Technical Aspects of MRI Signal Change Quantification After Gadolinium-Based Contrast Agents' Administration

Over the last 2years several studies have been published regarding gadolinium deposition in brain structures in patients with normal renal function after repeated administrations of gadolinium-based contrast agents (GBCAs). Most of the publications are magnetic resonance imaging (MRI) based retrospective studies, where gadolinium deposition may be indirectly measured by evaluating changes in T1 signal intensity (SI) in brain tissue, particularly in the dentate nucleus (DN) and/or globus pallidi (GP). The direct correlation between T1 signal changes and gadolinium deposition was validated by human pathology studies. However, the variability of the MR equipment and parameters used across different publications, along with the inherent limitations of MRI to assess gadolinium in human tissues should be acknowledged when interpreting those studies. Nevertheless, MRI studies remain essential regarding gadolinium bio-distribution knowledge. The aim of this paper is to overview current knowledge of technical aspects of T1 signal intensity evaluation by MRI and describe confounding factors, with the intention to achieve higher accuracy and maximize reproducibility.info:eu-repo/semantics/publishedVersio

Gadolinium-Based Contrast Agent Accumulation and Toxicity: an Update

In current practice, gadolinium-based contrast agents have been considered safe when used at clinically recommended doses in patients without severe renal insufficiency. The causal relationship between gadolinium-based contrast agents and nephrogenic systemic fibrosis in patients with renal insufficiency resulted in new policies regarding the administration of these agents. After an effective screening of patients with renal disease by performing either unenhanced or reduced-dose-enhanced studies in these patients and by using the most stable contrast agents, nephrogenic systemic fibrosis has been largely eliminated since 2009. Evidence of in vivo gadolinium deposition in bone tissue in patients with normal renal function is well-established, but recent literature showing that gadolinium might also deposit in the brain in patients with intact blood-brain barriers caught many individuals in the imaging community by surprise. The purpose of this review was to summarize the literature on gadolinium-based contrast agents, tying together information on agent stability and animal and human studies, and to emphasize that low-stability agents are the ones most often associated with brain deposition.info:eu-repo/semantics/publishedVersio

Signal Intensity Change on Unenhanced T1-Weighted Images in Dentate Nucleus Following Gadobenate Dimeglumine in Patients With and Without Previous Multiple Administrations of Gadodiamide

OBJECTIVES: To evaluate the impact of previous administration of gadodiamide and neural tissue gadolinium deposition in patients who received gadobenate dimeglumine. METHODS: Our population included 62 patients who underwent at least three administrations of gadobenate dimeglumine, plus an additional contrast-enhanced last MRI for reference, divided into two groups: group 1, patients who in addition to gadobenate dimeglumine administrations had prior exposure to multiple doses of gadodiamide; group 2, patients without previous exposure to other gadolinium-based contrast agent (GBCAs). Quantitative analysis was performed on the first and last gadobenate dimeglumine MRIs in both groups. Dentate nucleus-to-middle cerebellar peduncle signal intensity ratios (DN/MCP) and relative change (RC) in signal over time were calculated and compared between groups using generalized additive model. RESULTS: Group 1 showed significant increase in baseline and follow-up DN/MCP compared to group 2 (p < 0.0001). The RC DN/MCP showed a non-statistically significant trend towards an increase in patients who underwent previous gadodiamide (p = 0.0735). CONCLUSION: There is increased T1 signal change over time in patients who underwent gadobenate dimeglumine and had received prior gadodiamide compared to those without known exposure to previous gadodiamide. A potentiating effect from prior gadodiamide on subsequent administered gadobenate dimeglumine may occur. KEY POINTS: • Neural gadolinium deposition is associated with multiple administrations of less stable GBCAs. • Less stable GBCA effect on subsequent more stable GBCA administrations is undetermined. • Significant increase of DN/MCP was seen in patients with previous gadodiamide exposure. • RC DN/MCP showed a non-significant increase in patients who received previous gadodiamide. • Potentiating effects from prior gadodiamide on subsequent administered gadobenate dimeglumine may occur.info:eu-repo/semantics/publishedVersio

Design of smart wireless changeover for continuous electric current feeding from power sources of variable capacities

Electric power has become a vital element for life today. Despite this importance, electric power consumers in Iraq suffer from the problem of noncontinuity and daily electric power supply interruption. This problem led to the use of various sources of electric power as an alternative to compensate for the shortage of electric power provided by the Iraqi national grid. In this work, a smart wireless changeover device is designed using wireless sensor networks technology aiming to solve problem caused by the multiplicity of power sources received at home and governmental buildings in Iraq by controlling operation of some electrical devices (which consume high current) in the home or workplace automatically when changing source of electricity from one to another. This solution will help to ensure the continuity of electric current feeding from power sources of variable capacities, also, to rationalize power consumption by assigning an operation priority to electric devices. Furthermore, a statistical measurement as a case study was performed in a building with a total power consumption of 160.8 KW/h. The result showed that the device functions effectively and it is capable of achieving an average saving in power of about 50% to 86% depending on the applied priorities and case study scenario

Gadolinium deposition disease: Initial description of a disease that has been around for a while

AbstractPurposeTo describe the clinical manifestations of presumed gadolinium toxicity in patients with normal renal function.Materials and methodsParticipants were recruited from two online gadolinium toxicity support groups. The survey was anonymous and individuals were instructed to respond to the survey only if they had evidence of normal renal function, evidence of gadolinium in their system beyond 30days of this MRI, and no pre-existent clinical symptoms and/or signs of this type.Results42 subjects responded to the survey (age: 28–69, mean 49.1±22.4years). The most common findings were: central pain (n=15), peripheral pain (n=26), headache (n=28), and bone pain (n=26). Only subjects with distal leg and arm distribution described skin thickening (n=22). Clouded mentation and headache were the symptoms described as persistent beyond 3months in 29 subjects. Residual disease was present in all patients. Twenty-eight patients described symptoms following administration of one brand of Gadolinium-Based Contrast Agent (GBCA), 21 after a single GBCA administration and 7 after multiple GBCA administrations, including: gadopentetate dimeglumine, n=9; gadodiamide, n=4; gadoversetamide, n=4; gadobenate dimeglumine, n=4; gadobutrol, n=1; gadoteridol, n=2; and unknown, n=4.ConclusionsGadolinium toxicity appears to arise following GBCA administration, which appears to contain clinical features seen in Nephrogenic Systemic Fibrosis, but also features not observed in that condition

Assessment of Body Mass Index and Nutritional Status in Pulmonary Tuberculosis Patients

Background: Pulmonary tuberculosis is a chronic infectious disease which affects nutritional status of the patients. The presence of poor nutritional status in pulmonary tuberculosis patients has been one of the most important determining factor in recommending adjuvant nutrient therapy to prevent oxidative stress and further complication. Objective: This study was designed to assess the nutritional status and body mass index of pulmonary tuberculosis patients. Patients and methods: During the period 1st of June 2010 to 30th of May 2011, a prospective study was done on 60 patients with active pulmonary tuberculosis and 60 controls. Levels of total protein (TP), albumin (ALB.), triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDLC), low density lipoprotein cholesterol (LDLC), and body mass index (BMI) were measured. Results: The mean levels of TP (59.5 ± 0.8g/dl), ALB (23.4 ± 1.8g/dl), TC (138.7 ± 4.9mg/dl), HDLC (32.2 ± 4.0mg/dl), LDLC (86.5 ± 1.3mg/dl) and TG (62.4 ± 1.3mg/dl) were significantly lower while the level of globulin (36.2 ± 1.2g/dl) was significantly higher in pulmonary tuberculosis patients when compared with controls (TP=81.2 ± 4.5g/dl; ALB= 50.0 ± 4.0g/dl; TC = 213.5 ± 26.8mg/dl; HDLC = 57.4 ± 8.5mg/dl; LDLC = 161.1 ± 28.3mg/dl; TG= 148.5 ± 37.1mg/dl; globulin = 31.4 ± 1.7g/dl respectively). (P <0.05) The body mass index (16.9 ± 1.1kg/m2) was significantly lower when compared with controls (BMI= 23.5 ± 2.1kg/m2). (P <0.05)20 Conclusion: There is a significant degree of nutritional depletion and weight loss in PTB patients than in general population. BMI is considered to be a useful technique for assessment of nutritional state of PTB. The nutritional derangement could call for prompt nutritional intervention in the management of pulmonary tuberculosis patients

A baseline survey of potentially toxic elements in the soil of north-west Syria following a decade of conflict

We present the first region-wide chemical survey of soils in NW Syria following more than a decade of ongoing conflict. We sampled topsoil at 66 sites, typically located in marginal agricultural (orchards, arable) or peri-urban settings, grouped around 21 localities covering the whole area of NW Syria currently under Syrian Opposition control. Samples were analysed in the UK using ICP-MS and ICP-OES. Topsoil total concentrations of heavy metals are broadly consistent with pre-war data from Aleppo and recent data from nearby Turkey. Principal Components Analysis (PCA) of associations among the sampling sites identified three groupings. Ni (133.30 ± 72.12 mg/kg) and Cr (122.14 ± 52.25 mg/kg) exist in all samples at levels in excess of typical European guideline thresholds for agricultural soil. Observed Cd (0.57 ± 0.93 mg/kg), Co (23.07 ± 18.48 mg/kg) and As (6.65 ± 4.51 mg/kg) concentrations are up to three times comparable values from nearby agricultural regions in southern Turkey. Maximum observed values for Cd, As, and Co, which exceed EU thresholds, are concentrated in a corridor around Sarmada to the west of Aleppo which has seen some of the most intense conflict-related impacts. Cu (28.33 ± 17.11 mg/kg), Pb (15.65 ± 10.85 mg/kg) and Zn (73.64 ± 40.15 mg/kg) also observe maxima in the Sarmada corridor, but show a more even distribution across the region, widely at values above comparable regional values for agriculture but below EU threshold concentrations. We interpret the occurrence of Ni-Cr as consistent with intensive agriculture using wastewater-contaminated irrigation and fertilisers. Cd-As-Co and Cu-Pb-Zn are likely anthropogenic and reflect intense pressures of conflict, informal settlement, unregulated industry and untreated wastewater irrigation on a historically agricultural region. The sampling method was designed to capture regional variations from a minimal dataset and it is likely that local topsoil concentrations at specific points of impact (proximal to locations of shelling, industry, effluent release or population) will be considerably higher than those reported here. This study establishes an important baseline reference for further targeted studies to identify and mitigate specific pollution hazards in this region of ongoing, extreme humanitarian and ecological threat

Morphometric Features of Tibial Attachment of Posterior Cruciate Ligament on Thiel Embalmed Cadavers

Background: The posterior cruciate ligament (PCL) is variable in terms of its origin, course and termination. The tibial insertion of the posterior cruciate ligament is variable and may have implications for accurate tunnel placement during reconstruction surgery. Methods: This study investigates this attachment in the Thiel embalmed cadaver of a 71-year-old female European Caucasian. The inferior attachment of the ligament was then examined histologically. Results: The attachment was macroscopically and microscopically examined, and found to terminate by forming a fan shape and blending with the periosteum. Histological examination confirmed that fibers extended up to 25 mm inferior to the ligament’s usual insertion point. Conclusions: These fibers are anatomically important, as they may be an additional supporting factor, assist with stabilization of the knee joint, and further inform surgical approaches to PCL reconstruction surgery

Analysis Of Fluid Flow Behavior In The Fractured Reservoirs: Review Paper

The naturally fractured reservoirs are considered complex reservoirs in the petroleum industries where the engineers face some difficulties in the modeling of naturally fractured reservoirs. The main problem of fractures is the tectonic movements of fractures which affect the hydrocarbons flow during transportation from matrix to fracture, and drilling and productions processes. This review paper presented some previous about hydrocarbons leakage, drilling and production damages, and modeling issues which caused a loss of hydrocarbons in the naturally fractured reservoirs. The purpose of this review paper is to analyze the hydrocarbons flow behavior during production processes even to reach the perfect model in this study. This review paper depended a lot on Warren and Root's theory and extended by using new parameters and assumptions. This study got on perfect results to analyze hydrocarbons flow. This review paper is shown that the difference in the properties of natural fractures affected the flow of hydrocarbons during the transition from the matrix to the fractures, which affected drilling operations and hydrocarbon production. In addition, dual-porosity affected the movement of the fluid. Dual porosity resulted in fractures and or dissolving that produces holes in the reservoir