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Ct doses

Tristan Pascart, Frédéric Lioté
This review article summarizes the relevant English literature on gout from 2010 through April 2017. It emphasizes that the current epidemiology of gout indicates a rising prevalence worldwide, not only in Western countries but also in Southeast Asia, in close relationship with the obesity and metabolic syndrome epidemics. New pathogenic mechanisms of chronic hyperuricaemia focus on the gut (microbiota, ABCG2 expression) after the kidney. Cardiovascular and renal comorbidities are the key points to consider in terms of management...
March 13, 2018: Rheumatology
Kurtis H Dekker, Rubin Hazarika, Matheus A Silveira, Kevin J Jordan
Optical cone beam computed tomography (CT) scanning of radiochromic gel dosimeters, using a CCD camera and a low stray light convergent source, provides fast, truly 3D radiation dosimetry with high accuracy. However, a key limiting factor in radiochromic gel dosimetry at large (⩾10 cm diameter) volumes is the initial attenuation of the dosimeters. It is not unusual to observe a 5-10×  difference in signal intensity through the dosimeter center versus through the surrounding medium in pre-irradiation images...
March 16, 2018: Physics in Medicine and Biology
Elizabeth G Mosher, John A Butman, Les R Folio, Nadia M Biassou, Choonsik Lee
OBJECTIVE: Radiation exposure of the lens during neck CT may increase a patient's risk of developing cataracts. Radiologists at the National Institutes of Health worked with technicians to modify the neck CT scanning procedure to include a reduction in the scanning range, a reduction in the tube potential (kilovoltage), and a change in neck positioning using a head tilt. We objectively quantified the organ dose changes after this procedure modification using a computer simulation. MATERIALS AND METHODS: We retrospectively analyzed CT images of 40 patients (20 men and 20 women) scanned before and after the procedure change...
March 16, 2018: AJR. American Journal of Roentgenology
Ekwu M Ameh, Sean Tyrrel, Jim Harris, Athanasios Ignatiou, Elena Orlova, Andreas Nocker
Disinfection aims at maximal inactivation of target organisms and the sustainable suppression of their regrowth. Whereas many disinfection efforts achieve efficient inactivation when the effect is measured directly after treatment, there are questions about the sustainability of this effect. One aspect is that the treated bacteria might recover and regain the ability to grow. In an environmental context, another question is how amenable surviving bacteria are to predation by omnipresent bacteriophages. Provisional data suggested that bacteria when subjected to sublethal heat stress might develop a phage-resistant phenotype...
March 15, 2018: Folia Microbiologica
Lu Xie, Wei Guo, Yi Yang, Tao Ji, Jie Xu
5,10-Methylenetrahydrofolate reductase (MTHFR), a key enzyme for folate metabolism, catalyses the irreversible conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, which is located at the end of the short arm (1p36.3). Two common non-synonymous variants, the C677T (Ala222Val) and A1298C (Glu429Ala), were mainly described with decreased enzymatic activity and an alteration of intracellular folate distribution. Osteosarcomas are currently treated with high dose of methotrexate (MTX). The decreased enzyme activity of MTHFR theoretically could increase the drug action of MTX and at the same time increase toxic and side effect...
February 20, 2018: Oncotarget
Margarita Braunagel, Florian Ortner, Ulf Schönermarck, Antje Habicht, Andreas Schindler, Manfred Stangl, Frederik F Strobl, Maximilian Reiser, Dirk A Clevert, Christoph Trumm, Andreas Helck
RATIONALE AND OBJECTIVE: The objective of this study was to assess an optimized renal multiphase computed tomography angiography (MP-CTA) protocol regarding reduction of contrast volume. MATERIALS AND METHODS: Thirty patients underwent MP-CTA (12 phases, every 3.5 seconds, 80 kV/120 mAs) using 30 mL of contrast medium. The quality of MP-CTA was assessed quantitatively measuring vessel attenuation, image noise, and contrast-to-noise ratio. MP-CTA was evaluated qualitatively regarding depiction of vessels, cortex differentiation, and motion artifacts (grades 1-4, 1 = best)...
March 12, 2018: Academic Radiology
Wen-Zhao Sun, Dan-Dan Zhang, Ying-Lin Peng, Li Chen, De-Hua Kang, Bin Wang, Xiao-Wu Deng
BACKGROUND: Conventional phantom-based planar dosimetry (2D-PBD) quality assurance (QA) using gamma pass rate (GP (%)) is inadequate to reflect clinically relevant dose error in intensity-modulated radiation therapy (IMRT), owing to a lack of information regarding patient anatomy and volumetric dose distribution. This study aimed to evaluate the dose distribution accuracy of IMRT delivery for nasopharyngeal carcinoma (NPC), which passed the 2D-PBD verification, using a measurement-guided 3D dose reconstruction (3D-MGR) method...
March 15, 2018: Radiation Oncology
Amanda N Seddon, Joshua Chaim, Oguz Akin, Esther Drill, Angela G Michael, Nelly Adel, Martin S Tallman
BACKGROUND: The current standard of care for the treatment of patients with newly diagnosed acute myeloid leukemia (AML) is an anthracycline plus cytarabine. Both anthracyclines and cytarabine have been associated with the development of typhlitis, a serious adverse event characterized by inflammation of the bowel wall in patients with profound neutropenia, diagnosed by abdominal CT imaging and clinical symptoms. Given the paucity of available data, the aim of our study was to determine the incidence of typhlitis among AML patients receiving induction chemotherapy with idarubicin 12 mg/m2 (IDA), daunorubicin 60 mg/m2 (DNA60), or daunorubicin 90 mg/m2 (DNA90)...
March 8, 2018: Leukemia Research
Mario Silva, Cornelia M Schaefer-Prokop, Colin Jacobs, Giovanni Capretti, Francesco Ciompi, Bram van Ginneken, Ugo Pastorino, Nicola Sverzellati
OBJECTIVES: The aim of this study was to compare computer-aided diagnosis (CAD) and visual reading for the detection of subsolid nodules (SSNs) in volumetrl measuremic low-dose computed tomography (LDCT) for lung cancer screening. MATERIALS AND METHODS: Prospective visual detection (VD) and manuaent of SSN were performed in the 2303 baseline volumetric LDCTs of the Multicenter Italian Lung Detection trial. Baseline and 2- and 4-year LDCTs underwent retrospective CAD analysis, subsequently reviewed by 2 experienced thoracic radiologists...
March 14, 2018: Investigative Radiology
Nathan Cho, Panagiotis Tsiamas, Esteban Velarde, Erik Tryggestad, Robert Jacques, Ross Berbeco, Todd McNutt, Peter Kazanzides, John Wong
PURPOSE: The Small Animal Radiation Research Platform (SARRP) has been developed for conformal micro irradiation with on-board cone-beam CT (CBCT) guidance. The graphics processing unit (GPU)-accelerated Superposition-Convolution (SC) method for dose computation has been integrated into the treatment planning system (TPS) for SARRP. This paper describes the validation of the SC method for the kilovoltage energy by comparing with EBT2 film measurements and Monte Carlo (MC) simulations...
March 15, 2018: Medical Physics
Atallah Baydoun, Neha Vapiwala, Lee E Ponsky, Musaddiq Awan, Ali Kassaee, David Sutton, Tarun K Podder, Yuxia Zhang, Donald Dobbins, Raymond F Muzic, Bryan Traughber, Mitchell Machtay, Rodney Ellis
PURPOSE: We conducted this dosimetric analysis to evaluate the feasibility of a multi-center stereotactic body radiation therapy (SBRT) trial for renal cell carcinoma (RCC) using different SBRT platforms. MATERIALS/METHODS: The computed tomography (CT) simulation images of 10 patients with unilateral RCC previously treated on a Phase 1 trial at Institution 1 were anonymized and shared with Institution 2 after IRB approval. Treatment planning was generated through five different platforms aiming a total dose of 48 Gy in three fractions...
March 14, 2018: Journal of Applied Clinical Medical Physics
D J Murphy, A Aghayev, M L Steigner
Non-invasive cross-sectional imaging techniques play a crucial role in the assessment of the varied manifestations of vascular disease. Vascular imaging encompasses a wide variety of pathology. Designing vascular imaging protocols can be challenging owing to the non-uniform velocity of blood in the aorta, differences in cardiac output between patients, and the effect of different disease states on blood flow. In this review, we provide the rationale behind-and a practical guide to-designing and implementing straightforward vascular computed tomography (CT) and magnetic resonance imaging (MRI) protocols...
March 14, 2018: Insights Into Imaging
Georg Böning, Willie M Lüdemann, Julius Chapiro, Martin Jonczyk, Bernd Hamm, Rolf W Günther, Bernhard Gebauer, Florian Streitparth
PURPOSE: The aim of this study was to evaluate the feasibility of cone-beam computed tomography (CBCT)-based real-time 3-D guidance of TIPSS placement and its positioning compared to standard guiding methods. MATERIALS AND METHODS: In a prospective, randomized, consecutive study design from 2015 to 2017, we included 21 patients in the CBCT guided group and 15 patients in the ultrasound (US) guided group. The prospective groups were compared in terms of success rate of intervention, portal vein puncture/procedure time, number of puncture attempts and applied dose...
March 14, 2018: Cardiovascular and Interventional Radiology
Satoru Morita, Hiroshi Yamazaki, Kenji Endo, Shingo Suzaki, Akira Mitsuhashi, Takafumi Shiohara, Midori Yatabe, Atsuhiro Ichihara, Shuji Sakai
PURPOSE: To assess the effectiveness of image fusion guidance (IF) with pre-procedural computed tomography (CT) with intraprocedural fluoroscopy for adrenal venous sampling (AVS). MATERIALS AND METHODS: AVS before and after ACTH stimulation including bilateral segmental sampling of effluent tributaries was performed in 62 patients with IF. A 3D volume rendering image, including adrenal glands and veins extracted from previously obtained contrast-enhanced CT images, was manually registered to the real-time X-ray fluoroscopy...
March 14, 2018: Cardiovascular and Interventional Radiology
Robyn Melanie Benz, Meritxell Alzamora Garcia, Felix Amsler, Johannes Voigt, Andreas Fieselmann, Anna Lucja Falkowski, Bram Stieltjes, Anna Hirschmann
Phantom-based initial performance assessment of a prototype three-dimensional (3-D) x-ray system and comparison of 3-D tomography with computed tomography (CT) were proposed. A 3-D image quality phantom was scanned with a prototype version of 3-D cone-beam CT imaging implemented on a twin robotic x-ray system using three trajectories (163 deg = table, 188 deg = upright, and 200 deg = side), six tube voltages (60, 70, 81, 90, 100, and 121 kV), and four detector doses (0.348, 0.696, 1.740, and [Formula: see text])...
January 2018: Journal of Medical Imaging
Yan Wu, Yaojun Jiang, Xueli Han, Mingyue Wang, Jianbo Gao
Background: To investigate the repeatability and accuracy of quantitative CT (QCT) measurement of bone mineral density (BMD) by low-mAs using iterative model reconstruction (IMR) technique based on phantom model. Methods: European spine phantom (ESP) was selected and measured on the Philips Brilliance iCT Elite FHD machine for 10 times. Data were transmitted to the QCT PRO workstation to measure BMD (mg/cm3 ) of the ESP (L1, L2, L3). Scanning method: the voltage of X-ray tube is 120 kV, the electric current of X-ray tube output in five respective groups A-E were: 20, 30, 40, 50 and 60 mAs...
February 2018: Quantitative Imaging in Medicine and Surgery
Valerio Nardone, Paolo Tini, Stefania Croci, Salvatore Francesco Carbone, Lucio Sebaste, Tommaso Carfagno, Giuseppe Battaglia, Pierpaolo Pastina, Giovanni Rubino, Maria Antonietta Mazzei, Luigi Pirtoli
Background: The aim of our work is to assess the potential role of texture analysis (TA), applied to computed tomography (CT) simulation scans, in relation to the development of insufficiency fractures (IFs) in patients undergoing radiation therapy (RT) for pelvic malignancies. Methods: We analyzed patients undergoing pelvic RT from Jan-2010 to Dec-2016, 31 of whom had developed IFs of the pelvis. We analyzed CT simulation scans using LifeX Software© , and in particular we selected three regions of interest (ROI): L5 body, the sacrum and both the femoral heads...
February 2018: Quantitative Imaging in Medicine and Surgery
Bin Chen, Wenqi Zhang, Bin Ji, Qingjie Ma, Dandan Li, Shi Gao
The present study aimed to determine the utility of99m Tc-3PRGD2 single photon emission computed tomography (SPECT)/computed tomography (CT) for the non-invasive monitoring of the response of integrin αv β3 expression to anti-angiogenic treatment with bevacizumab. Bevacizumab or vehicle therapy was performed in athymic nu/nu mice bearing A549 lung tumors (moderately high integrin αv β3 expression) or PC-3 prostate tumors (low integrin αv β3 expression) at a dose of 1 mg twice a week. The average tumor volume was 180±90 mm3 the day prior to baseline SPECT/CT...
April 2018: Oncology Letters
A Skiada, C Lass-Floerl, N Klimko, A Ibrahim, E Roilides, G Petrikkos
The diagnosis and treatment of mucormycosis are challenging. The incidence of the disease seems to be increasing. Hematological malignancies are the most common underlying disease in countries with high income and uncontrolled diabetes in developing countries. Clinical approach to diagnosis lacks sensitivity and specificity. Radiologically, multiple (≥10) nodules and pleural effusion are reportedly associated with pulmonary mucormycosis. Another finding on computerized tomography (CT) scan, which seems to indicate the presence of mucormycosis, is the reverse halo sign...
April 1, 2018: Medical Mycology: Official Publication of the International Society for Human and Animal Mycology
Jamie L Fleet, Stephanie N Dixon, Paul John Kuwornu, Varun K Dev, Manuel Montero-Odasso, Jorge Burneo, Amit X Garg
Gabapentin is an effective treatment for chronic neuropathic pain but may cause dizziness, drowsiness, and confusion in some older adults. The goal of this study was to assess the association between gabapentin dosing and adverse outcomes by obtaining estimates of the 30-day risk of hospitalization with altered mental status and mortality in older adults (mean age 76 years) in Ontario, Canada initiated on high dose (>600 mg/day; n = 34,159) compared to low dose (≤600 mg/day; n = 76,025) oral gabapentin in routine outpatient care...
2018: PloS One
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