-energy-computed-tomography
#15
Jan Borggrefe, Jonathan Kottlors, Mahmood Mirza, Victor-Frederic Neuhaus, Nuran Abdullayev, Volker Maus, Christoph Kabbasch, David Maintz, Anastasios Mpotsaris
BACKGROUND AND PURPOSE: In unenhanced computed tomography (CT) of acute ischemic stroke, the density of occluding clots is associated with the content of red blood cells and successful recanalization with stent thrombectomy. However, no CT marker for fibrin content is established. In order to improve clot diagnostics, we conducted an in vitro study to investigate thrombus composition of histologically defined ovine blood clots with unenhanced and contrast-enhanced CT using spectral detector CT (SDCT)...
May 23, 2017: Clinical Neuroradiology
https://www.readbyqxmd.com/read/28536603/impact-of-fatty-liver-on-acute-pancreatitis-severity
#16
Seung Bae Yoon, In Seok Lee, Moon Hyung Choi, Kyungjin Lee, Hyoju Ham, Hyun Jin Oh, Se Hwan Park, Chul-Hyun Lim, Myung-Gyu Choi
Aim. Acute pancreatitis is typically a mild disease, but some patients develop severe courses. Fatty liver changes are seen in patients with acute pancreatitis, but its clinical significance has not been well-studied. We aimed to investigate the relationship between fatty liver and the severity of acute pancreatitis. Methods. Unenhanced CT images of patients with acute pancreatitis were retrospectively reviewed by a radiologist, and mean hepatic and splenic attenuation was measured in Hounsfield units (HU)...
2017: Gastroenterology Research and Practice
https://www.readbyqxmd.com/read/28527587/relationship-between-carotid-computed-tomography-dual-energy-and-brain-leukoaraiosis
#17
Luca Saba, Roberto Sanfilippo, Antonella Balestrieri, Fulvio Zaccagna, Giovanni Maria Argiolas, Jasjit S Suri, Roberto Montisci
BACKGROUND: The purpose of this study was to assess if there is a correlation between the carotid computed tomography (CT) Hounsfield unit (HU)-based plaque attenuation values measured using dual-energy CT (DECT) scanner and brain leukoaraiosis (LA). METHODS: Fifty consecutive patients (34 males, 16 females; mean age, 69 years; age range, 46-84 years) who underwent carotid CT and brain magnetic resonance imaging were included in the study. CT examinations were performed with a DECT scanner, and LA lesion volume quantification was performed using a semiautomated segmentation technique...
May 17, 2017: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
https://www.readbyqxmd.com/read/28521185/association-of-aortic-perivascular-adipose-tissue-density-with-aortic-calcification-in-women-with-systemic-lupus-erythematosus
#18
Kelly J Shields, Samar R El Khoudary, Joseph M Ahearn, Susan Manzi
BACKGROUND AND AIMS: Women with systemic lupus erythematosus (SLE) have an increased risk of cardiovascular disease (CVD). Perivascular adipose tissue (PVAT) surrounds the vascular wall, is associated with CVD risk factors, and may contribute to premature CVD in SLE. We previously found greater volumes of aortic PVAT associated with aortic calcification (AC) in female SLE patients. There is recent evidence that not only volume but adipose density may also be indicative of inflammation...
April 29, 2017: Atherosclerosis
https://www.readbyqxmd.com/read/28514529/the-effect-of-repeated-freeze-thaw-cycles-on-human-muscle-tissue-visualized-by-post-mortem-computed-tomography-pmct
#19
Anthony C Klop, Marloes E M Vester, Kerri L Colman, Jan M Ruijter, Rick R van Rijn, Roelof-Jan Oostra
INTRODUCTION: The aim of this study was to determine whether effects of repetitive freeze-thaw cycles, with various thawing temperatures, on human muscle tissue can be quantified using post-mortem computed tomography (PMCT) technology. An additional objective was to determine the preferred thawing temperature for muscle tissue in this study. MATERIALS & METHODS: Human cadaver upper extremities were divided into two different thawing temperature groups and underwent a series of four freeze-thaw cycles in total...
May 17, 2017: Clinical Anatomy
https://www.readbyqxmd.com/read/28509766/brown-adipose-tissue-detected-by-pet-ct-imaging-is-associated-with-less-central-obesity
#20
Aileen L Green, Ulas Bagci, Sarfaraz Hussein, Patrick V Kelly, Razi Muzaffar, Brent A Neuschwander-Tetri, Medhat M Osman
PURPOSE: This retrospective review was performed to determine whether patients with brown adipose tissue (BAT) detected by fluorine-18-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) imaging have less central obesity than BMI-matched control patients without detectable BAT. PATIENTS AND METHODS: Thirty-seven adult oncology patients with F-FDG BAT uptake were retrospectively identified from PET/CT studies from 2011 to 2013. The control cohort consisted of 74 adult oncology patients without detectable F-FDG BAT uptake matched for BMI/sex/season...
May 15, 2017: Nuclear Medicine Communications
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