Myocardial Damage Detected by Late Gadolinium Enhancement Cardiovascular Magnetic Resonance Is Associated With Subsequent Hospitalization for Heart Failure

PubMed Central

Wong, Timothy C.; Piehler, Kayla M.; Zareba, Karolina M.; Lin, Kathie; Phrampus, Ashley; Patel, Agam; Moon, James C.; Ugander, Martin; Valeti, Uma; Holtz, Jonathan E.; Fu, Bo; Chang, Chung‐Chou H.; Mathier, Michael; Kellman, Peter; Butler, Javed; Gheorghiade, Mihai; Schelbert, Erik B.

2013-01-01

Background Hospitalization for heart failure (HHF) is among the most important problems confronting medicine. Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) robustly identifies intrinsic myocardial damage. LGE may indicate inherent vulnerability to HHF, regardless of etiology, across the spectrum of heart failure stage or left ventricular ejection fraction (LVEF). Methods and Results We enrolled 1068 consecutive patients referred for CMR where 448 (42%) exhibited LGE. After a median of 1.4 years (Q1 to Q3: 0.9 to 2.0 years), 57 HHF events occurred, 15 deaths followed HHF, and 43 deaths occurred without antecedent HHF (58 total deaths). Using multivariable Cox regression adjusting for LVEF, heart failure stage, and other covariates, LGE was associated with first HHF after CMR (HR: 2.70, 95% CI: 1.32 to 5.50), death (HR: 2.13, 95% CI: 1.08 to 4.21), or either death or HHF (HR: 2.52, 95% CI: 1.49 to 4.25). Quantifying LGE extent yielded similar results; more LGE equated higher risks. LGE improved model discrimination (IDI: 0.016, 95% CI: 0.005 to 0.028, P=0.002) and reclassification of individuals at risk (continuous NRI: 0.40, 95% CI: 0.05 to 0.70, P=0.024). Adjustment for competing risks of death that shares common risk factors with HHF strengthened the LGE and HHF association (HR: 4.85, 95% CI: 1.40 to 16.9). Conclusions The presence and extent of LGE is associated with vulnerability for HHF, including higher risks of HHF across the spectrum of heart failure stage and LVEF. Even when LVEF is severely decreased, those without LGE appear to fare reasonably well. LGE may enhance risk stratification for HHF and may enhance both clinical and research efforts to reduce HHF through targeted treatment. PMID:24249712

The Prognostic Value of Late Gadolinium-Enhanced Cardiac Magnetic Resonance Imaging in Nonischemic Dilated Cardiomyopathy: A Review and Meta-Analysis.

PubMed

Becker, Marthe A J; Cornel, Jan H; van de Ven, Peter M; van Rossum, Albert C; Allaart, Cornelis P; Germans, Tjeerd

2018-04-13

This review and meta-analysis reviews the prognostic value of cardiac magnetic resonance (CMR) in nonischemic dilated cardiomyopathy (DCM). Late gadolinium-enhanced (LGE) CMR is a noninvasive method to determine the underlying cause of DCM and previous studies reported the prognostic value of the presence of LGE to identify patients at risk of major adverse cardiovascular events. PubMed was searched for studies describing the prognostic implication of LGE in patients with DCM for the specified endpoints cardiovascular mortality, major ventricular arrhythmic events including appropriate implantable cardioverter-defibrillator therapy, rehospitalization for heart failure, and left ventricular reverse remodeling. Data from 34 studies were included, with a total of 4,554 patients. Contrast enhancement was present in 44.8% of DCM patients. Patients with LGE had increased cardiovascular mortality (odds ratio [OR]: 3.40; 95% confidence interval [CI]: 2.04 to 5.67), ventricular arrhythmic events (OR: 4.52; 95% CI: 3.41 to 5.99), and rehospitalization for heart failure (OR: 2.66; 95% CI: 1.67 to 4.24) compared with those without LGE. Moreover, the absence of LGE predicted left ventricular reverse remodeling (OR: 0.15; 95% CI: 0.06 to 0.36). The presence of LGE on CMR substantially worsens prognosis for adverse cardiovascular events in DCM patients, and the absence indicates left ventricular reverse remodeling. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Evaluation of state-of-the-art segmentation algorithms for left ventricle infarct from late Gadolinium enhancement MR images.

PubMed

Karim, Rashed; Bhagirath, Pranav; Claus, Piet; James Housden, R; Chen, Zhong; Karimaghaloo, Zahra; Sohn, Hyon-Mok; Lara Rodríguez, Laura; Vera, Sergio; Albà, Xènia; Hennemuth, Anja; Peitgen, Heinz-Otto; Arbel, Tal; Gonzàlez Ballester, Miguel A; Frangi, Alejandro F; Götte, Marco; Razavi, Reza; Schaeffter, Tobias; Rhode, Kawal

2016-05-01

Studies have demonstrated the feasibility of late Gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging for guiding the management of patients with sequelae to myocardial infarction, such as ventricular tachycardia and heart failure. Clinical implementation of these developments necessitates a reproducible and reliable segmentation of the infarcted regions. It is challenging to compare new algorithms for infarct segmentation in the left ventricle (LV) with existing algorithms. Benchmarking datasets with evaluation strategies are much needed to facilitate comparison. This manuscript presents a benchmarking evaluation framework for future algorithms that segment infarct from LGE CMR of the LV. The image database consists of 30 LGE CMR images of both humans and pigs that were acquired from two separate imaging centres. A consensus ground truth was obtained for all data using maximum likelihood estimation. Six widely-used fixed-thresholding methods and five recently developed algorithms are tested on the benchmarking framework. Results demonstrate that the algorithms have better overlap with the consensus ground truth than most of the n-SD fixed-thresholding methods, with the exception of the Full-Width-at-Half-Maximum (FWHM) fixed-thresholding method. Some of the pitfalls of fixed thresholding methods are demonstrated in this work. The benchmarking evaluation framework, which is a contribution of this work, can be used to test and benchmark future algorithms that detect and quantify infarct in LGE CMR images of the LV. The datasets, ground truth and evaluation code have been made publicly available through the website: https://www.cardiacatlas.org/web/guest/challenges. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Prognostic Value of Myocardial Scarring on CMR in Patients With Cardiac Sarcoidosis.

PubMed

Coleman, G Cameron; Shaw, Peter W; Balfour, Pelbreton C; Gonzalez, Jorge A; Kramer, Christopher M; Patel, Amit R; Salerno, Michael

2017-04-01

This study sought to perform a systematic review and meta-analysis to understand the prognostic value of myocardial scarring as evidenced by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging in patients with known or suspected cardiac sarcoidosis. Although CMR is increasingly used for the diagnosis of cardiac sarcoidosis, the prognostic value of CMR has been less well described in this population. PubMed, Cochrane CENTRAL, and metaRegister of Controlled Trials were searched for CMR studies with ≥1 year of prognostic data. Primary endpoints were all-cause mortality and a composite outcome of arrhythmogenic events (ventricular arrhythmia, implantable cardioverter-defibrillator shock, sudden cardiac death) plus all-cause mortality during follow-up. Summary effect estimates were generated with random-effects modeling. Ten studies were included, involving a total of 760 patients with a mean follow-up of 3.0 ± 1.1 years. Patients had a mean age of 53 years, 41% were male, 95.3% had known extracardiac sarcoidosis, and 21.6% had known cardiac sarcoidosis. The average ejection fraction was 57.8 ± 9.1%. Patients with LGE had higher odds for all-cause mortality (odds ratio [OR]: 3.06; p < 0.03) and higher odds of the composite outcome (OR: 10.74; p < 0.00001) than those without LGE. Patients with LGE had an increased annualized event rate of the composite outcome (11.9% vs. 1.1%; p < 0.0001). In patients with known or suspected cardiac sarcoidosis, the presence of LGE on CMR imaging is associated with increased odds of both all-cause mortality and arrhythmogenic events. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Myocardial Extracellular Volume Estimation by CMR Predicts Functional Recovery Following Acute MI.

PubMed

Kidambi, Ananth; Motwani, Manish; Uddin, Akhlaque; Ripley, David P; McDiarmid, Adam K; Swoboda, Peter P; Broadbent, David A; Musa, Tarique Al; Erhayiem, Bara; Leader, Joshua; Croisille, Pierre; Clarysse, Patrick; Greenwood, John P; Plein, Sven

2017-09-01

In the setting of reperfused acute myocardial infarction (AMI), the authors sought to compare prediction of contractile recovery by infarct extracellular volume (ECV), as measured by T1-mapping cardiac magnetic resonance (CMR), with late gadolinium enhancement (LGE) transmural extent. The transmural extent of myocardial infarction as assessed by LGE CMR is a strong predictor of functional recovery, but accuracy of the technique may be reduced in AMI. ECV mapping by CMR can provide a continuous measure associated with the severity of tissue damage within infarcted myocardium. Thirty-nine patients underwent acute (day 2) and convalescent (3 months) CMR scans following AMI. Cine imaging, tissue tagging, T2-weighted imaging, modified Look-Locker inversion T1 mapping natively and 15 min post-gadolinium-contrast administration, and LGE imaging were performed. The ability of acute infarct ECV and acute transmural extent of LGE to predict convalescent wall motion, ejection fraction (EF), and strain were compared per-segment and per-patient. Per-segment, acute ECV and LGE transmural extent were associated with convalescent wall motion score (p < 0.01; p < 0.01, respectively). ECV had higher accuracy than LGE extent to predict improved wall motion (area under receiver-operating characteristics curve 0.77 vs. 0.66; p = 0.02). Infarct ECV ≤0.5 had sensitivity 81% and specificity 65% for prediction of improvement in segmental function; LGE transmural extent ≤0.5 had sensitivity 61% and specificity 71%. Per-patient, ECV and LGE correlated with convalescent wall motion score (r = 0.45; p < 0.01; r = 0.41; p = 0.02, respectively) and convalescent EF (p < 0.01; p = 0.04). ECV and LGE extent were not significantly correlated (r = 0.34; p = 0.07). In multivariable linear regression analysis, acute infarct ECV was independently associated with convalescent infarct strain and EF (p = 0.03; p = 0.04), whereas LGE was not (p = 0.29; p = 0.24). Acute infarct ECV

Role of late gadolinium enhancement cardiovascular magnetic resonance in the risk stratification of hypertrophic cardiomyopathy.

PubMed

Ismail, Tevfik F; Jabbour, Andrew; Gulati, Ankur; Mallorie, Amy; Raza, Sadaf; Cowling, Thomas E; Das, Bibek; Khwaja, Jahanzaib; Alpendurada, Francisco D; Wage, Ricardo; Roughton, Michael; McKenna, William J; Moon, James C; Varnava, Amanda; Shakespeare, Carl; Cowie, Martin R; Cook, Stuart A; Elliott, Perry; O'Hanlon, Rory; Pennell, Dudley J; Prasad, Sanjay K

2014-12-01

Myocardial fibrosis identified by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) in patients with hypertrophic cardiomyopathy (HCM) is associated with adverse cardiovascular events, but its value as an independent risk factor for sudden cardiac death (SCD) is unknown. We investigated the role of LGE-CMR in the risk stratification of HCM. We conducted a prospective cohort study in a tertiary referral centre. Consecutive patients with HCM (n=711, median age 56.3 years, IQR 46.7-66.6; 70.0% male) underwent LGE-CMR and were followed for a median 3.5 years. The primary end point was SCD or aborted SCD. Overall, 471 patients (66.2%) had myocardial fibrosis (median 5.9% of left ventricular mass, IQR: 2.2-13.3). Twenty-two (3.1%) reached the primary end point. The extent but not the presence of fibrosis was a significant univariable predictor of the primary end point (HR per 5% LGE: 1.24, 95% CI 1.06 to 1.45; p=0.007 and HR for LGE: 2.69, 95% CI 0.91 to 7.97; p=0.073, respectively). However, on multivariable analysis, only LV-EF remained statistically significant (HR: 0.92, 95% CI 0.89 to 0.95; p<0.001). For the secondary outcome of cardiovascular mortality/aborted SCD, the presence and the amount of fibrosis were significant predictors on univariable but not multivariable analysis after adjusting for LV-EF and non-sustained ventricular tachycardia. The amount of myocardial fibrosis was a strong univariable predictor of SCD risk. However, this effect was not maintained after adjusting for LV-EF. Further work is required to elucidate the interrelationship between fibrosis and traditional predictors of outcome in HCM. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Gadolinium-enhanced computed tomographic angiography: current status.

PubMed

Rosioreanu, Alex; Alberico, Ronald A; Litwin, Alan; Hon, Man; Grossman, Zachary D; Katz, Douglas S

2005-01-01

This article reviews the research to date, as well as our clinical experience from two institutions, on gadolinium-enhanced computed tomographic angiography (gCTA) for imaging the body. gCTA may be an appropriate examination for the small percentage of patients who would benefit from noninvasive vascular imaging, but who have contraindications to both iodinated contrast and magnetic resonance imaging. gCTA is more expensive than CTA with iodinated contrast, due to the dose of gadolinium administered, and gCTA has limitations compared with CTA with iodinated contrast, in that parenchymal organs are not optimally enhanced at doses of 0.5 mmol/kg or lower. However, in our experience, gCTA has been a very useful problem-solving examination in carefully selected patients. With the advent of 16-64 detector CT, in combination with bolus tracking, we believe that the overall dose of gadolinium needed for diagnostic CTA examinations, while relatively high, can be safely administered.

Myocardial Fibrosis in Competitive Triathletes Detected by Contrast-Enhanced CMR Correlates With Exercise-Induced Hypertension and Competition History.

PubMed

Tahir, Enver; Starekova, Jitka; Muellerleile, Kai; von Stritzky, Alexandra; Münch, Julia; Avanesov, Maxim; Weinrich, Julius M; Stehning, Christian; Bohnen, Sebastian; Radunski, Ulf K; Freiwald, Eric; Blankenberg, Stefan; Adam, Gerhard; Pressler, Axel; Patten, Monica; Lund, Gunnar K

2017-12-08

This study analyzed the presence of myocardial fibrosis detected by late gadolinium-enhancement (LGE) cardiac magnetic resonance (CMR) in correlation with the performance of competitive triathletes objectified by an exercise test and individual competition history. Myocardial fibrosis detected by LGE CMR has been reported to occur in 0% to 50% of asymptomatic athletes. However, the cause and mechanisms of myocardial fibrosis are unclear. Eighty-three asymptomatic triathletes undergoing >10 training h per week (43 ± 10 years of age; 65% male) and 36 sedentary controls were studied by using LGE and extracellular volume (ECV) CMR. Parameters of physical fitness were measured by spiroergometry. Triathletes reported their lifetime competition results. LGE CMR revealed focal nonischemic myocardial fibrosis in 9 of 54 (17%) male triathletes (LGE + ) but in none of the female triathletes (p < 0.05). LGE + triathletes had higher peak exercise systolic blood pressure (213 ± 24 mm Hg) than LGE - triathletes (194 ± 26 mm Hg; p < 0.05). Furthermore, left ventricular mass index was higher in LGE + triathletes (93 ± 7 g/m 2 ) than in LGE - triathletes (84 ± 11 g/m 2 ; p < 0.05). ECV in LGE - myocardium was higher in LGE + triathletes (26.3 ± 1.8%) than in LGE - triathletes (24.4 ± 2.2%; p < 0.05). LGE + triathletes completed longer cumulative distances in swimming and cycling races and participated more often in middle and Iron Man distances than LGE - triathletes. A cycling race distance of >1,880 km completed during competition had the highest accuracy to predict LGE, with an area under the curve value of 0.876 (p < 0.0001), resulting in high sensitivity (89%) and specificity (79%). Multivariate analysis identified peak exercise systolic blood pressure (p < 0.05) and the swimming race distance (p < 0.01) as independent predictors of LGE presence. Myocardial fibrosis in asymptomatic triathletes seems to be associated with exercise-induced hypertension and

Probability mapping of scarred myocardium using texture and intensity features in CMR images

PubMed Central

2013-01-01

Background The myocardium exhibits heterogeneous nature due to scarring after Myocardial Infarction (MI). In Cardiac Magnetic Resonance (CMR) imaging, Late Gadolinium (LG) contrast agent enhances the intensity of scarred area in the myocardium. Methods In this paper, we propose a probability mapping technique using Texture and Intensity features to describe heterogeneous nature of the scarred myocardium in Cardiac Magnetic Resonance (CMR) images after Myocardial Infarction (MI). Scarred tissue and non-scarred tissue are represented with high and low probabilities, respectively. Intermediate values possibly indicate areas where the scarred and healthy tissues are interwoven. The probability map of scarred myocardium is calculated by using a probability function based on Bayes rule. Any set of features can be used in the probability function. Results In the present study, we demonstrate the use of two different types of features. One is based on the mean intensity of pixel and the other on underlying texture information of the scarred and non-scarred myocardium. Examples of probability maps computed using the mean intensity of pixel and the underlying texture information are presented. We hypothesize that the probability mapping of myocardium offers alternate visualization, possibly showing the details with physiological significance difficult to detect visually in the original CMR image. Conclusion The probability mapping obtained from the two features provides a way to define different cardiac segments which offer a way to identify areas in the myocardium of diagnostic importance (like core and border areas in scarred myocardium). PMID:24053280

Multi-vendor, multicentre comparison of contrast-enhanced SSFP and T2-STIR CMR for determining myocardium at risk in ST-elevation myocardial infarction

PubMed Central

Nordlund, David; Klug, Gert; Heiberg, Einar; Koul, Sasha; Larsen, Terje H.; Hoffmann, Pavel; Metzler, Bernhard; Erlinge, David; Atar, Dan; Aletras, Anthony H.; Carlsson, Marcus; Engblom, Henrik; Arheden, Håkan

2016-01-01

Aims Myocardial salvage, determined by cardiac magnetic resonance imaging (CMR), is used as end point in cardioprotection trials. To calculate myocardial salvage, infarct size is related to myocardium at risk (MaR), which can be assessed by T2-short tau inversion recovery (T2-STIR) and contrast-enhanced steady-state free precession magnetic resonance imaging (CE-SSFP). We aimed to determine how T2-STIR and CE-SSFP perform in determining MaR when applied in multicentre, multi-vendor settings. Methods and results A total of 215 patients from 17 centres were included after percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction. CMR was performed within 1–8 days. These patients participated in the MITOCARE or CHILL-MI cardioprotection trials. Additionally, 8 patients from a previous study, imaged 1 day post-CMR, were included. Late gadolinium enhancement, T2-STIR, and CE-SSFP images were acquired on 1.5T MR scanners (Philips, Siemens, or GE). In 65% of the patients, T2-STIR was of diagnostic quality compared with 97% for CE-SSFP. In diagnostic quality images, there was no difference in MaR by T2-STIR and CE-SSFP (bias: 0.02 ± 6%, P = 0.96, r2 = 0.71, P < 0.001), or between treatment and control arms. No change in size or quality of MaR nor ability to identify culprit artery was seen over the first week after the acute event (P = 0.44). Conclusion In diagnostic quality images, T2-STIR and CE-SSFP provide similar estimates of MaR, were constant over the first week, and were not affected by treatment. CE-SSFP had a higher degree of diagnostic quality images compared with T2 imaging for sequences from two out of three vendors. Therefore, CE-SSFP is currently more suitable for implementation in multicentre, multi-vendor clinical trials. PMID:27002140

Delayed enhancement cardiac computed tomography for the assessment of myocardial infarction: from bench to bedside

PubMed Central

2017-01-01

A large number of studies support the increasingly relevant prognostic value of the presence and extent of delayed enhancement (DE), a surrogate marker of fibrosis, in diverse etiologies. Gadolinium and iodinated based contrast agents share similar kinetics, thus leading to comparable myocardial characterization with cardiac magnetic resonance (CMR) and cardiac computed tomography (CT) at both first-pass perfusion and DE imaging. We review the available evidence of DE imaging for the assessment of myocardial infarction (MI) using cardiac CT (CTDE), from animal to clinical studies, and from 16-slice CT to dual-energy CT systems (DECT). Although both CMR and gadolinium agents have been originally deemed innocuous, a number of concerns (though inconclusive and very rare) have been recently issued regarding safety issues, including DNA double-strand breaks related to CMR, and gadolinium-associated nephrogenic systemic fibrosis and deposition in the skin and certain brain structures. These concerns have to be considered in the context of non-negligible rates of claustrophobia, increasing rates of patients with implantable cardiac devices, and a number of logistic drawbacks compared with CTDE, such as higher costs, longer scanning times, and difficulties to scan patients with impaired breath-holding capabilities. Overall, these issues might encourage the role of CTDE as an alternative for DE-CMR in selected populations. PMID:28540211

Cardiovascular magnetic resonance imaging (CMR) reveals characteristic pattern of myocardial damage in patients with mitochondrial myopathy.

PubMed

Yilmaz, Ali; Gdynia, Hans-Jürgen; Ponfick, Matthias; Rösch, Sabine; Lindner, Alfred; Ludolph, Albert C; Sechtem, Udo

2012-04-01

Mitochondrial myopathy comprises various clinical subforms of neuromuscular disorders that are characterised by impaired mitochondrial energy metabolism due to dysfunction of the mitochondrial respiratory chain. No comprehensive and targeted cardiovascular magnetic resonance (CMR) studies have been performed so far in patients with mitochondrial disorders. The present study aimed at characterising cardiac disease manifestations in patients with mitochondrial myopathy and elucidating the in vivo cardiac damage pattern of patients with different subforms of mitochondrial disease by CMR studies. In a prospective study, 37 patients with mitochondrial myopathy underwent comprehensive neurological and cardiac evaluations including physical examination, resting ECG and CMR. The CMR studies comprised cine-CMR, T2-weighted "edema" imaging and T1-weighted late-gadolinium-enhancement (LGE) imaging. Various patterns and degrees of skeletal myopathy were present in the participants of this study, whereas clinical symptoms such as chest pain symptoms (in eight (22%) patients) and various degrees of dyspnea (in 16 (43%) patients) were less frequent. Pathological ECG findings were documented in eight (22%) patients. T2-weighted "edema" imaging was positive in one (3%) patient with MELAS (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes) only. LGE imaging demonstrated the presence of non-ischemic LGE in 12 (32%) patients: 10 out of 24 (42%) patients with CPEO (chronic progressive external ophthalmoplegia) or KSS (Kearns-Sayre syndrome) and 2 of 3 (67%) patients with MELAS were LGE positive. All 10 LGE-positive patients with CPEO or KSS demonstrated a potentially typical pattern of diffuse intramural LGE in the left-ventricular (LV) inferolateral segments. Cardiac involvement is a frequent finding in patients with mitochondrial myopathy. A potentially characteristic pattern of diffuse intramural LGE in the LV inferolateral segments was identified in

Late Gadolinium Enhancement Amount As an Independent Risk Factor for the Incidence of Adverse Cardiovascular Events in Patients with Stage C or D Heart Failure

PubMed Central

Liu, Tong; Ma, Xiaohai; Liu, Wei; Ling, Shukuan; Zhao, Lei; Xu, Lei; Song, Deli; Liu, Jie; Sun, Zhonghua; Fan, Zhanming; Luo, Taiyang; Kang, Junping; Liu, Xiaohui; Dong, Jianzeng

2016-01-01

Background: Myocardial fibrosis (MF) is a risk factor for poor prognosis in dilated cardiomyopathy (DCM). Late gadolinium enhancement (LGE) of the myocardium on cardiac magnetic resonance (CMR) represents MF. We examined whether the LGE amount increases the incidence of adverse cardiovascular events in patients with stage C or D heart failure (HF). Methods: Eighty-four consecutive patients with stage C or D HF, either ischemic or non-ischemic, were enrolled. Comprehensive clinical and CMR evaluations were performed. All patients were followed up for a composite endpoint of cardiovascular death, heart transplantation, and cardiac resynchronization therapy with defibrillator (CRT-D). Results: LGE was present in 79.7% of the end-stage HF patients. LGE distribution patterns were mid-wall, epi-myocardial, endo-myocardial, and the morphological patterns were patchy, transmural, and diffuse. During the average follow-up of 544 days, 13 (15.5%) patients had endpoint events: 7 patients cardiac death, 2 patients heart transplantation, and 4 patients underwent CRT-D implantation. On univariate analysis, LGE quantification on cardiac magnetic resonance, blood urine nitrogen, QRS duration on electrocardiogram, left ventricular end-diastolic diameter (LVEDD), and left ventricular end-diastolic volume (LVEDV) on CMR had the strongest associations with the composite endpoint events. However, on multivariate analysis for both Model I (after adjusting for age, sex, and body mass index) and Model II (after adjusting for age, sex, BMI, renal function, QRS duration, and atrial fibrillation on electrocardiogram, the etiology of HF, LVEF, CMR-LVEDD, and CMR-LVEDV), LGE amount was a significant risk factor for composite endpoint events (Model I 6SD HR 1.037, 95%CI 1.005–1.071, p = 0.022; Model II 6SD HR 1.045, 95%CI 1.001–1.084, p = 0.022). Conclusion: LGE amount from high-scale threshold on CMR increased the incidence of adverse cardiovascular events for patients in either stage C or

Clinical predictors of cardiac magnetic resonance late gadolinium enhancement in patients with atrial fibrillation.

PubMed

Chrispin, Jonathan; Ipek, Esra Gucuk; Habibi, Mohammadali; Yang, Eunice; Spragg, David; Marine, Joseph E; Ashikaga, Hiroshi; Rickard, John; Berger, Ronald D; Zimmerman, Stefan L; Calkins, Hugh; Nazarian, Saman

2017-03-01

This study aims to examine the association of clinical co-morbidities with the presence of left atrial (LA) late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR). Previous studies have established the severity of LA LGE to be associated with atrial fibrillation (AF) recurrence following AF ablation. We sought to determine whether baseline clinical characteristics were associated with LGE extent among patients presenting for an initial AF ablation. The cohort consisted of 179 consecutive patients with no prior cardiac ablation procedures who underwent pre-procedure LGE-CMR. The extent of LA LGE for each patient was calculated using the image intensity ratio, normalized to the mean blood pool intensity, corresponding to a bipolar voltage ≤0.3 mV. The association of LGE extent with baseline clinical characteristics was examined using non-parametric and multivariable models. The mean age of the cohort was 60.9 ± 9.6 years and 128 (72%) were male. In total, 56 (31%) patients had persistent AF. The mean LA volume was 118.4 ± 41.6 mL, and the mean LA LGE extent was 14.1 ± 10.4%. There was no association with any clinical variables with LGE extent by quartiles in the multivariable model. Extent of LGE as a continuous variable was positively, but weakly associated with LA volume in a multivariable model adjusting for age, body mass index, AF persistence, and left ventricular ejection fraction (1.5% scar/mL, P = 0.038). In a cohort of patients presenting for initial AF ablation, the presence of pre-ablation LA LGE extent was weakly, but positively associated with increasing LA volume. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Non‐invasive evaluation of the myocardial substrate of cardiac amyloidosis by gadolinium cardiac magnetic resonance

PubMed Central

Perugini, E; Rapezzi, C; Piva, T; Leone, O; Bacchi‐Reggiani, L; Riva, L; Salvi, F; Lovato, L; Branzi, A; Fattori, R

2006-01-01

Objective To investigate the prevalence and distribution of gadolinium (Gd) enhancement at cardiac magnetic resonance (CMR) imaging in patients with cardiac amyloidosis (CA) and to look for associations with clinical, morphological, and functional features. Patients and design 21 patients with definitely diagnosed CA (nine with immunoglobulin light chain amyloidosis and 12 transthyretin related) underwent Gd‐CMR. Results Gd enhancement was detected in 16 of 21 (76%) patients. Sixty six of 357 (18%) segments were enhanced, more often at the mid ventricular level. Transmural extension of enhancement within each patient significantly correlated with left ventricular (LV) end systolic volume (r  =  0.58). The number of enhanced segments correlated with LV end diastolic volume (r  =  0.76), end systolic volume (r  =  0.6), and left atrial size (r  =  0.56). Segments with > 50% extensive transmural enhancement more often were severely hypokinetic or akinetic (p  =  0.001). Patients with > 2 enhanced segments had significantly lower 12 lead QRS voltage and Sokolow‐Lyon index. No relation was apparent with any other clinical, morphological, functional, or histological characteristics. Conclusion Gd enhancement is common but not universally present in CA, probably due to expansion of infiltrated interstitium. The segmental and transmural distribution of the enhancement is highly variable, and mid‐ventricular regions are more often involved. Enhancement appears to be associated with impaired segmental and global contractility and a larger atrium. PMID:15939726

Association of left ventricular late gadolinium enhancement with left atrial low voltage areas in patients with atrial fibrillation.

PubMed

Stegmann, Clara; Jahnke, Cosima; Paetsch, Ingo; Hilbert, Sebastian; Arya, Arash; Bollmann, Andreas; Hindricks, Gerhard; Sommer, Philipp

2018-02-06

Presence of late gadolinium enhancement (LGE) is related to adverse cardiovascular outcome. Many patients suffering from atrial fibrillation (AF) undergo cardiovascular magnetic resonance (CMR) imaging prior to ablation. Since quantification of atrial fibrosis still lacks reproducibility, we sought to investigate risk factors for the presence of left ventricular (LV)-LGE and a possible correlation between ventricular fibrosis as defined by positive LGE and pathological atrial voltage maps evaluated by 3D mapping systems. Between May 2015 and January 2017, 241 patients with AF (73% persistent AF, 71% male, mean age 62.8 ± 10.1 years, Redo procedure in 24%, AF history 4.5 ± 5.2 years) underwent CMR including LV LGE prior to pulmonary vein (PV) isolation at Heart Center Leipzig. Depending on CMR results, two groups were separated: 'LV-LGE negative' (Group A, n = 197, 82%) and 'LV-LGE positive' (Group B, n = 44, 18%). To identify low voltage areas (LVA), a 3D electro-anatomic map was created during PV isolation. Multivariate analysis revealed male gender [odds ratio (OR) 7.6, 95% confidence interval (95% CI) 2.4-23.9, P = 0.001] and an increased CHA2DS2VASc Score (OR 1.6, 95% CI 1.2-2.2, P = 0.004) as significantly associated with LV-LGE. Impaired left ventricular ejection fraction, LV dilatation, larger LA size and, enlarged septum diameter occurred significantly more often in the 'LGE positive' group. Low voltage areas were detected in 83 patients overall (34%): Group A: n = 64/197 (33%), Group B: n = 19/44 (43%) (P = 0.177). Male gender and high CHA2DS2VASc Score are significantly associated with presence of LV-LGE, but LV-LGE is not associated with left atrial LVA. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.

Diagnostic performance of dark-blood T2-weighted CMR for evaluation of acute myocardial injury.

PubMed

Srichai, Monvadi B; Lim, Ruth P; Lath, Narayan; Babb, James; Axel, Leon; Kim, Daniel

2013-01-01

We compared the image quality and diagnostic performance of 2 fat-suppression methods for black-blood T2-weighted fast spin-echo (FSE), which are as follows: (a) short T1 inversion recovery (STIR; FSE-STIR) and (b) spectral adiabatic inversion recovery (SPAIR; FSE-SPAIR), for detection of acute myocardial injury. Edema-sensitive T2-weighted FSE cardiac magnetic resonance (CMR) imaging is useful in detecting acute myocardial injury but may experience reduced myocardial signal and signal dropout. The SPAIR pulse aims to eliminate artifacts associated with the STIR pulse. A total of 65 consecutive patients referred for CMR evaluation of myocardial structure and function underwent FSE-STIR and FSE-SPAIR, in addition to cine and late gadolinium enhancement (LGE) CMR. T2-weighted FSE images were independently evaluated by 2 readers for image quality and artifacts (Likert scale of 1-5; best-worst) and presence of increased myocardial signal suggestive of edema. In addition, clinical CMR interpretation, incorporating all CMR sequences available, was recorded for comparison. Diagnostic performance of each T2-weighted sequence was measured using recent (<30 days) troponin elevation greater than 2 times the upper limit of normal as the reference standard for acute myocardial injury. Of the 65 patients, there were 21 (32%) with acute myocardial injury. Image quality and artifact scores were significantly better with FSE-SPAIR compared with FSE-STIR (2.15 vs 2.68, P < 0.01; 2.62 vs 3.05, P < 0.01, respectively). The sensitivity, specificity, positive predictive value, and negative predictive value for acute myocardial injury were as follows: 29%, 93%, 67%, and 73% for FSE-SPAIR; 38%, 91%, 67%, and 75% for FSE-STIR; 71%, 98%, 94%, and 88% for clinical interpretation including LGE, T2, and wall motion. There was a statistically significant difference in sensitivity between the clinical interpretation and each of the T2-weighted sequences but not between each T2-weighted sequence

Self-Gated Late Gadolinium Enhancement at 7T to Image Rats with Reperfused Acute Myocardial Infarction.

PubMed

Wang, Lei; Chen, Yushu; Zhang, Bing; Chen, Wei; Wang, Chunhua; Song, Li; Xu, Ziqian; Zheng, Jie; Gao, Fabao

2018-01-01

A failed electrocardiography (ECG)-trigger often leads to a long acquisition time (TA) and deterioration in image quality. The purpose of this study was to evaluate and optimize the technique of self-gated (SG) cardiovascular magnetic resonance (CMR) for cardiac late gadolinium enhancement (LGE) imaging of rats with myocardial infarction/reperfusion. Cardiovascular magnetic resonance images of 10 rats were obtained using SG-LGE or ECG with respiration double-gating (ECG-RESP-gating) method at 7T to compare differences in image interference and TA between the two methods. A variety of flip angles (FA: 10°-80°) and the number of repetitions (NR: 40, 80, 150, and 300) were investigated to determine optimal scan parameters of SG-LGE technique based on image quality score and contrast-to-noise ratio (CNR). Self-gated late gadolinium enhancement allowed successful scan in 10 (100%) rats. However, only 4 (40%) rats were successfully scanned with the ECG-RESP-gating method. TAs with SG-LGE varied depending on NR used (TA: 41, 82, 154, and 307 seconds, corresponding to NR of 40, 80, 150, and 300, respectively). For the ECG-RESP-gating method, the average TA was 220 seconds. For SG-LGE images, CNR (42.5 ± 5.5, 43.5 ± 7.5, 54 ± 9, 59.5 ± 8.5, 56 ± 13, 54 ± 8, and 41 ± 9) and image quality score (1.85 ± 0.75, 2.20 ± 0.83, 2.85 ± 0.37, 3.85 ± 0.52, 2.8 ± 0.51, 2.45 ± 0.76, and 1.95 ± 0.60) were achieved with different FAs (10°, 15°, 20°, 25°, 30°, 35°, and 40°, respectively). Optimal FAs of 20°-30° and NR of 80 were recommended. Self-gated technique can improve image quality of LGE without irregular ECG or respiration gating. Therefore, SG-LGE can be used an alternative method of ECG-RESP-gating.

Growth Control in Colon Epithelial Cells: Gadolinium Enhances Calcium-Mediated Growth Regulation

PubMed Central

Attili, Durga; Jenkins, Brian; Aslam, Muhammad Nadeem; Dame, Michael K.

2013-01-01

Gadolinium, a member of the lanthanoid family of transition metals, interacts with calcium-binding sites on proteins and other biological molecules. The overall goal of the present investigation was to determine if gadolinium could enhance calcium-induced epithelial cell growth inhibition in the colon. Gadolinium at concentrations as low as 1–5 µM combined with calcium inhibits proliferation of human colonic epithelial cells more effectively than calcium alone. Gadolinium had no detectable effect on calcium-induced differentiation in the same cells based on change in cell morphology, induction of E-cadherin synthesis, and translocation of E-cadherin from the cytosol to the cell surface. When the colon epithelial cells were treated with gadolinium and then exposed to increased calcium concentrations, movement of extracellular calcium into the cell was suppressed. In contrast, gadolinium treatment had no effect on ionomycin-induced release of stored intracellular calcium into the cytoplasm. Whether these in vitro observations can be translated into an approach for reducing abnormal proliferation in the colonic mucosa (including polyp formation) is not known. These results do, however, provide an explanation for our recent findings that a multi-mineral supplement containing all of the naturally occurring lanthanoid metals including gadolinium are more effective than calcium alone in preventing colon polyp formation in mice on a high-fat diet. PMID:23008064

Growth control in colon epithelial cells: gadolinium enhances calcium-mediated growth regulation.

PubMed

Attili, Durga; Jenkins, Brian; Aslam, Muhammad Nadeem; Dame, Michael K; Varani, James

2012-12-01

Gadolinium, a member of the lanthanoid family of transition metals, interacts with calcium-binding sites on proteins and other biological molecules. The overall goal of the present investigation was to determine if gadolinium could enhance calcium-induced epithelial cell growth inhibition in the colon. Gadolinium at concentrations as low as 1-5 μM combined with calcium inhibits proliferation of human colonic epithelial cells more effectively than calcium alone. Gadolinium had no detectable effect on calcium-induced differentiation in the same cells based on change in cell morphology, induction of E-cadherin synthesis, and translocation of E-cadherin from the cytosol to the cell surface. When the colon epithelial cells were treated with gadolinium and then exposed to increased calcium concentrations, movement of extracellular calcium into the cell was suppressed. In contrast, gadolinium treatment had no effect on ionomycin-induced release of stored intracellular calcium into the cytoplasm. Whether these in vitro observations can be translated into an approach for reducing abnormal proliferation in the colonic mucosa (including polyp formation) is not known. These results do, however, provide an explanation for our recent findings that a multi-mineral supplement containing all of the naturally occurring lanthanoid metals including gadolinium are more effective than calcium alone in preventing colon polyp formation in mice on a high-fat diet.

Harvesting NASA's Common Metadata Repository (CMR)

NASA Technical Reports Server (NTRS)

Shum, Dana; Durbin, Chris; Norton, James; Mitchell, Andrew

2017-01-01

As part of NASA's Earth Observing System Data and Information System (EOSDIS), the Common Metadata Repository (CMR) stores metadata for over 30,000 datasets from both NASA and international providers along with over 300M granules. This metadata enables sub-second discovery and facilitates data access. While the CMR offers a robust temporal, spatial and keyword search functionality to the general public and international community, it is sometimes more desirable for international partners to harvest the CMR metadata and merge the CMR metadata into a partner's existing metadata repository. This poster will focus on best practices to follow when harvesting CMR metadata to ensure that any changes made to the CMR can also be updated in a partner's own repository. Additionally, since each partner has distinct metadata formats they are able to consume, the best practices will also include guidance on retrieving the metadata in the desired metadata format using CMR's Unified Metadata Model translation software.

Deep learning enables reduced gadolinium dose for contrast-enhanced brain MRI.

PubMed

Gong, Enhao; Pauly, John M; Wintermark, Max; Zaharchuk, Greg

2018-02-13

There are concerns over gadolinium deposition from gadolinium-based contrast agents (GBCA) administration. To reduce gadolinium dose in contrast-enhanced brain MRI using a deep learning method. Retrospective, crossover. Sixty patients receiving clinically indicated contrast-enhanced brain MRI. 3D T 1 -weighted inversion-recovery prepped fast-spoiled-gradient-echo (IR-FSPGR) imaging was acquired at both 1.5T and 3T. In 60 brain MRI exams, the IR-FSPGR sequence was obtained under three conditions: precontrast, postcontrast images with 10% low-dose (0.01mmol/kg) and 100% full-dose (0.1 mmol/kg) of gadobenate dimeglumine. We trained a deep learning model using the first 10 cases (with mixed indications) to approximate full-dose images from the precontrast and low-dose images. Synthesized full-dose images were created using the trained model in two test sets: 20 patients with mixed indications and 30 patients with glioma. For both test sets, low-dose, true full-dose, and the synthesized full-dose postcontrast image sets were compared quantitatively using peak-signal-to-noise-ratios (PSNR) and structural-similarity-index (SSIM). For the test set comprised of 20 patients with mixed indications, two neuroradiologists scored blindly and independently for the three postcontrast image sets, evaluating image quality, motion-artifact suppression, and contrast enhancement compared with precontrast images. Results were assessed using paired t-tests and noninferiority tests. The proposed deep learning method yielded significant (n = 50, P < 0.001) improvements over the low-dose images (>5 dB PSNR gains and >11.0% SSIM). Ratings on image quality (n = 20, P = 0.003) and contrast enhancement (n = 20, P < 0.001) were significantly increased. Compared to true full-dose images, the synthesized full-dose images have a slight but not significant reduction in image quality (n = 20, P = 0.083) and contrast enhancement (n = 20, P = 0.068). Slightly

Subcellular SIMS imaging of gadolinium isotopes in human glioblastoma cells treated with a gadolinium containing MRI agent

NASA Astrophysics Data System (ADS)

Smith, Duane R.; Lorey, Daniel R.; Chandra, Subhash

2004-06-01

Neutron capture therapy is an experimental binary radiotherapeutic modality for the treatment of brain tumors such as glioblastoma multiforme. Recently, neutron capture therapy with gadolinium-157 has gained attention, and techniques for studying the subcellular distribution of gadolinium-157 are needed. In this preliminary study, we have been able to image the subcellular distribution of gadolinium-157, as well as the other six naturally abundant isotopes of gadolinium, with SIMS ion microscopy. T98G human glioblastoma cells were treated for 24 h with 25 mg/ml of the metal ion complex diethylenetriaminepentaacetic acid Gd(III) dihydrogen salt hydrate (Gd-DTPA). Gd-DTPA is a contrast enhancing agent used for MRI of brain tumors, blood-brain barrier impairment, diseases of the central nervous system, etc. A highly heterogeneous subcellular distribution was observed for gadolinium-157. The nuclei in each cell were distinctly lower in gadolinium-157 than in the cytoplasm. Even within the cytoplasm the gadolinium-157 was heterogeneously distributed. The other six naturally abundant isotopes of gadolinium were imaged from the same cells and exhibited a subcellular distribution consistent with that observed for gadolinium-157. These observations indicate that SIMS ion microscopy may be a viable approach for subcellular studies of gadolinium containing neutron capture therapy drugs and may even play a major role in the development and validation of new gadolinium contrast enhancing agents for diagnostic MRI applications.

Diagnostic performance of semi-quantitative and quantitative stress CMR perfusion analysis: a meta-analysis.

PubMed

van Dijk, R; van Assen, M; Vliegenthart, R; de Bock, G H; van der Harst, P; Oudkerk, M

2017-11-27

Stress cardiovascular magnetic resonance (CMR) perfusion imaging is a promising modality for the evaluation of coronary artery disease (CAD) due to high spatial resolution and absence of radiation. Semi-quantitative and quantitative analysis of CMR perfusion are based on signal-intensity curves produced during the first-pass of gadolinium contrast. Multiple semi-quantitative and quantitative parameters have been introduced. Diagnostic performance of these parameters varies extensively among studies and standardized protocols are lacking. This study aims to determine the diagnostic accuracy of semi- quantitative and quantitative CMR perfusion parameters, compared to multiple reference standards. Pubmed, WebOfScience, and Embase were systematically searched using predefined criteria (3272 articles). A check for duplicates was performed (1967 articles). Eligibility and relevance of the articles was determined by two reviewers using pre-defined criteria. The primary data extraction was performed independently by two researchers with the use of a predefined template. Differences in extracted data were resolved by discussion between the two researchers. The quality of the included studies was assessed using the 'Quality Assessment of Diagnostic Accuracy Studies Tool' (QUADAS-2). True positives, false positives, true negatives, and false negatives were subtracted/calculated from the articles. The principal summary measures used to assess diagnostic accuracy were sensitivity, specificity, andarea under the receiver operating curve (AUC). Data was pooled according to analysis territory, reference standard and perfusion parameter. Twenty-two articles were eligible based on the predefined study eligibility criteria. The pooled diagnostic accuracy for segment-, territory- and patient-based analyses showed good diagnostic performance with sensitivity of 0.88, 0.82, and 0.83, specificity of 0.72, 0.83, and 0.76 and AUC of 0.90, 0.84, and 0.87, respectively. In per territory

Kondo effect and enhanced magnetic properties in gadolinium functionalized carbon nanotube supramolecular complex.

PubMed

Ncube, S; Coleman, C; Strydom, A; Flahaut, E; de Sousa, A; Bhattacharyya, S

2018-05-23

We report on the enhancement of magnetic properties of multiwalled carbon nanotubes (MWNTs) functionalized with a gadolinium based supramolecular complex. By employing a newly developed synthesis technique we find that the functionalization method of the nanocomposite enhances the strength of magnetic interaction leading to a large effective moment of 15.79 µ B and non-superparamagnetic behaviour unlike what has been previously reported. Saturating resistance at low temperatures is fitted with the numerical renormalization group formula verifying the Kondo effect for magnetic impurities on a metallic electron system. Magnetoresistance shows devices fabricated from aligned gadolinium functionalized MWNTs (Gd-Fctn-MWNTs) exhibit spin-valve switching behaviour of up to 8%. This study highlights the possibility of enhancing magnetic interactions in carbon systems through chemical modification, moreover we demonstrate the rich physics that might be useful for developing spin based quantum computing elements based on one-dimensional (1D) channels.

Myocardial Fibrosis in Hypertrophic Cardiomyopathy: Volumetric Assessment of Late Enhancement Provided by Cardiac Computed Tomography.

PubMed

Langer, Christoph; Schaefer, Philipp; Lutz, Matthias; Eden, Matthias; Hohnhorst, Mirko; Harders, Hauke; Faber, Lothar; Jansen, Olav; Both, Marcus; Frey, Norbert

2015-01-01

With subgroups of patients with hypertrophic cardiomyopathy (HCM) confers a 4% to 5% risk for adverse prognosis. Besides left-ventricular muscle mass (LV-MM) myocardial fibrosis (MF) assessable by late gadolinium enhancement in cardiovascular magnetic resonance (LGE-CMR) has been related to that. Myocardial fibrosis can also be demonstrated by late enhancement (LE) in late-enhanced multislice computed tomography (leMDCT). This analysis investigates leMDCT whether to enable quantification of LE load in terms of LE mass by percent LV-MM in HCM. In a prospective validation study, we included 30 consecutive patients with HCM who underwent leMDCT (64 slice) and LGE-CMR (1.5 T). The leMDCT scan was performed 7 minutes after injection of iodine contrast (Iopromid). Endocardial and epicardial planimetry served for the assessment of LV-MM. Visually detectable LE was quantified using the manual quantification method resulting in LE by percent LV-MM (%LE). The LGE-CMR data served for validation. Mean (SD) age was 64.1 (13.9) years. Myocardial fibrosis prevalence was 63.3% (19/30 patients indentified by both leMDCT and LGE-CMR). In leMDCT, tissue density in LE areas compared with normal myocardium was higher (138.2 [23.9] HU vs 98.4 [16.5] HU, P < 0.001) but lower than in the LV cavity (138.2 [23.9] HU vs 169.2 [35.9] HU, P < 0.001). Late enhancement mass in leMDCT seemed to be 7.9 (8.5) g LE versus 8.6 [11] g LGE in CMR (P = 0.497, r = 0.95) resulting in a leMDCT/LGE-CMR relation of 1.2. Referring LE mass to LV-MM gave an LE proportion measured by leMDCT of 4 (3.9) %LE versus 3.9 (4.1) %LGE in LGE-CMR (r = 0.88, P = 0.75). Intraobserver/interobserver reliability of LE mass assessment showed an intraclass correlation coefficient of 0.99 and 0.97. In patients with HCM, leMDCT provides volumetric assessment of LE mass-absolutely and by percent LV-MM.

Quantitative assessment of the rheumatoid synovial microvascular bed by gadolinium-DTPA enhanced magnetic resonance imaging

PubMed Central

Gaffney, K.; Cookson, J.; Blades, S.; Coumbe, A.; Blake, D.

1998-01-01

OBJECTIVE—To examine the relation between rate of synovial membrane enhancement, intra-articular pressure (IAP), and histologically determined synovial vascularity in rheumatoid arthritis, using gadolinium-DTPA enhanced magnetic resonance imaging (MRI).
METHODS—Dynamic gadolinium-DTPA enhanced MRI was performed in 31 patients with knee synovitis (10 patients IAP study, 21 patients vascular morphometry study). Rate of synovial membrane enhancement was quantified by line profile analysis using the image processing package ANALYZE. IAP was measured using an intra-compartmental pressure monitor system. Multiple synovial biopsy specimens were obtained by a blind biopsy technique. Blood vessels were identified immunohistochemically using the endothelial cell marker QBend30 and quantified (blood vessel numerical density and fractional area).
RESULTS—Median blood vessel numerical density and fractional area were 77.5/mm2 (IQR; 69.3-110.7) and 5.6% (IQR; 3.4-8.5) respectively. The rate of synovial membrane enhancement (median 2.74 signal intensity units/s, IQR 2.0-3.8) correlated with both blood vessel numerical density (r = 0.46, p < 0.05) and blood vessel fractional area (r = 0.55, p < 0.02). IAP did not influence the rate of enhancement.
CONCLUSIONS—Gadolinium-DTPA enhanced MRI may prove to be a valuable technique for evaluating drugs that influence angiogenesis.

 Keywords: magnetic resonance imaging; rheumatoid arthritis; synovitis; vascularity PMID:9640130

The Utility of Cardiac Magnetic Resonance Imaging in the Diagnosis of Cardiac Sarcoidosis.

PubMed

Stanton, Kelly M; Ganigara, Madhusudan; Corte, Peter; Celermajer, David S; McGuire, Mark A; Torzillo, Paul J; Corte, Tamera J; Puranik, Rajesh

2017-11-01

Autopsy reports suggest that cardiac sarcoidosis occurs in 20 to 25% of patients with pulmonary sarcoidosis, yet the clinical ante-mortem diagnosis is made in only 5% of cases. Current diagnostic algorithms are complex and lack sensitivity. Cardiac Magnetic Resonance imaging (CMR) provides an opportunity to detect myocardial involvement in sarcoidosis. The aim of this study is to determine the prevalence and clinical significance of late gadolinium enhancement (LGE) on CMR in patients with sarcoidosis. Consecutive patients with biopsy-proven sarcoidosis undergoing CMR were retrospectively evaluated for cardiac sarcoidosis. Medical records were correlated with CMR. Forty-six patients were evaluated. Late gadolinium enhancement was present in 22%, indicating myocardial involvement, and 70% had corresponding hyper-intense T2 signal indicating active inflammation. Late gadolinium enhancement was 18%+/-9.7% of overall left ventricular (LV) mass and most commonly located in the basal to mid septum. There was no association between LGE and cardiovascular symptoms or pulmonary stage. Eighty per cent of patients with LGE did not fulfill conventional diagnostic criteria for cardiac sarcoidosis. However, LGE was associated with clinically significant arrhythmia (p<0.01) and a lower LVEF (p=0.04). Using CMR, we identified a higher prevalence of cardiac sarcoidosis than previously reported clinical studies, a prevalence which is more consistent with autopsy data. The presence of LGE was highly correlated with clinically significant arrhythmias and lower LVEF. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). All rights reserved.

Imaging of cauda equina edema in lumbar canal stenosis by using gadolinium-enhanced MR imaging: experimental constriction injury.

PubMed

Kobayashi, S; Uchida, K; Takeno, K; Baba, H; Suzuki, Y; Hayakawa, K; Yoshizawa, H

2006-02-01

It has been reported that disturbance of blood flow arising from circumferential compression of the cauda equina by surrounding tissue plays a major role in the appearance of neurogenic intermittent claudication (NIC) associated with lumbar spinal canal stenosis (LSCS). We created a model of LSCS to clarify the mechanism of enhancement within the cauda equina on gadolinium-enhanced MR images from patients with LSCS. In 20 dogs, a lumbar laminectomy was performed by applying circumferential constriction to the cauda equina by using a silicon tube, to produce 30% stenosis of the circumferential diameter of the dural tube. After 1 and 3 weeks, gadolinium and Evans blue albumin were injected intravenously at the same time. The sections were used to investigate the status of the blood-nerve barrier function under a fluorescence microscope and we compared gadolinium-enhanced MR images with Evans blue albumin distribution in the nerve. The other sections were used for light and transmission electron microscopic study. In this model, histologic examination showed congestion and dilation in many of the intraradicular veins, as well as inflammatory cell infiltration. The intraradicular edema caused by venous congestion and Wallerian degeneration can also occur at sites that are not subject to mechanical compression. Enhanced MR imaging showed enhancement of the cauda equina at the stenosed region, demonstrating the presence of edema. Gadolinium-enhanced MR imaging may be a useful tool for the diagnosis of microcirculatory disorders of the cauda equina associated with LSCS.

MRI of normal and abnormal duodenum using Half-Fourier Single-Shot RARE and gadolinium-enhanced spoiled gradient echo sequences.

PubMed

Marcos, H B; Semelka, R C; Noone, T C; Woosley, J T; Lee, J K

1999-07-01

The objective of this research was two-fold: First, to describe the normal and abnormal MR appearances of the duodenum using combined Half-Fourier Acquisition Single Shot RARE (HASTE) and gadolinium-enhanced standard and fat suppressed spoiled gradient echo (SGE) sequences. The second objective was to assess the ability of these combined sequences to detect and characterize duodenal diseases. MR examinations were performed on fifty consecutive patients with no clinical history of duodenal diseases, who were 1) imaged with HASTE and gadolinium-enhanced standard and fat suppressed SGE sequences and 2) referred to MR examination for reasons other than duodenal diseases, and were reviewed retrospectively to determine the normal MR appearances of the duodenum. A second population of patients with abnormal duodenum who were imaged with the same MR sequences were included in the second part of this study. This population was composed of 20 consecutive patients with subsequently proven duodenal abnormalities, including: malrotation (2), diverticula (4), intussusception (1), sprue (1), polyps (2), neurofibroma (1), lymphoma (1), Zollinger Ellison syndrome (1), metastatic disease (1), Crohn's disease (1), and wall thickening and duodenitis (5). Normal measurements of the duodenum are described. Abnormalities of wall thickness and duodenal masses required combined HASTE and gadolinium-enhanced SGE images to evaluate well. Abnormalities of the bowel lumen (e.g., diverticula and intussusception), and developmental variants (e.g., malrotation), were sufficiently visualized on HASTE images alone. Bowel inflammation was best shown on gadolinium-enhanced fat suppressed SGE images. HASTE and gadolinium-enhanced fat suppressed SGE sequences are complementary techniques for the demonstration of normal and abnormal duodenum. The combined use of both sequences allows evaluation of different aspects of bowel diseases; abnormalities of position, lumen, and contents are well shown on HASTE

Applying Amide Proton Transfer MR Imaging to Hybrid Brain PET/MR: Concordance with Gadolinium Enhancement and Added Value to [18F]FDG PET.

PubMed

Sun, Hongzan; Xin, Jun; Zhou, Jinyuan; Lu, Zaiming; Guo, Qiyong

2018-06-01

The purpose of this study is to evaluate the diagnostic concordance and metric correlations of amide proton transfer (APT) imaging with gadolinium-enhanced magnetic resonance imaging (MRI) and 2-deoxy-2-[ 18 F-]fluoro-D-glucose ([ 18 F]FDG) positron emission tomography (PET), using hybrid brain PET/MRI. Twenty-one subjects underwent brain gadolinium-enhanced [ 18 F]FDG PET/MRI prospectively. Imaging accuracy was compared between unenhanced MRI, MRI with enhancement, APT-weighted (APTW) images, and PET based on six diagnostic criteria. Among tumors, the McNemar test was further used for concordance assessment between gadolinium-enhanced imaging, APT imaging, and [ 18 F]FDG PET. As well, the relation of metrics between APT imaging and PET was analyzed by the Pearson correlation analysis. APT imaging and gadolinium-enhanced MRI showed superior and similar diagnostic accuracy. APTW signal intensity and gadolinium enhancement were concordant in 19 tumors (100 %), while high [ 18 F]FDG avidity was shown in only 12 (63.2 %). For the metrics from APT imaging and PET, there was significant correlation for 13 hypermetabolic tumors (P < 0.05) and no correlation for the remaining six [ 18 F]FDG-avid tumors. APT imaging can be used to increase diagnostic accuracy with no need to administer gadolinium chelates. APT imaging may provide an added value to [ 18 F]FDG PET in the evaluation of tumor metabolic activity during brain PET/MR studies.

Cardiovascular Magnetic Resonance and prognosis in cardiac amyloidosis

PubMed Central

Maceira, Alicia M; Prasad, Sanjay K; Hawkins, Philip N; Roughton, Michael; Pennell, Dudley J

2008-01-01

Background Cardiac involvement is common in amyloidosis and associated with a variably adverse outcome. We have previously shown that cardiovascular magnetic resonance (CMR) can assess deposition of amyloid protein in the myocardial interstitium. In this study we assessed the prognostic value of late gadolinium enhancement (LGE) and gadolinium kinetics in cardiac amyloidosis in a prospective longitudinal study. Materials and methods The pre-defined study end point was all-cause mortality. We prospectively followed a cohort of 29 patients with proven cardiac amyloidosis. All patients underwent biopsy, 2D-echocardiography and Doppler studies, 123I-SAP scintigraphy, serum NT pro BNP assay, and CMR with a T1 mapping method and late gadolinium enhancement (LGE). Results Patients with were followed for a median of 623 days (IQ range 221, 1436), during which 17 (58%) patients died. The presence of myocardial LGE by itself was not a significant predictor of mortality. However, death was predicted by gadolinium kinetics, with the 2 minute post-gadolinium intramyocardial T1 difference between subepicardium and subendocardium predicting mortality with 85% accuracy at a threshold value of 23 ms (the lower the difference the worse the prognosis). Intramyocardial T1 gradient was a better predictor of survival than FLC response to chemotherapy (Kaplan Meier analysis P = 0.049) or diastolic function (Kaplan-Meier analysis P = 0.205). Conclusion In cardiac amyloidosis, CMR provides unique information relating to risk of mortality based on gadolinium kinetics which reflects the severity of the cardiac amyloid burden. PMID:19032744

Achieving Sub-Second Search in the CMR

NASA Astrophysics Data System (ADS)

Gilman, J.; Baynes, K.; Pilone, D.; Mitchell, A. E.; Murphy, K. J.

2014-12-01

The Common Metadata Repository (CMR) is the next generation Earth Science Metadata catalog for NASA's Earth Observing data. It joins together the holdings from the EOS Clearing House (ECHO) and the Global Change Master Directory (GCMD), creating a unified, authoritative source for EOSDIS metadata. The CMR allows ingest in many different formats while providing consistent search behavior and retrieval in any supported format. Performance is a critical component of the CMR, ensuring improved data discovery and client interactivity. The CMR delivers sub-second search performance for any of the common query conditions (including spatial) across hundreds of millions of metadata granules. It also allows the addition of new metadata concepts such as visualizations, parameter metadata, and documentation. The CMR's goals presented many challenges. This talk will describe the CMR architecture, design, and innovations that were made to achieve its goals. This includes: * Architectural features like immutability and backpressure. * Data management techniques such as caching and parallel loading that give big performance gains. * Open Source and COTS tools like Elasticsearch search engine. * Adoption of Clojure, a functional programming language for the Java Virtual Machine. * Development of a custom spatial search plugin for Elasticsearch and why it was necessary. * Introduction of a unified model for metadata that maps every supported metadata format to a consistent domain model.

A polymeric fastener can easily functionalize liposome surfaces with gadolinium for enhanced magnetic resonance imaging.

PubMed

Smith, Cartney E; Shkumatov, Artem; Withers, Sarah G; Yang, Binxia; Glockner, James F; Misra, Sanjay; Roy, Edward J; Wong, Chun-Ho; Zimmerman, Steven C; Kong, Hyunjoon

2013-11-26

Common methods of loading magnetic resonance imaging (MRI) contrast agents into nanoparticles often suffer from challenges related to particle formation, complex chemical modification/purification steps, and reduced contrast efficiency. This study presents a simple, yet advanced process to address these issues by loading gadolinium, an MRI contrast agent, exclusively on a liposome surface using a polymeric fastener. The fastener, so named for its ability to physically link the two functional components together, consisted of chitosan substituted with diethylenetriaminepentaacetic acid (DTPA) to chelate gadolinium, as well as octadecyl chains to stabilize the modified chitosan on the liposome surface. The assembly strategy, mimicking the mechanisms by which viruses and proteins naturally anchor to a cell, provided greater T1 relaxivity than liposomes loaded with gadolinium in both the interior and outer leaflet. Gadolinium-coated liposomes were ultimately evaluated in vivo using murine ischemia models to highlight the diagnostic capability of the system. Taken together, this process decouples particle assembly and functionalization and, therefore, has considerable potential to enhance imaging quality while alleviating many of the difficulties associated with multifunctional particle fabrication.

A Polymeric Fastener can Easily Functionalize Liposome Surfaces with Gadolinium for Enhanced Magnetic Resonance Imaging

PubMed Central

Smith, Cartney E.; Shkumatov, Artem; Withers, Sarah G.; Glockner, James F.; Misra, Sanjay; Roy, Edward J.; Wong, Chun-Ho; Zimmerman, Steven C.; Kong, Hyunjoon

2013-01-01

Common methods of loading magnetic resonance imaging (MRI) contrast agents into nanoparticles often suffer from challenges related to particle formation, complex chemical modification/purification steps, and reduced contrast efficiency. This study presents a simple, yet advanced process to address these issues by loading gadolinium, an MRI contrast agent, exclusively on a liposome surface using a polymeric fastener. The fastener, so named for its ability to physically link the two functional components together, consisted of chitosan substituted with diethylenetriaminepentaacetic acid (DTPA) to chelate gadolinium, as well as octadecyl chains to stabilize the modified chitosan on the liposome surface. The assembly strategy, mimicking the mechanisms by which viruses and proteins naturally anchor to a cell, provided greater T1 relaxivity than liposomes loaded with gadolinium in both the interior and outer leaflet. Gadolinium-coated liposomes were ultimately evaluated in vivo using murine ischemia models to highlight the diagnostic capability of the system. Taken together, this process decouples particle assembly and functionalization, and therefore has considerable potential to enhance imaging quality while alleviating many of the difficulties associated with multifunctional particle fabrication. PMID:24083377

Cardiac magnetic resonance findings predict increased resource utilization in elective coronary artery bypass grafting.

PubMed

Berry, Colin; Zimmerli, Lukas U; Steedman, Tracey; Foster, John E; Dargie, Henry J; Berg, Geoffrey A; Dominiczak, Anna F; Delles, Christian

2008-03-01

Morbidity following CABG (coronary artery bypass grafting) is difficult to predict and leads to increased healthcare costs. We hypothesized that pre-operative CMR (cardiac magnetic resonance) findings would predict resource utilization in elective CABG. Over a 12-month period, patients requiring elective CABG were invited to undergo CMR 1 day prior to CABG. Gadolinium-enhanced CMR was performed using a trueFISP inversion recovery sequence on a 1.5 tesla scanner (Sonata; Siemens). Clinical data were collected prospectively. Admission costs were quantified based on standardized actual cost/day. Admission cost greater than the median was defined as 'increased'. Of 458 elective CABG cases, 45 (10%) underwent pre-operative CMR. Pre-operative characteristics [mean (S.D.) age, 64 (9) years, mortality (1%) and median (interquartile range) admission duration, 7 (6-8) days] were similar in patients who did or did not undergo CMR. In the patients undergoing CMR, eight (18%) and 11 (24%) patients had reduced LV (left ventricular) systolic function by CMR [LVEF (LV ejection fraction) <55%] and echocardiography respectively. LE (late enhancement) with gadolinium was detected in 17 (38%) patients. The average cost/day was $2723. The median (interquartile range) admission cost was $19059 ($10891-157917). CMR LVEF {OR (odds ratio), 0.93 [95% CI (confidence interval), 0.87-0.99]; P=0.03} and SV (stroke volume) index [OR 1.07 (95% CI, 1.00-1.14); P=0.02] predicted increased admission cost. CMR LVEF (P=0.08) and EuroScore tended to predict actual admission cost (P=0.09), but SV by CMR (P=0.16) and LV function by echocardiography (P=0.95) did not. In conclusion, in this exploratory investigation, pre-operative CMR findings predicted admission duration and increased admission cost in elective CABG surgery. The cost-effectiveness of CMR in risk stratification in elective CABG surgery merits prospective assessment.

Novel structural features drive DNA binding properties of Cmr, a CRP family protein in TB complex mycobacteria.

PubMed

Ranganathan, Sridevi; Cheung, Jonah; Cassidy, Michael; Ginter, Christopher; Pata, Janice D; McDonough, Kathleen A

2018-01-09

Mycobacterium tuberculosis (Mtb) encodes two CRP/FNR family transcription factors (TF) that contribute to virulence, Cmr (Rv1675c) and CRPMt (Rv3676). Prior studies identified distinct chromosomal binding profiles for each TF despite their recognizing overlapping DNA motifs. The present study shows that Cmr binding specificity is determined by discriminator nucleotides at motif positions 4 and 13. X-ray crystallography and targeted mutational analyses identified an arginine-rich loop that expands Cmr's DNA interactions beyond the classical helix-turn-helix contacts common to all CRP/FNR family members and facilitates binding to imperfect DNA sequences. Cmr binding to DNA results in a pronounced asymmetric bending of the DNA and its high level of cooperativity is consistent with DNA-facilitated dimerization. A unique N-terminal extension inserts between the DNA binding and dimerization domains, partially occluding the site where the canonical cAMP binding pocket is found. However, an unstructured region of this N-terminus may help modulate Cmr activity in response to cellular signals. Cmr's multiple levels of DNA interaction likely enhance its ability to integrate diverse gene regulatory signals, while its novel structural features establish Cmr as an atypical CRP/FNR family member. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Influence of acquired obesity on coronary vessel wall late gadolinium enhancement in discordant monozygote twins.

PubMed

Makowski, Marcus R; Jansen, Christian H P; Ebersberger, Ullrich; Schaeffter, Tobias; Razavi, Reza; Mangino, Massimo; Spector, Tim D; Botnar, Rene M; Greil, Gerald F

2017-11-01

The aim of this study was to investigate the impact of BMI on late gadolinium enhancement (LGE) of the coronary artery wall in identical monozygous twins discordant for BMI. Coronary LGE represents a useful parameter for the detection and quantification of atherosclerotic coronary vessel wall disease. Thirteen monozygote female twin pairs (n = 26) with significantly different BMIs (>1.6 kg/m2) were recruited out of >10,000 twin pairs (TwinsUK Registry). A coronary 3D-T2prep-TFE MR angiogram and 3D-IR-TFE vessel wall scan were performed prior to and following the administration of 0.2 mmol/kg of Gd-DTPA on a 1.5 T MR scanner. The number of enhancing coronary segments and contrast to noise ratios (CNRs) of the coronary wall were quantified. An increase in BMI was associated with an increased number of enhancing coronary segments (5.3 ± 1.5 vs. 3.5 ± 1.6, p < 0.0001) and increased coronary wall enhancement (6.1 ± 1.1 vs. 4.8 ± 0.9, p = 0.0027) compared to matched twins with lower BMI. This study in monozygous twins indicates that acquired factors predisposing to obesity, including lifestyle and environmental factors, result in increased LGE of the coronary arteries, potentially reflecting an increase in coronary atherosclerosis in this female study population. • BMI-discordant twins allow the investigation of the influence of lifestyle factors independent from genetic confounders. • Only thirteen obesity-discordant twins were identified underlining the strong genetic component of BMI. • In female twins, a BMI increase is associated with increased coronary late gadolinium enhancement. • Increased late gadolinium enhancement in the coronary vessel wall potentially reflects increased atherosclerosis.

Multiparametric Cardiac Magnetic Resonance Survey in Children With Thalassemia Major: A Multicenter Study.

PubMed

Casale, Maddalena; Meloni, Antonella; Filosa, Aldo; Cuccia, Liana; Caruso, Vincenzo; Palazzi, Giovanni; Gamberini, Maria Rita; Pitrolo, Lorella; Putti, Maria Caterina; D'Ascola, Domenico Giuseppe; Casini, Tommaso; Quarta, Antonella; Maggio, Aurelio; Neri, Maria Giovanna; Positano, Vincenzo; Salvatori, Cristina; Toia, Patrizia; Valeri, Gianluca; Midiri, Massimo; Pepe, Alessia

2015-08-01

Cardiovascular magnetic resonance (CMR) plays a key role in the management of thalassemia major patients, but few data are available in pediatric population. This study aims at a retrospective multiparametric CMR assessment of myocardial iron overload, function, and fibrosis in a cohort of pediatric thalassemia major patients. We studied 107 pediatric thalassemia major patients (61 boys, median age 14.4 years). Myocardial and liver iron overload were measured by T2* multiecho technique. Atrial dimensions and biventricular function were quantified by cine images. Late gadolinium enhancement images were acquired to detect myocardial fibrosis. All scans were performed without sedation. The 21.4% of the patients showed a significant myocardial iron overload correlated with lower compliance to chelation therapy (P<0.013). Serum ferritin ≥2000 ng/mL and liver iron concentration ≥14 mg/g/dw were detected as the best threshold for predicting cardiac iron overload (P=0.001 and P<0.0001, respectively). A homogeneous pattern of myocardial iron overload was associated with a negative cardiac remodeling and significant higher liver iron concentration (P<0.0001). Myocardial fibrosis by late gadolinium enhancement was detected in 15.8% of the patients (youngest children 13 years old). It was correlated with significant lower heart T2* values (P=0.022) and negative cardiac remodeling indexes. A pathological magnetic resonance imaging liver iron concentration was found in the 77.6% of the patients. Cardiac damage detectable by a multiparametric CMR approach can occur early in thalassemia major patients. So, the first T2* CMR assessment should be performed as early as feasible without sedation to tailor the chelation treatment. Conversely, late gadolinium enhancement CMR should be postponed in the teenager age. © 2015 American Heart Association, Inc.

Cardiovascular Magnetic Resonance Imaging of Myocardial Infarction, Viability, and Cardiomyopathies

PubMed Central

West, Amy M.; Kramer, Christopher M.

2010-01-01

Cardiovascular magnetic resonance provides the opportunity for a truly comprehensive evaluation of patients with a history of MI, with regards to characterizing the extent of disease, impact on LV function and degree of viable myocardium. The use of contrast-enhanced CMR for first-pass perfusion and late gadolinium enhancement is a powerful technique for delineating areas of myocardial ischemia and infarction. Using a combination of T2-weighted and contrast-enhanced CMR images, information about the acuity of an infarct can be obtained. There is an extensive amount of literature using contrast-enhanced CMR to predict myocardial functional recovery with revascularization in patients with ischemic cardiomyopathies. In addition, CMR imaging in patients with cardiomyopathies can distinguish between ischemic and non-ischemic etiologies, with the ability to further characterize the underlying pathology for non-ischemic cardiomyopathies. PMID:20197150

The prognostic value of T1 mapping and late gadolinium enhancement cardiovascular magnetic resonance imaging in patients with light chain amyloidosis.

PubMed

Lin, Lu; Li, Xiao; Feng, Jun; Shen, Kai-Ni; Tian, Zhuang; Sun, Jian; Mao, Yue-Ying; Cao, Jian; Jin, Zheng-Yu; Li, Jian; Selvanayagam, Joseph B; Wang, Yi-Ning

2018-01-03

Cardiac impairment is associated with high morbidity and mortality in immunoglobulin light chain (AL) type amyloidosis, for which early identification and risk stratification is vital. For myocardial tissue characterization, late gadolinium enhancement (LGE) is a classic and most commonly performed cardiovascular magnetic resonance (CMR) parameter. T1 mapping with native T1 and extracellular volume (ECV) are recently developed quantitative parameters. We aimed to investigate the prognostic value of native T1, ECV and LGE in patients with AL amyloidosis. Eighty-two patients (55.5 ± 8.5 years; 52 M) and 20 healthy subjects (53.2 ± 11.7 years; 10 M) were prospectively recruited. All subjects underwent CMR with LGE imaging and T1 mapping using a Modified Look-Locker Inversion-recovery (MOLLI) sequence on a 3 T scanner. Native T1 and ECV were measured semi-automatically using a dedicated CMR software. The left ventricular (LV) LGE pattern was classified as none, patchy, and global groups. Global LGE was considered when there was diffuse, transmural LGE in more than half of the short axis images. Follow-up was performed for all-cause mortality using Cox proportional hazards regression analysis and Kaplan-Meier survival curves. The patients demonstrated an increase in native T1 (1438 ± 120 ms vs. 1283 ± 46 ms, P = 0.001) and ECV (43.9 ± 10.9% vs. 27.0 ± 1.7%, P = 0.001) compared to healthy controls. Native T1, ECV and LGE showed significant correlation with Mayo Stage, and ECV and LGE showed significant correlation with echocardiographic E/E' and LV ejection fraction. During the follow-up for a median time of 8 months, 21 deaths occurred. ECV ≥ 44.0% (hazard ratio [HR] 7.249, 95% confidence interval (CI) 1.751-13.179, P = 0.002) and global LGE (HR 4.804, 95% CI 1.971-12.926, P = 0.001) were independently prognostic for mortality over other clinical and imaging parameters. In subgroups with the same LGE pattern

Gadolinium Distribution in Cerebrospinal Fluid after Administration of a Gadolinium-based MR Contrast Agent in Humans.

PubMed

Berger, Florian; Kubik-Huch, Rahel A; Niemann, Tilo; Schmid, Hans Ruedi; Poetzsch, Michael; Froehlich, Johannes M; Beer, Jürg H; Thali, Michael J; Kraemer, Thomas

2018-05-08

Purpose To evaluate whether gadolinium penetrates human cerebrospinal fluid (CSF) after MR imaging (MRI) with a gadolinium-based contrast agent (GBCA). Materials and Methods For this retrospective study, the authors analyzed 60 CSF samples from 57 patients (median age, 50 years; range, 3-92 years) who underwent one contrast material-enhanced MRI examination with gadoterate meglumine within 60 days of CSF extraction between January and December 2016. CSF samples from patients who underwent MRI without contrast material administration (n = 22) or those who underwent contrast-enhanced MRI at least 1 year before extraction (n = 2) were analyzed and used as control samples. CSF measurements were performed with inductively coupled plasma mass spectrometry by monitoring the gadolinium 158 isotope. Statistical analyses were performed by using a preliminary Kruskal-Wallis test. Results Higher CSF gadolinium concentrations were detected within the first 8 hours after GBCA administration (mean concentration, 1152 ng/mL ± 734.6). Concentrations were lower between 8 and 48 hours (872 ng/mL ± 586). After 48 hours, gadolinium was almost completely cleared from CSF (121 ng/mL ± 296.3). All but two samples from the 24 control patients (median age, 60.5 years; range, 19-79 years) were negative for the presence of gadolinium. Those samples were from patients who had undergone GBCA-enhanced MRI examination more than a year before CSF extraction (0.1 and 0.2 ng/mL after 1 and 3 years, respectively). The concentrations in patients with chronic renal insufficiency (n = 3), cerebral toxoplasmosis (n = 1), and liver cirrhosis (n = 1) were higher than the mean concentrations. Conclusion Gadoterate meglumine can be detected in human CSF after intravenous administration. © RSNA, 2018.

Application of an oscillation-type linear cadmium telluride detector to enhanced gadolinium K-edge computed tomography

NASA Astrophysics Data System (ADS)

Matsukiyo, Hiroshi; Sato, Eiichi; Hagiwara, Osahiko; Abudurexiti, Abulajiang; Osawa, Akihiro; Enomoto, Toshiyuki; Watanabe, Manabu; Nagao, Jiro; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun

2011-03-01

A linear cadmium telluride (CdTe) detector is useful for carrying out energy-discrimination X-ray imaging, including computed tomography (CT). To perform enhanced gadolinium K-edge CT, we used an oscillation-type linear CdTe detector with an energy resolution of 1.2 keV. CT is performed by repeating the linear scan and the rotation of an object. Penetrating X-ray photons from the object are detected by the CdTe detector, and event signals of X-ray photons are produced using charge-sensitive and shaping amplifiers. Both the photon energy and the energy width are selected using a multichannel analyzer, and the number of photons is counted by a counter card. In energy-discrimination CT, tube voltage and current were 80 kV and 20 μA, respectively, and X-ray intensity was 1.55 μGy/s at 1.0 m from the source at a tube voltage of 80 kV. Demonstration of enhanced gadolinium K-edge X-ray CT was carried out by selecting photons with energies just beyond gadolinium K-edge energy of 50.3 keV.

Focal Reduction in Cardiac 123I-Metaiodobenzylguanidine Uptake in Patients With Anderson-Fabry Disease.

PubMed

Yamamoto, Saori; Suzuki, Hideaki; Sugimura, Koichiro; Tatebe, Shunsuke; Aoki, Tatsuo; Miura, Masanobu; Yaoita, Nobuhiro; Sato, Haruka; Kozu, Katuya; Ota, Hideki; Takanami, Kentaro; Takase, Kei; Shimokawa, Hiroaki

2016-11-25

It remains to be elucidated whether cardiac sympathetic nervous activity is impaired in patients with Anderson-Fabry disease (AFD).Methods and Results:We performed 123 I-meta-iodobenzylguanidine (MIBG) scintigraphy and gadolinium-enhanced cardiovascular magnetic resonance (CMR) in 5 AFD patients. MIBG uptake in the inferolateral wall, where wall thinning and delayed enhancement were noted on CMR, was significantly lower compared with the anteroseptal wall. The localized reduction in MIBG uptake was also noted in 2 patients with no obvious abnormal findings on CMR. Cardiac sympathetic nervous activity is impaired in AFD before development of structural myocardial abnormalities. (Circ J 2016; 80: 2550-2551).

Gadolinium Deposition in Human Brain Tissues after Contrast-enhanced MR Imaging in Adult Patients without Intracranial Abnormalities.

PubMed

McDonald, Robert J; McDonald, Jennifer S; Kallmes, David F; Jentoft, Mark E; Paolini, Michael A; Murray, David L; Williamson, Eric E; Eckel, Laurence J

2017-11-01

Purpose To determine whether gadolinium deposits in neural tissues of patients with intracranial abnormalities following intravenous gadolinium-based contrast agent (GBCA) exposure might be related to blood-brain barrier integrity by studying adult patients with normal brain pathologic characteristics. Materials and Methods After obtaining antemortem consent and institutional review board approval, the authors compared postmortem neuronal tissue samples from five patients who had undergone four to 18 gadolinium-enhanced magnetic resonance (MR) examinations between 2005 and 2014 (contrast group) with samples from 10 gadolinium-naive patients who had undergone at least one MR examination during their lifetime (control group). All patients in the contrast group had received gadodiamide. Neuronal tissues from the dentate nuclei, pons, globus pallidus, and thalamus were harvested and analyzed with inductively coupled plasma mass spectrometry (ICP-MS), transmission electron microscopy with energy-dispersive x-ray spectroscopy, and light microscopy to quantify, localize, and assess the effects of gadolinium deposition. Results Tissues from the four neuroanatomic regions of gadodiamide-exposed patients contained 0.1-19.4 μg of gadolinium per gram of tissue in a statistically significant dose-dependent relationship (globus pallidus: ρ = 0.90, P = .04). In contradistinction, patients in the control group had undetectable levels of gadolinium with ICP-MS. All patients had normal brain pathologic characteristics at autopsy. Three patients in the contrast group had borderline renal function (estimated glomerular filtration rate <45 mL/min/1.73 m 2 ) and hepatobiliary dysfunction at MR examination. Gadolinium deposition in the contrast group was localized to the capillary endothelium and neuronal interstitium and, in two cases, within the nucleus of the cell. Conclusion Gadolinium deposition in neural tissues after GBCA administration occurs in the absence of intracranial

Neurosarcoidosis--demonstration of meningeal disease by gadolinium enhanced magnetic resonance imaging.

PubMed Central

Khaw, K T; Manji, H; Britton, J; Schon, F

1991-01-01

Arriving at a firm diagnosis of neurosarcoidosis continues to pose serious problems, particularly when evidence of granulomatous disease outside the nervous system is lacking. The commonest mode of presentation of neurosarcoidosis is with cranial nerve palsies. Two cases of presumed neurosarcoidosis with cranial nerve palsies showed clear evidence of focal meningeal disease on gadolinium-DTPA enhanced MRI brain scans. Although not specific for sarcoidosis, this technique may be very useful in aiding the diagnosis in suspected cases. Images PMID:1880510

CMR Catalog Service for the Web

NASA Technical Reports Server (NTRS)

Newman, Doug; Mitchell, Andrew

2016-01-01

With the impending retirement of Global Change Master Directory (GCMD) Application Programming Interfaces (APIs) the Common Metadata Repository (CMR) was charged with providing a collection-level Catalog Service for the Web (CSW) that provided the same level of functionality as GCMD. This talk describes the capabilities of the CMR CSW API with particular reference to the support of the Committee on Earth Observation Satellites (CEOS) Working Group on Information Systems and Services (WGISS) Integrated Catalog (CWIC).

Gadolinium-enhanced inner ear magnetic resonance imaging for evaluation of delayed endolymphatic hydrops, including a bilateral case.

PubMed

Fukushima, Munehisa; Oya, Ryohei; Akazawa, Hitoshi; Tsuruta, Yukinori; Inohara, Hidenori

2016-01-01

The data suggests that gadolinium-enhanced inner ear MR imaging is useful for diagnosis of delayed endolymphatic hydrops (DEH) because it is independent of inner ear function, and the size of the affected endolymphatic space is clearly enlarged. This study was performed to semi-quantitatively evaluate the endolymphatic space in patients with all types of DEH using gadolinium-enhanced inner ear magnetic resonance (MR) imaging. Seven patients (age range = 21-77 years; five female, two male) with ipsilateral DEH (n = 5), contralateral DEH (n = 1), and bilateral DEH (n = 1). All patients underwent 3T MR imaging 4 h after intravenous injection of gadolinium. Software was used to determine the size of the endolymphatic space. Pure tone audiometry and caloric testing using an electronystagmogram were carried out. One side of the endolymphatic space was dominantly extended in patients with ipsilateral DEH, and both sides of the space were extended in patients with contralateral and bilateral DEH. In patients with ipsilateral DEH, the volume ratio of endolymph to vestibule was 2.5-4.3-times that in the unaffected ear. The volume ratio of endolymph to vestibule was nearly equal in patients with contralateral and bilateral DEH.

SWI enhances vein detection using gadolinium in multiple sclerosis

PubMed Central

Mazzoni, Lorenzo N; Moretti, Marco; Grammatico, Matteo; Chiti, Stefano; Massacesi, Luca

2015-01-01

Susceptibility weighted imaging (SWI) combined with the FLAIR sequence provides the ability to depict in vivo the perivenous location of inflammatory demyelinating lesions – one of the most specific pathologic features of multiple sclerosis (MS). In addition, in MS white matter (WM) lesions, gadolinium-based contrast media (CM) can increase vein signal loss on SWI. This report focuses on two cases of WM inflammatory lesions enhancing on SWI images after CM injection. In these lesions in fact the CM increased the contrast between the parenchyma and the central vein allowing as well, in one of the two cases, the detection of a vein not visible on the same SWI sequence acquired before CM injection. PMID:25815209

Differences in quantitative assessment of myocardial scar and gray zone by LGE-CMR imaging using established gray zone protocols.

PubMed

Mesubi, Olurotimi; Ego-Osuala, Kelechi; Jeudy, Jean; Purtilo, James; Synowski, Stephen; Abutaleb, Ameer; Niekoop, Michelle; Abdulghani, Mohammed; Asoglu, Ramazan; See, Vincent; Saliaris, Anastasios; Shorofsky, Stephen; Dickfeld, Timm

2015-02-01

Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging is the gold standard for myocardial scar evaluation. Heterogeneous areas of scar ('gray zone'), may serve as arrhythmogenic substrate. Various gray zone protocols have been correlated to clinical outcomes and ventricular tachycardia channels. This study assessed the quantitative differences in gray zone and scar core sizes as defined by previously validated signal intensity (SI) threshold algorithms. High quality LGE-CMR images performed in 41 cardiomyopathy patients [ischemic (33) or non-ischemic (8)] were analyzed using previously validated SI threshold methods [Full Width at Half Maximum (FWHM), n-standard deviation (NSD) and modified-FWHM]. Myocardial scar was defined as scar core and gray zone using SI thresholds based on these methods. Scar core, gray zone and total scar sizes were then computed and compared among these models. The median gray zone mass was 2-3 times larger with FWHM (15 g, IQR: 8-26 g) compared to NSD or modified-FWHM (5 g, IQR: 3-9 g; and 8 g. IQR: 6-12 g respectively, p < 0.001). Conversely, infarct core mass was 2.3 times larger with NSD (30 g, IQR: 17-53 g) versus FWHM and modified-FWHM (13 g, IQR: 7-23 g, p < 0.001). The gray zone extent (percentage of total scar that was gray zone) also varied significantly among the three methods, 51 % (IQR: 42-61 %), 17 % (IQR: 11-21 %) versus 38 % (IQR: 33-43 %) for FWHM, NSD and modified-FWHM respectively (p < 0.001). Considerable variability exists among the current methods for MRI defined gray zone and scar core. Infarct core and total myocardial scar mass also differ using these methods. Further evaluation of the most accurate quantification method is needed.

Intraoperative Near-Infrared Optical Imaging Can Localize Gadolinium-Enhancing Gliomas During Surgery

PubMed Central

Lee, John Y-K.; Thawani, Jayesh P.; Pierce, John; Zeh, Ryan; Martinez-Lage, Maria; Chanin, Michelle; Venegas, Ollin; Nims, Sarah; Learned, Kim; Keating, Jane; Singhal, Sunil

2016-01-01

Background Although real-time localization of gliomas has improved with intraoperative image guidance systems, these tools are limited by brain shift, surgical cavity deformation, and expense. Objective To propose a novel method to perform near-infrared (NIR) imaging during glioma resections based on preclinical and clinical investigations, in order to localize tumors and to potentially identify residual disease. Methods Fifteen patients were identified and administered an FDA-approved, NIR contrast agent (Second Window indocyanine green [ICG], 5 mg/kg) prior to surgical resection. An NIR camera was utilized to localize the tumor prior to resection and to visualize surgical margins following resection. Neuropathology and MR imaging data were used to assess the accuracy and precision of NIR-fluorescence in identifying tumor tissue. Results NIR visualization of 15 gliomas (10 glioblastoma multiforme, 1 anaplastic astrocytoma, 2 low grade astrocytoma, 1 juvenile pilocytic astrocytoma, and 1 ganglioglioma) was performed 22.7 hours (mean) after intravenous injection of ICG. During surgery, 12/15 tumors were visualized with the NIR camera. The mean signal-to-background ratio was 9.5 ± 0.8 and fluorescence was noted through the dura to a maximum parenchymal depth of 13 mm. The best predictor of positive fluorescence was enhancement on T1-weighted imaging; this correlated with SBR (P = .03). Non-enhancing tumors did not demonstrate NIR fluorescence. Using pathology as the gold standard, the technique demonstrated a sensitivity of 98% and specificity of 45% to identify tumor in gadolinium-enhancing specimens (n = 71). Conclusion Using Second Window ICG, gadolinium-enhancing tumors can be localized through brain parenchyma intraoperatively. Its utility for margin detection is promising but limited by lower specificity. PMID:27741220

Risk stratification for therapeutic management and prognosis.

PubMed

Coelho-Filho, Otavio R; Nallamshetty, Leelakrishna; Kwong, Raymond Y

2009-07-01

In coronary artery disease (CAD), cardiac magnetic resonance (CMR) imaging can integrate several types of pulse-sequence examinations (eg, myocardial perfusion, cine wall motion, T2-weighted imaging for myocardial edema, late gadolinium enhancement, and CMR angiography) that can provide anatomic, functional, and physiologic information about the heart in a single imaging session. Because of this ability to interrogate myocardial physiology using different pulse sequence techniques within a single CMR session, this technique has been recognized increasingly in many centers as the test of choice for assessing patients who present with cardiomyopathy of undetermined cause. This article first reviews the current evidence supporting the prognosticating role of CMR in assessing CAD and then discusses CMR applications and prognostication in many non-coronary cardiac conditions.

Gadolinium-free MR in coarctation-can contrast-enhanced MR angiography be replaced?

PubMed

Kalmar, Peter I; Koestenberger, Martin; Marterer, Robert; Tschauner, Sebastian; Sorantin, Erich

2016-01-01

To determine the difference in vessel measurements, signal-to-noise ratio (SNR), and voxel size between contrast-enhanced and noncontrast magnetic resonance techniques in patients with coarctation of the aorta (CoA). In 39 patients, vessel size, SNR, and voxel size were compared in cine magnetic resonance imaging (MRI), gadolinium-free magnetic resonance angiography (Gd-free MRA), and contrast-enhanced MRA (ce-MRA). There was no significant difference in measurement and SNR, but there was a significant difference in voxel size (P<.001). Our results show that, in CoA patients, monitoring of vessel size using cine MRI and Gd-free MRA is equivalent to ce-MRA while being less invasive. Copyright © 2016 Elsevier Inc. All rights reserved.

Novel cardiac magnetic resonance biomarkers: native T1 and extracellular volume myocardial mapping.

PubMed

Cannaò, Paola Maria; Altabella, Luisa; Petrini, Marcello; Alì, Marco; Secchi, Francesco; Sardanelli, Francesco

2016-04-28

Cardiac magnetic resonance (CMR) is a non-invasive diagnostic tool playing a key role in the assessment of cardiac morphology and function as well as in tissue characterization. Late gadolinium enhancement is a fundamental CMR technique for detecting focal or regional abnormalities such as scar tissue, replacement fibrosis, or inflammation using qualitative, semi-quantitative, or quantitative methods, but not allowing for evaluating the whole myocardium in the presence of diffuse disease. The novel T1 mapping approach permits a quantitative assessment of the entire myocardium providing a voxel-by-voxel map of native T1 relaxation time, obtained before the intravenous administration of gadolinium-based contrast material. Combining T1 data obtained before and after contrast injection, it is also possible to calculate the voxel-by-voxel extracellular volume (ECV), resulting in another myocardial parametric map. This article describes technical challenges and clinical perspectives of these two novel CMR biomarkers: myocardial native T1 and ECV mapping.

Crystallization and preliminary X-ray diffraction analysis of the CRISPR-Cas RNA-silencing Cmr complex.

PubMed

Osawa, Takuo; Inanaga, Hideko; Numata, Tomoyuki

2015-06-01

Clustered regularly interspaced short palindromic repeat (CRISPR)-derived RNA (crRNA) and CRISPR-associated (Cas) proteins constitute a prokaryotic adaptive immune system (CRISPR-Cas system) that targets and degrades invading genetic elements. The type III-B CRISPR-Cas Cmr complex, composed of the six Cas proteins (Cmr1-Cmr6) and a crRNA, captures and cleaves RNA complementary to the crRNA guide sequence. Here, a Cmr1-deficient functional Cmr (CmrΔ1) complex composed of Pyrococcus furiosus Cmr2-Cmr3, Archaeoglobus fulgidus Cmr4-Cmr5-Cmr6 and the 39-mer P. furiosus 7.01-crRNA was prepared. The CmrΔ1 complex was cocrystallized with single-stranded DNA (ssDNA) complementary to the crRNA guide by the vapour-diffusion method. The crystals diffracted to 2.1 Å resolution using synchrotron radiation at the Photon Factory. The crystals belonged to the triclinic space group P1, with unit-cell parameters a = 75.5, b = 76.2, c = 139.2 Å, α = 90.3, β = 104.8, γ = 118.6°. The asymmetric unit of the crystals is expected to contain one CmrΔ1-ssDNA complex, with a Matthews coefficient of 2.03 Å(3) Da(-1) and a solvent content of 39.5%.

Gadolinium Enhanced MR Coronary Vessel Wall Imaging at 3.0 Tesla.

PubMed

Kelle, Sebastian; Schlendorf, Kelly; Hirsch, Glenn A; Gerstenblith, Gary; Fleck, Eckart; Weiss, Robert G; Stuber, Matthias

2010-10-11

Purpose. We evaluated the influence of the time between low-dose gadolinium (Gd) contrast administration and coronary vessel wall enhancement (LGE) detected by 3T magnetic resonance imaging (MRI) in healthy subjects and patients with coronary artery disease (CAD). Materials and Methods. Four healthy subjects (4 men, mean age 29 ± 3 years and eleven CAD patients (6 women, mean age 61 ± 10 years) were studied on a commercial 3.0 Tesla (T) whole-body MR imaging system (Achieva 3.0 T; Philips, Best, The Netherlands). T1-weighted inversion-recovery coronary magnetic resonance imaging (MRI) was repeated up to 75 minutes after administration of low-dose Gadolinium (Gd) (0.1 mmol/kg Gd-DTPA). Results. LGE was seen in none of the healthy subjects, however in all of the CAD patients. In CAD patients, fifty-six of 62 (90.3%) segments showed LGE of the coronary artery vessel wall at time-interval 1 after contrast. At time-interval 2, 34 of 42 (81.0%) and at time-interval 3, 29 of 39 evaluable segments (74.4%) were enhanced. Conclusion. In this work, we demonstrate LGE of the coronary artery vessel wall using 3.0 T MRI after a single, low-dose Gd contrast injection in CAD patients but not in healthy subjects. In the majority of the evaluated coronary segments in CAD patients, LGE of the coronary vessel wall was already detectable 30-45 minutes after administration of the contrast agent.

Liver acquisition with acceleration volume acquisition gadolinium-enhanced magnetic resonance combined with T2 sequences in the diagnosis of local recurrence of rectal cancer.

PubMed

Cao, Wuteng; Li, Fangqian; Gong, Jiaying; Liu, Dechao; Deng, Yanhong; Kang, Liang; Zhou, Zhiyang

2016-11-22

To investigate the efficacy of liver acquisition with acceleration volume acquisition (LAVA) gadolinium-enhanced magnetic resonance (MR) sequences and to assess its added accuracy in diagnosing local recurrence (LR) of rectal cancer with conventional T2-weighted fast spin echo (FSE) sequences. Pelvic MRI, including T2-weighted FSE sequences, gadolinium-enhanced sequences of LAVA and T1-weighted FSE with fat suppression, was performed on 225 patients with postoperative rectal cancer. Two readers evaluated the presence of LR according to "T2" (T2 sequences only), "T2 + LAVA-Gad" (LAVA and T2 imaging), and "T2 + T1-fs-Gad" (T1 fat suppression-enhanced sequence with T2 images). To evaluate diagnostic efficiency, imaging quality with LAVA and T1-fs-Gad by subjective scores and the signal intensity (SI) ratio. In the result, the SI ratio of LAVA was significantly higher than that of T1-fs-Gad (p = 0.0001). The diagnostic efficiency of "T2 + LAVA-Gad" was better than that of "T2 + T1-fs-Gad" (p = 0.0016 for Reader 1, p = 0.0001 for Reader 2) and T2 imaging only (p = 0.0001 for Reader 1; p = 0.0001 for Reader 2). Therefore, LAVA gadolinium-enhanced MR increases the accuracy of diagnosis of LR from rectal cancer and could replace conventional T1 gadolinium-enhanced sequences in the postoperative pelvic follow-up of rectal cancer.

Investigation of suspected Guillain-Barre syndrome in childhood: what is the role for gadolinium enhanced magnetic resonance imaging of the spine?

PubMed

Smith, Nicholas; Pereira, John; Grattan-Smith, Padraic

2014-10-01

To review the role of gadolinium-enhanced magnetic resonance imaging of the spine in the diagnosis of paediatric Guillain-Barre syndrome and compare it with nerve conduction studies and cerebrospinal fluid analysis. A retrospective review of investigations undertaken in children admitted to our institution with acute Guillain-Barre syndrome over a 10-year period was performed. Seven of eight children (88%) displayed post-gadolinium nerve root enhancement consistent with Guillain-Barre syndrome. This compared with supportive nerve conduction studies in 21/24 children (88%) and cerebrospinal fluid protein analysis consistent with the diagnosis in 16/20 children (80%). Nerve conduction studies are the recognised 'gold standard' technique for confirming a clinical diagnosis of Guillain-Barre syndrome. In this study, a high positive rate was demonstrated. While more experience is necessary, this study and the literature support gadolinium enhanced magnetic resonance imaging of the spine as a valuable, although not necessarily superior, investigation in the diagnosis of Guillain-Barre syndrome. It may be of particular benefit when specialist neurophysiology expertise is unavailable. © 2010 The Authors. Journal compilation © 2010 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

Localized Spatio-Temporal Constraints for Accelerated CMR Perfusion

PubMed Central

Akçakaya, Mehmet; Basha, Tamer A.; Pflugi, Silvio; Foppa, Murilo; Kissinger, Kraig V.; Hauser, Thomas H.; Nezafat, Reza

2013-01-01

Purpose To develop and evaluate an image reconstruction technique for cardiac MRI (CMR)perfusion that utilizes localized spatio-temporal constraints. Methods CMR perfusion plays an important role in detecting myocardial ischemia in patients with coronary artery disease. Breath-hold k-t based image acceleration techniques are typically used in CMR perfusion for superior spatial/temporal resolution, and improved coverage. In this study, we propose a novel compressed sensing based image reconstruction technique for CMR perfusion, with applicability to free-breathing examinations. This technique uses local spatio-temporal constraints by regularizing image patches across a small number of dynamics. The technique is compared to conventional dynamic-by-dynamic reconstruction, and sparsity regularization using a temporal principal-component (pc) basis, as well as zerofilled data in multi-slice 2D and 3D CMR perfusion. Qualitative image scores are used (1=poor, 4=excellent) to evaluate the technique in 3D perfusion in 10 patients and 5 healthy subjects. On 4 healthy subjects, the proposed technique was also compared to a breath-hold multi-slice 2D acquisition with parallel imaging in terms of signal intensity curves. Results The proposed technique results in images that are superior in terms of spatial and temporal blurring compared to the other techniques, even in free-breathing datasets. The image scores indicate a significant improvement compared to other techniques in 3D perfusion (2.8±0.5 vs. 2.3±0.5 for x-pc regularization, 1.7±0.5 for dynamic-by-dynamic, 1.1±0.2 for zerofilled). Signal intensity curves indicate similar dynamics of uptake between the proposed method with a 3D acquisition and the breath-hold multi-slice 2D acquisition with parallel imaging. Conclusion The proposed reconstruction utilizes sparsity regularization based on localized information in both spatial and temporal domains for highly-accelerated CMR perfusion with potential utility in free

Diagnostic and prognostic value of cardiovascular magnetic resonance in non-ischaemic cardiomyopathies

PubMed Central

2012-01-01

Cardiovascular Magnetic Resonance (CMR) is recognised as a valuable clinical tool which in a single scan setting can assess ventricular volumes and function, myocardial fibrosis, iron loading, flow quantification, tissue characterisation and myocardial perfusion imaging. The advent of CMR using extrinsic and intrinsic contrast-enhanced protocols for tissue characterisation have dramatically changed the non-invasive work-up of patients with suspected or known cardiomyopathy. Although the technique initially focused on the in vivo identification of myocardial necrosis through the late gadolinium enhancement (LGE) technique, recent work highlighted the ability of CMR to provide more detailed in vivo tissue characterisation to help establish a differential diagnosis of the underlying aetiology, to exclude an ischaemic substrate and to provide important prognostic markers. The potential application of CMR in the clinical approach of a patient with suspected non-ischaemic cardiomyopathy is discussed in this review. PMID:22857649

Structure of the Cmr2 Subunit of the CRISPR-Cas RNA Silencing Complex

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cocozaki, Alexis I.; Ramia, Nancy F.; Shao, Yaming

Cmr2 is the largest and an essential subunit of a CRISPR RNA-Cas protein complex (the Cmr complex) that cleaves foreign RNA to protect prokaryotes from invading genetic elements. Cmr2 is thought to be the catalytic subunit of the effector complex because of its N-terminal HD nuclease domain. Here, however, we report that the HD domain of Cmr2 is not required for cleavage by the complex in vitro. The 2.3 {angstrom} crystal structure of Pyrococcus furiosus Cmr2 (lacking the HD domain) reveals two adenylyl cyclase-like and two {alpha}-helical domains. The adenylyl cyclase-like domains are arranged as in homodimeric adenylyl cyclases andmore » bind ADP and divalent metals. However, mutagenesis studies show that the metal- and ADP-coordinating residues of Cmr2 are also not critical for cleavage by the complex. Our findings suggest that another component provides the catalytic function and that the essential role by Cmr2 does not require the identified ADP- or metal-binding or HD domains in vitro.« less

Gadolinium accumulation in organs of Sprague-Dawley® rats after implantation of a biodegradable magnesium-gadolinium alloy.

PubMed

Myrissa, Anastasia; Braeuer, Simone; Martinelli, Elisabeth; Willumeit-Römer, Regine; Goessler, Walter; Weinberg, Annelie Martina

2017-01-15

Biodegradable magnesium implants are under investigation because of their promising properties as medical devices. For enhancing the mechanical properties and the degradation resistance, rare earth elements are often used as alloying elements. In this study Mg10Gd pins were implanted into Sprague-Dawley® rats. The pin volume loss and a possible accumulation of magnesium and gadolinium in the rats' organs and blood were investigated in a long-term study over 36weeks. The results showed that Mg10Gd is a fast disintegrating material. Already 12weeks after implantation the alloy is fragmented to smaller particles, which can be found within the intramedullary cavity and the cortical bones. They disturbed the bone remodeling until the end of the study. The results concerning the elements' distribution in the animals' bodies were even more striking, since an accumulation of gadolinium could be observed in the investigated organs over the whole time span. The most affected tissue was the spleen, with up to 3240μgGd/kg wet mass, followed by the lung, liver and kidney (up to 1040, 685 and 207μgGd/kg). In the brain, muscle and heart, the gadolinium concentrations were much smaller (less than 20μg/kg), but an accumulation could still be detected. Interestingly, blood serum samples showed no accumulation of magnesium and gadolinium. This is the first time that an accumulation of gadolinium in animal organs was observed after the application of a gadolinium-containing degradable magnesium implant. These findings demonstrate the importance of future investigations concerning the distribution of the constituents of new biodegradable materials in the body, to ensure the patients' safety. In the last years, biodegradable Mg alloys are under investigation due to their promising properties as orthopaedic devices used for bone fracture stabilization. Gadolinium as Rare Earth Element enhances the mechanical properties of Mg-Gd alloys but its toxicity in humans is still questionable

Bi-atrial fibrosis detected using three-dimensional late gadolinium enhancement magnetic resonance imaging in a patient with cardiac sarcoidosis.

PubMed

Spence, Stewart; Pena, Elena; Thornhill, Rebecca E; Nery, Pablo B; Birnie, David H

2018-05-01

Presented is the case of a 62-year old male with a history of sarcoidosis and sinus node dysfunction, who underwent late gadolinium enhancement magnetic resonance imaging, which demonstrated left ventricular hyperenhancement and bi-atrial fibrosis.

Cardio-hepatic risk assessment by CMR imaging in liver transplant candidates.

PubMed

Reddy, Sahadev T; Thai, Ngoc L; Oliva, Jose; Tom, Kusum B; Dishart, Michael K; Doyle, Mark; Yamrozik, June A; Williams, Ronald B; Shah, Moneal; Wani, Adil; Singh, Anil; Maheswary, Rishi; Biederman, Robert W W

2018-03-02

The preoperative workup of orthotopic liver transplantation (OLT) patients is practically complex given the need for multiple imaging modalities. We recently demonstrated in our proof-of-concept study the value of a one-stop-shop approach using cardiovascular MRI (CMR) to address this complex problem. However, this approach requires further validation in a larger cohort, as detection of hepatocellular carcinoma (HCC) as well as cardiovascular risk assessment is critically important in these patients. We hypothesized that coronary risk assessment and HCC detectability is acceptable using the one-stop-shop CMR approach. In this observational study, patients underwent CMRI evaluation including cardiac function, stress CMR, thoracoabdominal MRA, and abdominal MRI on a standard MRI scanner in one examination. Over 8 years, 252 OLT candidates underwent evaluation in the cardiac MRI suit. The completion rates for each segment of the CMR examination were 99% for function, 95% completed stress CMR, 93% completed LGE for viability, 85% for liver MRI, and 87% for MRA. A negative CMR stress examination had 100% CAD event-free survival at 12 months. A total of 63 (29%) patients proceeded to OLT. Explant pathology confirmed detection/exclusion of HCC. This study further defines the population suitable for the one-stop-shop CMR concept for preop evaluation of OLT candidates providing a road map for integrated testing in this complex patient population for evaluation of cardiac risk and detection of HCC lesions. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Utility of late gadolinium enhancement in pediatric cardiac MRI.

PubMed

Etesami, Maryam; Gilkeson, Robert C; Rajiah, Prabhakar

2016-07-01

Late gadolinium enhancement (LGE) cardiac magnetic resonance (MR) imaging sequence is increasingly used in the evaluation of pediatric cardiovascular disorders, and although LGE might be a normal feature at the sites of previous surgeries, it is pathologically seen as a result of extracellular space expansion, either from acute cell damage or chronic scarring or fibrosis. LGE is broadly divided into ischemic and non-ischemic patterns. LGE caused by myocardial infarction occurs in a vascular distribution and always involves the subendocardial portion, progressively involving the outer regions in a waveform pattern. Non-ischemic cardiomyopathies can have a mid-myocardial (either linear or patchy), subepicardial or diffuse subendocardial distribution. Idiopathic dilated cardiomyopathy can have a linear mid-myocardial pattern, while hypertrophic cardiomyopathy can have fine, patchy enhancement in hypertrophied and non-hypertrophied segments as well as right ventricular insertion points. Myocarditis and sarcoidosis have a mid-myocardial or subepicardial pattern of LGE. Fabry disease typically affects the basal inferolateral segment while Danon disease typically spares the septum. Pericarditis is characterized by diffuse or focal pericardial thickening and enhancement. Thrombus, the most common non-neoplastic cardiac mass, is characterized by absence of enhancement in all sequences, while neoplastic masses show at least some contrast enhancement, depending on the pathology. Regardless of the etiology, presence of LGE is associated with a poor prognosis. In this review, we describe the technical modifications required for performing LGE cardiac MR sequence in children, review and illustrate the patterns of LGE in children, and discuss their clinical significance.

[Diagnostic performance of surface electrocardiogram in early detection of chagasic cardiomyopathy].

PubMed

Bochard-Villanueva, Bruno; Estornell-Erill, Jordi; Fabregat-Andrés, Óscar; García-González, Pilar; Morell-Cabedo, Salvador; Ridocci-Soriano, Francisco

2015-03-15

Contrast-enhanced cardiac magnetic resonance imaging (CMR) allows early detection of myocardial involvement by Trypanosoma cruzi infection. The aim of our study was to assess the diagnostic performance of the surface electrocardiogram (ECG) in the early detection of Chagas' cardiomyopathy (CCM) compared with CMR. We included 43 asymptomatic patients (30 women, 42 ± 9.8 years), diagnosed of Chagas disease. The sample was divided into 2 groups according to the presence (n=17) or absence (n=26) of electrocardiographic abnormalities. All patients underwent CMR and late gadolinium enhancement (LGE) was used as a marker of early myocardial involvement. Six (14%) patients had a LGE significantly higher in the group who had electrocardiographic abnormalities (29 vs. 4%, P<.05). With CMR as the method of reference, the ECG had a sensitivity of 83% and a negative predictive value of 96% to detect CCM. ECG is a useful, inexpensive and globally available tool for the screening of CCM in asymptomatic patients but with proven myocardial involvement in CMR. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

Gadolinium toxicity and treatment.

PubMed

Ramalho, Joana; Ramalho, Miguel; Jay, Michael; Burke, Lauren M; Semelka, Richard C

2016-12-01

Gadolinium based contrast agents (GBCAs) play an important role in the diagnostic evaluation of many patients. The safety of these agents has been once again questioned after gadolinium deposits were observed and measured in brain and bone of patients with normal renal function. This retention of gadolinium in the human body has been termed "gadolinium storage condition". The long-term and cumulative effects of retained gadolinium in the brain and elsewhere are not as yet understood. Recently, patients who report that they suffer from chronic symptoms secondary to gadolinium exposure and retention created gadolinium-toxicity on-line support groups. Their self-reported symptoms have recently been published. Bone and joint complaints, and skin changes were two of the most common complaints. This condition has been termed "gadolinium deposition disease". In this review we will address gadolinium toxicity disorders, from acute adverse reactions to GBCAs to gadolinium deposition disease, with special emphasis on the latter, as it is the most recently described and least known. Copyright © 2016 Elsevier Inc. All rights reserved.

Resolution of abnormal cardiac MRI T2 signal following immune suppression for cardiac sarcoidosis.

PubMed

Crouser, Elliott D; Ruden, Emily; Julian, Mark W; Raman, Subha V

2016-08-01

Cardiac MR (CMR) with late gadolinium enhancement is commonly used to detect cardiac damage in the setting of cardiac sarcoidosis. The addition of T2 mapping to CMR was recently shown to enhance cardiac sarcoidosis detection and correlates with increased cardiac arrhythmia risk. This study was conducted to determine if CMR T2 abnormalities and related arrhythmias are reversible following immune suppression therapy. A retrospective study of subjects with cardiac sarcoidosis with abnormal T2 signal on baseline CMR and a follow-up CMR study at least 4 months later was conducted at The Ohio State University from 2011 to 2015. Immune suppression treated participants had a significant reduction in peak myocardial T2 value (70.0±5.5 vs 59.2±6.1 ms, pretreatment vs post-treatment; p=0.017), and 83% of immune suppression treated subjects had objective improvement in cardiac arrhythmias. Two subjects who had received inadequate immune suppression treatment experienced progression of cardiac sarcoidosis. This report indicates that abnormal CMR T2 signal represents an acute inflammatory manifestation of cardiac sarcoidosis that is potentially reversible with adequate immune suppression therapy. Copyright © 2016 American Federation for Medical Research.

Exploratory use of cardiovascular magnetic resonance imaging in liver transplantation: a one-stop shop for preoperative cardiohepatic evaluation.

PubMed

Reddy, Sahadev T; Thai, Ngoc L; Fakhri, Asghar A; Oliva, Jose; Tom, Kusum B; Dishart, Michael K; Doyle, Mark; Yamrozik, June A; Williams, Ronald B; Grant, Saundra B; Poydence, Jacqueline; Shah, Moneal; Singh, Anil; Nathan, Swami; Biederman, Robert W W

2013-11-15

Preoperative cardiovascular risk stratification in orthotopic liver transplantation candidates has proven challenging due to limitations of current noninvasive modalities. Additionally, the preoperative workup is logistically cumbersome and expensive given the need for separate cardiac, vascular, and abdominal imaging. We evaluated the feasibility of a "one-stop shop" in a magnetic resonance suite, performing assessment of cardiac structure, function, and viability, along with simultaneous evaluation of thoracoabdominal vasculature and liver anatomy. In this pilot study, patients underwent steady-state free precession sequences and stress cardiac magnetic resonance (CMR), thoracoabdominal magnetic resonance angiography, and abdominal magnetic resonance imaging (MRI) on a standard MRI scanner. Pharmacologic stress was performed using regadenoson, adenosine, or dobutamine. Viability was assessed using late gadolinium enhancement. Over 2 years, 51 of 77 liver transplant candidates (mean age, 56 years; 35% female; mean Model for End-stage Liver Disease score, 10.8; range, 6-40) underwent MRI. All referred patients completed standard dynamic CMR, 98% completed stress CMR, 82% completed late gadolinium enhancement for viability, 94% completed liver MRI, and 88% completed magnetic resonance angiography. The mean duration of the entire study was 72 min, and 45 patients were able to complete the entire examination. Among all 51 patients, 4 required follow-up coronary angiography (3 for evidence of ischemia on perfusion CMR and 1 for postoperative ischemia), and none had flow-limiting coronary disease. Nine proceeded to orthotopic liver transplantation (mean 74 days to transplantation after MRI). There were six ascertained mortalities in the nontransplant group and one death in the transplanted group. Explant pathology confirmed 100% detection/exclusion of hepatocellular carcinoma. No complications during CMR examination were encountered. In this proof-of-concept study, it

Gadolinium-enhanced MR images of the growing piglet skeleton: ionic versus nonionic contrast agent.

PubMed

Menezes, Nina M; Olear, Elizabeth A; Li, Xiaoming; Connolly, Susan A; Zurakowski, David; Foley, Mary; Shapiro, Frederic; Jaramillo, Diego

2006-05-01

To determine whether there are differences in the distribution of ionic and nonionic gadolinium-based contrast agents by evaluating contrast enhancement of the physis, epiphyseal cartilage, secondary ossification center, and metaphysis in the knees of normal piglets. Following approval from the Subcommittee on Research Animal Care, knees of 12 3-week-old piglets were imaged at 3-T magnetic resonance (MR) imaging after intravenous injection of gadoteridol (nonionic contrast agent; n = 6) or gadopentetate dimeglumine (ionic contrast agent; n = 6). Early enhancement evaluation with gradient-echo MR imaging was quantified and compared (Student t test) by means of enhancement ratios. Distribution of contrast material was assessed and compared (Student t test) by means of T1 measurements obtained before and at three 15-minute intervals after contrast agent administration. The relative visibility of the physis, epiphyseal cartilage, secondary ossification center, and metaphysis was qualitatively assessed by two observers and compared (Wilcoxon signed rank test). Differences in matrix content and cellularity that might explain the imaging findings were studied at histologic evaluation. Enhancement ratios were significantly higher for gadoteridol than for gadopentetate dimeglumine in the physis, epiphyseal cartilage, and secondary ossification center (P < .05). After contrast agent administration, T1 values decreased sharply for both agents-but more so for gadoteridol. Additionally, there was less variability in T1 values across structures with this contrast agent. Gadoteridol resulted in greater visibility of the physis, while gadopentetate dimeglumine resulted in greater contrast between the physis and metaphysis (P < .05). The results suggest different roles for the two gadolinium-based contrast agents: The nonionic contrast medium is better suited for evaluating perfusion and anatomic definition in the immature skeleton, while the ionic contrast medium is better for

Varied exposure to carcinogenic, mutagenic, and reprotoxic (CMR) chemicals in occupational settings in France.

PubMed

Havet, Nathalie; Penot, Alexis; Morelle, Magali; Perrier, Lionel; Charbotel, Barbara; Fervers, Béatrice

2017-02-01

To explore varied exposure to carcinogenic, mutagenic, and reprotoxic chemicals (CMR) for French employees. Our study assessed data from the French national cross-sectional survey of occupational risks (SUMER) that was conducted in 2010 in a national representative sample of employees. We selected 28 CMR agents that were classified by the International Agency for Research on Cancer or European Union as being known or presumed to have CMR potential in humans. The association of individual and job characteristics with exposure prevalence, duration, and intensity of the CMR agents during a 1-week period was examined using multilevel logistic regression analysis. Overall, 10.4% of employees in 2010 were exposed to one or more CMR agents at their workplace, and 3.4% were subjected to multiple CMR exposures. Blue-collar workers, night-shift workers and workers with short-term employment contracts experienced higher exposure prevalence (p < 0.01) and intensity (p < 0.05). Blue-collar workers and shift workers experienced also longer exposure duration (p < 0.001). Conversely, managers, workers of large companies, and women were less exposed to CMR agents (p < 0.001). The presence of a Committee for Health, Safety, and Working Conditions, and intervention by Occupational Health and Safety officers were significantly associated with reduced exposure intensities (p < 0.001 and p < 0.05). Establishment of European CMR regulations and the existence of an applicable substitution principle reduced the exposure duration (p < 0.001) and intensity (p < 0.05). Our results point out disparities in CMR exposure and identify high-priority targets for prevention measures to help reducing social health discrepancies.

Usefulness of the advanced neuroimaging protocol based on plain and gadolinium-enhanced constructive interference in steady state images for gamma knife radiosurgery and planning microsurgical procedures for skull base tumors.

PubMed

Hayashi, Motohiro; Chernov, Mikhail F; Tamura, Noriko; Yomo, Shoji; Tamura, Manabu; Horiba, Ayako; Izawa, Masahiro; Muragaki, Yoshihiro; Iseki, Hiroshi; Okada, Yoshikazu; Ivanov, Pavel; Régis, Jean; Takakura, Kintomo

2013-01-01

Gamma Knife radiosurgery (GKS) is currently performed with 0.1 mm preciseness, which can be designated microradiosurgery. It requires advanced methods for visualizing the target, which can be effectively attained by a neuroimaging protocol based on plain and gadolinium-enhanced constructive interference in steady state (CISS) images. Since 2003, the following thin-sliced images are routinely obtained before GKS of skull base lesions in our practice: axial CISS, gadolinium-enhanced axial CISS, gadolinium-enhanced axial modified time-of-flight (TOF), and axial computed tomography (CT). Fusion of "bone window" CT and magnetic resonance imaging (MRI), and detailed three-dimensional (3D) delineation of the anatomical structures are performed with the Leksell GammaPlan (Elekta Instruments AB). Recently, a similar technique has been also applied to evaluate neuroanatomy before open microsurgical procedures. Plain CISS images permit clear visualization of the cranial nerves in the subarachnoid space. Gadolinium-enhanced CISS images make the tumor "lucid" but do not affect the signal intensity of the cranial nerves, so they can be clearly delineated in the vicinity to the lesion. Gadolinium-enhanced TOF images are useful for 3D evaluation of the interrelations between the neoplasm and adjacent vessels. Fusion of "bone window" CT and MRI scans permits simultaneous assessment of both soft tissue and bone structures and allows 3D estimation and correction of MRI distortion artifacts. Detailed understanding of the neuroanatomy based on application of the advanced neuroimaging protocol permits performance of highly conformal and selective radiosurgical treatment. It also allows precise planning of the microsurgical procedures for skull base tumors.

Normal spinal bone marrow in adults: dynamic gadolinium-enhanced MR imaging.

PubMed

Montazel, Jean-Luc; Divine, Marine; Lepage, Eric; Kobeiter, Hicham; Breil, Stephane; Rahmouni, Alain

2003-12-01

To determine the patterns of dynamic enhancement of normal spinal bone marrow in adults at gadolinium-enhanced magnetic resonance (MR) imaging and the changes that occur with aging. Dynamic contrast material-enhanced MR imaging of the thoracolumbar spine was performed in 71 patients. The maximum percentage of enhancement (Emax), enhancement slope, and enhancement washout were determined from bone marrow enhancement time curves (ETCs). The bone marrow signal intensity on T1-weighted spin-echo MR images was qualitatively classified into three grade categories. Quantitative ETC values were correlated with patient age and bone marrow fat content grade. Statistical analysis included mean t test comparison, analysis of variance, and regression analysis of the correlations between age and quantitative MR parameters. Emax, slope, and washout varied widely among the patients. Emax values were obtained within 1 minute after contrast material injection and ranged from 0% to 430%. Emax values were significantly higher in patients younger than 40 years than in those aged 40 years or older (P <.001). These values decreased with increasing age in a logarithmic relationship (r = 0.71). Emax values decreased as fat content increased, but some overlap among the fat content grades was noted. Analysis of variance revealed that Emax was significantly related to age (younger than 40 years vs 40 years or older) (P <.001) and fat content grade (P <.001) but not significantly related to sex. Dynamic contrast-enhanced MR imaging patterns of normal spinal bone marrow are dependent mainly on patient age and fat content.

Myocardial oedema as the sole marker of acute injury in Takotsubo cardiomyopathy: a cardiovascular magnetic resonance (CMR) study.

PubMed

Iacucci, Ilaria; Carbone, Iacopo; Cannavale, Giuseppe; Conti, Bettina; Iampieri, Ilaria; Rosati, Riccardo; Sardella, Gennaro; Frustaci, Andrea; Fedele, Francesco; Catalano, Carlo; Francone, Marco

2013-12-01

The main hallmark of Takotsubo cardiomyopathy (TT-CMP) is transient ischaemia, with completely reversible regional contractile dysfunction, which involves the mid-apical segments and shows no angiographic signs of coronary artery disease (CAD). The acute and reversible myocardial injury suggests that tissue oedema may be an important marker of disease. Seventeen patients with a clinical and angiographic diagnosis of TT-CMP underwent cardiovascular magnetic resonance (CMR) imaging in the acute phase and at follow-up after 4 months. A standard acquisition protocol including turbo spin echo (TSE) T2-weighted short-tau inversion-recovery (T2 STIR), steady-state free-precession cine (SSFP cine) and lateenhancement (LE) imaging after gadolinium benzyloxypropionic tetraacetic acid (Gd-BOPTA) administration was performed. All images were analysed, and data on oedema and LE were correlated with regional dysfunction and histological findings from endomyocardial biopsy (EMB) where available. In all patients, T2 STIR images showed a diffuse homogeneous hyperintensity that extended to all mid-apical segments and perfectly matched the area of regional dysfunction, reflecting tissue oedema. In the five patients who underwent EMB, histology confirmed the massive interstitial oedema associated with typical contraction-band necrosis. No cases of LE were observed. At follow-up, complete regression of oedema was observed in all cases, with significant recovery of regional and global left ventricular (LV) function (ejection fraction from 48.7% to 59.8%). Myocardial oedema on CMR is a characteristic feature of acute TT-CMP, which reflects acute inflammation and acute myocardial injury. It could therefore be used as a specific marker of disease severity.

Synthesis and evaluation of gadolinium complexes based on PAMAM as MRI contrast agents.

PubMed

Yan, Guo-Ping; Hu, Bin; Liu, Mai-Li; Li, Li-Yun

2005-03-01

Diethylenetriaminepentaacetic acid (DTPA) and pyridoxamine (PM) were incorporated into the amine groups on the surface of ammonia-core poly(amidoamine) dendrimers (PAMAM, Generation 2.0-5.0) to obtain dendritic ligands. These dendritic ligands were reacted with gadolinium chloride to yield the corresponding dendritic gadolinium (Gd) complexes. The dendritic ligands and their gadolinium complexes were characterized by(1)HNMR, IR, UV and elemental analysis. Relaxivity studies showed that the dendritic gadolinium complexes possessed higher relaxation effectiveness compared with the clinically used Gd-DTPA. After administration of the dendritic gadolinium complexes (0.09 mmol kg(-1) ) to rats, magnetic resonance imaging of the liver indicated that the dendritic gadolinium complexes containing pyridoxamine groups enhanced the contrast of the MR images of the liver, provided prolonged intravascular duration and produced highly contrasted visualization of blood vessels.

Novel Approach for In Vivo Detection of Vulnerable Coronary Plaques using Molecular 3-T CMR Imaging with an Albumin-Binding Probe.

PubMed

Engel, Leif-Christopher; Landmesser, Ulf; Gigengack, Kevin; Wurster, Thomas; Manes, Constantina; Girke, Georg; Jaguszewski, Milosz; Skurk, Carsten; Leistner, David M; Lauten, Alexander; Schuster, Andreas; Hamm, Bernd; Botnar, Rene M; Makowski, Marcus R; Bigalke, Boris

2018-01-12

This study sought to investigate the potential of the noninvasive albumin-binding probe gadofosveset-enhanced cardiac magnetic resonance (GE-CMR) for detection of coronary plaques that can cause acute coronary syndromes (ACS). ACS are frequently caused by rupture or erosion of coronary plaques that initially do not cause hemodynamically significant stenosis and are therefore not detected by invasive x-ray coronary angiography (XCA). A total of 25 patients with ACS or symptoms of stable coronary artery disease underwent GE-CMR, clinically indicated XCA, and optical coherence tomography (OCT) within 24 h. GE-CMR was performed approximately 24 h following a 1-time application of gadofosveset-trisodium. Contrast-to-noise ratio (CNR) was quantified within coronary segments in comparison with blood signal. A total of 207 coronary segments were analyzed on GE-CMR. Segments containing a culprit lesion in ACS patients (n = 11) showed significant higher signal enhancement (CNR) following gadofosveset-trisodium application than segments without culprit lesions (n = 196; 6.1 [3.9 to 16.5] vs. 2.1 [0.5 to 3.5]; p < 0.001). GE-CMR was able to correctly identify culprit coronary lesions in 9 of 11 segments (sensitivity 82%) and correctly excluded culprit coronary lesions in 162 of 195 segments (specificity 83%). Additionally, segmented areas of thin-cap fibroatheroma (n = 22) as seen on OCT demonstrated significantly higher CNR than segments without coronary plaque or segments containing early atherosclerotic lesions (n = 185; 9.2 [3.3 to 13.7] vs. 2.1 [0.5 to 3.4]; p = 0.001). In this study, we demonstrated for the first time the noninvasive detection of culprit coronary lesions and thin-cap fibroatheroma of the coronary arteries in vivo by using GE-CMR. This method may represent a novel approach for noninvasive cardiovascular risk prediction. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Porphyrin-containing polyaspartamide gadolinium complexes as potential magnetic resonance imaging contrast agents.

PubMed

Yan, Guo-Ping; Li, Zhen; Xu, Wei; Zhou, Cheng-Kai; Yang, Lian; Zhang, Qiao; Li, Liang; Liu, Fan; Han, Lin; Ge, Yuan-Xing; Guo, Jun-Fang

2011-04-04

Porphyrin-containing polyaspartamide ligands (APTSPP-PHEA-DTPA) were synthesized by the incorporation of diethylenetriaminepentaacetic acid (DTPA) and 5-(4'-aminophenyl)-10,15,20-tris(4'-sulfonatophenyl) porphyrin, trisodium salt (APTSPP) into poly-α,β-[N-(2-hydroxyethyl)-l-aspartamide] (PHEA). These ligands were further reacted with gadolinium chloride to produce macromolecule-gadolinium complexes (APTSPP-PHEA-DTPA-Gd). Experimental data of (1)H NMR, IR, UV and elemental analysis evidenced the formation of the polyaspartamide ligands and gadolinium complexes. In vitro and in vivo property tests indicated that APTSPP-PHEA-DTPA-Gd possessed noticeably higher relaxation effectiveness, less toxicity to HeLa cells, and significantly higher enhanced signal intensities (SI) of the VX2 carcinoma in rabbits with lower injection dose requirement than that of Gd-DTPA. Moreover, APTSPP-PHEA-DTPA-Gd was found to greatly enhance the contrast of MR images of the VX2 carcinoma, providing prolonged intravascular duration, and distinguished the VX2 carcinoma and normal tissues in rabbits according to MR image signal enhancements. These porphyrin-containing polyaspartamide gadolinium complexes can be used as the candidates of contrast agents for targeted MRI to tumors. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Gadolinium diethylenetriaminopentaacetic acid-loaded chitosan microspheres for gadolinium neutron-capture therapy.

PubMed

Saha, Tapan Kumar; Ichikawa, Hideki; Fukumori, Yoshinobu

2006-12-11

In order to provide a suitable device that would contain water-soluble drugs, highly water-soluble gadolinium diethylenetriaminopentaacetic acid-loaded chitosan microspheres (CMS-Gd-DTPA) were prepared by the emulsion method using glutaraldehyde as a cross-linker and Span 80 as a surfactant for gadolinium neutron-capture therapy of cancer. The gadolinium content and the mass median diameter of CMS-Gd-DTPA were estimated. The size and morphology of the CMS-Gd-DTPA were strongly influenced by the initial applied weight ratio of Gd-DTPA:chitosan. FTIR spectra showed that the electrostatic interaction between chitosan and Gd-DTPA accelerated the formation of gadolinium-enriched chitosan microspheres. Sufficient amounts of glutaraldehyde and Span 80 were necessary for producing discrete CMS-Gd-DTPA. The CMS-Gd-DTPA having a mass median diameter 11.7microm and 11.6% of gadolinium could be used in Gd-NCT following intratumoral injection.

Gadolinium enhanced cardiovascular magnetic resonance in Anderson-Fabry disease. Evidence for a disease specific abnormality of the myocardial interstitium.

PubMed

Moon, James C C; Sachdev, Bhavesh; Elkington, Andrew G; McKenna, William J; Mehta, Atul; Pennell, Dudley J; Leed, Philip J; Elliott, Perry M

2003-12-01

Anderson-Fabry Disease (AFD), an X-linked disorder of sphingolipid metabolism, is a cause of idiopathic left ventricular hypertrophy but the mechanism of hypertrophy is poorly understood. Gadolinium enhanced cardiovascular magnetic resonance can detect focal myocardial fibrosis. We hypothesised that hyperenhancement would be present in AFD. Eighteen males (mean 43+/-14 years) and eight female heterozygotes (mean 48+/-12 years) with AFD underwent cine and late gadolinium cardiovascular magnetic resonance. Nine male (50%) had myocardial hyperenhancement ranging from 3.4% to 20.6% (mean 7.7+/-5.7%) of total myocardium; in males, percentage hyperenhancement related to LV mass index (r=0.78, P=0.0002) but not to ejection fraction or left ventricular volumes. Lesser hyperenhancement was also found in four (50%) heterozygous females (mean 4.6%). In 12 (92%) patients with abnormal gadolinium uptake, hyperenhancement occurred in the basal infero-lateral wall where, unlike myocardial infarction, it was not sub-endocardial. In two male patients with severe LVH (left ventricular hypertrophy) and systolic impairment there was additional hyperenhancement in other myocardial segments. These observations suggests that myocardial fibrosis occurs in AFD and may contribute to the hypertrophy and the natural history of the disease.

Association of Left Atrial Function and Left Atrial Enhancement in Patients with Atrial Fibrillation: A Cardiac Magnetic Resonance Study

PubMed Central

Habibi, Mohammadali; Lima, Joao A.C.; Khurram, Irfan M.; Zimmerman, Stefan L.; Zipunnikov, Vadim; Fukumoto, Kotaro; Spragg, David; Ashikaga, Hiroshi; Rickard, John; Marine, Joseph E.; Calkins, Hugh; Nazarian, Saman

2015-01-01

Background Atrial fibrillation (AF) is associated with left atrial (LA) structural and functional changes. Cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) and feature-tracking are capable of noninvasive quantification of LA fibrosis and myocardial motion, respectively. We sought to examine the association of phasic LA function with LA enhancement in patients with AF. Methods and Results LA structure and function was measured in 90 AF patients (age 61 ± 10 years, 76% male) referred for ablation and 14 healthy volunteers. Peak global longitudinal LA strain (PLAS), LA systolic strain rate (SR-s), and early (SR-ed) and late diastolic (SR-ld) strain rates were measured using cine-CMR images acquired during sinus rhythm. The degree of LGE was quantified. Compared to patients with paroxysmal AF (60% of cohort), those with persistent AF had larger maximum LA volume index (LAVImax, 56 ± 17ml/m2 versus 49 ± 13ml/m2 p=0.036), and increased LGE (27.1± 11.7% versus 36.8 ± 14.8% p<0.001). Aside from LA active emptying fraction, all LA parameters (passive emptying fraction, PLAS, SR-s, SR-ed and SR-ld) were lower in patients with persistent AF (p< 0.05 for all). Healthy volunteers had less LGE and higher LA functional parameters compared to AF patients (p<0.05 for all). In multivariable analysis, increased LGE was associated with lower LA passive emptying fraction, PLAS, SR-s, SR-ed, and SR-ld (p<0.05 for all). Conclusions Increased LA enhancement is associated with decreased LA reservoir, conduit, and booster pump functions. Phasic measurement of LA function using feature-tracking CMR may add important information regarding the physiological importance of LA fibrosis. PMID:25652181

Gadolinium-Conjugated Gold Nanoshells for Multimodal Diagnostic Imaging and Photothermal Cancer Therapy

PubMed Central

Coughlin, Andrew J.; Ananta, Jeyarama S.; Deng, Nanfu; Larina, Irina V.; Decuzzi, Paolo

2014-01-01

Multimodal imaging offers the potential to improve diagnosis and enhance the specificity of photothermal cancer therapy. Toward this goal, we have engineered gadolinium-conjugated gold nanoshells and demonstrated that they enhance contrast for magnetic resonance imaging, X-Ray, optical coherence tomography, reflectance confocal microscopy, and two-photon luminescence. Additionally, these particles effectively convert near-infrared light to heat, which can be used to ablate cancer cells. Ultimately, these studies demonstrate the potential of gadolinium-nanoshells for image-guided photothermal ablation. PMID:24115690

Left ventricular strain and its pattern estimated from cine CMR and validation with DENSE

NASA Astrophysics Data System (ADS)

Gao, Hao; Allan, Andrew; McComb, Christie; Luo, Xiaoyu; Berry, Colin

2014-07-01

Measurement of local strain provides insight into the biomechanical significance of viable myocardium. We attempted to estimate myocardial strain from cine cardiovascular magnetic resonance (CMR) images by using a b-spline deformable image registration method. Three healthy volunteers and 41 patients with either recent or chronic myocardial infarction (MI) were studied at 1.5 Tesla with both cine and DENSE CMR. Regional circumferential and radial left ventricular strains were estimated from cine and DENSE acquisitions. In all healthy volunteers, there was no difference for peak circumferential strain (- 0.18 ± 0.04 versus - 0.18 ± 0.03, p = 0.76) between cine and DENSE CMR, however peak radial strain was overestimated from cine (0.84 ± 0.37 versus 0.49 ± 0.2, p < 0.01). In the patient study, the peak strain patterns predicted by cine were similar to the patterns from DENSE, including the strain evolution related to recovery time and strain patterns related to MI scar extent. Furthermore, cine-derived strain disclosed different strain patterns in MI and non-MI regions, and regions with transmural and non-transmural MI as DENSE. Although there were large variations with radial strain measurements from cine CMR images, useful circumferential strain information can be obtained from routine clinical CMR imaging. Cine strain analysis has potential to improve the diagnostic yield from routine CMR imaging in clinical practice.

Assessment of canine BEST1 variations identifies new mutations and establishes an independent bestrophinopathy model (cmr3)

PubMed Central

Wickström, Kaisa; Slavik, Julianna; Lindauer, Sarah J.; Ahonen, Saija; Schelling, Claude; Lohi, Hannes; Guziewicz, Karina E.; Aguirre, Gustavo D.

2010-01-01

Purpose Mutations in bestrophin 1 (BEST1) are associated with a group of retinal disorders known as bestrophinopathies in man and canine multifocal retinopathies (cmr) in the dog. To date, the dog is the only large animal model suitable for the complex characterization and in-depth studies of Best-related disorders. In the first report of cmr, the disease was described in a group of mastiff-related breeds (cmr1) and the Coton de Tulear (cmr2). Additional breeds, e.g., the Lapponian herder (LH) and others, subsequently were recognized with similar phenotypes, but linked loci are unknown. Analysis of the BEST1 gene aimed to identify mutations in these additional populations and extend our understanding of genotype–phenotype associations. Methods Animals were subjected to routine eye exams, phenotypically characterized, and samples were collected for molecular studies. Known BEST1 mutations were assessed, and the canine BEST1 coding exons were amplified and sequenced in selected individuals that exhibited a cmr compatible phenotype but that did not carry known mutations. Resulting sequence changes were genotyped in several different breeds and evaluated in the context of the phenotype. Results Seven novel coding variants were identified in exon 10 of cBEST1. Two linked mutations were associated with cmr exclusive to the LH breed (cmr3). Two individuals of Jämthund and Norfolk terrier breeds were heterozygous for two conservative changes, but these were unlikely to have disease-causing potential. Another three substitutions were found in the Bernese mountain dog that were predicted to have a deleterious effect on protein function. Previously reported mutations were excluded from segregation in these populations, but cmr1 was confirmed in another mastiff-related breed, the Italian cane corso. Conclusions A third independent canine model for human bestrophinopathies has been established in the LH breed. While exhibiting a phenotype comparable to cmr1 and cmr2, the

Making Metadata Better with CMR and MMT

NASA Technical Reports Server (NTRS)

Gilman, Jason Arthur; Shum, Dana

2016-01-01

Ensuring complete, consistent and high quality metadata is a challenge for metadata providers and curators. The CMR and MMT systems provide providers and curators options to build in metadata quality from the start and also assess and improve the quality of already existing metadata.

Gadolinium Endohedral Metallofullerene-Based MRI Contrast Agents

NASA Astrophysics Data System (ADS)

Bolskar, Robert D.

With the ability to encapsulate and carry the highly paramagnetic Gd3+ ion, gadolinium endohedral metallofullerenes or "gadofullerenes" are being explored as alternatives to the chelate complexes that are currently used for contrast-enhanced magnetic resonance imaging (MRI). Reviewed here are the various water-soluble derivatives of the gadofullerenes Gd@C82, Gd@C60, and Gd3N@C80 that have been investigated as MRI contrast agents. The water proton r1 relaxivities of gadofullerenes can be more than an order of magnitude higher than those of clinically used chelate agents. Gadofullerene relaxivity mechanisms have been studied, and multiple factors are found to contribute to their high relaxivities. In vitro and in vivoT1-weighted MRI tests of gadofullerene derivatives have shown their utility as bright image-enhancing agents. The gadofullerene MRI contrast agents are a promising new and unique style of gadolinium carrier for advanced imaging applications, including cellular and molecular imaging.

Emerging MRI Methods in Translational Cardiovascular Research

PubMed Central

Vandsburger, Moriel H; Epstein, Frederick H

2011-01-01

Cardiac magnetic resonance imaging (CMR) has become a reference standard modality for imaging of left ventricular (LV) structure and function, and, using late gadolinium enhancement, for imaging myocardial infarction. Emerging CMR techniques enable a more comprehensive examination of the heart, making CMR an excellent tool for use in translational cardiovascular research. Specifically, emerging CMR methods have been developed to measure the extent of myocardial edema, changes in ventricular mechanics, changes in tissue composition as a result of fibrosis, and changes in myocardial perfusion as a function of both disease and infarct healing. New CMR techniques also enable the tracking of labeled cells, molecular imaging of biomarkers of disease, and changes in calcium flux in cardiomyocytes. In addition, MRI can quantify blood flow velocity and wall shear stress in large blood vessels. Almost all of these techniques can be applied in both pre-clinical and clinical settings, enabling both the techniques themselves and the knowledge gained using such techniques in pre-clinical research to be translated from the lab bench to the patient bedside. PMID:21452060

The number of unrecognized myocardial infarction scars detected at DE-MRI increases during a 5-year follow-up.

PubMed

Themudo, Raquel; Johansson, Lars; Ebeling-Barbier, Charlotte; Lind, Lars; Ahlström, Håkan; Bjerner, Tomas

2017-02-01

In an elderly population, the prevalence of unrecognized myocardial infarction (UMI) scars found via late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging was more frequent than expected. This study investigated whether UMI scars detected with LGE-CMR at age 70 would be detectable at age 75 and whether the scar size changed over time. From 248 participants that underwent LGE-CMR at age 70, 185 subjects underwent a follow-up scan at age 75. A myocardial infarction (MI) scar was defined as late enhancement involving the subendocardium. In the 185 subjects that underwent follow-up, 42 subjects had a UMI scar at age 70 and 61 subjects had a UMI scar at age 75. Thirty-seven (88 %) of the 42 UMI scars seen at age 70 were seen in the same myocardial segment at age 75. The size of UMI scars did not differ between age 70 and 75. The prevalence of UMI scars detected at LGE-CMR increases with age. During a 5-year follow-up, 88 % (37/42) of the UMI scars were visible in the same myocardial segment, reassuring that UMI scars are a consistent finding. The size of UMI scars detected during LGE-CMR did not change over time. • UMI scars detected by LGE-CMR are frequent in elderly. • The prevalence of UMI scars detected with LGE-CMR increases with age. • UMI scar size does not change over time.

Gadolinium-enhanced magnetic resonance angiography in renal artery stenosis: comparison with digital subtraction angiography.

PubMed

Law, Y M; Tay, K H; Gan, Y U; Cheah, F K; Tan, B S

2008-04-01

To evaluate the accuracy of gadolinium-enhanced magnetic resonance angiography in assessing renal artery stenosis compared to catheter digital subtraction angiography. Retrospective study. Singapore General Hospital. Records of patients who underwent magnetic resonance angiography as well as digital subtraction angiography for assessment of renal artery stenosis from January 2003 to December 2005 were reviewed. There were 27 patients (14 male, 13 female) with a mean age of 62 (range, 44-77) years. There were 10 patients with renal transplants; their native renal arteries were not evaluated. Each of the two experienced interventional and body magnetic resonance radiologists, who were blinded to the results, reviewed the digital subtraction angiography and magnetic resonance angiography images respectively. Digital subtraction angiography was used as the standard of reference. A total of 39 renal arteries from these 27 patients were evaluated. One of the arteries was previously stented and could not be assessed with magnetic resonance angiography due to severe artefacts. Of the remaining 38 renal arteries, two were graded as normal, seven as having mild stenosis (<50%), eight as having moderate stenosis (> or =50% but <75%), and 21 as having severe stenosis (> or =75%). Magnetic resonance angiography and digital subtraction angiography were concordant in 89% of the arteries; magnetic resonance angiography overestimated the degree of stenosis in 8% and underestimated it in 3% of them. In the evaluation of clinically significant renal artery stenosis (> or =50%) with magnetic resonance angiography, the overall sensitivity, specificity, positive predictive value, and negative predictive value were 97%, 67%, 90%, and 86% respectively. The sensitivity and specificity of magnetic resonance angiography in transplant renal artery stenosis was 100%. CONCLUSION. Our experience suggested that gadolinium-enhanced magnetic resonance angiography is a sensitive non

Do we need gadolinium-based contrast medium for brain magnetic resonance imaging in children?

PubMed

Dünger, Dennis; Krause, Matthias; Gräfe, Daniel; Merkenschlager, Andreas; Roth, Christian; Sorge, Ina

2018-06-01

Brain imaging is the most common examination in pediatric magnetic resonance imaging (MRI), often combined with the use of a gadolinium-based contrast medium. The application of gadolinium-based contrast medium poses some risk. There is limited evidence of the benefits of contrast medium in pediatric brain imaging. To assess the diagnostic gain of contrast-enhanced sequences in brain MRI when the unenhanced sequences are normal. We retrospectively assessed 6,683 brain MR examinations using contrast medium in children younger than 16 years in the pediatric radiology department of the University Hospital Leipzig to determine whether contrast-enhanced sequences delivered additional, clinically relevant information to pre-contrast sequences. All examinations were executed using a 1.5-T or a 3-T system. In 8 of 3,003 (95% confidence interval 0.12-0.52%) unenhanced normal brain examinations, a relevant additional finding was detected when contrast medium was administered. Contrast enhancement led to a change in diagnosis in only one of these cases. Children with a normal pre-contrast brain MRI rarely benefit from contrast medium application. Comparing these results to the risks and disadvantages of a routine gadolinium application, there is substantiated numerical evidence for avoiding routine administration of gadolinium in a pre-contrast normal MRI examination.

Nanoamplifiers synthesized from gadolinium and gold nanocomposites for magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Tian, Xiumei; Shao, Yuanzhi; He, Haoqiang; Liu, Huan; Shen, Yingying; Huang, Wenlin; Li, Li

2013-03-01

We have synthesized an efficient and highly sensitive nanoamplifier composed of gadolinium-doped silica nanoparticles and gold nanoparticles (AuNPs). Magnetic resonance imaging (MRI) in vitro and in vivo assays revealed enhancement of signal sensitivity, which may be explained by electron transfer between water and gadolinium-doped nanoparticles, apparent in the presence of gold. In vitro and in vivo evaluation demonstrated nanoamplifier incurred minimal cytotoxicity and immunotoxicity, increased stability, and gradual excretion patterns. Tumor targeted properties were preliminarily determined when the nanoamplifier was injected into mouse models of colon cancer liver metastasis. Furthermore, although AuNPs departed from the nanoamplifiers in specific mice tissues, optical and magnetic resonance imaging was efficient, especially in metastatic tumors. These assays validate our nanoamplifier as an effective MRI signal enhancer with sensitive cancer diagnosis potential.We have synthesized an efficient and highly sensitive nanoamplifier composed of gadolinium-doped silica nanoparticles and gold nanoparticles (AuNPs). Magnetic resonance imaging (MRI) in vitro and in vivo assays revealed enhancement of signal sensitivity, which may be explained by electron transfer between water and gadolinium-doped nanoparticles, apparent in the presence of gold. In vitro and in vivo evaluation demonstrated nanoamplifier incurred minimal cytotoxicity and immunotoxicity, increased stability, and gradual excretion patterns. Tumor targeted properties were preliminarily determined when the nanoamplifier was injected into mouse models of colon cancer liver metastasis. Furthermore, although AuNPs departed from the nanoamplifiers in specific mice tissues, optical and magnetic resonance imaging was efficient, especially in metastatic tumors. These assays validate our nanoamplifier as an effective MRI signal enhancer with sensitive cancer diagnosis potential. Electronic supplementary information

Myocardial Tissue Characterization by Magnetic Resonance Imaging

PubMed Central

Ferreira, Vanessa M.; Piechnik, Stefan K.; Robson, Matthew D.; Neubauer, Stefan

2014-01-01

Cardiac magnetic resonance (CMR) imaging is a well-established noninvasive imaging modality in clinical cardiology. Its unsurpassed accuracy in defining cardiac morphology and function and its ability to provide tissue characterization make it well suited for the study of patients with cardiac diseases. Late gadolinium enhancement was a major advancement in the development of tissue characterization techniques, allowing the unique ability of CMR to differentiate ischemic heart disease from nonischemic cardiomyopathies. Using T2-weighted techniques, areas of edema and inflammation can be identified in the myocardium. A new generation of myocardial mapping techniques are emerging, enabling direct quantitative assessment of myocardial tissue properties in absolute terms. This review will summarize recent developments involving T1-mapping and T2-mapping techniques and focus on the clinical applications and future potential of these evolving CMR methodologies. PMID:24576837

Navigator-gated 3D blood oxygen level-dependent CMR at 3.0-T for detection of stress-induced myocardial ischemic reactions.

PubMed

Jahnke, Cosima; Gebker, Rolf; Manka, Robert; Schnackenburg, Bernhard; Fleck, Eckart; Paetsch, Ingo

2010-04-01

This study determined the value of navigator-gated 3-dimensional blood oxygen level-dependent (BOLD) cardiac magnetic resonance (CMR) at 3.0-T for the detection of stress-induced myocardial ischemic reactions. Although BOLD CMR has been introduced for characterization of myocardial oxygenation status, previously reported CMR approaches suffered from a low signal-to-noise ratio and motion-related artifacts with impaired image quality and a limited diagnostic value in initial patient studies. Fifty patients with suspected or known coronary artery disease underwent CMR at 3.0-T followed by invasive X-ray angiography within 48 h. Three-dimensional BOLD images were acquired during free breathing with full coverage of the left ventricle in a short-axis orientation. The BOLD imaging was performed at rest and under adenosine stress, followed by stress and rest first-pass perfusion and delayed enhancement imaging. Quantitative coronary X-ray angiography (QCA) was used for coronary stenosis definition (diameter reduction > or =50%). The BOLD and first-pass perfusion images were semiquantitatively evaluated (for BOLD imaging, signal intensity differences between stress and rest [DeltaSI]; for perfusion imaging, myocardial perfusion reserve index [MPRI]). The image quality of BOLD CMR at rest and during adenosine stress was considered good to excellent in 90% and 84% of the patients, respectively. The DeltaSI measurements differed significantly between normal myocardium, myocardium supplied by a stenotic coronary artery, and infarcted myocardium (p < 0.001). The receiver-operator characteristic analysis identified a cutoff value of DeltaSI = 2.7% for the detection of coronary stenosis, resulting in a sensitivity and specificity of 85.0% and 80.5%, respectively. An MPRI cutoff value of 1.35 yielded a sensitivity and specificity of 89.5% and 85.8%, respectively. The DeltaSI significantly correlated with the degree of coronary stenosis (r = -0.65, p < 0.001). Additionally, Delta

The histological basis of late gadolinium enhancement cardiovascular magnetic resonance in a patient with Anderson-Fabry disease.

PubMed

Moon, James C; Sheppard, Mary; Reed, Emma; Lee, Phillip; Elliott, Perry M; Pennell, Dudley J

2006-01-01

Anderson-Fabry Disease (AFD) is a storage disease that mimics hypertrophic cardiomyopathy. Late gadolinium enhancement (LGE) by cardiovascular magnetic resonance occurs in approximately 50% of patients in the basal inferolateral LV wall, but how an intracellular storage disease causes focal LGE is unknown. We present a whole-heart histological validation that LGE is caused by focal myocardial collagen scarring. This scarring may be the substrate for electrical re-entry and sudden arrhythmic death. The reasons for this distribution of fibrosis are unclear, but may reflect inhomogeneous left ventricular wall stress.

Prognostic Value of Late Gadolinium Enhancement Cardiovascular Magnetic Resonance in Cardiac Amyloidosis.

PubMed

Fontana, Marianna; Pica, Silvia; Reant, Patricia; Abdel-Gadir, Amna; Treibel, Thomas A; Banypersad, Sanjay M; Maestrini, Viviana; Barcella, William; Rosmini, Stefania; Bulluck, Heerajnarain; Sayed, Rabya H; Patel, Ketna; Mamhood, Shameem; Bucciarelli-Ducci, Chiara; Whelan, Carol J; Herrey, Anna S; Lachmann, Helen J; Wechalekar, Ashutosh D; Manisty, Charlotte H; Schelbert, Eric B; Kellman, Peter; Gillmore, Julian D; Hawkins, Philip N; Moon, James C

2015-10-20

The prognosis and treatment of the 2 main types of cardiac amyloidosis, immunoglobulin light chain (AL) and transthyretin (ATTR) amyloidosis, are substantially influenced by cardiac involvement. Cardiovascular magnetic resonance with late gadolinium enhancement (LGE) is a reference standard for the diagnosis of cardiac amyloidosis, but its potential for stratifying risk is unknown. Two hundred fifty prospectively recruited subjects, 122 patients with ATTR amyloid, 9 asymptomatic mutation carriers, and 119 patients with AL amyloidosis, underwent LGE cardiovascular magnetic resonance. Subjects were followed up for a mean of 24±13 months. LGE was performed with phase-sensitive inversion recovery (PSIR) and without (magnitude only). These were compared with extracellular volume measured with T1 mapping. PSIR was superior to magnitude-only inversion recovery LGE because PSIR always nulled the tissue (blood or myocardium) with the longest T1 (least gadolinium). LGE was classified into 3 patterns: none, subendocardial, and transmural, which were associated with increasing amyloid burden as defined by extracellular volume (P<0.0001), with transitions from none to subendocardial LGE at an extracellular volume of 0.40 to 0.43 (AL) and 0.39 to 0.40 (ATTR) and to transmural at 0.48 to 0.55 (AL) and 0.47 to 0.59 (ATTR). Sixty-seven patients (27%) died. Transmural LGE predicted death (hazard ratio, 5.4; 95% confidence interval, 2.1-13.7; P<0.0001) and remained independent after adjustment for N-terminal pro-brain natriuretic peptide, ejection fraction, stroke volume index, E/E', and left ventricular mass index (hazard ratio, 4.1; 95% confidence interval, 1.3-13.1; P<0.05). There is a continuum of cardiac involvement in systemic AL and ATTR amyloidosis. Transmural LGE is determined reliably by PSIR and represents advanced cardiac amyloidosis. The PSIR technique provides incremental information on outcome even after adjustment for known prognostic factors. © 2015 The Authors.

The Effect of gadolinium on the ESR response of alanine and ammonium tartrate exposed to thermal neutrons.

PubMed

Marrale, Maurizio; Brai, Maria; Gennaro, Gaetano; Bartolotta, Antonio; D'Oca, Maria Cristina

2008-02-01

Many efforts have been made to develop neutron capture therapy (NCT) for cancer treatment. Among the challenges in using NCT is the characterization of the features of the mixed radiation field and of its components. In this study, we examined the enhancement of the ESR response of pellets of alanine and ammonium tartrate with gadolinium oxide exposed to a thermal neutron beam. In particular, the ESR response of these dosimeters as a function of the gadolinium content inside the dosimeter was analyzed. We found that the addition of gadolinium improves the sensitivity of both alanine and ammonium tartrate. However, the use of gadolinium reduces or abolishes tissue equivalence because of its high atomic number (Z(Gd) = 64). Therefore, it is necessary to find the optimum compromise between the sensitivity to thermal neutrons and the reduction of tissue equivalence. Our analysis showed that a low concentration of gadolinium oxide (of the order of 5% of the total mass of the dosimeter) can enhance the thermal neutron sensitivity more than 13 times with an insignificant reduction of tissue equivalence.

Progressing Toward a Cohesive Pediatric 18F-FDG PET/MR Protocol: Is Administration of Gadolinium Chelates Necessary?

PubMed

Klenk, Christopher; Gawande, Rakhee; Tran, Vy Thao; Leung, Jennifer Trinh; Chi, Kevin; Owen, Daniel; Luna-Fineman, Sandra; Sakamoto, Kathleen M; McMillan, Alex; Quon, Andy; Daldrup-Link, Heike E

2016-01-01

With the increasing availability of integrated PET/MR scanners, the utility and need for MR contrast agents for combined scans is questioned. The purpose of our study was to evaluate whether administration of gadolinium chelates is necessary for evaluation of pediatric tumors on (18)F-FDG PET/MR images. First, in 119 pediatric patients with primary and secondary tumors, we used 14 diagnostic criteria to compare the accuracy of several MR sequences: unenhanced T2-weighted fast spin-echo imaging; unenhanced diffusion-weighted imaging; and-before and after gadolinium chelate contrast enhancement-T1-weighted 3-dimensional spoiled gradient echo LAVA (liver acquisition with volume acquisition) imaging. Next, in a subset of 36 patients who had undergone (18)F-FDG PET within 3 wk of MRI, we fused the PET images with the unenhanced T2-weighted MR images (unenhanced (18)F-FDG PET/MRI) and the enhanced T1-weighted MR images (enhanced (18)F-FDG PET/MRI). Using the McNemar test, we compared the accuracy of the two types of fused images using the 14 diagnostic criteria. We also evaluated the concordance between (18)F-FDG avidity and gadolinium chelate enhancement. The standard of reference was histopathologic results, surgical notes, and follow-up imaging. There was no significant difference in diagnostic accuracy between the unenhanced and enhanced MR images. Accordingly, there was no significant difference in diagnostic accuracy between the unenhanced and enhanced (18)F-FDG PET/MR images. (18)F-FDG avidity and gadolinium chelate enhancement were concordant in 30 of the 36 patients and 106 of their 123 tumors. Gadolinium chelate administration is not necessary for accurate diagnostic characterization of most solid pediatric malignancies on (18)F-FDG PET/MR images, with the possible exception of focal liver lesions. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Removal of gadolinium by peritoneal dialysis.

PubMed

Murashima, M; Drott, H R; Carlow, D; Shaw, L M; Milone, M; Bachman, M; Tsai, D E; Yang, S-L; Bloom, R D

2008-05-01

An association between gadolinium-containing contrast and the development of nephrogenic systemic fibrosis (NSF) has been increasingly recognized. For patients receiving hemodialysis (HD) who are exposed to gadolinium, the Federal Drug Administration (FDA) recommends HD to remove this contrast agent in order to minimize the risk of NSF. This study examines if gadolinium can be removed by frequent exchanges by peritoneal dialysis (PD). Following administration of 0.1 mmol/kg of gadodiamide to a patient with end-stage renal disease, the serum clearance of this contrast agent by automated PD was examined. 10 and 15 exchanges of PD using an automated cycler were respectively performed during the first and second 24-hour periods after gadolinium exposure. Serum gadolinium levels were measured 1 hour after the gadolinium administration, then at 24 and 48 hours after PD was initiated. 90% of the gadolinium was removed from the circulation in 2 days with a regimen of 10-15 exchanges per day of PD. For patients on chronic maintenance PD who receive gadolinium, our case suggests that a temporary intensive automated PD regimen, aimed at maximizing clearance of this contrast agent immediately after exposure, could be an effective alternative when institution of HD is problematic.

PET-CMR in heart failure - synergistic or redundant imaging?

PubMed

Quail, Michael A; Sinusas, Albert J

2017-07-01

Imaging in heart failure (HF) provides data for diagnosis, prognosis and disease monitoring. Both MRI and nuclear imaging techniques have been successfully used for this purpose in HF. Positron Emission Tomography-Cardiac Magnetic Resonance (PET-CMR) is an example of a new multimodality diagnostic imaging technique with potential applications in HF. The threshold for adopting a new diagnostic tool to clinical practice must necessarily be high, lest they exacerbate costs without improving care. New modalities must demonstrate clinical superiority, or at least equivalence, combined with another important advantage, such as lower cost or improved patient safety. The purpose of this review is to outline the current status of multimodality PET-CMR with regard to HF applications, and determine whether the clinical utility of this new technology justifies the cost.

Reticular Appearance on Gadolinium-enhanced T1- and Diffusion-weighted MRI, and Low Apparent Diffusion Coefficient Values in Microcystic Meningioma Cysts.

PubMed

Terada, Yukinori; Toda, Hiroki; Okumura, Ryosuke; Ikeda, Naokado; Yuba, Yoshiaki; Katayama, Toshiro; Iwasaki, Koichi

2018-03-01

Microcystic meningioma, a rare meningioma subtype, can present diagnostic difficulty. We aimed to investigate the historadiological properties of microcystic meningioma using conventional magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) analysis. We retrospectively analyzed conventional MRI and DWI results of six microcystic meningioma cases by examining their appearance and determining their apparent diffusion coefficient (ADC) values. The ADC values of the intratumoral components were normalized with ADC values of the cerebrospinal fluid in the lateral ventricle (ADC ratios). As cystic formations are frequently associated with microcystic meningiomas, their MRI characteristics were compared with the imaging data from 11 cystic meningiomas of non-microcystic subtypes. We found that cysts in microcystic meningioma tended to have a reticular appearance on DWI, as they did on gadolinium-enhanced T1-weighted imaging. Additionally, these reticular cysts had significantly lower ADC ratios than microcystic non-reticular and non-microcystic cysts. These DWI characteristics likely reflect the histological properties of microcystic meningioma. A reticular appearance on gadolinium-enhanced T1-weighted MRI and DWI, and cyst formation with relatively low ADC values can be diagnostic markers of microcystic meningiomas.

Structural, optical and magnetic properties of gadolinium sesquioxide nanobars synthesized via thermal decomposition of gadolinium oxalate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manigandan, R.; Giribabu, K.; Suresh, R.

2013-10-15

Graphical abstract: - Highlights: • The cubic Gd{sub 2}O{sub 3} nanobars are synthesized by decomposition of C{sub 6}H{sub 20}Gd{sub 2}O{sub 22}. • The nanoparticles are rectangular bar shape with high porous surface. • The combination of magnetic and optical properties within a single particle. • The Gd{sub 2}O{sub 3} nanobars have tailorable nanostructure, wide bandgap and are paramagnetic. - Abstract: Gadolinium oxide nanobars were obtained by thermal decomposition of gadolinium oxalate, which was synthesized by the chemical precipitation method along with glycerol. The functional group analysis and formation of gadolinium oxide from gadolinium oxalate were characterized by the Fourier transformmore » infrared spectroscopy and thermo gravimetric analyzer. The crystal structure, average crystallite size, and lattice parameter were analyzed by X-ray diffraction technique. Moreover, Raman shifts, elemental composition and morphology of the gadolinium oxide was widely investigated by the laser Raman microscope, X-ray photoelectron spectroscopy, FE-SEM-EDAX and HR-TEM, respectively. Furthermore, the optical properties like band gap, absorbance measurement of the gadolinium oxide were extensively examined. In addition, the paramagnetic property of gadolinium oxide nanobars was explored by the vibrating sample magnetometer.« less

Myocardial T1 mapping and extracellular volume quantification: a Society for Cardiovascular Magnetic Resonance (SCMR) and CMR Working Group of the European Society of Cardiology consensus statement

PubMed Central

2013-01-01

Rapid innovations in cardiovascular magnetic resonance (CMR) now permit the routine acquisition of quantitative measures of myocardial and blood T1 which are key tissue characteristics. These capabilities introduce a new frontier in cardiology, enabling the practitioner/investigator to quantify biologically important myocardial properties that otherwise can be difficult to ascertain clinically. CMR may be able to track biologically important changes in the myocardium by: a) native T1 that reflects myocardial disease involving the myocyte and interstitium without use of gadolinium based contrast agents (GBCA), or b) the extracellular volume fraction (ECV)–a direct GBCA-based measurement of the size of the extracellular space, reflecting interstitial disease. The latter technique attempts to dichotomize the myocardium into its cellular and interstitial components with estimates expressed as volume fractions. This document provides recommendations for clinical and research T1 and ECV measurement, based on published evidence when available and expert consensus when not. We address site preparation, scan type, scan planning and acquisition, quality control, visualisation and analysis, technical development. We also address controversies in the field. While ECV and native T1 mapping appear destined to affect clinical decision making, they lack multi-centre application and face significant challenges, which demand a community-wide approach among stakeholders. At present, ECV and native T1 mapping appear sufficiently robust for many diseases; yet more research is required before a large-scale application for clinical decision-making can be recommended. PMID:24124732

Enhancements in hepatobiliary imaging: the spectrum of gadolinium-ethoxybenzyl diethylenetriaminepentaacetic acid usages in hepatobiliary magnetic resonance imaging.

PubMed

Channual, Stephanie; Pahwa, Anokh; Lu, David S; Raman, Steven S

2016-09-01

Gadolinium-ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) is a unique hepatocyte-specific contrast agent approved for clinical use in the United States in 2008. Gd-EOB-DTPA-enhanced MR has shown to improve detection and characterization of hepatic lesions. Gd-EOB-DTPA is now being routinely used in daily clinical practice worldwide. Therefore, it is important for radiologists to be familiar with the potential uses and pitfalls of Gd-EOB-DTPA, which extends beyond the assessment of focal hepatic lesions. The purpose of this article is to review the various usages of Gd-EOB-DTPA in hepatobiliary MR imaging.

Pathophysiology of gadolinium-associated systemic fibrosis

PubMed Central

Drel, Viktor; Gorin, Yves

2016-01-01

Systemic fibrosis from gadolinium-based magnetic resonance imaging contrast is a scourge for the afflicted. Although gadolinium-associated systemic fibrosis is a rare condition, the threat of litigation has vastly altered clinical practice. Most theories concerning the etiology of the fibrosis are grounded in case reports rather than experiment. This has led to the widely accepted conjecture that the relative affinity of certain contrast agents for the gadolinium ion inversely correlates with the risk of succumbing to the disease. How gadolinium-containing contrast agents trigger widespread and site-specific systemic fibrosis and how chronicity is maintained are largely unknown. This review highlights experimentally-derived information from our laboratory and others that pertain to our understanding of the pathophysiology of gadolinium-associated systemic fibrosis. PMID:27147669

The Role of CMR and Others in Project Implementation using the CM Method to Support the Government

NASA Astrophysics Data System (ADS)

Tada, Hiroshi; Miyatake, Ichiro; Mouri, Junji; Endo, Kenji; Fueta, Toshiharu

In Japan, the construction management (CM) method has been introduced as a measure to support the governmental agencies, in developing and maintaining local infrastructures, or in executing public works projects in an appropriate manner, etc. The scope of work of the Construction Manager (CMR) of the CM method is specified as work items, in the special specification document for CM services contained in the contract documents, as a reflection of the client's expectations towards the performance of CMR. However, the CM services has been conducted as required on a case-by-case basis, because it is not possible to anticipate the actual construction status in advance, and thus the special specification document does not provide full detail of the scope of work of CMR. In such case, there may be a difference in the way the scope of work in the special specification document is recognized between the client and the CMR, which could make the CM method less effective. Moreover, there is a case in which the role sharing between the client and the CMR is not clearly defined, and both parties may engage in the same task in such case, causing an obstacle for smooth project implementation. For this reason, it is required to prepare the special specification document which clearly defines the scope of work of CMR, by examining the status of application of the CM method in actual project cases, and to improve the practices of the CM method as necessary. In view of this background, this study looks in to the actual project cases using the CM method, for the purpose of clarifying the actual scope of work of CMR for each task item defined in the special specification document, and the role sharing between the client and CMR, in the aim of contributing the promotion of the use and the effective application of the CM method.

Determination of Location, Size and Transmurality of Chronic Myocardial Infarction Without Exogenous Contrast Media Using Cardiac Magnetic Resonance Imaging at 3T

PubMed Central

Kali, Avinash; Cokic, Ivan; Tang, Richard L Q; Yang, Hsin-Jung; Sharif, Behzad; Marbán, Eduardo; Li, Debiao; Berman, Daniel; Dharmakumar, Rohan

2014-01-01

Background LGE CMR is a powerful method for characterizing MI, but the requisite gadolinium infusion is estimated to be contraindicated in nearly 20% of MI patients due to end-stage chronic kidney disease. The purpose of this study is to investigate whether T1 Cardiovascular-Magnetic-Resonance Imaging (CMR) obtained without contrast agents at 3T could be an alternative to Late-Gadolinium-Enhanced (LGE) CMR for characterizing chronic myocardial infarctions (MIs) using a canine model of MI. Methods and Results Canines (n=29) underwent CMR at 7 days (acute, AMI) and 4 months (chronic, CMI) post-MI. Infarct location, size and transmurality measured using native T1 maps and LGE images at 1.5T and 3T were compared. Resolution of edema between AMI and CMI was examined with T2 maps. T1 maps overestimated infarct size and transmurality relative to LGE images in AMI (p=0.016 and p=0.007, respectively), which was not observed in CMI (p=0.49 and p=0.81, respectively), at 3T. T1 maps underestimated infarct size and transmurality relative to LGE images in AMI and CMI (p<0.001), at 1.5T. Relative to the remote territories, T1 of the infarcted myocardium was increased in CMI and AMI (p<0.05); and T2 of the infarcted myocardium was increased in AMI (p<0.001), but not in CMI (p >0.20) at both field strengths. Histology showed extensive replacement fibrosis within the CMI territories. CMI detection sensitivity and specificity of T1 CMR at 3T were 95% and 97%, respectively. Conclusions Native T1 maps at 3T can determine the location, size and transmurality of CMI with high diagnostic accuracy. Patient studies are necessary for clinical translation. PMID:24682268

Characteristics of Gadolinium Oxide Nanoparticles Using Terahertz Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Dongkyu; Maeng, Inhee; Son, Joo-Hiuk

2009-04-19

The penetration property of the terahertz electromagnetic (THz) wave is relevant to its use. We used the THz wave spectroscopy system which easily penetrates some materials that do not contain water, e.g., plastic and ceramics. The system has been developed for several purposes, including measuring the properties of semiconductors and bio-materials, and detecting plastic bombs and ceramic knives at airports. It is also used for medical imaging systems, such as magnetic resonance imaging (MRI), at some research institutes. It can show not only the difference in amplitude, but also the difference of the phase of each point of sample. MRImore » technology usually uses contrast agents to enhance the quality of the image. Gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA), made with a heavy metal ion, is commonly used as a clinical MRI contrast agent. Gadolinium oxide (Gd{sub 2}O{sub 3}) nanoparticle is a new contrast agent. It serves to equip the core of each particle with antibodies or ligands. It can freely circulate in blood vessels without amassing in the liver or lungs. This study shows the characteristics of gadolinium oxide nanoparticles to further advance terahertz medical imaging.« less

Importance of CMR within the Task Force Criteria for the diagnosis of ARVC in children and adolescents.

PubMed

Etoom, Yousef; Govindapillai, Sindu; Hamilton, Robert; Manlhiot, Cedric; Yoo, Shi-Joon; Farhan, Maryam; Sarikouch, Samir; Peters, Brigitte; McCrindle, Brian W; Grosse-Wortmann, Lars

2015-03-17

Cardiac magnetic resonance (CMR) is a component of the revised Task Force Criteria (rTFC) for the diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC). However, its diagnostic value in a pediatric population is unknown. This study examined the contribution of CMR to diagnosing ARVC using the rTFC in a pediatric population. Clinical CMR studies of 142 pediatric patients evaluated for ARVC between 2005 and 2009 were reviewed. Patients were categorized into "definitive," "borderline," "possible," or "no" ARVC diagnostic groups based on the rTFC. The extent to which each element of the rTFC contributed to diagnosing ARVC was determined using a c-statistics model. A total of 23 (16%), 32 (23%), 37 (26%), and 50 (35%) patients had definite, borderline, possible, and no ARVC, respectively, applying the rTFC. The prevalence of regional wall motion abnormalities in these groups was 83%, 53%, 22%, and 16%, respectively (p < 0.001). By CMR, right ventricular end-diastolic volumes were 118 ± 31 cc/m², 108 ± 22 cc/m², 94 ± 14 cc/m², and 92 ± 18 cc/m², respectively (p < 0.001). Right ventricular fatty infiltration and fibrosis were detected in only 1 and 3 patients, respectively, all of whom had definitive ARVC. Of all rTFC major criteria, CMR had the largest c-statistic decline (c = -0.163). Eleven of the 23 patients (48%) with definite ARVC would not have been in this group if CMR had not been performed. CMR parameters are important contributors to a diagnosis of ARVC in children, using the rTFC. Fatty infiltration and myocardial fibrosis provide limited value in children and adolescents. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Apparent diffusion coefficient for molecular subtyping of non-gadolinium-enhancing WHO grade II/III glioma: volumetric segmentation versus two-dimensional region of interest analysis.

PubMed

Thust, S C; Hassanein, S; Bisdas, S; Rees, J H; Hyare, H; Maynard, J A; Brandner, S; Tur, C; Jäger, H R; Yousry, T A; Mancini, L

2018-03-23

To investigate if quantitative apparent diffusion coefficient (ADC) measurements can predict genetic subtypes of non-gadolinium-enhancing gliomas, comparing whole tumour against single slice analysis. Volumetric T2-derived masks of 44 gliomas were co-registered to ADC maps with ADC mean (ADC mean ) calculated. For the slice analysis, two observers placed regions of interest in the largest tumour cross-section. The ratio (ADC ratio ) between ADC mean in the tumour and normal appearing white matter was calculated for both methods. Isocitrate dehydrogenase (IDH) wild-type gliomas showed the lowest ADC values throughout (p < 0.001). ADC mean in the IDH-mutant 1p19q intact group was significantly higher than in the IDH-mutant 1p19q co-deleted group (p < 0.01). A volumetric ADC mean threshold of 1201 × 10 -6 mm 2 /s identified IDH wild-type with a sensitivity of 83% and a specificity of 86%; a volumetric ADC ratio cut-off value of 1.65 provided a sensitivity of 80% and a specificity of 92% (area under the curve (AUC) 0.9-0.94). A slice ADC ratio threshold for observer 1 (observer 2) of 1.76 (1.83) provided a sensitivity of 80% (86%), specificity of 91% (100%) and AUC of 0.95 (0.96). The intraclass correlation coefficient was excellent (0.98). ADC measurements can support the distinction of glioma subtypes. Volumetric and two-dimensional measurements yielded similar results in this study. • Diffusion-weighted MRI aids the identification of non-gadolinium-enhancing malignant gliomas • ADC measurements may permit non-gadolinium-enhancing glioma molecular subtyping • IDH wild-type gliomas have lower ADC values than IDH-mutant tumours • Single cross-section and volumetric ADC measurements yielded comparable results in this study.

Prognostic Value of Late Gadolinium Enhancement Cardiovascular Magnetic Resonance in Cardiac Amyloidosis

PubMed Central

Fontana, Marianna; Pica, Silvia; Reant, Patricia; Abdel-Gadir, Amna; Treibel, Thomas A.; Banypersad, Sanjay M.; Maestrini, Viviana; Barcella, William; Rosmini, Stefania; Bulluck, Heerajnarain; Sayed, Rabya H.; Patel, Ketna; Mamhood, Shameem; Bucciarelli-Ducci, Chiara; Whelan, Carol J.; Herrey, Anna S.; Lachmann, Helen J.; Wechalekar, Ashutosh D.; Manisty, Charlotte H.; Schelbert, Eric B.; Kellman, Peter; Gillmore, Julian D.; Hawkins, Philip N.

2015-01-01

Background— The prognosis and treatment of the 2 main types of cardiac amyloidosis, immunoglobulin light chain (AL) and transthyretin (ATTR) amyloidosis, are substantially influenced by cardiac involvement. Cardiovascular magnetic resonance with late gadolinium enhancement (LGE) is a reference standard for the diagnosis of cardiac amyloidosis, but its potential for stratifying risk is unknown. Methods and Results— Two hundred fifty prospectively recruited subjects, 122 patients with ATTR amyloid, 9 asymptomatic mutation carriers, and 119 patients with AL amyloidosis, underwent LGE cardiovascular magnetic resonance. Subjects were followed up for a mean of 24±13 months. LGE was performed with phase-sensitive inversion recovery (PSIR) and without (magnitude only). These were compared with extracellular volume measured with T1 mapping. PSIR was superior to magnitude-only inversion recovery LGE because PSIR always nulled the tissue (blood or myocardium) with the longest T1 (least gadolinium). LGE was classified into 3 patterns: none, subendocardial, and transmural, which were associated with increasing amyloid burden as defined by extracellular volume (P<0.0001), with transitions from none to subendocardial LGE at an extracellular volume of 0.40 to 0.43 (AL) and 0.39 to 0.40 (ATTR) and to transmural at 0.48 to 0.55 (AL) and 0.47 to 0.59 (ATTR). Sixty-seven patients (27%) died. Transmural LGE predicted death (hazard ratio, 5.4; 95% confidence interval, 2.1–13.7; P<0.0001) and remained independent after adjustment for N-terminal pro-brain natriuretic peptide, ejection fraction, stroke volume index, E/E′, and left ventricular mass index (hazard ratio, 4.1; 95% confidence interval, 1.3–13.1; P<0.05). Conclusions— There is a continuum of cardiac involvement in systemic AL and ATTR amyloidosis. Transmural LGE is determined reliably by PSIR and represents advanced cardiac amyloidosis. The PSIR technique provides incremental information on outcome even after

Stress perfusion magnetic resonance imaging to detect coronary artery lesions in children.

PubMed

Vijarnsorn, Chodchanok; Noga, Michelle; Schantz, Daryl; Pepelassis, Dion; Tham, Edythe B

2017-05-01

Stress perfusion cardiovascular magnetic resonance (CMR) is used widely in adult ischemic heart disease, but data in children is limited. We sought to evaluate feasibility, accuracy and prognostic value of stress CMR in children with suspected coronary artery disease (CAD). Stress CMR was reviewed from two pediatric centers over 5 years using a standard pharmacologic protocol. Wall motion abnormalities, perfusion deficits and late enhancement were correlated with coronary angiogram (CAG) when available, and clinical status at 1 year follow-up for major adverse cardiovascular events (MACE; coronary revascularization, non-fatal myocardial infarction and death due to CAD) was recorded. Sixty-four stress perfusion CMR studies in 48 children (10.9 ± 4.8 years) using adenosine; 59 (92%) and dipyridamole; 5 (8%), were reviewed. Indications were Kawasaki disease (39%), post arterial switch operation (12.5%), post heart transplantation (12.5%), post anomalous coronary artery repair (11%), chest pain (11%), suspected myocarditis or CAD (3%), post coronary revascularization (3%), and others (8%). Twenty-six studies were performed under sedation. Of all studies performed, 66% showed no evidence of ischemia or infarction, 28% had perfusion deficits and 6% had late gadolinium enhancement (LGE) without perfusion deficit. Compared to CAG, the positive predictive value (PPV) of stress CMR was 80% with negative predictive value (NPV) of 88%. At 1 year clinical follow-up, the PPV and NPV of stress CMR to predict MACE were 78 and 98%. Stress-perfusion CMR, in combination with LGE and wall motion-analysis is a feasible and an accurate method of diagnosing CAD in children. In difficult cases, it also helps guide clinical intervention by complementing conventional CAG with functional information.

Impact of arrhythmia on diagnostic performance of adenosine stress CMR in patients with suspected or known coronary artery disease.

PubMed

Greulich, Simon; Steubing, Hannah; Birkmeier, Stefan; Grün, Stefan; Bentz, Kerstin; Sechtem, Udo; Mahrholdt, Heiko

2015-11-05

The diagnostic performance of adenosine stress cardiovascular magnetic resonance (CMR) in patients with arrhythmias presenting for work-up of suspected or known CAD is largely unknown, since most CMR studies currently available exclude arrhythmic patients from analysis fearing gating problems, or other artifacts will impair image quality. The primary aim of our study was to evaluate the diagnostic performance of adenosine stress CMR for detection of significant coronary stenosis in patients with arrhythmia presenting for 1) work-up of suspected coronary artery disease (CAD), or 2) work-up of ischemia in known CAD. Patients with arrhythmia referred for work-up of suspected CAD or work-up of ischemia in known CAD undergoing adenosine stress CMR were included if they had coronary angiography within four weeks of CMR. One hundred fifty-nine patients were included (n = 64 atrial fibrillation, n = 87 frequent ventricular extrasystoles, n = 8 frequent supraventricular extrasystoles). Of these, n = 72 had suspected CAD, and n = 87 had known CAD. Diagnostic accuracy of the adenosine stress CMR for detection of significant CAD was 73 % for the entire population (sensitivity 72 %, specificity 76 %). Diagnostic accuracy was 75 % (sensitivity 80 %, specificity 74 %) in patients with suspected CAD, and 74 % (sensitivity 71 %, specificity 79 %) in the group with known CAD. For different types of arrhythmia, diagnostic accuracy of CMR was 70 % in the atrial fibrillation group, and 79 % in patients with ventricular extrasystoles. On a per coronary territory analysis, diagnostic accuracy of CMR was 77 % for stenosis of the left and 82 % for stenosis of the right coronary artery. The present data demonstrates good diagnostic performance of adenosine stress CMR for detection of significant coronary stenosis in patients with arrhythmia presenting for work-up of suspected CAD, or work-up of ischemia in known CAD. This holds true for a per patient, as

Myocardial fibrosis as the first sign of cardiac involvement in a male patient with Fabry disease: report of a clinical case and discussion on the utility of the magnetic resonance in Fabry pathology.

PubMed

Sechi, Annalisa; Nucifora, Gaetano; Piccoli, Gianluca; Dardis, Andrea; Bembi, Bruno

2014-07-16

Cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) imaging is increasingly used to assess myocardial involvement in patients with Fabry disease, an X linked lipid storage disorder. However, it is often proposed as an optional tool. A different cardiomyopathic disease progression between male and female patients was hypothesised in previous studies, as in female myocardial fibrosis was found without left ventricular (LV) hypertrophy, while myocardial fibrosis was always detected in association to LV hypertrophy in men. A male Caucasian patient, 19 years old, diagnosed through a family-based molecular screening, presented with LGE of the LV inferolateral wall evidenced at the CMR, without LV hypertrophy, or other clinical signs of the disease. This is the first report of cardiac fibrosis as the first sign of organ involvement in a male patient with Fabry disease. This finding stresses the importance of performing CMR with LGE imaging for the initial staging and monitoring of Fabry patients of both genders.

Myocardial fibrosis as the first sign of cardiac involvement in a male patient with Fabry disease: report of a clinical case and discussion on the utility of the magnetic resonance in Fabry pathology

PubMed Central

2014-01-01

Background Cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) imaging is increasingly used to assess myocardial involvement in patients with Fabry disease, an X linked lipid storage disorder. However, it is often proposed as an optional tool. A different cardiomyopathic disease progression between male and female patients was hypothesised in previous studies, as in female myocardial fibrosis was found without left ventricular (LV) hypertrophy, while myocardial fibrosis was always detected in association to LV hypertrophy in men. Case presentation A male Caucasian patient, 19 years old, diagnosed through a family-based molecular screening, presented with LGE of the LV inferolateral wall evidenced at the CMR, without LV hypertrophy, or other clinical signs of the disease. Conclusion This is the first report of cardiac fibrosis as the first sign of organ involvement in a male patient with Fabry disease. This finding stresses the importance of performing CMR with LGE imaging for the initial staging and monitoring of Fabry patients of both genders. PMID:25026990

Usefulness of the dynamic gadolinium-enhanced magnetic resonance imaging with simultaneous acquisition of coronal and sagittal planes for detection of pituitary microadenomas.

PubMed

Lee, Han Bee; Kim, Sung Tae; Kim, Hyung-Jin; Kim, Keon Ha; Jeon, Pyoung; Byun, Hong Sik; Choi, Jin Wook

2012-03-01

Does dynamic gadolinium-enhanced imaging with simultaneous acquisition of coronal and sagittal planes improve diagnostic accuracy of pituitary microadenomas compared with coronal images alone? Fifty-six patients underwent 3-T sella MRI including dynamic simultaneous acquisition of coronal and sagittal planes after gadolinium injection. According to conspicuity, lesions were divided into four scores (0, no; 1, possible; 2, probable; 3, definite delayed enhancing lesion). Additional information on supplementary sagittal images compared with coronal ones was evaluated with a 4-point score (0, no; 1, possible; 2, probable; 3, definite additional information). Accuracy of tumour detection was calculated. Average scores for lesion detection of a combination of two planes, coronal, and sagittal images were 2.59, 2.32, and 2.18. 6/10 lesions negative on coronal images were detected on sagittal ones. Accuracy of a combination of two planes, of coronal and of sagittal images was 92.86%, 82.14% and 75%. Six patients had probable or definite additional information on supplementary sagittal images compared with coronal ones alone (10.71%). Dynamic MRI with combined coronal and sagittal planes was more accurate for detection of pituitary microadenomas than routinely used coronal images. Simultaneous dynamic enhanced acquisition can make study time fast and costs low. We present a new dynamic MRI technique for evaluating pituitary microadenomas • This technique provides simultaneous acquisition of contrast enhanced coronal and sagittal images. • This technique makes the diagnosis more accurate and reduces the examination time. • Such MR imaging only requires one single bolus of contrast agent.

Clinical Utility and Future Applications of PET/CT and PET/CMR in Cardiology

PubMed Central

Pan, Jonathan A.; Salerno, Michael

2016-01-01

Over the past several years, there have been major advances in cardiovascular positron emission tomography (PET) in combination with either computed tomography (CT) or, more recently, cardiovascular magnetic resonance (CMR). These multi-modality approaches have significant potential to leverage the strengths of each modality to improve the characterization of a variety of cardiovascular diseases and to predict clinical outcomes. This review will discuss current developments and potential future uses of PET/CT and PET/CMR for cardiovascular applications, which promise to add significant incremental benefits to the data provided by each modality alone. PMID:27598207

Use of gadolinium-based magnetic resonance imaging contrast agents and awareness of brain gadolinium deposition among pediatric providers in North America.

PubMed

Mithal, Leena B; Patel, Payal S; Mithal, Divakar; Palac, Hannah L; Rozenfeld, Michael N

2017-05-01

Numerous recent articles have reported brain gadolinium deposition when using linear but not macrocyclic gadolinium-based contrast agents (GBCAs). To determine the current landscape of gadolinium use among pediatric institutions and the knowledge base of radiologists and referring providers with regard to GBCAs and brain gadolinium deposition. We e-mailed voluntary closed surveys to 5,390 physicians in various pediatric professional societies between January 2016 and March 2016. We used chi-square and Fisher exact tests to compare response distributions among specialties. We found that 80% of surveyed pediatric hospitals use macrocyclic contrast agents. In the last year, 58% switched their agent, most commonly to gadoterate meglumine, with the most common reason being brain gadolinium deposition. Furthermore, surveys indicated that 23% of hospitals are considering switching, and, of these, 83% would switch to gadoterate meglumine; the most common reasons were brain gadolinium deposition and safety. Radiologists were more aware of brain gadolinium deposition than non-radiologist physicians (87% vs. 26%; P<0.0001). Radiologists and referring providers expressed similar levels of concern (95% and 89%). Twelve percent of radiologists and 2% of referring providers reported patients asking about brain gadolinium deposition. Radiologists were significantly more comfortable addressing patient inquiries than referring pediatric physicians (48% vs. 6%; P<0.0001). The number of MRIs requested by referring pediatric physicians correlated with their knowledge of brain gadolinium deposition, contrast agent used by their hospital, and comfort discussing brain gadolinium deposition with patients (P<0.0001). Since the discovery of brain gadolinium deposition, many pediatric hospitals have switched to or plan to switch to a more stable macrocyclic MR contrast agent, most commonly gadoterate meglumine. Despite this, there is need for substantial further education of radiologists and

Cmr1/WDR76 defines a nuclear genotoxic stress body linking genome integrity and protein quality control.

PubMed

Gallina, Irene; Colding, Camilla; Henriksen, Peter; Beli, Petra; Nakamura, Kyosuke; Offman, Judith; Mathiasen, David P; Silva, Sonia; Hoffmann, Eva; Groth, Anja; Choudhary, Chunaram; Lisby, Michael

2015-03-30

DNA replication stress is a source of genomic instability. Here we identify changed mutation rate 1 (Cmr1) as a factor involved in the response to DNA replication stress in Saccharomyces cerevisiae and show that Cmr1--together with Mrc1/Claspin, Pph3, the chaperonin containing TCP1 (CCT) and 25 other proteins--define a novel intranuclear quality control compartment (INQ) that sequesters misfolded, ubiquitylated and sumoylated proteins in response to genotoxic stress. The diversity of proteins that localize to INQ indicates that other biological processes such as cell cycle progression, chromatin and mitotic spindle organization may also be regulated through INQ. Similar to Cmr1, its human orthologue WDR76 responds to proteasome inhibition and DNA damage by relocalizing to nuclear foci and physically associating with CCT, suggesting an evolutionarily conserved biological function. We propose that Cmr1/WDR76 plays a role in the recovery from genotoxic stress through regulation of the turnover of sumoylated and phosphorylated proteins.

Cmr1/WDR76 defines a nuclear genotoxic stress body linking genome integrity and protein quality control

PubMed Central

Gallina, Irene; Colding, Camilla; Henriksen, Peter; Beli, Petra; Nakamura, Kyosuke; Offman, Judith; Mathiasen, David P.; Silva, Sonia; Hoffmann, Eva; Groth, Anja; Choudhary, Chunaram; Lisby, Michael

2015-01-01

DNA replication stress is a source of genomic instability. Here we identify changed mutation rate 1 (Cmr1) as a factor involved in the response to DNA replication stress in Saccharomyces cerevisiae and show that Cmr1—together with Mrc1/Claspin, Pph3, the chaperonin containing TCP1 (CCT) and 25 other proteins—define a novel intranuclear quality control compartment (INQ) that sequesters misfolded, ubiquitylated and sumoylated proteins in response to genotoxic stress. The diversity of proteins that localize to INQ indicates that other biological processes such as cell cycle progression, chromatin and mitotic spindle organization may also be regulated through INQ. Similar to Cmr1, its human orthologue WDR76 responds to proteasome inhibition and DNA damage by relocalizing to nuclear foci and physically associating with CCT, suggesting an evolutionarily conserved biological function. We propose that Cmr1/WDR76 plays a role in the recovery from genotoxic stress through regulation of the turnover of sumoylated and phosphorylated proteins. PMID:25817432

Breakthrough reactions of iodinated and gadolinium contrast media after oral steroid premedication protocol.

PubMed

Jingu, Akiko; Fukuda, Junya; Taketomi-Takahashi, Ayako; Tsushima, Yoshito

2014-10-06

Adverse reactions to iodinated and gadolinium contrast media are an important clinical issue. Although some guidelines have proposed oral steroid premedication protocols to prevent adverse reactions, some patients may have reactions to contrast media in spite of premedication (breakthrough reaction; BTR).The purpose of this study was to assess the frequency, type and severity of BTR when following an oral steroid premedication protocol. All iodinated and gadolinium contrast-enhanced radiologic examinations between August 2011 and February 2013 for which the premedication protocol was applied in our institution were assessed for BTRs. The protocol was applied to a total of 252 examinations (153 patients, ages 15-87 years; 63 males, 90 females). Of these, 152 were for prior acute adverse reactions to contrast media, 85 were for a history of bronchial asthma, and 15 were for other reasons. There were 198 contrast enhanced CTs and 54 contrast enhanced MRIs. There were nine BTR (4.5%) for iodinated contrast media, and only one BTR (1.9%) for gadolinium contrast media: eight were mild and one was moderate. No patient who had a mild index reaction (IR) had a severe BTR. Incidence of BTRs when following the premedication protocol was low. This study by no means proves the efficacy of premedication, but provides some support for following a premedication protocol to improve safety of contrast-enhanced examinations when prior adverse reactions are mild, or when there is a history of asthma.

Breakthrough reactions of iodinated and gadolinium contrast media after oral steroid premedication protocol

PubMed Central

2014-01-01

Background Adverse reactions to iodinated and gadolinium contrast media are an important clinical issue. Although some guidelines have proposed oral steroid premedication protocols to prevent adverse reactions, some patients may have reactions to contrast media in spite of premedication (breakthrough reaction; BTR). The purpose of this study was to assess the frequency, type and severity of BTR when following an oral steroid premedication protocol. Methods All iodinated and gadolinium contrast-enhanced radiologic examinations between August 2011 and February 2013 for which the premedication protocol was applied in our institution were assessed for BTRs. Results The protocol was applied to a total of 252 examinations (153 patients, ages 15–87 years; 63 males, 90 females). Of these, 152 were for prior acute adverse reactions to contrast media, 85 were for a history of bronchial asthma, and 15 were for other reasons. There were 198 contrast enhanced CTs and 54 contrast enhanced MRIs. There were nine BTR (4.5%) for iodinated contrast media, and only one BTR (1.9%) for gadolinium contrast media: eight were mild and one was moderate. No patient who had a mild index reaction (IR) had a severe BTR. Conclusion Incidence of BTRs when following the premedication protocol was low. This study by no means proves the efficacy of premedication, but provides some support for following a premedication protocol to improve safety of contrast-enhanced examinations when prior adverse reactions are mild, or when there is a history of asthma. PMID:25287952

Cardiovascular magnetic resonance imaging in hypertrophic cardiomyopathy: Current state of the art.

PubMed

Kamal, Muhammad Umar; Riaz, Irbaz Bin; Janardhanan, Rajesh

2016-01-01

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy with a prevalence of 1:500 (0.2%) in the general population. Sudden cardiac death (SCD) is the most feared presentation of HCM. Therefore, it is essential to identify individuals at high risk in order to prevent SCD. The absence of conventional risk factors does not nullify the risk of HCM related SCD. Although echocardiography is currently the most widely used imaging modality, cardiac magnetic resonance (CMR) allows detailed characterization of the HCM phenotype, which makes it possible to differentiate HCM from other causes of left ventricular hypertrophy. CMR has the potential to further refine risk stratification. Late gadolinium enhancement (LGE) on CMR is a high-risk feature and there is emerging data to suggest that the presence of LGE should be employed as a marker for major adverse outcomes such as SCD, arrhythmias, systolic and diastolic heart failure. Hence, LGE on CMR may be considered an additional risk factor for SCD in HCM patients and should be incorporated in decision-making for implant-able cardioverter defibrillator implantation to aid primary prevention. Novel markers such as the extent of myocardial fibrosis on CMR must be accounted for comprehensive risk stratifica-tion of HCM patients. The purpose of this review is to discuss the current status and emerging role of CMR in HCM.

Myocardial Blood Volume Is Associated with Myocardial Oxygen Consumption: An Experimental Study with CMR in a Canine Model

PubMed Central

McCommis, Kyle S.; Zhang, Haosen; Goldstein, Thomas A.; Misselwitz, Bernd; Abendschein, Dana R.; Gropler, Robert J.; Zheng, Jie

2009-01-01

OBJECTIVES To evaluate the feasibility of cardiovascular MR (CMR) to determine regional myocardial perfusion and O2 metabolism, and assess the role of myocardial blood volume (MBV) on oxygen supply. BACKGROUND Coronary artery disease presents as an imbalance of myocardial oxygen supply and demand. We have developed relevant CMR methods to determine the relationship of myocardial blood flow (MBF) and MBV to oxygen consumption (MVO2) during pharmacologic hyperemia. METHODS Twenty-one mongrel dogs were studied with varying stenosis severities imposed on the proximal left anterior descending (LAD) coronary artery. MBF and MBV were determined by CMR first-pass perfusion, while the oxygen extraction fraction (OEF) and MVO2 were determined by the myocardial Blood-Oxygen-Level-Dependent (BOLD) effect and Fick’s law, respectively. MR imaging was performed at rest, and during either dipyridamole-induced vasodilation or dobutamine-induced hyperemia. Regional differences in myocardial perfusion and oxygenation were then evaluated. RESULTS Dipyridamole and dobutamine both led to 145–200% increases in MBF and 50–80% increases in MBV in normal perfused myocardium. As expected, MVO2 increased more significantly with dobutamine (~175%) than dipyridamole (~40%). Coronary stenosis resulted in an attenuation of MBF, MBV, and MVO2 in both the LAD-subtended stenosis region and the left circumflex subtended remote region. Liner regression analysis showed that MBV reserve appears to be more correlated with MVO2 reserve during dobutamine stress than MBF reserve, particularly in the stenotic regions. Conversely, MBF reserve appears to be more correlated with MVO2 reserve during dipyridamole, although neither of these differences was significant. CONCLUSIONS Noninvasive evaluation of both myocardial perfusion and oxygenation by CMR facilitates direct monitoring of regional myocardial ischemia and provides a valuable tool for better understanding microvascular pathophysiology. These

Gadolinium Enhancement in Intracranial Atherosclerotic Plaque and Ischemic Stroke: A Systematic Review and Meta-Analysis.

PubMed

Gupta, Ajay; Baradaran, Hediyeh; Al-Dasuqi, Khalid; Knight-Greenfield, Ashley; Giambrone, Ashley E; Delgado, Diana; Wright, Drew; Teng, Zhongzhao; Min, James K; Navi, Babak B; Iadecola, Costantino; Kamel, Hooman

2016-08-15

Gadolinium enhancement on high-resolution magnetic resonance imaging (MRI) has been proposed as a marker of inflammation and instability in intracranial atherosclerotic plaque. We performed a systematic review and meta-analysis to summarize the association between intracranial atherosclerotic plaque enhancement and acute ischemic stroke. We searched the medical literature to identify studies of patients undergoing intracranial vessel wall MRI for evaluation of intracranial atherosclerotic plaque. We recorded study data and assessed study quality, with disagreements in data extraction resolved by a third reader. A random-effects odds ratio was used to assess whether, in any given patient, cerebral infarction was more likely in the vascular territory supplied by an artery with MRI-detected plaque enhancement as compared to territory supplied by an artery without enhancement. We calculated between-study heterogeneity using the Cochrane Q test and publication bias using the Begg-Mazumdar test. Eight articles published between 2011 and 2015 met inclusion criteria. These studies provided information about plaque enhancement characteristics from 295 arteries in 330 patients. We found a significant positive relationship between MRI enhancement and cerebral infarction in the same vascular territory, with a random effects odds ratio of 10.8 (95% CI 4.1-28.1, P<0.001). No significant heterogeneity (Q=11.08, P=0.14) or publication bias (P=0.80) was present. Intracranial plaque enhancement on high-resolution vessel wall MRI is strongly associated with ischemic stroke. Evaluation for plaque enhancement on MRI may be a useful test to improve diagnostic yield in patients with ischemic strokes of undetermined etiology. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Comparison of exercise electrocardiography and stress perfusion CMR for the detection of coronary artery disease in women

PubMed Central

2012-01-01

Background Exercise electrocardiography (ECG) is frequently used in the work-up of patients with suspected coronary artery disease (CAD), however the accuracy is reduced in women. Cardiovascular magnetic resonance (CMR) stress testing can accurately diagnose CAD in women. To date, a direct comparison of CMR to ECG has not been performed. Methods and results We prospectively enrolled 88 consecutive women with chest pain or other symptoms suggestive of CAD. Patients underwent a comprehensive clinical evaluation, exercise ECG, a CMR stress test including perfusion and infarct imaging, and x-ray coronary angiography (CA) within 24 hours. CAD was defined as stenosis ≥70% on quantitative analysis of CA. Exercise ECG, CMR and CA was completed in 68 females (age 66.4 ± 8.8 years, number of CAD risk factors 3.5 ± 1.4). The prevalence of CAD on CA was 29%. The Duke treadmill score (DTS) in the entire group was −3.0 ± 5.4 and was similar in those with and without CAD (−4.5 ± 5.8 and −2.4 ± 5.1; P = 0.12). Sensitivity, specificity and accuracy for CAD diagnosis was higher for CMR compared with exercise ECG (sensitivities 85% and 50%, P = 0.02, specificities 94% and 73%, P = 0.01, and accuracies 91% and 66%, P = 0.0007, respectively). Even after applying the DTS the accuracy of CMR was higher compared to exercise ECG (area under ROC curve 0.94 ± 0.03 vs 0.56 ± 0.07; P = 0.0001). Conclusions In women with intermediate-to-high risk for CAD who are able to exercise and have interpretable resting ECG, CMR stress perfusion imaging has higher accuracy for the detection of relevant obstruction of the epicardial coronaries when directly compared to exercise ECG. PMID:22697372

Strain analysis in CRT candidates using the novel segment length in cine (SLICE) post-processing technique on standard CMR cine images.

PubMed

Zweerink, Alwin; Allaart, Cornelis P; Kuijer, Joost P A; Wu, LiNa; Beek, Aernout M; van de Ven, Peter M; Meine, Mathias; Croisille, Pierre; Clarysse, Patrick; van Rossum, Albert C; Nijveldt, Robin

2017-12-01

Although myocardial strain analysis is a potential tool to improve patient selection for cardiac resynchronization therapy (CRT), there is currently no validated clinical approach to derive segmental strains. We evaluated the novel segment length in cine (SLICE) technique to derive segmental strains from standard cardiovascular MR (CMR) cine images in CRT candidates. Twenty-seven patients with left bundle branch block underwent CMR examination including cine imaging and myocardial tagging (CMR-TAG). SLICE was performed by measuring segment length between anatomical landmarks throughout all phases on short-axis cines. This measure of frame-to-frame segment length change was compared to CMR-TAG circumferential strain measurements. Subsequently, conventional markers of CRT response were calculated. Segmental strains showed good to excellent agreement between SLICE and CMR-TAG (septum strain, intraclass correlation coefficient (ICC) 0.76; lateral wall strain, ICC 0.66). Conventional markers of CRT response also showed close agreement between both methods (ICC 0.61-0.78). Reproducibility of SLICE was excellent for intra-observer testing (all ICC ≥0.76) and good for interobserver testing (all ICC ≥0.61). The novel SLICE post-processing technique on standard CMR cine images offers both accurate and robust segmental strain measures compared to the 'gold standard' CMR-TAG technique, and has the advantage of being widely available. • Myocardial strain analysis could potentially improve patient selection for CRT. • Currently a well validated clinical approach to derive segmental strains is lacking. • The novel SLICE technique derives segmental strains from standard CMR cine images. • SLICE-derived strain markers of CRT response showed close agreement with CMR-TAG. • Future studies will focus on the prognostic value of SLICE in CRT candidates.

Characteristics of Gadolinium Oxide Nanoparticles Using Terahertz Spectroscopy (abstract)

NASA Astrophysics Data System (ADS)

Lee, Dongkyu; Maeng, Inhee; Oh, Seung Jae; Kim, Taekhoon; Cho, Byung Kyu; Lee, Kwangyeol; Son, Joo-Hiuk

2009-04-01

The penetration property of the terahertz electromagnetic (THz) wave is relevant to its use. We used the THz wave spectroscopy system which easily penetrates some materials that do not contain water, e.g., plastic and ceramics. The system has been developed for several purposes, including measuring the properties of semiconductors and bio-materials, and detecting plastic bombs and ceramic knives at airports. It is also used for medical imaging systems, such as magnetic resonance imaging (MRI), at some research institutes. It can show not only the difference in amplitude, but also the difference of the phase of each point of sample. MRI technology usually uses contrast agents to enhance the quality of the image. Gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA), made with a heavy metal ion, is commonly used as a clinical MRI contrast agent. Gadolinium oxide (Gd2O3) nanoparticle is a new contrast agent. It serves to equip the core of each particle with antibodies or ligands. It can freely circulate in blood vessels without amassing in the liver or lungs. This study shows the characteristics of gadolinium oxide nanoparticles to further advance terahertz medical imaging.

Bone marrow with diffuse tumor infiltration in patients with lymphoproliferative diseases: dynamic gadolinium-enhanced MR imaging.

PubMed

Rahmouni, Alain; Montazel, Jean-Luc; Divine, Marine; Lepage, Eric; Belhadj, Karim; Gaulard, Philippe; Bouanane, Mohamed; Golli, Mondher; Kobeiter, Hicham

2003-12-01

To evaluate gadolinium enhancement of bone marrow in patients with lymphoproliferative diseases and diffuse bone marrow involvement. Dynamic contrast material-enhanced magnetic resonance (MR) imaging of the thoracolumbar spine was performed in 42 patients with histologically proved diffuse bone marrow involvement and newly diagnosed myeloma (n = 31), non-Hodgkin lymphoma (n = 8), or Hodgkin disease (n = 3). The maximum percentage of enhancement (Emax), enhancement slope, and enhancement washout were determined from enhancement time curves (ETCs). A three-grade system for scoring bone marrow involvement was based on the percentage of neoplastic cells in bone marrow samples. Quantitative ETC values for the 42 patients were compared with ETC values for healthy subjects and with grades of bone marrow involvement by using mean t test comparisons. Receiver operating characteristic (ROC) analysis was conducted by comparing Emax values between patients with and those without bone marrow involvement. Baseline and follow-up MR imaging findings were compared in nine patients. Significant differences in Emax (P <.001), slope (P <.001), and washout (P =.005) were found between subjects with normal bone marrow and patients with diffuse bone marrow involvement. ROC analysis results showed Emax values to have a diagnostic accuracy of 99%. Emax, slope, and washout values increased with increasing bone marrow involvement grade. The mean Emax increased from 339% to 737%. Contrast enhancement decreased after treatment in all six patients who responded to treatment but not in two of three patients who did not respond to treatment. Dynamic contrast-enhanced MR images can demonstrate increased bone marrow enhancement in patients with lymphoproliferative diseases and marrow involvement.

4D MUSIC CMR: value-based imaging of neonates and infants with congenital heart disease.

PubMed

Nguyen, Kim-Lien; Han, Fei; Zhou, Ziwu; Brunengraber, Daniel Z; Ayad, Ihab; Levi, Daniel S; Satou, Gary M; Reemtsen, Brian L; Hu, Peng; Finn, J Paul

2017-04-03

4D Multiphase Steady State Imaging with Contrast (MUSIC) acquires high-resolution volumetric images of the beating heart during uninterrupted ventilation. We aim to evaluate the diagnostic performance and clinical impact of 4D MUSIC in a cohort of neonates and infants with congenital heart disease (CHD). Forty consecutive neonates and infants with CHD (age range 2 days to 2 years, weight 1 to 13 kg) underwent 3.0 T CMR with ferumoxytol enhancement (FE) at a single institution. Independently, two readers graded the diagnostic image quality of intra-cardiac structures and related vascular segments on FE-MUSIC and breath held FE-CMRA images using a four-point scale. Correlation of the CMR findings with surgery and other imaging modalities was performed in all patients. Clinical impact was evaluated in consensus with referring surgeons and cardiologists. One point was given for each of five key outcome measures: 1) change in overall management, 2) change in surgical approach, 3) reduction in the need for diagnostic catheterization, 4) improved assessment of risk-to-benefit for planned intervention and discussion with parents, 5) accurate pre-procedural roadmap. All FE-CMR studies were completed successfully, safely and without adverse events. On a four-point scale, the average FE-MUSIC image quality scores were >3.5 for intra-cardiac structures and >3.0 for coronary arteries. Intra-cardiac morphology and vascular anatomy were well visualized with good interobserver agreement (r = 0.46). Correspondence between the findings on MUSIC, surgery, correlative imaging and autopsy was excellent. The average clinical impact score was 4.2 ± 0.9. In five patients with discordant findings on echo/MUSIC (n = 5) and catheter angiography/MUSIC (n = 1), findings on FE-MUSIC were shown to be accurate at autopsy (n = 1) and surgery (n = 4). The decision to undertake biventricular vs univentricular repair was amended in 2 patients based on FE-MUSIC findings

Hyperintense Dentate Nuclei on T1-Weighted MRI: Relation to Repeat Gadolinium Administration

PubMed Central

Adin, M.E.; Kleinberg, L.; Vaidya, D.; Zan, E.; Mirbagheri, S.; Yousem, D.M.

2016-01-01

BACKGROUND AND PURPOSE A hyperintense appearance of the dentate nucleus on T1-weighted MR images has been related to various clinical conditions, but the etiology remains indeterminate. We aimed to investigate the possible associations between a hyperintense appearance of the dentate nucleus on T1-weighted MR images in patients exposed to radiation and factors including, but not limited to, the cumulative number of contrast-enhanced MR images, amount of gadolinium administration, dosage of ionizing radiation, and patient demographics. MATERIALS AND METHODS The medical records of 706 consecutive patients who were treated with brain irradiation at The Johns Hopkins Medical Institutions between 1995 and 2010 were blindly reviewed by 2 readers. RESULTS One hundred eighty-four subjects were included for dentate nuclei analysis. Among the 184 subjects who cumulatively underwent 2677 MR imaging studies following intravenous gadolinium administration, 103 patients had hyperintense dentate nuclei on precontrast T1-weighted MR images. The average number of gadolinium-enhanced MR imaging studies performed in the group with normal dentate nuclei was significantly lower than that of the group with hyperintense dentate nuclei. The average follow-up time was 62.5 months. No significant difference was observed between hyperintense and normal dentate nuclei groups in terms of exposed radiation dose, serum creatinine and calcium/phosphate levels, patient demographics, history of chemotherapy, and strength of the scanner. No dentate nuclei abnormalities were found on the corresponding CT scans of patients with hyperintense dentate nuclei (n = 44). No dentate nuclei abnormalities were found in 53 healthy volunteers. CONCLUSIONS Repeat performance of gadolinium-enhanced studies likely contributes to a long-standing hyperintense appearance of dentate nuclei on precontrast T1-weighted-MR images. PMID:26294649

Gadolinium-DTPA enhanced magnetic resonance imaging of bone cysts in patients with rheumatoid arthritis.

PubMed Central

Gubler, F M; Algra, P R; Maas, M; Dijkstra, P F; Falke, T H

1993-01-01

OBJECTIVES--To examine the contents of intraosseous cysts in patients with rheumatoid arthritis (RA) through the signal intensity characteristics on gadolinium-DTPA (Gd-DTPA) enhanced magnetic resonance imaging. METHODS--The hand or foot joints of nine patients with the cystic form of RA (where the initial radiological abnormality consisted of intraosseous cysts without erosions) were imaged before and after intravenous administration of Gd-DTPA. A 0.6 unit, T1 weighted spin echo and T2* weighted gradient echo were used to obtain images in at least two perpendicular planes. RESULTS--Most cysts showed a low signal intensity on the non-enhanced T1 weighted (spin echo) images and a high signal intensity on the T2* weighted (gradient echo) images, consistent with a fluid content. No cyst showed an enhancement of signal intensity on the T1 weighted images after intravenous administration of Gd-DTPA, whereas synovium hyperplasia at the site of bony erosions did show an increased signal intensity after Gd-DTPA. Magnetic resonance imaging detected more cysts (as small as 2 mm) than plain films, and the cysts were located truly intraosseously. In six patients no other joint abnormalities were identified by magnetic resonance imaging; the three other patients also showed, after Gd-DTPA administration, an enhanced synovium at the site of bony erosions. CONCLUSIONS--It is suggested that intraosseous bone cysts in patients with RA do not contain hyperaemic synovial proliferation. The bone cysts in patients with the cystic form of RA may be the only joint abnormality. Images PMID:8257207

Long term effects of cocaine on the heart assessed by cardiovascular magnetic resonance at 3T

PubMed Central

2014-01-01

Background Cocaine is an addictive, sympathomimetic drug with potentially lethal effects. The prevalence and features of cocaine cardiotoxicity are not well known. We aimed to assess these effects using a comprehensive cardiovascular magnetic resonance (CMR) protocol in a large group of asymptomatic cocaine users. Methods Consecutive (n = 94, 81 males, 36.6 ±7 years), non-selected, cocaine abusers were recruited and had a medical history, examination, ECG, blood test and CMR. The CMR study included measurement of left and right ventricular (LV, RV) dimensions and ejection fraction (EF), sequences for detection of myocardial oedema and late gadolinium enhancement (LGE). Images were compared to a cohort of healthy controls. Results Years of regular cocaine use were 13.9 ± 9. When compared to the age-matched healthy cohort, the cocaine abusers had increased LV end-systolic volume, LV mass index and RV end-systolic volume, with decreased LVEF and RVEF. No subject had myocardial oedema, but 30% had myocardial LGE indicating myocardial damage. Conclusions CMR detected cardiovascular disease in 71% of this cohort of consecutive asymptomatic cocaine abusers and mean duration of abuse was related to probability of LV systolic dysfunction. PMID:24758161

Simultaneous Right and Left Heart Real-Time, Free-Breathing CMR Flow Quantification Identifies Constrictive Physiology

PubMed Central

Thavendiranathan, Paaladinesh; Verhaert, David; Walls, Michael C.; Bender, Jacob A.; Rajagopalan, Sanjay; Chung, Yiu-Cho; Simonetti, Orlando P.; Raman, Subha V.

2015-01-01

OBJECTIVES The purpose of this study was to evaluate the ability of a novel cardiac magnetic resonance (CMR) real-time phase contrast (RT-PC) flow measurement technique to reveal the discordant respirophasic changes in mitral and tricuspid valve in flow indicative of the abnormal hemodynamics seen in constrictive pericarditis (CP). BACKGROUND Definitive diagnosis of CP requires identification of constrictive hemodynamics with or without pericardial thickening. CMR to date has primarily provided morphological assessment of the pericardium. METHODS Sixteen patients (age 57 ± 13 years) undergoing CMR to assess known or suspected CP and 10 controls underwent RT-PC that acquired simultaneous mitral valve and tricuspid valve inflow velocities over 10 s of unrestricted breathing. The diagnosis of CP was confirmed via clinical history, diagnostic imaging, cardiac catheterization, intraoperative findings, and histopathology. RESULTS Ten patients had CP, all with increased pericardial thickness (6.2 ± 1.0 mm). RT-PC imaging demonstrated discordant respirophasic changes in atrioventricular valve inflow velocities in all CP patients, with mean ± SD mitral valve and tricuspid valve inflow velocity variation of 46 ± 20% and 60 ± 15%, respectively, compared with 16 ± 8% and 24 ± 11% in patients without CP (p < 0.004 vs. patients with CP for both) and 17 ± 5% and 31 ± 13% in controls (p < 0.001 vs. patients with CP for both). There was no difference in atrioventricular valve inflow velocity variation between patients without CP compared with controls (p > 0.3 for both). Respiratory variation exceeding 25% across the mitral valve yielded a sensitivity of 100%, a specificity of 100%, and an area under the receiver-operating characteristic curve of 1.0 to detect CP physiology. Using a cutoff of 45%, variation of transtricuspid valve velocity had a sensitivity of 90%, a specificity of 88%, and an area under the receiver-operating characteristic curve of 0.98. CONCLUSIONS

Biological control of Rhizoctonia root rot on bean by phenazine- and cyclic lipopeptide-producing Pseudomonas CMR12a

USDA-ARS?s Scientific Manuscript database

Pseudomonas CMR12a was previously selected as an efficient biocontrol strain producing phenazines and cyclic lipopeptides (CLPs). In this study, biocontrol capacity of Pseudomonas CMR12a against Rhizoctonia root rot of bean and the involvement of phenazines and CLPs in this ability were tested. Two ...

Feature tracking CMR reveals abnormal strain in preclinical arrhythmogenic right ventricular dysplasia/ cardiomyopathy: a multisoftware feasibility and clinical implementation study.

PubMed

Bourfiss, Mimount; Vigneault, Davis M; Aliyari Ghasebeh, Mounes; Murray, Brittney; James, Cynthia A; Tichnell, Crystal; Mohamed Hoesein, Firdaus A; Zimmerman, Stefan L; Kamel, Ihab R; Calkins, Hugh; Tandri, Harikrishna; Velthuis, Birgitta K; Bluemke, David A; Te Riele, Anneline S J M

2017-09-01

Regional right ventricular (RV) dysfunction is the hallmark of Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy (ARVD/C), but is currently only qualitatively evaluated in the clinical setting. Feature Tracking Cardiovascular Magnetic Resonance (FT-CMR) is a novel quantitative method that uses cine CMR to calculate strain values. However, most prior FT-CMR studies in ARVD/C have focused on global RV strain using different software methods, complicating implementation of FT-CMR in clinical practice. We aimed to assess the clinical value of global and regional strain using FT-CMR in ARVD/C and to determine differences between commercially available FT-CMR software packages. We analyzed cine CMR images of 110 subjects (39 overt ARVD/C [mutation+/phenotype+], 40 preclinical ARVD/C [mutation+/phenotype-] and 31 control) for global and regional (subtricuspid, anterior, apical) RV strain in the horizontal longitudinal axis using four FT-CMR software methods (Multimodality Tissue Tracking, TomTec, Medis and Circle Cardiovascular Imaging). Intersoftware agreement was assessed using Bland Altman plots. For global strain, all methods showed reduced strain in overt ARVD/C patients compared to control subjects (p < 0.041), whereas none distinguished preclinical from control subjects (p > 0.275). For regional strain, overt ARVD/C patients showed reduced strain compared to control subjects in all segments which reached statistical significance in the subtricuspid region for all software methods (p < 0.037), in the anterior wall for two methods (p < 0.005) and in the apex for one method (p = 0.012). Preclinical subjects showed abnormal subtricuspid strain compared to control subjects using one of the software methods (p = 0.009). Agreement between software methods for absolute strain values was low (Intraclass Correlation Coefficient = 0.373). Despite large intersoftware variability of FT-CMR derived strain values, all four software methods distinguished

Cardiovascular magnetic resonance in the evaluation of hypertrophic and infiltrative cardiomyopathies.

PubMed

O'Hanlon, Rory; Pennell, Dudley J

2009-07-01

There is often considerable phenotypic overlap in hypertrophic and infiltrative cardiomyopathies. This overlap creates difficulties, when using routine imaging modalities, in arriving at a conclusive diagnosis. Cardiovascular magnetic resonance (CMR) can make diagnosis easier and more certain. Used with gadolinium contrast agent for tissue characterization, CMR offers a superior field of view and temporal resolution, enabling clinicians to make more confident assessments of etiology. CMR may also be a useful modality for stratifying risk and monitoring treatment responses over time in patients with hypertrophic or infiltrative cardiomyopathies. This article highlights the role of CMR in the assessment and, if relevant, the risk stratification of hypertrophic and infiltrative cardiomyopathies.

Geometrically confined ultrasmall gadolinium oxide nanoparticles boost the T1 contrast ability

NASA Astrophysics Data System (ADS)

Ni, Kaiyuan; Zhao, Zhenghuan; Zhang, Zongjun; Zhou, Zijian; Yang, Li; Wang, Lirong; Ai, Hua; Gao, Jinhao

2016-02-01

High-performance magnetic resonance imaging (MRI) contrast agents and novel contrast enhancement strategies are urgently needed for sensitive and accurate diagnosis. Here we report a strategy to construct a new T1 contrast agent based on the Solomon-Bloembergen-Morgan (SBM) theory. We loaded the ultrasmall gadolinium oxide nanoparticles into worm-like interior channels of mesoporous silica nanospheres (Gd2O3@MSN nanocomposites). This unique structure endows the nanocomposites with geometrical confinement, high molecular tumbling time, and a large coordinated number of water molecules, which results in a significant enhancement of the T1 contrast with longitudinal proton relaxivity (r1) as high as 45.08 mM-1 s-1. Such a high r1 value of Gd2O3@MSN, compared to those of ultrasmall Gd2O3 nanoparticles and gadolinium-based clinical contrast agents, is mainly attributed to the strong geometrical confinement effect. This strategy provides new guidance for developing various high-performance T1 contrast agents for sensitive imaging and disease diagnosis.High-performance magnetic resonance imaging (MRI) contrast agents and novel contrast enhancement strategies are urgently needed for sensitive and accurate diagnosis. Here we report a strategy to construct a new T1 contrast agent based on the Solomon-Bloembergen-Morgan (SBM) theory. We loaded the ultrasmall gadolinium oxide nanoparticles into worm-like interior channels of mesoporous silica nanospheres (Gd2O3@MSN nanocomposites). This unique structure endows the nanocomposites with geometrical confinement, high molecular tumbling time, and a large coordinated number of water molecules, which results in a significant enhancement of the T1 contrast with longitudinal proton relaxivity (r1) as high as 45.08 mM-1 s-1. Such a high r1 value of Gd2O3@MSN, compared to those of ultrasmall Gd2O3 nanoparticles and gadolinium-based clinical contrast agents, is mainly attributed to the strong geometrical confinement effect. This strategy

Implementation and evaluation of a community-based medication reconciliation (CMR) system at the hospital-community interface of care.

PubMed

Bailey, Allan L; Moe, Grace; Moe, Jessica; Oland, Ryan

2009-01-01

The WestView community-based medication reconciliation (CMR) aims to decrease medication error risk. A clinical pharmacist visits patients' homes within 72 hours of hospital discharge and compares medications in discharge orders, family physicians' charts, community pharmacy profiles and in the home. Discrepancies are discussed and reconciled with the dispenser, hospital prescriber and follow-up care provider. The CMR demonstrates successful integration that is patient-centred and standardized, bridging the hospital-community interface and improving information flow and communication channels across a family-physician-led multi-disciplinary team. A concurrent research study will evaluate the impact of CMR on health services utilization and to develop a risk prediction model.

A new automatic algorithm for quantification of myocardial infarction imaged by late gadolinium enhancement cardiovascular magnetic resonance: experimental validation and comparison to expert delineations in multi-center, multi-vendor patient data.

PubMed

Engblom, Henrik; Tufvesson, Jane; Jablonowski, Robert; Carlsson, Marcus; Aletras, Anthony H; Hoffmann, Pavel; Jacquier, Alexis; Kober, Frank; Metzler, Bernhard; Erlinge, David; Atar, Dan; Arheden, Håkan; Heiberg, Einar

2016-05-04

Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) using magnitude inversion recovery (IR) or phase sensitive inversion recovery (PSIR) has become clinical standard for assessment of myocardial infarction (MI). However, there is no clinical standard for quantification of MI even though multiple methods have been proposed. Simple thresholds have yielded varying results and advanced algorithms have only been validated in single center studies. Therefore, the aim of this study was to develop an automatic algorithm for MI quantification in IR and PSIR LGE images and to validate the new algorithm experimentally and compare it to expert delineations in multi-center, multi-vendor patient data. The new automatic algorithm, EWA (Expectation Maximization, weighted intensity, a priori information), was implemented using an intensity threshold by Expectation Maximization (EM) and a weighted summation to account for partial volume effects. The EWA algorithm was validated in-vivo against triphenyltetrazolium-chloride (TTC) staining (n = 7 pigs with paired IR and PSIR images) and against ex-vivo high resolution T1-weighted images (n = 23 IR and n = 13 PSIR images). The EWA algorithm was also compared to expert delineation in 124 patients from multi-center, multi-vendor clinical trials 2-6 days following first time ST-elevation myocardial infarction (STEMI) treated with percutaneous coronary intervention (PCI) (n = 124 IR and n = 49 PSIR images). Infarct size by the EWA algorithm in vivo in pigs showed a bias to ex-vivo TTC of -1 ± 4%LVM (R = 0.84) in IR and -2 ± 3%LVM (R = 0.92) in PSIR images and a bias to ex-vivo T1-weighted images of 0 ± 4%LVM (R = 0.94) in IR and 0 ± 5%LVM (R = 0.79) in PSIR images. In multi-center patient studies, infarct size by the EWA algorithm showed a bias to expert delineation of -2 ± 6 %LVM (R = 0.81) in IR images (n = 124) and 0 ± 5%LVM (R = 0.89) in

Direct comparison of intra-articular versus intravenous delayed gadolinium-enhanced MRI of hip joint cartilage.

PubMed

Zilkens, Christoph; Miese, Falk; Kim, Young-Jo; Jäger, Marcus; Mamisch, Tallal C; Hosalkar, Harish; Antoch, Gerald; Krauspe, Rüdiger; Bittersohl, Bernd

2014-01-01

To investigate the potential of delayed gadolinium-enhanced magnetic resonance imaging in cartilage (dGEMRIC) after intra-articular (ia) contrast agent administration at 3 Tesla (T), a paired study comparing intravenous (iv) dGEMRIC (standard) with ia-dGEMRIC was performed. Thirty-five symptomatic patients with suspected cartilage damage underwent ia- and iv-dGEMRIC. MRI was performed with a 3T system wherein the interval between both measurements was 2 weeks. For iv-dGEMRIC, FDA approved Gd-DOTA(-) was injected intravenously 45 min before the MRI scan. For ia-dGEMRIC, 10-20 mL of a 2 mM solution of Gd- DOTA(-) was injected under fluoroscopic guidance 30 min before the MRI scan. Both ia- and iv-dGEMRIC demonstrated the typical T1Gd pattern in hip joint cartilage with increasing values toward the superior regions in acetabular cartilage reflecting the higher glycosaminoglycan (GAG) content in the main weight-bearing area. Correlation analysis revealed a moderate correlation between both techniques (r = 0.439, P-value < 0.001), whereas the T1Gd values for iv-dGEMRIC were significantly higher than those for ia-dGEMRIC. This corresponds with the Bland-Altman plot analysis, which revealed a systemic bias (higher T1Gd values after iv gadolinium application) of ∼70 ms. Ia-dGEMRIC was able to reveal the characteristic T1Gd pattern in hip joint cartilage confirming the sensitivity of ia-dGEMRIC for GAG. In addition, there was a significant correlation between iv-dGEMRIC and ia-dGEMRIC. However, the T1Gd values after ia contrast media application were significantly lower than those after iv application that has to be considered for future studies. Copyright © 2013 Wiley Periodicals, Inc.

Use of Cardiac Magnetic Resonance Imaging to Evaluate Cardiac Structure, Function and Fibrosis in Children with Infantile Pompe Disease on Enzyme Replacement Therapy

PubMed Central

Barker, Piers C.A.; Pasquali, Sara K.; Darty, Stephen; Ing, Richard J.; Li, Jennifer S.; Kim, Raymond J.; DeArmey, Stephanie; Kishnani, Priya S.; Campbell, Michael J.

2010-01-01

Background Pompe disease (acid α-glucosidase deficiency) is one of several lysosomal storage diseases amenable to treatment with enzyme replacement therapy (ERT). While echocardiography (echo) has been the standard method to evaluate the cardiac response to ERT, cardiac magnetic resonance imaging (CMR) has the advantage of better tissue definition and characterization of myocardial fibrosis. However, CMR for Pompe disease is not frequently performed due to the high risk of sedation. We report the first use of CMR in a feasible protocol to quantify left ventricular (LV) mass, function, and presence of myocardial fibrosis in the Pompe population. Methods Children with Pompe disease on ERT were assessed with transthoracic echo and CMR over a 3 year period at a single institution. Echocardiography was performed using standard techniques without sedation. CMR was performed using retrospectively gated and real-time imaging, with and without sedation. LV mass indexed to body surface area (LVMI) and ejection fraction (EF) were measured by both echo and CMR, and evaluated for change over time. Myocardial fibrosis was assessed with CMR by delayed enhancement imaging 5-10 min after gadolinium contrast using single-shot inversion recovery sequences with inversion time set to null the myocardium. Results Seventeen CMR scans were successfully performed in 10 subjects with Pompe disease (median age at first CMR 9 months, range 1-38 months, 80% male), with sedation only performed for 4 studies. There was a median interval of 5 months (range 0-34 months) from start of ERT to first CMR (baseline). At baseline, median indexed LVMI by CMR (140.0 g/m2, range 43.8-334.0) tended to be lower than that assessed by echo (median 204.0 g/m2, range 52.0-385.0), but did not reach statistical significance. At baseline, CMR EF was similar to that assessed by echo (55% vs. 55%). Overall, there was not a significant decrease in CMR measured LVMI over time (CMR median LVMI at baseline 94 g/m2

MRI-based evidence for myocardial involvement in women with hypereosinophilic syndrome.

PubMed

Miszalski-Jamka, Tomasz; Szczeklik, Wojciech; Karwat, Krzysztof; Sokołowska, Barbara; Gąsior, Jolanta; Rucińska, Małgorzata; Mazur, Wojciech; Skotnicki, Aleksander; Kereiakes, Dean J; Urbańczyk, Małgorzata; Jaźwiec, Przemysław; Musiał, Jacek

2015-01-01

The aim of the study was to assess the presence and spectrum of cardiac abnormalities identified by cardiac magnetic resonance (CMR) in women with hypereosinophilic syndrome (HES) of undefined etiology, who present with normal electrocardiography (ECG) and transthoracic echocardiography (TTE) and no history of heart disease. Ten women (mean age, 48 ± 14 years) with HES of undefined etiology, normal ECG and TTE, and no history of heart disease underwent CMR. CMR showed cardiac abnormalities in 6 subjects. Five patients had nonischemic late gadolinium enhancement (LGE) lesions within the left ventricular (LV) myocardium, and 3 patients demonstrated CMR evidence of myocardial inflammation. The LV ejection fraction was 68.5 ± 5.7%, and the end-diastolic volume index was 62.7 ± 14.7 mL/m(2). The maximum measured blood eosinophil count correlated with LVLGE volume (r = 0.80, P = 0.006) and was 11374 ± 6242 cells/μL and 4114 ± 2972 cells/μL (P = 0.047) in patients with and without LGE lesions, respectively. The actual blood eosinophil count in subjects with and without CMR evidence of myocarditis was 1058 ± 520 cells/μL and 354 ± 377 cells/μL (P = 0.04), respectively. Despite normal ECG, TTE, and absence of history of heart disease, women with HES of unknown etiology frequently demonstrate cardiac abnormalities on CMR, the presence and extent of which are related to blood eosinophil count.

The dosimetric impact of gadolinium-based contrast media in GBM brain patient plans for a MRI-Linac

NASA Astrophysics Data System (ADS)

Bilal Ahmad, Syed; Paudel, Moti Raj; Sarfehnia, Arman; Kim, Anthony; Pang, Geordi; Ruschin, Mark; Sahgal, Arjun; Keller, Brian M.

2017-08-01

Dosimetric effects of gadolinium based contrast media (Gadovist) were evaluated for the Elekta MRI linear accelerator using the research version of the Monaco treatment planning system (TPS). In order to represent a gadolinium uptake, the contrast was manually assigned to a phantom as well as to the gross tumour volume (GTV) of 6 glioblastoma multiforme (GBM) patients. A preliminary estimate of the dose enhancement, due to gadolinium, was performed using the phantom irradiated with a single beam. A more complicated assessment was performed for the GBM patients using a 7 field IMRT technique. The material table in Monaco was modified in order to identify the presence of a non-biological material. The dose distribution was modelled using GPUMCD (MC algorithm in Monaco) for an unmodified (or default) material table (DMT) as well as for a modified (or custom) material table (CMT) for both the phantom and patients. Various concentrations ranging between 8 and 157 mg ml-1 were used to represent the gadolinium uptake in the patient’s GTV. It was assumed that the gadolinium concentration remained the same for the entire course of radiation treatment. Results showed that at the tissue-Gadovist interface, inside the phantom, dose scored using the DMT was 7% lower compared to that using the CMT for 157 mg ml-1 concentration of gadolinium. Dosimetric differences in the case of the patient study were measured using the DVH parameters. D 50% was higher by 6% when the DMT was used compared to the CMT for dose modelling for a gadolinium concentration of 157 mg ml-1. This difference decreased gradually with decreasing concentration of gadolinium. It was concluded that dosimetric differences can be quantified in Monaco if the tumour-gadolinium concentration is more than 23 mg ml-1. If the gadolinium concentration is lower than 23 mg ml-1, then a correction for the presence of gadolinium may not be necessary in the TPS.

The dosimetric impact of gadolinium-based contrast media in GBM brain patient plans for a MRI-Linac.

PubMed

Ahmad, Syed Bilal; Paudel, Moti Raj; Sarfehnia, Arman; Kim, Anthony; Pang, Geordi; Ruschin, Mark; Sahgal, Arjun; Keller, Brian M

2017-08-01

Dosimetric effects of gadolinium based contrast media (Gadovist) were evaluated for the Elekta MRI linear accelerator using the research version of the Monaco treatment planning system (TPS). In order to represent a gadolinium uptake, the contrast was manually assigned to a phantom as well as to the gross tumour volume (GTV) of 6 glioblastoma multiforme (GBM) patients. A preliminary estimate of the dose enhancement, due to gadolinium, was performed using the phantom irradiated with a single beam. A more complicated assessment was performed for the GBM patients using a 7 field IMRT technique. The material table in Monaco was modified in order to identify the presence of a non-biological material. The dose distribution was modelled using GPUMCD (MC algorithm in Monaco) for an unmodified (or default) material table (DMT) as well as for a modified (or custom) material table (CMT) for both the phantom and patients. Various concentrations ranging between 8 and 157 mg ml -1 were used to represent the gadolinium uptake in the patient's GTV. It was assumed that the gadolinium concentration remained the same for the entire course of radiation treatment. Results showed that at the tissue-Gadovist interface, inside the phantom, dose scored using the DMT was 7% lower compared to that using the CMT for 157 mg ml -1 concentration of gadolinium. Dosimetric differences in the case of the patient study were measured using the DVH parameters. D 50% was higher by 6% when the DMT was used compared to the CMT for dose modelling for a gadolinium concentration of 157 mg ml -1 . This difference decreased gradually with decreasing concentration of gadolinium. It was concluded that dosimetric differences can be quantified in Monaco if the tumour-gadolinium concentration is more than 23 mg ml -1 . If the gadolinium concentration is lower than 23 mg ml -1 , then a correction for the presence of gadolinium may not be necessary in the TPS.

Diagnostic contribution of cardiac magnetic resonance in patients with acute coronary syndrome and culprit-free angiograms.

PubMed

Kawecki, Damian; Morawiec, Beata; Monney, Pierre; Pellaton, Cyril; Wojciechowska, Celina; Jojko, Joanna; Basiak, Marcin; Przywara-Chowaniec, Brygida; Fournier, Stephane; Nowalany-Kozielska, Ewa; Schwitter, Juerg; Muller, Olivier

2015-01-14

In spite of robust knowledge about underlying ischemic myocardial damage, acute coronary syndromes (ACS) with culprit-free angiograms raise diagnostic concerns. The present study aimed to evaluate the additional value of cardiac magnetic resonance (CMR) over commonly available non-CMR standard tests, for the differentiation of myocardial injury in patients with ACS and non-obstructed coronary arteries. Patients with ACS, elevated hs-TnT, and a culprit-free angiogram were prospectively enrolled into the study between January 2009 and July 2013. After initial evaluation with standard tests (ECG, echocardiography, hs-TnT) and provisional exclusion of acute myocardial infarction (AMI) in coronary angiogram, patients were referred for CMR with the suspicion of myocarditis or Takotsubo cardiomyopathy (TTC). According to the result of CMR, patients were reclassified as having myocarditis, AMI, TTC, or non-injured myocardium as assessed by late gadolinium enhancement. Out of 5110 patients admitted with ACS, 75 had normal coronary angiograms and entered the study; 69 of them (92%) were suspected for myocarditis and 6 (8%) for TTC. After CMR, 49 patients were finally diagnosed with myocarditis (65%), 3 with TTC (4%), 7 with AMI (9%), and 16 (21%) with non-injured myocardium. The provisional diagnosis was changed or excluded in 23 patients (31%), with a 9% rate of unrecognized AMI. The study results suggest that the evaluation of patients with ACS and culprit-free angiogram should be complemented by a CMR examination, if available, because the initial work-up with non-CMR tests leads to a significant proportion of misdiagnosed AMI.

Gadolinium-based nanoparticles to improve the hadrontherapy performances.

PubMed

Porcel, Erika; Tillement, Olivier; Lux, François; Mowat, Pierre; Usami, Noriko; Kobayashi, Katsumi; Furusawa, Yoshiya; Le Sech, Claude; Li, Sha; Lacombe, Sandrine

2014-11-01

Nanomedicine is proposed as a novel strategy to improve the performance of radiotherapy. High-Z nanoparticles are known to enhance the effects of ionizing radiation. Recently, multimodal nanoparticles such as gadolinium-based nanoagents were proposed to amplify the effects of x-rays and g-rays and to improve MRI diagnosis. For tumors sited in sensitive tissues, childhood cases and radioresistant cancers, hadrontherapy is considered superior to x-rays and g-rays. Hadrontherapy, based on fast ion radiation, has the advantage of avoiding damage to the tissues behind the tumor; however, the damage caused in front of the tumor is its major limitation. Here, we demonstrate that multimodal gadolinium-based nanoparticles amplify cell death with fast ions used as radiation. Molecular scale experiments give insights into the mechanisms underlying the amplification of radiation effects. This proof-of-concept opens up novel perspectives for multimodal nanomedicine in hadrontherapy, ultimately reducing negative radiation effects in healthy tissues in front of the tumor. Gadolinium-chelating polysiloxane nanoparticles were previously reported to amplify the anti-tumor effects of x-rays and g-rays and to serve as MRI contrast agents. Fast ion radiation-based hadrontherapy avoids damage to the tissues behind the tumor, with a major limitation of tissue damage in front of the tumor. This study demonstrates a potential role for the above nanoagents in optimizing hadrontherapy with preventive effects in healthy tissue and amplified cell death in the tumor. Copyright © 2014 Elsevier Inc. All rights reserved.

Comparison of cardiogoniometry and electrocardiography with perfusion cardiac magnetic resonance imaging and late gadolinium enhancement.

PubMed

Birkemeyer, Ralf; Toelg, Ralph; Zeymer, Uwe; Wessely, Rainer; Jäckle, Sebastian; Hairedini, Bajram; Lübke, Mike; Aßfalg, Manfred; Jung, Werner

2012-12-01

Cardiogoniometry (CGM) is a spatio-temporal five-lead resting electrocardiographic method utilizing automated analysis. The purpose of this study was to determine CGM's and electrocardiography (ECG)'s accuracy for detecting myocardial ischaemia and/or lesions in comparison with perfusion cardiac magnetic resonance imaging (CMRI) and late gadolinium enhancement (LGE). Forty (n= 40) patients with suspected or known stable coronary artery disease were examined by CGM and resting ECG directly prior to CMRI including adenosine stress perfusion (ASP) and LGE. The investigators visually reading the CMRI were blinded to the CGM and ECG results. Half of the patients (n= 20) had a normal CMRI while the other half presented with either abnormal ASP and/or detectable LGE. Cardiogoniometry yielded an accuracy of 83% (sensitivity 70%) and ECG of 63% (sensitivity 35%) compared with CMRI. In this pilot study CGM compares more favourably than ECG with the detection of ischaemia and/or structural myocardial lesions on CMRI.

Comparison of Contrast-Enhanced Ultrasound and Gadolinium-Ethoxybenzyl-Diethylenetriamine Pentaacetic Acid-Enhanced MRI for the Diagnosis of Macroscopic Type of Hepatocellular Carcinoma.

PubMed

Iwamoto, Takayuki; Imai, Yasuharu; Kogita, Sachiyo; Igura, Takumi; Sawai, Yoshiyuki; Fukuda, Kazuto; Yamaguchi, Yoshitaka; Matsumoto, Yasushi; Nakahara, Masanori; Morimoto, Osakuni; Seki, Yasushi; Ohashi, Hiroshi; Fujita, Norihiko; Kudo, Masatoshi; Takehara, Tetsuo

We compared the efficacy of contrast-enhanced ultrasound sonography (CEUS) with sonazoid and gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI for the assessment of macroscopic classification of nodular hepatocellular carcinoma (HCC). Seventy-seven consecutive patients with 79 surgically resected HCCs who underwent both preoperative CEUS and Gd-EOB-DTPA-enhanced MRI were enrolled in this retrospective study. Based on the macroscopic diagnosis of resected specimens, nodules were categorized into the simple nodular (SN) and non-SN type HCC. Two hepatologists independently assessed image datasets of the post-vascular phase of CEUS and hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI to compare their diagnostic performance. Gd-EOB-DTPA-enhanced MRI enabled the evaluation of macroscopic classification in a significantly larger number of nodules than CEUS (78/79 (98.7%) vs. 70/79 (88.6%), p < 0.05). Of 70 nodules that could be evaluated by both modalities, 41 and 29 nodules were pathologically categorized as SN and non-SN, respectively. The areas under the receiver operating characteristic curve (AUC) for non-SN did not differ between CEUS and Gd-EOB-DTPA-enhanced MRI (reader 1: 0.748 for CEUS, 0.808 for MRI; reader 2: 0.759 for CEUS, 0.787 for MRI). The AUC of combined CEUS and Gd-EOB-DTPA-enhanced MRI for SN HCC was 0.855 (reader 1) and 0.824 (reader 2), indicating higher AUC values for the combined modalities. The diagnostic performance for macroscopic classification of nodular HCC of CEUS was comparable with that of Gd-EOB-DTPA-enhanced MRI, although some HCCs could not be evaluated by CEUS owing to lower detectability. The combination of the 2 modalities had a more accurate diagnostic performance. © 2016 S. Karger AG, Basel.

Comparison of gadolinium-EOB-DTPA-enhanced and diffusion-weighted liver MRI for detection of small hepatic metastases.

PubMed

Shimada, Kotaro; Isoda, Hiroyoshi; Hirokawa, Yuusuke; Arizono, Shigeki; Shibata, Toshiya; Togashi, Kaori

2010-11-01

To compare the accuracy of gadolinium ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI with that of diffusion-weighted MRI (DWI) in the detection of small hepatic metastases (2 cm or smaller). Forty-five patients underwent abdominal MRI at 3 T, including T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), heavily T2WI (HASTE), DWI with a b-value of 500 s/mm(2) and contrast-enhanced MRI with Gd-EOB-DTPA. Two groups were assigned and compared: group A (T1WI, T2WI, HASTE and contrast-enhanced study with Gd-EOB-DTPA), and group B (T1WI, T2WI, HASTE and DWI). Two observers independently interpreted the images obtained in a random order. For all hepatic metastases, the diagnostic performance using each imaging set was evaluated by receiver-operating characteristic (ROC) curve analysis. A total of 51 hepatic metastases were confirmed. The area under the ROC curve (Az) of group A was larger than that of group B, and the difference in the mean Az values between the two image sets was statistically significant, whereas, there were three metastases that lay near thin vessels or among multiple cysts and were better visualised in group B than in group A. Gd-EOB-DTPA-enhanced MRI showed higher accuracy in the detection of small metastases than DWI.

Involvement of phenazines and biosurfactants in biocontrol of Pythium myriotylum root rot on cocoyam by Pseudomonas sp. CMR12A

USDA-ARS?s Scientific Manuscript database

Pseudomonas sp. CMR12a was isolated from the rhizosphere of the tropical tuber crop cocoyam and produces both phenazines and cyclic lipopeptide (CLP) biosurfactants. CMR12a was shown to be an efficient biocontrol agent of P. myriotylum on cocoyam. To assess the importance of phenazine and biosurfact...

Electrical and Structural Substrate of Arrhythmogenic Right Ventricular Cardiomyopathy Determined Using Noninvasive Electrocardiographic Imaging and Late Gadolinium Magnetic Resonance Imaging.

PubMed

Andrews, Christopher M; Srinivasan, Neil T; Rosmini, Stefania; Bulluck, Heerajnarain; Orini, Michele; Jenkins, Sharon; Pantazis, Antonis; McKenna, William J; Moon, James C; Lambiase, Pier D; Rudy, Yoram

2017-07-01

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a significant cause of sudden cardiac death in the young. Improved noninvasive assessment of ARVC and better understanding of the disease substrate are important for improving patient outcomes. We studied 20 genotyped ARVC patients with a broad spectrum of disease using electrocardiographic imaging (a method for noninvasive cardiac electrophysiology mapping) and advanced late gadolinium enhancement cardiac magnetic resonance scar imaging. Compared with 20 healthy controls, ARVC patients had longer ventricular activation duration (median, 52 versus 42 ms; P =0.007) and prolonged mean epicardial activation-recovery intervals (a surrogate for local action potential duration; median, 275 versus 241 ms; P =0.014). In these patients, we observed abnormal and varied epicardial activation breakthrough locations and regions of nonuniform conduction and fractionated electrograms. Nonuniform conduction and fractionated electrograms were present in the early concealed phase of ARVC. Electrophysiological abnormalities colocalized with late gadolinium enhancement scar, indicating a relationship with structural disease. Premature ventricular contractions were common in ARVC patients with variable initiation sites in both ventricles. Premature ventricular contraction rate increased with exercise, and within anatomic segments, it correlated with prolonged repolarization, electric markers of scar, and late gadolinium enhancement (all P <0.001). Electrocardiographic imaging reveals electrophysiological substrate properties that differ in ARVC patients compared with healthy controls. A novel mechanistic finding is the presence of repolarization abnormalities in regions where ventricular ectopy originates. The results suggest a potential role for electrocardiographic imaging and late gadolinium enhancement in early diagnosis and noninvasive follow-up of ARVC patients. © 2017 American Heart Association, Inc.

Diuretic-enhanced gadolinium excretory MR urography: comparison of conventional gradient-echo sequences and echo-planar imaging.

PubMed

Nolte-Ernsting, C C; Tacke, J; Adam, G B; Haage, P; Jung, P; Jakse, G; Günther, R W

2001-01-01

The aim of this study was to investigate the utility of different gadolinium-enhanced T1-weighted gradient-echo techniques in excretory MR urography. In 74 urologic patients, excretory MR urography was performed using various T1-weighted gradient-echo (GRE) sequences after injection of gadolinium-DTPA and low-dose furosemide. The examinations included conventional GRE sequences and echo-planar imaging (GRE EPI), both obtained with 3D data sets and 2D projection images. Breath-hold acquisition was used primarily. In 20 of 74 examinations, we compared breath-hold imaging with respiratory gating. Breath-hold imaging was significantly superior to respiratory gating for the visualization of pelvicaliceal systems, but not for the ureters. Complete MR urograms were obtained within 14-20 s using 3D GRE EPI sequences and in 20-30 s with conventional 3D GRE sequences. Ghost artefacts caused by ureteral peristalsis often occurred with conventional 3D GRE imaging and were almost completely suppressed in EPI sequences (p < 0.0001). Susceptibility effects were more pronounced on GRE EPI MR urograms and calculi measured 0.8-21.7% greater in diameter compared with conventional GRE sequences. Increased spatial resolution degraded the image quality only in GRE-EPI urograms. In projection MR urography, the entire pelvicaliceal system was imaged by acquisition of a fast single-slice sequence and the conventional 2D GRE technique provided superior morphological accuracy than 2D GRE EPI projection images (p < 0.0003). Fast 3D GRE EPI sequences improve the clinical practicability of excretory MR urography especially in old or critically ill patients unable to suspend breathing for more than 20 s. Conventional GRE sequences are superior to EPI in high-resolution detail MR urograms and in projection imaging.

The evolution of gadolinium based contrast agents: from single-modality to multi-modality

NASA Astrophysics Data System (ADS)

Zhang, Li; Liu, Ruiqing; Peng, Hui; Li, Penghui; Xu, Zushun; Whittaker, Andrew K.

2016-05-01

Gadolinium-based contrast agents are extensively used as magnetic resonance imaging (MRI) contrast agents due to their outstanding signal enhancement and ease of chemical modification. However, it is increasingly recognized that information obtained from single modal molecular imaging cannot satisfy the higher requirements on the efficiency and accuracy for clinical diagnosis and medical research, due to its limitation and default rooted in single molecular imaging technique itself. To compensate for the deficiencies of single function magnetic resonance imaging contrast agents, the combination of multi-modality imaging has turned to be the research hotpot in recent years. This review presents an overview on the recent developments of the functionalization of gadolinium-based contrast agents, and their application in biomedicine applications.

Nephrogenic Systemic Fibrosis Manifesting a Decade After Exposure to Gadolinium.

PubMed

Larson, Krista N; Gagnon, Amy L; Darling, Melissa D; Patterson, James W; Cropley, Thomas G

2015-10-01

Nephrogenic systemic fibrosis (NSF) is a fibrosing skin disorder that develops in patients with kidney failure and has been linked to exposure to gadolinium-containing contrast agents. The time between exposure to gadolinium and the initial presentation of NSF is typically weeks to months but has been documented to be as long as 3½ years. We report a case of NSF developing 10 years after exposure to gadolinium. A long-term hemodialysis patient was exposed to gadolinium several times between 1998 and 2004 during magnetic resonance angiography of his abdominal vessels and arteriovenous fistula. In 2014, he was seen at our clinic with new dermal papules and plaques. Biopsy of affected skin showed thickening of collagen, CD34+ spindle cells, and increased mucin in the dermis, supporting the diagnosis of NSF. The clinical history and histopathological features of this case support the diagnosis of NSF 10 years after exposure to gadolinium. Although the use of gadolinium contrast agents in patients with kidney failure has markedly decreased, patients with exposure to gadolinium years to decades previously may manifest the disease.

Accumulation of MRI contrast agents in malignant fibrous histiocytoma for gadolinium neutron capture therapy.

PubMed

Fujimoto, T; Ichikawa, H; Akisue, T; Fujita, I; Kishimoto, K; Hara, H; Imabori, M; Kawamitsu, H; Sharma, P; Brown, S C; Moudgil, B M; Fujii, M; Yamamoto, T; Kurosaka, M; Fukumori, Y

2009-07-01

Neutron-capture therapy with gadolinium (Gd-NCT) has therapeutic potential, especially that gadolinium is generally used as a contrast medium in magnetic resonance imaging (MRI). The accumulation of gadolinium in a human sarcoma cell line, malignant fibrosis histiocytoma (MFH) Nara-H, was visualized by the MRI system. The commercially available MRI contrast medium Gd-DTPA (Magnevist, dimeglumine gadopentetate aqueous solution) and the biodegradable and highly gadopentetic acid (Gd-DTPA)-loaded chitosan nanoparticles (Gd-nanoCPs) were prepared as MRI contrast agents. The MFH cells were cultured and collected into three falcon tubes that were set into the 3-tesra MRI system to acquire signal intensities from each pellet by the spin echo method, and the longitudinal relaxation time (T1) was calculated. The amount of Gd in the sample was measured by inductively coupled plasma atomic emission spectrography (ICP-AES). The accumulation of gadolinium in cells treated with Gd-nanoCPs was larger than that in cells treated with Gd-DTPA. In contrast, and compared with the control, Gd-DTPA was more effective than Gd-nanoCPs in reducing T1, suggesting that the larger accumulation exerted the adverse effect of lowering the enhancement of MRI. Further studies are warranted to gain insight into the therapeutic potential of Gd-NCT.

Use of cardiac magnetic resonance imaging to evaluate cardiac structure, function and fibrosis in children with infantile Pompe disease on enzyme replacement therapy.

PubMed

Barker, Piers C A; Pasquali, Sara K; Darty, Stephen; Ing, Richard J; Li, Jennifer S; Kim, Raymond J; DeArmey, Stephanie; Kishnani, Priya S; Campbell, Michael J

2010-12-01

Pompe disease (acid α-glucosidase deficiency) is one of several lysosomal storage diseases amenable to treatment with enzyme replacement therapy (ERT). While echocardiography (echo) has been the standard method to evaluate the cardiac response to ERT, cardiac magnetic resonance imaging (CMR) has the advantage of a better tissue definition and characterization of myocardial fibrosis. However, CMR for Pompe disease is not frequently performed due to a high risk of sedation. We report the first use of CMR in a feasible protocol to quantify left ventricular (LV) mass, function, and the presence of myocardial fibrosis in the Pompe population. Children with Pompe disease on ERT were assessed with transthoracic echo and CMR over a 3 year period at a single institution. Echocardiography was performed using standard techniques without sedation. CMR was performed using retrospectively gated and real-time imaging, with and without sedation. LV mass indexed to body surface area (LVMI) and ejection fraction (EF) were measured by both echo and CMR, and evaluated for change over time. Myocardial fibrosis was assessed by CMR with delayed enhancement imaging 5-10 min after gadolinium contrast using single shot inversion recovery sequences with inversion time set to null the signal from normal myocardium. Seventeen CMR scans were successfully performed in 10 subjects with Pompe disease (median age at first CMR is 9 months, range 1-38 months, 80% male), with sedation only performed in 4 studies. There was a median interval of 5 months (range 0-34 months) from the start of ERT to first CMR (baseline). At baseline, the median indexed LVMI by CMR (140.0 g/m(2), range 43.8-334.0) tended to be lower than that assessed by echo (median 204.0 g/m(2), range 52.0-385.0), but did not reach statistical significance. At baseline, CMR EF was similar to that assessed by echo (55% vs. 55%). Overall, there was no significant decrease in CMR measured LVMI over time (CMR median LVMI at baseline 94 g

Nephrogenic systemic fibrosis (NSF): a late adverse reaction to some of the gadolinium based contrast agents

PubMed Central

Marckmann, Peter; Logager, Vibeke B.

2007-01-01

Abstract Until recently it was believed that extracellular gadolinium based contrast agents were safe for both the kidneys and all other organs within the dose range up to 0.3 mmol/kg body weight. However, in 2006, it was demonstrated that some gadolinium based contrast agents may trigger the development of nephrogenic systemic fibrosis, a generalised fibrotic disorder, in renal failure patients. Accordingly, the use of gadodiamide and gadopentate dimeglumine for renal failure patients was banned in Europe in spring 2007. The same two compounds should only be used cautiously in patients with moderate renal dysfunction. The current paper reviews the situation (July 2007) regarding gadolinium based contrast agent and the severe delayed reaction to some of these agents. The fear of nephrogenic systemic fibrosis should not lead to a denial of a well indicated enhanced magnetic resonance imaging examination. PMID:17905680

Cardiac involvement in ANCA (+) and ANCA (-) Churg-Strauss syndrome evaluated by cardiovascular magnetic resonance.

PubMed

Mavrogeni, Sophie; Karabela, Georgia; Gialafos, Elias; Stavropoulos, Efthymios; Spiliotis, George; Katsifis, Gikas; Kolovou, Genovefa

2013-10-01

The cardiovascular magnetic resonance (CMR) pattern of Churg-Strauss syndrome (CSS) includes myopericarditis, diffuse subendocardial vasculitis or myocardial infarction with or without cardiac symptoms and is usually associated with lack of antineutrophil cytoplasmic antibodies (ANCA). To correlate the CMR pattern with ANCA in CSS, compare it with healthy controls and systemic lupus erythematosus (SLE) patients and re-evaluate 2 yrs after the first CMR. 28 consecutive CSS, aged 42±7 yrs, were referred for CMR and 2 yrs re-evaluation. The CMR included left ventricular ejection fraction (LVEF), T2-weighted (T2-W), early (EGE) and late gadolinium enhanced (LGE) imaging. Their results were compared with 28 systemic lupus erythematosus (SLE) under remission and 28 controls with normal myocardial perfusion, assessed by scintigraphy. CMR revealed acute cardiac lesions in all ANCA (-) CSS with active disease and acute cardiac symptoms and only in one asymptomatic ANCA (+) CSS, with active disease. Diffuse subendocardial fibrosis (DSF) or past myocarditis was identified in both ANCA(+) and ANCA (-) CSS, but with higher incidence and fibrosis amount in ANCA (-) CSS (p<0.05). In comparison to SLE, both ANCA (+) and ANCA (-) CSS had higher incidence of DSF, lower incidence of myocarditis and no evidence of myocardial infarction, due to coronary artery disease (p<0.05). In 2 yrs CMR follow up, 1/3 of CSS with DSF presented LV function deterioration and one died, although immunosuppressive treatment was given early after CSS diagnosis. Cardiac involvement either as DSF or myocarditis, can be detected in both ANCA (+) and ANCA (-) CSS, although more clinically overt in ANCA (-). DSF carries an ominous prognosis for LV function. CMR, due to its capability to detect disease severity, before cardiac dysfunction takes place, is an excellent tool for CSS risk stratification and treatment individualization.

Tracing gadolinium-based contrast agents from surface water to drinking water by means of speciation analysis.

PubMed

Birka, Marvin; Wehe, Christoph A; Hachmöller, Oliver; Sperling, Michael; Karst, Uwe

2016-04-01

In recent decades, a significant amount of anthropogenic gadolinium has been released into the environment as a result of the broad application of contrast agents for magnetic resonance imaging (MRI). Since this anthropogenic gadolinium anomaly has also been detected in drinking water, it has become necessary to investigate the possible effect of drinking water purification on these highly polar microcontaminats. Therefore, a novel highly sensitive method for speciation analysis of gadolinium is presented. For that purpose, the hyphenation of hydrophilic interaction liquid chromatography (HILIC) and inductively coupled plasma-mass spectrometry (ICP-MS) was employed. In order to enhance the detection power, sample introduction was carried out by ultrasonic nebulization. In combination with a novel HILIC method using a diol-based stationary phase, it was possible to achieve superior limits of detection for frequently applied gadolinium-based contrast agents below 20pmol/L. With this method, the contrast agents Gd-DTPA, Gd-DOTA and Gd-BT-DO3A were determined in concentrations up to 159pmol/L in samples from several waterworks in a densely populated region of Germany alongside the river Ruhr as well as from a waterworks near a catchment lake. Thereby, the direct impact of anthropogenic gadolinium species being present in the surface water on the amount of anthropogenic gadolinium in drinking water was shown. There was no evidence for the degradation of contrast agents, the release of Gd(3+) or the presence of further Gd species. Copyright © 2016 Elsevier B.V. All rights reserved.

Characterization of the biliary tract by virtual ultrasonography constructed by gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging.

PubMed

Koizumi, Yohei; Hirooka, Masashi; Ochi, Hironori; Tokumoto, Yoshio; Takechi, Megumi; Hiraoka, Atsushi; Ikeda, Yoshio; Kumagi, Teru; Matsuura, Bunzo; Abe, Masanori; Hiasa, Yoichi

2015-04-01

This study aimed at prospectively evaluating bile duct anatomy on ultrasonography and evaluating the safety and utility of radiofrequency ablation (RFA) assisted by virtual ultrasonography from gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI). The institutional review board approved this study, and patients provided written informed consent prior to entry into the study. Bile duct anatomy was assessed in 201 patients who underwent Gd-EOB-DTPA-enhanced MRI for the evaluation of hepatic tumor. Eighty-one of these patients subsequently underwent RFA assisted by ultrasound imaging. In 23 patients, the tumor was located within 5 mm of the central bile duct, as demonstrated by MRI. Virtual ultrasonography constructed by Gd-EOB-enhanced MRI was able to visualize the common bile duct, left hepatic duct, and right hepatic duct in 96.5, 94.0, and 89.6 % of cases, respectively. The target hepatic tumor nodule and biliary duct could be detected with virtual ultrasonography in all patients, and no severe complications occurred. The running pattern of the bile ducts could be recognized on conventional ultrasound by referencing virtual ultrasonography constructed by Gd-EOB-DTPA-enhanced MRI. RFA assisted by this imaging strategy did not result in bile duct injury.

Gadolinium photoionization process

DOEpatents

Paisner, J.A.; Comaskey, B.J.; Haynam, C.A.; Eggert, J.H.

1993-04-13

A method is provided for selective photoionization of the odd-numbered atomic mass gadolinium isotopes 155 and 157. The selective photoionization is accomplished by circular or linear parallel polarized laser beam energy effecting a three-step photoionization pathway.

Gadolinium photoionization process

DOEpatents

Paisner, Jeffrey A.; Comaskey, Brian J.; Haynam, Christopher A.; Eggert, Jon H.

1993-01-01

A method is provided for selective photoionization of the odd-numbered atomic mass gadolinium isotopes 155 and 157. The selective photoionization is accomplished by circular or linear parallel polarized laser beam energy effecting a three-step photoionization pathway.

Non-volumetric echocardiographic indices and qualitative assessment of right ventricular systolic function in Ebstein's anomaly: comparison with CMR-derived ejection fraction in 49 patients.

PubMed

Kühn, Andreas; Meierhofer, Christian; Rutz, Tobias; Rondak, Ina-Christine; Röhlig, Christoph; Schreiber, Christian; Fratz, Sohrab; Ewert, Peter; Vogt, Manfred

2016-08-01

Ebstein's anomaly (EA) is often associated with right ventricular (RV) dysfunction. Data on echocardiographic quantification of RV function are, however, rare. The aim of this study was to determine how non-volumetric echocardiographic indices and qualitative assessment of global systolic RV function correlate with cardiovascular magnetic resonance (CMR)-derived RV ejection fraction (EF). We compared six echocardiographic indices and qualitative assessment of RV function with the gold standard CMR. A total of 49 unoperated patients with EA and a mean age of 32 ± 18 years were examined. Tricuspid annular plane systolic excursion, tissue Doppler myocardial velocities (peak S and IVA) and 2D strain and strain rate measures for the RV were compared with CMR-derived EF. Only 2D global longitudinal strain (2D-GLS), out of the six parameters investigated, showed a weak, although statistically significant correlation with CMR-derived RVEF (R = -0.4, P = 0.01). Using a cut-off value of -20.15, 2D-GLS sensitivity (77%) and specificity (46%) in detecting patients with a CMR-derived EF of <50% were comparable with qualitative assessment (sensitivity 77%, specificity 45%). Overall echocardiographic parameters of RV function correlate poorly with CMR-derived EF in patients with EA. Only 2D global longitudinal RV strain correlated weakly with CMR-derived RVEF. However, the sensitivity and specificity for detecting RV dysfunction using 2D strain imaging were comparable with qualitative RV functional assessment. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Hybrid Calcium Phosphate-Polymeric Micelles Incorporating Gadolinium Chelates for Imaging-Guided Gadolinium Neutron Capture Tumor Therapy.

PubMed

Mi, Peng; Dewi, Novriana; Yanagie, Hironobu; Kokuryo, Daisuke; Suzuki, Minoru; Sakurai, Yoshinori; Li, Yanmin; Aoki, Ichio; Ono, Koji; Takahashi, Hiroyuki; Cabral, Horacio; Nishiyama, Nobuhiro; Kataoka, Kazunori

2015-06-23

Gadolinium (Gd) chelates-loaded nanocarriers have high potential for achieving magnetic resonance imaging (MRI)-guided Gd neutron capture therapy (GdNCT) of tumors. Herein, we developed calcium phosphate micelles hybridized with PEG-polyanion block copolymers, and incorporated with the clinical MRI contrast agent Gd-diethylenetriaminepentaacetic acid (Gd-DTPA/CaP). The Gd-DTPA/CaP were nontoxic to cancer cells at the concentration of 100 μM based on Gd-DTPA, while over 50% of the cancer cells were killed by thermal neutron irradiation at this concentration. Moreover, the Gd-DTPA/CaP showed a dramatically increased accumulation of Gd-DTPA in tumors, leading to the selective contrast enhancement of tumor tissues for precise tumor location by MRI. The enhanced tumor-to-blood distribution ratio of Gd-DTPA/CaP resulted in the effective suppression of tumor growth without loss of body weight, indicating the potential of Gd-DTPA/CaP for safe cancer treatment.

Cardiac magnetic resonance and the need for routine cardiac catheterization in single ventricle patients prior to Fontan: a comparison of 3 groups: pre-Fontan CMR versus cath evaluation.

PubMed

Fogel, Mark A; Pawlowski, Thomas W; Whitehead, Kevin K; Harris, Matthew A; Keller, Marc S; Glatz, Andrew C; Zhu, Winnie; Shore, David; Diaz, Laura K; Rome, Jonathan J

2012-09-18

This study investigated whether cardiac magnetic resonance (CMR) and echocardiography (echo) can replace catheterization (cath) for routine evaluation prior to Fontan and under what circumstances CMR and cath are used together. Routine cath prior to Fontan has been utilized for years; noninvasive methods, however, may be sufficient. This study reviews clinical data in 119 consecutive patients investigating 3 groups: those who underwent CMR alone (MR; n = 41), cath alone (C; n = 41), or both cath and CMR (C+M; n = 37) prior to Fontan. No clinically significant differences were noted in patient characteristics, hemodynamics, or clinical status prior to or after surgery between the C and MR groups. CMR added information in 82%. There were no discrepant findings between CMR and cath data in the C+M group. Diagnostic success was ≥95% in all groups. Of those undergoing Fontan completion, the C+M group had similar outcomes to C and MR; C and CMR were utilized in combination to assess aortopulmonary collaterals or the need for an intervention or evaluate its success. Echo could not delineate pulmonary arterial anatomy in 46% to 53% of patients. The C+M and C groups were exposed to 6.8 ± 4.1 mSv of radiation. Single ventricle patients not requiring an intervention can undergo successful Fontan completion with CMR and echo alone with similar short-term outcomes to C, which was used as a control, preventing an invasive test and exposure to radiation. CMR can add information in a significant number of patients. Cath and CMR are utilized together for interventions and assessment of aortopulmonary collaterals. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

In vitro study of novel gadolinium-loaded liposomes guided by GBI-10 aptamer for promising tumor targeting and tumor diagnosis by magnetic resonance imaging.

PubMed

Gu, Meng-Jie; Li, Kun-Feng; Zhang, Lan-Xin; Wang, Huan; Liu, Li-Si; Zheng, Zhuo-Zhao; Han, Nan-Yin; Yang, Zhen-Jun; Fan, Tian-Yuan

2015-01-01

Novel gadolinium-loaded liposomes guided by GBI-10 aptamer were developed and evaluated in vitro to enhance magnetic resonance imaging (MRI) diagnosis of tumor. Nontargeted gadolinium-loaded liposomes were achieved by incorporating amphipathic material, Gd (III) [N,N-bis-stearylamidomethyl-N'-amidomethyl] diethylenetriamine tetraacetic acid, into the liposome membrane using lipid film hydration method. GBI-10, as the targeting ligand, was then conjugated onto the liposome surface to get GBI-10-targeted gadolinium-loaded liposomes (GTLs). Both nontargeted gadolinium-loaded liposomes and GTLs displayed good dispersion stability, optimal size, and zeta potential for tumor targeting, as well as favorable imaging properties with enhanced relaxivity compared with a commercial MRI contrast agent (CA), gadopentetate dimeglumine. The use of GBI-10 aptamer in this liposomal system was intended to result in increased accumulation of gadolinium at the periphery of C6 glioma cells, where the targeting extracellular matrix protein tenascin-C is overexpressed. Increased cellular binding of GTLs to C6 cells was confirmed by confocal microscopy, flow cytometry, and MRI, demonstrating the promise of this novel delivery system as a carrier of MRI contrast agent for the diagnosis of tumor. These studies provide a new strategy furthering the development of nanomedicine for both diagnosis and therapy of tumor.

In vitro study of novel gadolinium-loaded liposomes guided by GBI-10 aptamer for promising tumor targeting and tumor diagnosis by magnetic resonance imaging

PubMed Central

Gu, Meng-Jie; Li, Kun-Feng; Zhang, Lan-Xin; Wang, Huan; Liu, Li-Si; Zheng, Zhuo-Zhao; Han, Nan-Yin; Yang, Zhen-Jun; Fan, Tian-Yuan

2015-01-01

Novel gadolinium-loaded liposomes guided by GBI-10 aptamer were developed and evaluated in vitro to enhance magnetic resonance imaging (MRI) diagnosis of tumor. Nontargeted gadolinium-loaded liposomes were achieved by incorporating amphipathic material, Gd (III) [N,N-bis-stearylamidomethyl-N′-amidomethyl] diethylenetriamine tetraacetic acid, into the liposome membrane using lipid film hydration method. GBI-10, as the targeting ligand, was then conjugated onto the liposome surface to get GBI-10-targeted gadolinium-loaded liposomes (GTLs). Both nontargeted gadolinium-loaded liposomes and GTLs displayed good dispersion stability, optimal size, and zeta potential for tumor targeting, as well as favorable imaging properties with enhanced relaxivity compared with a commercial MRI contrast agent (CA), gadopentetate dimeglumine. The use of GBI-10 aptamer in this liposomal system was intended to result in increased accumulation of gadolinium at the periphery of C6 glioma cells, where the targeting extracellular matrix protein tenascin-C is overexpressed. Increased cellular binding of GTLs to C6 cells was confirmed by confocal microscopy, flow cytometry, and MRI, demonstrating the promise of this novel delivery system as a carrier of MRI contrast agent for the diagnosis of tumor. These studies provide a new strategy furthering the development of nanomedicine for both diagnosis and therapy of tumor. PMID:26316749

Contrast-enhanced computed tomography plus gadolinium-ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging for gross classification of hepatocellular carcinoma.

PubMed

Chen, Chuang; Zhao, Hui; Fu, Xu; Huang, LuoShun; Tang, Min; Yan, XiaoPeng; Sun, ShiQuan; Jia, WenJun; Mao, Liang; Shi, Jiong; Chen, Jun; He, Jian; Zhu, Jin; Qiu, YuDong

2017-05-02

Accurate gross classification through imaging is critical for determination of hepatocellular carcinoma (HCC) patient prognoses and treatment strategies. The present retrospective study evaluated the utility of contrast-enhanced computed tomography (CE-CT) combined with gadolinium-ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) for diagnosis and classification of HCCs prior to surgery. Ninety-four surgically resected HCC nodules were classified as simple nodular (SN), SN with extranodular growth (SN-EG), confluent multinodular (CMN), or infiltrative (IF) types. SN-EG, CMN and IF samples were grouped as non-SN. The abilities of the two imaging modalities to differentiate non-SN from SN HCCs were assessed using the EOB-MRI hepatobiliary phase and CE-CT arterial, portal, and equilibrium phases. Areas under the ROC curves for non-SN diagnoses were 0.765 (95% confidence interval [CI]: 0.666-0.846) for CE-CT, 0.877 (95% CI: 0.793-0.936) for EOB-MRI, and 0.908 (95% CI: 0.830-0.958) for CE-CT plus EOB-MRI. Sensitivities, specificities, and accuracies with respect to identification of non-SN tumors of all sizes were 71.4%, 81.6%, and 75.5% for CE-CT; 96.4%, 78.9%, and 89.3% for EOB-MRI; and 98.2%, 84.2%, and 92.5% for CE-CT plus EOB-MRI. These results show that CE-CT combined with EOB-MRI offers a more accurate imaging evaluation for HCC gross classification than either modality alone.

Gadolinium-Induced Fibrosis.

PubMed

Todd, Derrick J; Kay, Jonathan

2016-01-01

Gadolinium-based contrast agents (GBCAs), once believed to be safe for patients with renal disease, have been strongly associated with nephrogenic systemic fibrosis (NSF), a severe systemic fibrosing disorder that predominantly afflicts individuals with advanced renal dysfunction. We provide a historical perspective on the appearance and disappearance of NSF, including its initial recognition as a discrete clinical entity, its association with GBCA exposure, and the data supporting a causative relationship between GBCA exposure and NSF. On the basis of this body of evidence, we propose that the name gadolinium-induced fibrosis (GIF) more accurately reflects the totality of knowledge regarding this disease. Use of high-risk GBCAs, such as formulated gadodiamide, should be avoided in patients with renal disease. Restriction of GBCA use in this population has almost completely eradicated new cases of this debilitating condition. Emerging antifibrotic therapies may be useful for patients who suffer from GIF.

Comodulation Masking Release (CMR) in Children and the Influence of Reading Status

ERIC Educational Resources Information Center

Zettler, Cynthia M.; Sevcik, Rose A.; Morris, Robin D.; Clarkson, Marsha G.

2008-01-01

Purpose: Research suggests that children with reading disabilities (RD) have difficulty processing temporal and spectral components of sounds. Comodulation masking release (CMR) measures a listener's ability to use temporal and spectral information in noise to identify a signal. The purpose of this study was to determine whether children with RD…

Gadolinium Brain Deposition after Macrocyclic Gadolinium Administration: A Pediatric Case-Control Study.

PubMed

Tibussek, Daniel; Rademacher, Christin; Caspers, Julian; Turowski, Bernd; Schaper, Jörg; Antoch, Gerald; Klee, Dirk

2017-10-01

Purpose To determine whether signal intensity (SI) in T1 sequences as a potential indicator of gadolinium deposition increases after repeated administration of the macrocyclic gadolinium-based contrast agents (GBCAs) gadoteridol and gadoterate meglumine in a pediatric cohort. Materials and Methods This retrospective case-control study of children with brain tumors who underwent nine or more contrast material-enhanced brain magnetic resonance (MR) imaging studies from 2008 to 2015 was approved by the local ethics board. Informed consent was obtained for MR imaging. Twenty-four case patients aged 5-18 years and appropriate control patients with nonpathologic MR neuroimaging findings (and no GBCA administration), matched for age and sex, were inculded. SI was measured on unenhanced T1-weighted MR images for the following five regions of interest (ROIs): the dentate nucleus (DN), pons, substantia nigra (SN), pulvinar thalami, and globus pallidus (GP). Paired t tests were used to compare SI and SI ratios (DN to pons, GP to thalamus) between case patients and control patients. Pearson correlations between relative signal changes and the number of GBCA administrations and total GBCA dose were calculated. Results The mean number of GBCA administrations was 14.2. No significant differences in mean SI for any ROI and no group differences were found when DN-to-pons and GP-to-pulvinar ratios were compared (DN-to-pons ratio in case patients: mean, 1.0083 ± 0.0373 [standard deviation]; DN-to-pons ratio in control patients: mean, 1.0183 ± 0.01917; P = .37; GP-to-pulvinar ratio in case patients: mean, 1.1335 ± 0.04528; and GP-to-pulvinar ratio in control patients: mean, 1.1141 ± 0.07058; P = .29). No correlation was found between the number of GBCA administrations or the total amount of GBCA administered and signal change for any ROI. (Number of GBCA applications: DN: r = -0.254, P = .31; pons: r = -0.097, P = .65; SN: r = -0.194, P = .38; GP: r = -0.175, P = .41; pulvinar: r

Gadolinium Chelate Safety in Pregnancy: Barely Detectable Gadolinium Levels in the Juvenile Nonhuman Primate after in Utero Exposure.

PubMed

Prola-Netto, Joao; Woods, Mark; Roberts, Victoria H J; Sullivan, Elinor L; Miller, Christina Ann; Frias, Antonio E; Oh, Karen Y

2018-01-01

Purpose To determine whether gadolinium remains in juvenile nonhuman primate tissue after maternal exposure to intravenous gadoteridol during pregnancy. Materials and Methods Gravid rhesus macaques and their offspring (n = 10) were maintained, as approved by the institutional animal care and utilization committee. They were prospectively studied as part of a pre-existing ongoing research protocol to evaluate the effects of maternal malnutrition on placental and fetal development. On gestational days 85 and 135, they underwent placental magnetic resonance imaging after intravenous gadoteridol administration. Amniocentesis was performed on day 135 prior to administration of the second dose of gadoteridol. After delivery, the offspring were followed for 7 months. Tissue samples from eight different organs and from blood were harvested from each juvenile macaque. Gadolinium levels were measured by using inductively coupled plasma mass spectrometry. Results Gadolinium concentration in the amniotic fluid was 0.028 × 10 -5 %ID/g (percentage injected dose per gram of tissue) 50 days after administration of one gadoteridol dose. Gadolinium was most consistently detected in the femur (mean, 2.5 × 10 -5 %ID/g; range, [0.81-4.1] × 10 -5 %ID/g) and liver (mean, 0.15 × 10 -5 %ID/g; range, [0-0.26] × 10 -5 %ID/g). Levels were undetectable in the remaining sampled tissues, with the exception of one juvenile skin sample (0.07 × 10 -5 %ID/g), one juvenile spleen sample (0.039 × 10 -5 %ID/g), and one juvenile brain (0.095 × 10 -5 %ID/g) and kidney (0.13 × 10 -5 %ID/g) sample. Conclusion The presence of gadoteridol in the amniotic fluid after maternal injection enables confirmation that it crosses the placenta. Extremely low levels of gadolinium are found in juvenile macaque tissues after in utero exposure to two doses of gadoteridol, indicating that a very small amount of gadolinium persists after delivery. © RSNA, 2017.

Fast left ventricle tracking in CMR images using localized anatomical affine optical flow

NASA Astrophysics Data System (ADS)

Queirós, Sandro; Vilaça, João. L.; Morais, Pedro; Fonseca, Jaime C.; D'hooge, Jan; Barbosa, Daniel

2015-03-01

In daily cardiology practice, assessment of left ventricular (LV) global function using non-invasive imaging remains central for the diagnosis and follow-up of patients with cardiovascular diseases. Despite the different methodologies currently accessible for LV segmentation in cardiac magnetic resonance (CMR) images, a fast and complete LV delineation is still limitedly available for routine use. In this study, a localized anatomically constrained affine optical flow method is proposed for fast and automatic LV tracking throughout the full cardiac cycle in short-axis CMR images. Starting from an automatically delineated LV in the end-diastolic frame, the endocardial and epicardial boundaries are propagated by estimating the motion between adjacent cardiac phases using optical flow. In order to reduce the computational burden, the motion is only estimated in an anatomical region of interest around the tracked boundaries and subsequently integrated into a local affine motion model. Such localized estimation enables to capture complex motion patterns, while still being spatially consistent. The method was validated on 45 CMR datasets taken from the 2009 MICCAI LV segmentation challenge. The proposed approach proved to be robust and efficient, with an average distance error of 2.1 mm and a correlation with reference ejection fraction of 0.98 (1.9 +/- 4.5%). Moreover, it showed to be fast, taking 5 seconds for the tracking of a full 4D dataset (30 ms per image). Overall, a novel fast, robust and accurate LV tracking methodology was proposed, enabling accurate assessment of relevant global function cardiac indices, such as volumes and ejection fraction

High-resolution gadolinium-enhanced 3D MRA of the infrapopliteal arteries. Lessons for improving bolus-chase peripheral MRA.

PubMed

Hood, Maureen N; Ho, Vincent B; Foo, Thomas K F; Marcos, Hani B; Hess, Sandra L; Choyke, Peter L

2002-09-01

Peripheral magnetic resonance angiography (MRA) is growing in use. However, methods of performing peripheral MRA vary widely and continue to be optimized, especially for improvement in illustration of infrapopliteal arteries. The main purpose of this project was to identify imaging factors that can improve arterial visualization in the lower leg using bolus chase peripheral MRA. Eighteen healthy adults were imaged on a 1.5T MR scanner. The calf was imaged using conventional three-station bolus chase three-dimensional (3D) MRA, two dimensional (2D) time-of-flight (TOF) MRA and single-station Gadolinium (Gd)-enhanced 3D MRA. Observer comparisons of vessel visualization, signal to noise ratios (SNR), contrast to noise ratios (CNR) and spatial resolution comparisons were performed. Arterial SNR and CNR were similar for all three techniques. However, arterial visualization was dramatically improved on dedicated, arterial-phase Gd-enhanced 3D MRA compared with the multi-station bolus chase MRA and 2D TOF MRA. This improvement was related to optimization of Gd-enhanced 3D MRA parameters (fast injection rate of 2 mL/sec, high spatial resolution imaging, the use of dedicated phased array coils, elliptical centric k-space sampling and accurate arterial phase timing for image acquisition). The visualization of the infrapopliteal arteries can be substantially improved in bolus chase peripheral MRA if voxel size, contrast delivery, and central k-space data acquisition for arterial enhancement are optimized. Improvements in peripheral MRA should be directed at these parameters.

Added value of cardiac magnetic resonance in etiological diagnosis of ventricular arrhythmias.

PubMed

Cabanelas, Nuno; Vidigal Ferreira, Maria João; Donato, Paulo; Gaspar, António; Pinto, Joana; Caseiro-Alves, Filipe; Providência, Luís Augusto

2013-10-01

Cardiac magnetic resonance (CMR) imaging is increasingly important in the diagnostic work-up of a wide range of heart diseases, including those with arrhythmogenic potential. To assess the added value of CMR in etiological diagnosis of ventricular arrhythmias after an inconclusive conventional investigation. Patients undergoing CMR between 2005 and 2011 for investigation of ventricular arrhythmias were included (n=113). All had documented arrhythmias. Those with a definite diagnosis from a previous investigation and those with evidence of coronary artery disease (acute coronary syndrome, typical angina symptoms, increase in biomarkers or positive stress test) were excluded. CMR results were considered relevant when they fulfilled diagnostic criteria. Of the 113 patients, 57.5% were male and mean age was 41.7 ± 16.2 years. Regarding the initial arrhythmia, 38.1% had ventricular fibrillation/sustained ventricular tachycardia (VF/VT) and 61.9% had less complex ventricular ectopy. CMR imaging showed criteria of a specific diagnosis in 42.5% of patients, was totally normal in 36.3%, and showed non-specific alterations in the remainder. In VF/VT patients, specific criteria were found in 60.4%, and in 31.4% of those with less complex ectopy. The most frequent diagnoses were arrhythmogenic right ventricular dysplasia, ventricular non-compaction and myopericarditis. It is worth noting that, although there was no evidence of previous coronary artery disease, 6.2% of patients had a late gadolinium enhancement distribution pattern compatible with myocardial infarction. CMR gives additional and important information in the diagnostic work-up of ventricular arrhythmias after an inconclusive initial investigation. The proportion of patients with diagnostic criteria was 42.5% (60.0% in those with VF/VT), and CMR was completely normal in 36.6%. Copyright © 2012 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

Gadolinium-based contrast agent toxicity: a review of known and proposed mechanisms.

PubMed

Rogosnitzky, Moshe; Branch, Stacy

2016-06-01

Gadolinium chelates are widely used as contrast media for magnetic resonance imaging. The approved gadolinium-based contrast agents (GBCAs) have historically been considered safe and well tolerated when used at recommended dosing levels. However, for nearly a decade, an association between GBCA administration and the development of nephrogenic systemic fibrosis (NSF) has been recognized in patients with severe renal impairment. This has led to modifications in clinical practices aimed at reducing the potential and incidence of NSF development. Newer reports have emerged regarding the accumulation of gadolinium in various tissues of patients who do not have renal impairment, including bone, brain, and kidneys. Despite the observations of gadolinium accumulation in tissues regardless of renal function, very limited clinical data regarding the potential for and mechanisms of toxicity is available. This significant gap in knowledge warrants retrospective cohort study efforts, as well as prospective studies that involve gadolinium ion (Gd(3+)) testing in patients exposed to GBCA. This review examines the potential biochemical and molecular basis of gadolinium toxicity, possible clinical significance of gadolinium tissue retention and accumulation, and methods that can limit gadolinium body burden.

Room temperature ferromagnetic gadolinium silicide nanoparticles

DOEpatents

Hadimani, Magundappa Ravi L.; Gupta, Shalabh; Harstad, Shane; Pecharsky, Vitalij; Jiles, David C.

2018-03-06

A particle usable as T₁ and T₂ contrast agents is provided. The particle is a gadolinium silicide (Gd₅Si₄) particle that is ferromagnetic at temperatures up to 290 K and is less than 2 .mu.m in diameter. An MRI contrast agent that includes a plurality of gadolinium silicide (Gd.sub.5Si.sub.4) particles that are less than 1 .mu.m in diameter is also provided. A method for creating gadolinium silicide (Gd₅Si₄) particles is also provided. The method includes the steps of providing a Gd₅Si₄ bulk alloy; grinding the Gd₅Si₄ bulk alloy into a powder; and milling the Gd₅Si₄ bulk alloy powder for a time of approximately 20 minutes or less.

Modified Wideband Three-Dimensional Late Gadolinium Enhancement MRI for Patients with Implantable Cardiac Devices

PubMed Central

Rashid, Shams; Rapacchi, Stanislas; Shivkumar, Kalyanam; Plotnik, Adam; Finn, J. Paul; Hu, Peng

2015-01-01

Purpose To study the effects of cardiac devices on three-dimensional (3D) late gadolinium enhancement (LGE) MRI and to develop a 3D LGE protocol for implantable cardioverter defibrillator (ICD) patients with reduced image artifacts. Theory and Methods The 3D LGE sequence was modified by implementing a wideband inversion pulse, which reduces hyperintensity artifacts, and by increasing bandwidth of the excitation pulse. The modified wideband 3D LGE sequence was tested in phantoms and evaluated in six volunteers and five patients with ICDs. Results Phantom and in vivo studies results demonstrated extended signal void and ripple artifacts in 3D LGE that were associated with ICDs. The reason for these artifacts was slab profile distortion and the subsequent aliasing in the slice-encoding direction. The modified wideband 3D LGE provided significantly reduced ripple artifacts than 3D LGE with wideband inversion only. Comparison of 3D and 2D LGE images demonstrated improved spatial resolution of the heart using 3D LGE. Conclusion Increased bandwidth of the inversion and excitation pulses can significantly reduce image artifacts associated with ICDs. Our modified wideband 3D LGE protocol can be readily used for imaging patients with ICDs given appropriate safety guidelines are followed. PMID:25772155

Dark-Blood Delayed Enhancement Cardiac Magnetic Resonance of Myocardial Infarction.

PubMed

Kim, Han W; Rehwald, Wolfgang G; Jenista, Elizabeth R; Wendell, David C; Filev, Peter; van Assche, Lowie; Jensen, Christoph J; Parker, Michele A; Chen, Enn-Ling; Crowley, Anna Lisa C; Klem, Igor; Judd, Robert M; Kim, Raymond J

2017-12-08

This study introduced and validated a novel flow-independent delayed enhancement technique that shows hyperenhanced myocardium while simultaneously suppressing blood-pool signal. The diagnosis and assessment of myocardial infarction (MI) is crucial in determining clinical management and prognosis. Although delayed enhancement cardiac magnetic resonance (DE-CMR) is an in vivo reference standard for imaging MI, an important limitation is poor delineation between hyperenhanced myocardium and bright LV cavity blood-pool, which may cause many infarcts to become invisible. A canine model with pathology as the reference standard was used for validation (n = 22). Patients with MI and normal controls were studied to ascertain clinical performance (n = 31). In canines, the flow-independent dark-blood delayed enhancement (FIDDLE) technique was superior to conventional DE-CMR for the detection of MI, with higher sensitivity (96% vs. 85%, respectively; p = 0.002) and accuracy (95% vs. 87%, respectively; p = 0.01) and with similar specificity (92% vs, 92%, respectively; p = 1.0). In infarcts that were identified by both techniques, the entire length of the endocardial border between infarcted myocardium and adjacent blood-pool was visualized in 33% for DE-CMR compared with 100% for FIDDLE. There was better agreement for FIDDLE-measured infarct size than for DE-CMR infarct size (95% limits-of-agreement, 2.1% vs. 5.5%, respectively; p < 0.0001). In patients, findings were similar. FIDDLE demonstrated higher accuracy for diagnosis of MI than DE-CMR (100% [95% confidence interval [CI]: 89% to 100%] vs. 84% [95% CI: 66% to 95%], respectively; p = 0.03). The study introduced and validated a novel CMR technique that improves the discrimination of the border between infarcted myocardium and adjacent blood-pool. This dark-blood technique provides diagnostic performance that is superior to that of the current in vivo reference standard for the imaging diagnosis of MI

Complex imaging features of accidental cerebral intraventricular gadolinium administration.

PubMed

Nayak, Nita B; Huang, Jimmy C; Hathout, Gasser M; Shaba, Wisam; El-Saden, Suzie M

2013-05-01

Gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) is a contrast agent commonly used for enhancing MRI. In this paper, the authors report on 2 cases of postoperative inadvertent administration of Gd-DTPA directly into a ventriculostomy tubing side port that was mistaken for intravenous tubing. Both cases demonstrated a low signal on MRI throughout the ventricular system and dependent portions of the subarachnoid spaces, which was originally believed to be CSF with areas of T1 shortening in the nondependent portions of the subarachnoid spaces, and misinterpreted as basal leptomeningeal enhancement and meningitis. The authors propose that the appearance of profound T1 hypointensity within the ventricles and diffuse susceptibility artifact along the ependyma is pathognomonic of intraventricular Gd-DTPA and should be recognized.

Use of gadolinium chloride as a contrast agent for imaging spruce knots by magnetic resonance

Treesearch

Thomas L. Eberhardt; Chi-Leung So; Amy H. Herlihy; Po-Wah So

2006-01-01

Treatments of knot-containing spruce wood blocks with a paramagnetic salt, gadolinium (III) chloride, in combination with solvent pretreatments, were evaluated as strategies to enhance the visualization of wood features by magnetic resonance imaging (MRI). Initial experiments with clear wood and excised knot samples showed differences in moisture uptake after...

Gadolinium chelate coated gold nanoparticles as contrast agents for both X-ray computed tomography and magnetic resonance imaging.

PubMed

Alric, Christophe; Taleb, Jacqueline; Le Duc, Géraldine; Mandon, Céline; Billotey, Claire; Le Meur-Herland, Alice; Brochard, Thierry; Vocanson, Francis; Janier, Marc; Perriat, Pascal; Roux, Stéphane; Tillement, Olivier

2008-05-07

Functionalized gold nanoparticles were applied as contrast agents for both in vivo X-ray and magnetic resonance imaging. These particles were obtained by encapsulating gold cores within a multilayered organic shell which is composed of gadolinium chelates bound to each other through disulfide bonds. The contrast enhancement in MRI stems from the presence of gadolinium ions which are entrapped in the organic shell, whereas the gold core provides a strong X-ray absorption. This study revealed that these particles suited for dual modality imaging freely circulate in the blood vessels without undesirable accumulation in the lungs, spleen, and liver.

Magnetic resonance characteristics and susceptibility weighted imaging of the brain in gadolinium encephalopathy.

PubMed

Samardzic, Dejan; Thamburaj, Krishnamoorthy

2015-01-01

To report the brain imaging features on magnetic resonance imaging (MRI) in inadvertent intrathecal gadolinium administration. A 67-year-old female with gadolinium encephalopathy from inadvertent high dose intrathecal gadolinium administration during an epidural steroid injection was studied with multisequence 3T MRI. T1-weighted imaging shows pseudo-T2 appearance with diffusion of gadolinium into the brain parenchyma, olivary bodies, and membranous labyrinth. Nulling of cerebrospinal fluid (CSF) signal is absent on fluid attenuation recovery (FLAIR). Susceptibility-weighted imaging (SWI) demonstrates features similar to subarachnoid hemorrhage. CT may demonstrate a pseudo-cerebral edema pattern given the high attenuation characteristics of gadolinium. Intrathecal gadolinium demonstrates characteristic imaging features on MRI of the brain and may mimic subarachnoid hemorrhage on susceptibility-weighted imaging. Identifying high dose gadolinium within the CSF spaces on MRI is essential to avoid diagnostic and therapeutic errors. Copyright © 2013 by the American Society of Neuroimaging.

Identification and Assessment of Cardiac Amyloidosis by Myocardial Strain Analysis of Cardiac Magnetic Resonance Imaging.

PubMed

Oda, Seitaro; Utsunomiya, Daisuke; Nakaura, Takeshi; Yuki, Hideaki; Kidoh, Masafumi; Morita, Kosuke; Takashio, Seiji; Yamamuro, Megumi; Izumiya, Yasuhiro; Hirakawa, Kyoko; Ishida, Toshifumi; Tsujita, Kenichi; Ueda, Mitsuharu; Yamashita, Taro; Ando, Yukio; Hata, Hiroyuki; Yamashita, Yasuyuki

2017-06-23

We explored the usefulness of myocardial strain analysis on cardiac magnetic resonance imaging (CMR) scans for the identification of cardiac amyloidosis.Methods and Results:The 61 patients with systemic amyloidosis underwent 3.0-T CMR, including CMR tagging and late-gadolinium enhanced (LGE) imaging. The circumferential strain (CS) of LGE-positive and LGE-negative patients was measured on midventricular short-axis images and compared. Logistic regression modeling of CMR parameters was performed to detect patients with LGE-positive cardiac amyloidosis. Of the 61 patients with systemic amyloidosis 48 were LGE-positive and 13 were LGE-negative. The peak CS was significantly lower in the LGE-positive than in the LGE-negative patients (-9.5±2.3 vs. -13.3±1.4%, P<0.01). The variability in the peak CS time was significantly greater in the LGE-positive than in the LGE-negative patients (46.1±24.5 vs. 21.2±20.1 ms, P<0.01). The peak CS significantly correlated with clinical biomarkers. The sensitivity, specificity, and accuracy of the diagnostic model using CS parameters for the identification of LGE-positive amyloidosis were 93.8%, 76.9%, and 90.2%, respectively. Myocardial strain analysis by CMR helped detect LGE-positive amyloidosis without the need for contrast medium. The peak CS and variability in the peak CS time may correlate with the severity of cardiac amyloid deposition and may be more sensitive than LGE imaging for the detection of early cardiac disease in patients with amyloidosis.

Left ventricular hypertrophy: The relationship between the electrocardiogram and cardiovascular magnetic resonance imaging.

PubMed

Bacharova, Ljuba; Ugander, Martin

2014-11-01

Conventional assessment of left ventricular hypertrophy (LVH) using the electrocardiogram (ECG), for example, by the Sokolow-Lyon, Romhilt-Estes or Cornell criteria, have relied on assessing changes in the amplitude and/or duration of the QRS complex of the ECG to quantify LV mass. ECG measures of LV mass have typically been validated by imaging with echocardiography or cardiovascular magnetic resonance imaging (CMR). However, LVH can be the result of diverse etiologies, and LVH is also characterized by pathological changes in myocardial tissue characteristics on the genetic, molecular, cellular, and tissue level beyond a pure increase in the number of otherwise normal cardiomyocytes. For example, slowed conduction velocity through the myocardium, which can be due to diffuse myocardial fibrosis, has been shown to be an important determinant of conventional ECG LVH criteria regardless of LV mass. Myocardial tissue characterization by CMR has emerged to not only quantify LV mass, but also detect and quantify the extent and severity of focal or diffuse myocardial fibrosis, edema, inflammation, myocarditis, fatty replacement, myocardial disarray, and myocardial deposition of amyloid proteins (amyloidosis), glycolipids (Fabry disease), or iron (siderosis). This can be undertaken using CMR techniques including late gadolinium enhancement (LGE), T1 mapping, T2 mapping, T2* mapping, extracellular volume fraction (ECV) mapping, fat/water-weighted imaging, and diffusion tensor CMR. This review presents an overview of current and emerging concepts regarding the diagnostic possibilities of both ECG and CMR for LVH in an attempt to narrow gaps in our knowledge regarding the ECG diagnosis of LVH. © 2014 Wiley Periodicals, Inc.

LGE Provides Incremental Prognostic Information Over Serum Biomarkers in AL Cardiac Amyloidosis.

PubMed

Boynton, Samuel J; Geske, Jeffrey B; Dispenzieri, Angela; Syed, Imran S; Hanson, Theodore J; Grogan, Martha; Araoz, Philip A

2016-06-01

This study sought to determine the prognostic value of cardiac magnetic resonance (CMR) late gadolinium enhancement (LGE) in amyloid light chain (AL) cardiac amyloidosis. Cardiac involvement is the major determinant of mortality in AL amyloidosis. CMR LGE is a marker of amyloid infiltration of the myocardium. The purpose of this study was to evaluate retrospectively the prognostic value of CMR LGE for determining all-cause mortality in AL amyloidosis and to compare the prognostic power with the biomarker stage. Seventy-six patients with histologically proven AL amyloidosis underwent CMR LGE imaging. LGE was categorized as global, focal patchy, or none. Global LGE was considered present if it was visualized on LGE images or if the myocardium nulled before the blood pool on a cine multiple inversion time (TI) sequence. CMR morphologic and functional evaluation, echocardiographic diastolic evaluation, and cardiac biomarker staging were also performed. Subjects' charts were reviewed for all-cause mortality. Cox proportional hazards analysis was used to evaluate survival in univariate and multivariate analysis. There were 40 deaths, and the median study follow-up period was 34.4 months. Global LGE was associated with all-cause mortality in univariate analysis (hazard ratio = 2.93; p < 0.001). In multivariate modeling with biomarker stage, global LGE remained prognostic (hazard ratio = 2.43; p = 0.01). Diffuse LGE provides incremental prognosis over cardiac biomarker stage in patients with AL cardiac amyloidosis. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Gadolinium chloride as a contrast agent for imaging wood composite components by magnetic resonance

Treesearch

Thomas L. Eberhardt; Chi-Leung So; Andrea Protti; Po-Wah So

2009-01-01

Although paramagnetic contrast agents have an established track record in medical uses of magnetic resonance imaging (MRI), only recently has a contrast agent been used for enhancing MRI images of solid wood specimens. Expanding on this concept, wood veneers were treated with a gadolinium-based contrast agent and used in a model system comprising three-ply plywood...

Density of Gadolinium Nitrate Solutions for the High Flux Isotope Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, Paul Allen; Lee, Denise L

2009-05-01

In late 1992, the High Flux Isotope Reactor (HFIR) was planning to switch the solution contained in the poison injection tank from cadmium nitrate to gadolinium nitrate. The poison injection system is an emergency system used to shut down the reactor by adding a neutron poison to the cooling water. This system must be able to supply a minimum of 69 pounds of gadolinium to the reactor coolant system in order to guarantee that the reactor would become subcritical. A graph of the density of gadolinium nitrate solutions over a concentration range of 5 to 30 wt% and a temperaturemore » range of 15 to 40{sup o}C was prepared. Routine density measurements of the solution in the poison injection tank are made by HFIR personnel, and an adaptation of the original graph is used to determine the gadolinium nitrate concentration. In late 2008, HFIR personnel decided that the heat tracing that was present on the piping for the poison injection system could be removed without any danger of freezing the solution; however, the gadolinium nitrate solution might get as cold as 5{sup o}C. This was outside the range of the current density-concentration correlation, so the range needed to be expanded. This report supplies a new density-concentration correlation that covers the extended temperature range. The correlation is given in new units, which greatly simplifies the calculation that is required to determine the pounds of gadolinium in the tank solution. The procedure for calculating the amount of gadolinium in the HFIR poison injection system is as follows: (1) Calculate the usable volume in the system; (2) Measure the density of the solution; (3) Calculate the gadolinium concentration using the following equation: Gd(lb/ft{sup 3}) = measured density (g/mL) x 34.681 - 34.785; (4) Calculate the amount of gadolinium in the system using the following equation: Amount of Gd(lb) = Gd concentration (lb/ft{sup 3}) x usable volume (ft{sup 3}). The equation in step 3 is exact for a

Structural and magnetic phase transitions in gadolinium under high pressures and low temperatures

DOE PAGES

Samudrala, Gopi K.; Tsoi, Georgiy M.; Weir, Samuel T.; ...

2014-11-07

High pressure structural transition studies have been carried out on rare earth metal gadolinium in a diamond anvil cell at room temperature to 169 GPa. Gadolinium has been compressed to 38% of its initial volume at this pressure. With increasing pressure, a crystal structure sequence of hcp → Smtype→ dhcp → fcc → dfcc → monoclinic has been observed in our studies on gadolinium. The measured equation of state of gadolinium is presented to 169 GPa at ambient temperature. Magnetic ordering temperature of gadolinium has been studied using designer diamond anvils to a pressure of 25 GP and a temperaturemore » of 10 K. The magnetic ordering temperature has been determined from the four-point electrical resistivity measurements carried out on gadolinium. Furthermore, our experiments show that the magnetic transition temperature decreases with increasing pressure to 19 GPa and then increases when gadolinium is subjected to higher pressures.« less

Structural and magnetic phase transitions in gadolinium under high pressures and low temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Samudrala, Gopi K.; Tsoi, Georgiy M.; Weir, Samuel T.

High pressure structural transition studies have been carried out on rare earth metal gadolinium in a diamond anvil cell at room temperature to 169 GPa. Gadolinium has been compressed to 38% of its initial volume at this pressure. With increasing pressure, a crystal structure sequence of hcp → Smtype→ dhcp → fcc → dfcc → monoclinic has been observed in our studies on gadolinium. The measured equation of state of gadolinium is presented to 169 GPa at ambient temperature. Magnetic ordering temperature of gadolinium has been studied using designer diamond anvils to a pressure of 25 GP and a temperaturemore » of 10 K. The magnetic ordering temperature has been determined from the four-point electrical resistivity measurements carried out on gadolinium. Furthermore, our experiments show that the magnetic transition temperature decreases with increasing pressure to 19 GPa and then increases when gadolinium is subjected to higher pressures.« less

Structural and magnetic phase transitions in gadolinium under high pressures and low temperatures

NASA Astrophysics Data System (ADS)

Samudrala, Gopi K.; Tsoi, Georgiy M.; Weir, Samuel T.; Vohra, Yogesh K.

2014-10-01

High pressure structural transition studies have been carried out on rare earth metal gadolinium in a diamond anvil cell at room temperature to 169 GPa. Gadolinium has been compressed to 38% of its initial volume at this pressure. With increasing pressure, a crystal structure sequence of hcp → Sm-type → dhcp → fcc → dfcc → monoclinic has been observed in our studies on gadolinium. The measured equation of state of gadolinium is presented to 169 GPa at ambient temperature. Magnetic ordering temperature of gadolinium has been studied using designer diamond anvils to a pressure of 25 GPa and a temperature of 10 K. The magnetic ordering temperature has been determined from the four-point electrical resistivity measurements carried out on gadolinium. Our experiments show that the magnetic transition temperature decreases with increasing pressure to 19 GPa and then increases when gadolinium is subjected to higher pressures.

[Studies of three-dimensional cardiac late gadolinium enhancement MRI at 3.0 Tesla].

PubMed

Ishimoto, Takeshi; Ishihara, Masaru; Ikeda, Takayuki; Kawakami, Momoe

2008-12-20

Cardiac late Gadolinium enhancement MR imaging has been shown to allow assessment of myocardial viability in patients with ischemic heart disease. The current standard approach is a 3D inversion recovery sequence at 1.5 Tesla. The aims of this study were to evaluate the technique feasibility and clinical utility of MR viability imaging at 3.0 Tesla in patients with myocardial infarction and cardiomyopathy. In phantom and volunteer studies, the inversion time required to suppress the signal of interests and tissues was prolonged at 3.0 Tesla. In the clinical study, the average inversion time to suppress the signal of myocardium at 3.0 Tesla with respect to MR viability imaging at 1.5 Tesla was at 15 min after the administration of contrast agent (304.0+/-29.2 at 3.0 Tesla vs. 283.9+/-20.9 at 1.5 Tesla). The contrast between infarction and viable myocardium was equal at both field strengths (4.06+/-1.30 at 3.0 Tesla vs. 4.42+/-1.85 at 1.5 Tesla). Even at this early stage, MR viability imaging at 3.0 Tesla provides high quality images in patients with myocardial infarction. The inversion time is significantly prolonged at 3.0 Tesla. The contrast between infarction and viable myocardium at 3.0 Tesla are equal to 1.5 Tesla. Further investigation is needed for this technical improvement, for clinical evaluation, and for limitations.

Studies of MRI relaxivities of gadolinium-labeled dendrons

NASA Astrophysics Data System (ADS)

Pan, Hongmu; Daniel, Marie-Christine

2011-05-01

In cancer detection, imaging techniques have a great importance in early diagnosis. The more sensitive the imaging technique and the earlier the tumor can be detected. Contrast agents have the capability to increase the sensitivity in imaging techniques such as magnetic resonance imaging (MRI). Until now, gadolinium-based contrast agents are mainly used for MRI, and show good enhancement. But improvement is needed for detection of smaller tumors at the earliest stage possible. The dendrons complexed with Gd(DOTA) were synthesized and evaluated as a new MRI contrast agent. The longitudinal and transverse relaxation effects were tested and compared with commercial drug Magnevist, Gd(DTPA).

Feasibility and safety of adenosine cardiovascular magnetic resonance in patients with MR conditional pacemaker systems at 1.5 Tesla.

PubMed

Klein-Wiele, Oliver; Garmer, Marietta; Urbien, Rhyan; Busch, Martin; Kara, Kaffer; Mateiescu, Serban; Grönemeyer, Dietrich; Schulte-Hermes, Michael; Garbrecht, Marc; Hailer, Birgit

2015-12-22

Cardiovascular Magnetic Resonance (CMR) with adenosine stress is a valuable diagnostic tool in coronary artery disease (CAD). However, despite the development of MR conditional pacemakers CMR is not yet established in clinical routine for pacemaker patients with known or suspected CAD. A possible reason is that adenosine stress perfusion for ischemia detection in CMR has not been studied in patients with cardiac conduction disease requiring pacemaker therapy. Other than under resting conditions it is unclear whether MR safe pacing modes (paused pacing or asynchronous mode) can be applied safely because the effect of adenosine on heart rate is not precisely known in this entity of patients. We investigate for the first time feasibility and safety of adenosine stress CMR in pacemaker patients in clinical routine and evaluate a pacing protocol that considers heart rate changes under adenosine. We retrospectively analyzed CMR scans of 24 consecutive patients with MR conditional pacemakers (mean age 72.1 ± 11.0 years) who underwent CMR in clinical routine for the evaluation of known or suspected CAD. MR protocol included cine imaging, adenosine stress perfusion and late gadolinium enhancement. Pacemaker indications were sinus node dysfunction (n = 18) and second or third degree AV block (n = 6). Under a pacing protocol intended to avoid competitive pacing on the one hand and bradycardia due to AV block on the other no arrhythmia occurred. Pacemaker stimulation was paused to prevent competitive pacing in sinus node dysfunction with resting heart rate >45 bpm. Sympatho-excitatory effect of adenosine led to a significant acceleration of heart rate by 12.3 ± 8.3 bpm (p < 0.001), no bradycardia occurred. On the contrary in AV block heart rate remained constant; asynchronous pacing above resting heart rate did not interfere with intrinsic rhythm. Adenosine stress CMR appears to be feasible and safe in patients with MR conditional pacemakers. Heart rate response to adenosine

Assessment of myocardial fibrosis with T1 mapping MRI.

PubMed

Everett, R J; Stirrat, C G; Semple, S I R; Newby, D E; Dweck, M R; Mirsadraee, S

2016-08-01

Myocardial fibrosis can arise from a range of pathological processes and its presence correlates with adverse clinical outcomes. Cardiac magnetic resonance (CMR) can provide a non-invasive assessment of cardiac structure, function, and tissue characteristics, which includes late gadolinium enhancement (LGE) techniques to identify focal irreversible replacement fibrosis with a high degree of accuracy and reproducibility. Importantly the presence of LGE is consistently associated with adverse outcomes in a range of common cardiac conditions; however, LGE techniques are qualitative and unable to detect diffuse myocardial fibrosis, which is an earlier form of fibrosis preceding replacement fibrosis that may be reversible. Novel T1 mapping techniques allow quantitative CMR assessment of diffuse myocardial fibrosis with the two most common measures being native T1 and extracellular volume (ECV) fraction. Native T1 differentiates normal from infarcted myocardium, is abnormal in hypertrophic cardiomyopathy, and may be particularly useful in the diagnosis of Anderson-Fabry disease and amyloidosis. ECV is a surrogate measure of the extracellular space and is equivalent to the myocardial volume of distribution of the gadolinium-based contrast medium. It is reproducible and correlates well with fibrosis on histology. ECV is abnormal in patients with cardiac failure and aortic stenosis, and is associated with functional impairment in these groups. T1 mapping techniques promise to allow earlier detection of disease, monitor disease progression, and inform prognosis; however, limitations remain. In particular, reference ranges are lacking for T1 mapping values as these are influenced by specific CMR techniques and magnetic field strength. In addition, there is significant overlap between T1 mapping values in healthy controls and most disease states, particularly using native T1, limiting the clinical application of these techniques at present. Copyright © 2016 The Royal College

Identification and characterization of gadolinium(III) complexes in biological tissue extracts.

PubMed

Kahakachchi, Chethaka L; Moore, Dennis A

2010-07-01

The gadolinium species present in a rat kidney following intravenous administration of a gadolinium-based magnetic resonance contrast agent (Optimark™, Gadoversetamide injection) to a rat was examined in the present study. The major gadolinium species in the supernatant of the rat kidney tissue extracts was determined by reversed-phase liquid chromatography with online inductively coupled plasma optical emission spectrometry (HPLC-ICP-OES). The identity of the compound was established by liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS) detection. The principal gadolinium(III) complex in a rat kidney tissue extract was identified as Gd-DTPA-BMEA 24 Hrs and 7 days after a single intravenous injection of Optimark™ (gadoversetamide; Gd-DTPA-BMEA) at a dose of 5 mmol Gd/kg body weight. The study demonstrated for the first time the feasibility of the use of two complementary techniques, HPLC-ICP-OES and HPLC-ESI-MS to study the in vivo behavior of gadolinium-based magnetic resonance contrast media.

Alkali metal and alkali earth metal gadolinium halide scintillators

DOEpatents

Bourret-Courchesne, Edith; Derenzo, Stephen E.; Parms, Shameka; Porter-Chapman, Yetta D.; Wiggins, Latoria K.

2016-08-02

The present invention provides for a composition comprising an inorganic scintillator comprising a gadolinium halide, optionally cerium-doped, having the formula A.sub.nGdX.sub.m:Ce; wherein A is nothing, an alkali metal, such as Li or Na, or an alkali earth metal, such as Ba; X is F, Br, Cl, or I; n is an integer from 1 to 2; m is an integer from 4 to 7; and the molar percent of cerium is 0% to 100%. The gadolinium halides or alkali earth metal gadolinium halides are scintillators and produce a bright luminescence upon irradiation by a suitable radiation.

Relaxivity enhancement of aquated Tris(β-diketonate)gadolinium(III) chelates by confinement within ultrashort single-walled carbon nanotubes.

PubMed

Law, Justin J; Guven, Adem; Wilson, Lon J

2014-01-01

Ultrashort single-walled carbon nanotubes loaded with gadolinium ions (gadonanotubes) have been previously shown to exhibit extremely high T1 -weighted relaxivities (>100 mm(-1) s(-1) ). To further examine the effect of nanoconfinement on the relaxivity of gadolinium-based contrast agents for magnetic resonance imaging, a series of ultrashort single-walled carbon nanotube (US-tube) materials internally loaded with gadolinium chelates have been prepared and studied. US-tubes were loaded with Gd(acac)3  · 2H2 O, Gd(hfac)3  · 2H2 O, and Gd(thd)3 (acac = acetylacetone, hfac = hexafluoroacetylacetone, thd = tetramethylheptanedione). The longitudinal relaxivities of the prepared materials determined at 25°C in a 1.5 T field were 103 mm(-1) s(-1) for Gd(acac)3  · 2H2 O@US-tubes, 105 mm(-1) s(-1) for Gd(hfac)3  · 2H2 O@US-tubes and 26 mm(-1) s(-1) for Gd(thd)3 @US-tubes. Compared with the relaxivities obtained for the unloaded chelates (<10 mm(-1) s(-1) ) as well as accounting for the T1 reduction observed for the empty US-tubes, the boost in relaxivity for chelate-loaded US-tubes is attributed to confinement within the nanotube and depends on the number of coordinated water molecules. Copyright © 2014 John Wiley & Sons, Ltd.

Gadolinium-based magnetic resonance imaging contrast agents in interventional radiology.

PubMed

Atar, Eli

2004-07-01

Gadolinium-based agents are widely used in magnetic resonance imaging as contrast agents. These agents are radio-opaque enough for diagnostic imaging of the vascular tree by using digitally subtracted images as well as for imaging of the biliary system and the urinary tract. The recommended doses for gadolinium do not impair renal function or cause adverse reactions in patients with iodine sensitivity; thus patients with such conditions can safely undergo diagnostic angiography, either by MRI angiography or by catheterization using gadolinium as contrast agent, for diagnostic and therapeutic purposes.

Laser-induced thermotherapy for the treatment of liver metastasis. Correlation of gadolinium-DTPA-enhanced MRI with histomorphologic findings to determine criteria for follow-up monitoring.

PubMed

Germer, C; Isbert, C M; Albrecht, D; Ritz, J P; Schilling, A; Roggan, A; Wolf, K J; Müller, G; Buhr, H

1998-11-01

To evaluate gadolinium (Gd)-diethylenetriamine-pentaacetic-acid (DTPA)-enhanced magnetic resonance imaging (MRI) for follow-up monitoring of laser-induced thermotherapy (LITT) and to determine a useful examination schedule. LITT of the liver was performed in 55 rabbits using a neodymium: yttrium-aluminum-garnet (Nd:YAG) laser (4-W power output, 840-s exposure time). Gd-DTPA MRI and histologic examinations were performed at different times (0-168 days). Laser-induced lesions underwent regeneration and volume size reduction (69% after 168 days). The correlation coefficient (MR vs. macroscopic analysis) for the mean lesion diameter was r = 0.96. Histology of lesions comprised the four zones that correlated best with MRI findings. Coagulation necroses immediately after LITT was seen as an area of no enhancement on Gd-DTPA MRI. Circular enhancement was first seen 72-96 h after LITT, which was due to early mesenchymal proliferation. Gd-DTPA MRI is a good monitoring procedure for LITT. MRI should be performed 24 and 96 h after LITT.

Cardiac sarcoidosis: challenges in clinical practice.

PubMed

Bakker, Anne L; Grutters, Jan C; Keijsers, Ruth G; Post, Martijn C

2017-09-01

To address the current recommendations for screening, diagnosis, and treatment of cardiac sarcoidosis and the difficulties to put these recommendations into clinical practice. The incidence of cardiac sarcoidosis appears to be higher than earlier reported, probably because of improved imaging techniques. Late gadolinium enhancement with cardiac MRI (LGE-CMR) and fluorodeoxyglucose positron emission tomography obtained a central role in the diagnostic algorithm and monitoring of disease activity. New techniques are being investigated: T1 and T2 mapping for early detection in CMR, a sarcoid-specific tracer in PET, integrated positron emission tomography/MRI scanners, and assessment of scar with LGE in cardiac computed tomography. Isolated cardiac sarcoidosis is an increasingly recognized phenotype, but still an enormous challenge in clinical practice. The prognostic value of (and extent of) LGE-CMR should be taken into account for risk assessment and internal cardiac defbrillator therapy, even in patients with preserved left ventricular function. Unfortunately, randomized controlled trials to guide immunosuppressive therapy are still lacking. A multidisciplinary approach to diagnose and treat cardiac sarcoidosis patients in specialized centers is strongly recommendable. Cardiac sarcoidosis is increasingly recognized because of improved imaging techniques; however, treatment of cardiac sarcoidosis is still mainly based on expert opinion.

Grade 3 ischemia on the admission electrocardiogram is associated with severe microvascular injury on cardiac magnetic resonance imaging after ST elevation myocardial infarction.

PubMed

Weaver, James C; Rees, David; Prasan, Ananth M; Ramsay, David D; Binnekamp, Maurits F; McCrohon, Jane A

2011-01-01

Grade 3 ischemia during ST elevation myocardial infarction (STEMI) is defined as ST elevation with distortion of the terminal portion of the QRS on electrocardiogram (ECG). The aim of this study was to evaluate the effect of ischemic grade on cardiac magnetic resonance (CMR) imaging infarct characteristics such as infarct size, microvascular obstruction (MVO), intramyocardial hemorrhage (IMH), and myocardial salvage. Patients with STEMI treated with primary percutaneous coronary intervention had a 12-lead ECG on presentation for analysis of ischemic grade. Gadolinium-enhanced CMR imaging was performed within 7 days to assess infarct size, MVO, IMH, and myocardial salvage. Of the 37 patients enrolled in the study, grade 3 ischemia was present in 32%. Those with grade 3 ischemia had higher peak troponin I levels (P = .013), more MVO (P < .001), more IMH (P < .001), larger infarct size (P = .025), and less myocardial salvage (P = .012). Regression analysis found that grade 3 ischemia, infarct size, and peak troponin I level were significantly associated with MVO and IMH. Grade 3 ischemia on the admission ECG during STEMI is closely associated with the development of severe microvascular damage on CMR imaging. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

59-year-old female with breathlessness.

PubMed

Scatteia, Alessandra; De Garate, Estefania; Bucciarelli-Ducci, Chiara

2016-10-15

A 59-year-old female underwent an electrocardiogram (ECG) and echocardiographic screening. Her brother died at quite a young age of kidney failure. Resting ECG showed borderline voltage criteria for left ventricular hypertrophy (LVH), with marked widespread T-wave inversion. Echocardiogram was normal, but in consideration of exertional breathlessness and abnormal baseline ECG, she underwent a coronary angiogram, which showed unobstructed coronaries. She was then referred to have a cardiac MR (CMR) for further characterisation. CMR images were acquired with a 1.5 T scanner and the imaging protocol included Steady-State Free Precession (SSFP) cine images (Figure 1A) as well as late gadolinium enhancement (LGE) images in the long-axis and short-axis planes covering the whole left ventricle (Figure 1B). In addition, native and postcontrast T1 mapping (Modified Look-Locker (MOLLI)) images were acquired for further tissue characterisation (Figure 1C and D, respectively). What is the most likely diagnosis based on CMR findings? Anderson-Fabry's disease (AFD)Cardiac amyloidosisGenotype (+), phenotype (-) hypertrophic cardiomyopathy (HCM)Myocardial iron overloadNormal heart. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Thermodynamic properties of gadolinium in Ga-Sn and Ga-Zn eutectic based alloys

NASA Astrophysics Data System (ADS)

Maltsev, Dmitry S.; Volkovich, Vladimir A.; Yamshchikov, Leonid F.; Chukin, Andrey V.

2016-09-01

Thermodynamic properties of gadolinium in Ga-Sn and Ga-Zn eutectic based alloys were studied. Temperature dependences of gadolinium activity in the studied alloys were determined at 573-1073 K employing the EMF method. Solubility of gadolinium in the Ga-Sn and Ga-Zn alloys was measured at 462-1073 K using IMCs sedimentation method. Activity coefficients as well as partial and excess thermodynamic functions of gadolinium in the studied alloys were calculated on the basis of the obtained experimental data.

MR imaging of the inner ear: comparison of a three-dimensional fast spin-echo sequence with use of a dedicated quadrature-surface coil with a gadolinium-enhanced spoiled gradient-recalled sequence.

PubMed

Naganawa, S; Ito, T; Fukatsu, H; Ishigaki, T; Nakashima, T; Ichinose, N; Kassai, Y; Miyazaki, M

1998-09-01

To prospectively evaluate the sensitivity and specificity of magnetic resonance (MR) imaging in the inner ear with a long echo train, three-dimensional (3D), asymmetric Fourier-transform, fast spin-echo (SE) sequence with use of a dedicated quadrature-surface phased-array coil to detect vestibular schwannoma in the cerebellopontine angle and the internal auditory canal. In 205 patients (410 ears) with ear symptoms, 1.5-T MR imaging was performed with unenhanced 3D asymmetric fast SE and gadolinium-enhanced 3D gradient-recalled (SPGR) sequences with use of a quadrature surface phased-array coil. The 3D asymmetric fast SE images were reviewed by two radiologists, with the gadolinium-enhanced 3D SPGR images used as the standard of reference. Nineteen lesions were detected in the 410 ears (diameter range, 2-30 mm; mean, 10.5 mm +/- 6.4 [standard deviation]; five lesions were smaller than 5 mm). With 3D asymmetric fast SE, sensitivity, specificity, and accuracy, respectively, were 100%, 99.5%, and 99.5% for observer 1 and 100%, 99.7%, and 99.8% for observer 2. The unenhanced 3D asymmetric fast SE sequence with a quadrature-surface phased-array coli allows the reliable detection of vestibular schwannoma in the cerebellopontine angle and internal auditory canal.

Detection of Anderson-Fabry cardiomyopathy with CMR in a patient with chest pain and elevated cardiac biomarkers.

PubMed

Albin, Glenn; Ryan, Michael; Heltne, Carl

2006-01-01

This case illustrates the utility of CMR in evaluating a patient with undiagnosed Anderson-Fabry disease who presented with chest pain, elevated cardiac biomarkers, normal coronary arteries, and an abnormal echocardiogram.

Diagnostic significance of gadolinium-DTPA (diethylenetriamine penta-acetic acid) enhanced magnetic resonance imaging in thrombolytic treatment for acute myocardial infarction: its potential in assessing reperfusion.

PubMed Central

van der Wall, E E; van Dijkman, P R; de Roos, A; Doornbos, J; van der Laarse, A; Manger Cats, V; van Voorthuisen, A E; Matheijssen, N A; Bruschke, A V

1990-01-01

The diagnostic value of gadolinium-DTPA (diethylenetriamine penta-acetic acid) enhanced magnetic resonance imaging in patients treated by thrombolysis for acute myocardial infarction was assessed in 27 consecutive patients who had a first acute myocardial infarction (14 anterior, 13 inferior) and who underwent thrombolytic treatment and coronary arteriography within 4 hours of the onset of symptoms. Magnetic resonance imaging was performed 93 hours (range 15-241) after the onset of symptoms. A Philips Gyroscan (0.5 T) was used, and spin echo measurements (echo time 30 ms) were made before and 20 minutes after intravenous injection of 0.1 mmol/kg gadolinium-DTPA. In all patients contrast enhancement of the infarcted areas was seen after Gd-DTPA. The signal intensities of the infarcted and normal values were used to calculate the intensity ratios. Mean (SD) intensity ratios after Gd-DTPA were significantly increased (1.15 (0.17) v 1.52 (0.29). Intensity ratios were higher in the 17 patients who underwent magnetic resonance imaging more than 72 hours after the onset of symptoms than in the 10 who underwent magnetic resonance imaging earlier, the difference being significantly greater after administration of Gd-DTPA (1.38 (0.12) v 1.61 (0.34). When patients were classified according to the site and size of the infarcted areas, or to reperfusion (n = 19) versus non-reperfusion (n = 8), the intensity ratios both before and after Gd-DTPA did not show significant differences. Magnetic resonance imaging with Gd-DTPA improved the identification of acutely infarcted areas, but with current techniques did not identify patients in whom thrombolytic treatment was successful. Images PMID:2310640

Reliability of gadolinium-enhanced magnetic resonance imaging findings and their correlation with clinical outcome in patients with sciatica.

PubMed

el Barzouhi, Abdelilah; Vleggeert-Lankamp, Carmen L A M; Lycklama à Nijeholt, Geert J; Van der Kallen, Bas F; van den Hout, Wilbert B; Koes, Bart W; Peul, Wilco C

2014-11-01

Gadolinium-enhanced magnetic resonance imaging (Gd-MRI) is often performed in the evaluation of patients with persistent sciatica after lumbar disc surgery. However, correlation between enhancement and clinical findings is debated, and limited data are available regarding the reliability of enhancement findings. To evaluate the reliability of Gd-MRI findings and their correlation with clinical findings in patients with sciatica. Prospective observational evaluation of patients who were enrolled in a randomized trial with 1-year follow-up. Patients with 6- to 12-week sciatica, who participated in a multicentre randomized clinical trial comparing an early surgery strategy with prolonged conservative care with surgery if needed. In total 204 patients underwent Gd-MRI at baseline and after 1 year. Patients were assessed by means of the Roland Disability Questionnaire (RDQ) for sciatica, visual analog scale (VAS) for leg pain, and patient-reported perceived recovery at 1 year. Kappa coefficients were used to assess interobserver reliability. In total, 204 patients underwent Gd-MRI at baseline and after 1 year. Magnetic resonance imaging findings were correlated to the outcome measures using the Mann-Whitney U test for continuous data and Fisher exact tests for categorical data. Poor-to-moderate agreement was observed regarding Gd enhancement of the herniated disc and compressed nerve root (kappa<0.41), which was in contrast with excellent interobserver agreement of the disc level of the herniated disc and compressed nerve root (kappa>0.95). Of the 59 patients with an enhancing herniated disc at 1 year, 86% reported recovery compared with 100% of the 12 patients with nonenhancing herniated discs (p=.34). Of the 12 patients with enhancement of the most affected nerve root at 1 year, 83% reported recovery compared with 85% of the 192 patients with no enhancement (p=.69). Patients with and without enhancing herniated discs or nerve roots at 1 year reported comparable

Self-assembled gemcitabine-gadolinium nanoparticles for magnetic resonance imaging and cancer therapy.

PubMed

Li, Lele; Tong, Rong; Li, Mengyuan; Kohane, Daniel S

2016-03-01

Nanoparticles with combined diagnostic and therapeutic functions are promising tools for cancer diagnosis and treatment. Here, we demonstrate a theranostic nanoparticle that integrates an active gemcitabine metabolite and a gadolinium-based magnetic resonance imaging agent via a facile supramolecular self-assembly synthesis, where the anti-cancer drug gemcitabine-5'-monophosphate (a phosphorylated active metabolite of the anti-cancer drug gemcitabine) was used to coordinate with Gd(III) to self-assemble into theranostic nanoparticles. The formulation exhibits a strong T1 contrast signal for magnetic resonance imaging of tumors in vivo, with enhanced retention time. Furthermore, the nanoparticles did not require other inert nanocarriers or excipients and thus had an exceptionally high drug loading (55 wt%), resulting in the inhibition of MDA-MB-231 tumor growth in mice. Recent advances in nanoparticle-based drug delivery systems have spurred the development of "theranostic" multifunctional nanoparticles, which combine therapeutic and diagnostic functionalities in a single formulation. Developing simple and efficient synthetic strategies for the construction of nanotheranostics with high drug loading remains a challenge. Here, we demonstrate a theranostic nanoparticle that integrates high loadings of an active gemcitabine metabolite and a gadolinium-based magnetic resonance imaging agent via a facile synthesis. The nanoparticles were better T1 contrast agents than currently used Gd-DTPA and had prolonged retention in tumor. Moreover they exhibited enhanced in vivo antitumor activity compared to free drug in a breast cancer xenograft mouse model. The strategy provides a scalable way to fabricate nanoparticles that enables enhancement of both therapeutic and diagnostic capabilities. Published by Elsevier Ltd.

Stress Cardiac MRI in Women With Myocardial Infarction and Nonobstructive Coronary Artery Disease.

PubMed

Mauricio, Rina; Srichai, Monvadi B; Axel, Leon; Hochman, Judith S; Reynolds, Harmony R

2016-10-01

In a prospective study, cardiac MRI (CMR) and intravascular ultrasound were performed in women with myocardial infarction (MI) and nonobstructive coronary artery disease (MINOCA). Forty participants underwent adenosine-stress CMR (sCMR). Abnormal perfusion may co-localize with ischemic late gadolinium enhancement (LGE) and T2-weighted signal hyperintensity (T2+), suggesting microvascular dysfunction contributed to MI. Qualitative perfusion analysis was performed by 2 independent readers. Abnormal myocardial perfusion reserve index (MPRI) was defined as global average ≤1.84. Abnormal rest perfusion was present in 10 patients (25%) and stress perfusion abnormalities in 25 (63%). Abnormal stress perfusion was not associated with LGE but tended to occur with T2+. Among patients with abnormal perfusion and LGE, the LGE pattern was ischemic in half. The locations of abnormal perfusion and LGE matched in 75%, T2+ in 100%. Abnormal stress perfusion was not associated with plaque disruption and matched in location in 63%. MPRI was abnormal in 10 patients (25%) and was not associated with LGE, T2+ or plaque disruption. Abnormal perfusion on sCMR is common among women with MINOCA. Abnormal perfusion usually co-localized with LGE and/or T2+ when present. Variability in LGE pattern leads to uncertainty about whether the finding of abnormal perfusion was cause or consequence of the tissue state leading to LGE. Low MPRI, possibly indicating diffuse microvascular disease, was observed with and without LGE and T2+. Multiple mechanisms may lead to abnormal perfusion on sCMR. Microvascular dysfunction may contribute to the pathogenesis of and coexist with other causes of MINOCA. © 2016 Wiley Periodicals, Inc.

Are gadolinium-based contrast media nephrotoxic? A renal biopsy study.

PubMed

Akgun, Hulya; Gonlusen, Gulfiliz; Cartwright, Joiner; Suki, Wadi N; Truong, Luan D

2006-09-01

Gadolinium-based contrast media were originally introduced as alternatives to iodinated media for magnetic resonance imaging. Although originally thought to be nonnephrotoxic, gadolinium-based contrast media have recently been reported to be associated with acute renal failure; the mechanism and the underlying renal injury are not completely understood. We report what is, to our knowledge, the first renal biopsy in this context. A 56-year-old patient underwent 2 consecutive vascular imaging procedures in conjunction with gadolinium-based contrast medium administration. A few days later, the patient developed acute renal failure. A renal biopsy showed acute tubular cell injury including patchy tubular cell necrosis, tubular cell degeneration, and marked proliferation of tubular cells, together with mild interstitial edema and interstitial inflammation, but without significant glomerular or vascular changes. During supportive therapy, renal function was partially regained. This case emphasizes the potential nephrotoxicity of gadolinium-based contrast media and suggests that the nephrotoxicity is related to potentially reversible acute tubular cell injury.

Diagnostic and Prognostic Value of CMR T1-Mapping in Patients With Heart Failure and Preserved Ejection Fraction.

PubMed

Rommel, Karl-Philipp; Lücke, Christian; Lurz, Philipp

2017-10-01

Heart failure with preserved ejection fraction (HFpEF) presents a major challenge in modern cardiology. Although this syndrome is of increasing prevalence and is associated with unfavorable outcomes, treatment trials have failed to establish effective therapies. Currently, solutions to this dilemma are being investigated, including categorizing and characterizing patients more diversely to individualize treatment. In this regard, new imaging techniques might provide important information. Diastolic dysfunction is a diagnostic and pathophysiological cornerstone in HFpEF and is believed to be caused by systemic inflammation with the development of interstitial myocardial fibrosis and myocardial stiffening. Cardiac magnetic resonance (CMR) T 1 -mapping is a novel tool, which allows noninvasive quantification of the extracellular space and diffuse myocardial fibrosis. This review provides an overview of the potential of myocardial tissue characterization with CMR T 1 mapping in HFpEF patients, outlining its diagnostic and prognostic implications and discussing future directions. We conclude that CMR T 1 mapping is potentially an effective tool for patient characterization in large-scale epidemiological, diagnostic, and therapeutic HFpEF trials beyond traditional imaging parameters. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Technical aspects of MRI signal change quantification after gadolinium-based contrast agents' administration.

PubMed

Ramalho, Joana; Ramalho, Miguel; AlObaidy, Mamdoh; Semelka, Richard C

2016-12-01

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. Copyright © 2016 Elsevier Inc. All rights reserved.

In vitro comparison of intracranial stent visibility using various concentrations of gadolinium contrast agent under 1.5 T and 3 T MR angiography.

PubMed

Chiang, Chen-Hua; Tseng, Ying-Chi; Chen, Ai-Chi; Huang, Yen-Lin; Chen, David Yen-Ting; Chen, Chi-Jen; Lin, Yen-Kuang; Hsu, Hui-Ling

2017-04-01

MR angiography (MRA) is an increasingly used evaluation method following intracranial stenting. However, the various artifacts created by the stent limit this technique. The purpose of this study was to investigate the effects of various concentrations of gadolinium contrast agent on the visibility and signal characteristics of two stents using the a contrast enhanced MRA technique. Two intracranial stents (Enterprise and Helistent) were placed in polyvinyl chloride tubes as vascular phantoms. They were filled with six different doses of gadolinium contrast agent (1.0, 2.0, 4.0, 6.0, 8.0, and 10.0 mmol/L dimeglumine gadopentetate, respectively) and imaged using 3 T and 1.5 T MR systems. Relative in-stent signal (RIS) was calculated and artificial luminal narrowing (ALN) was obtained using pixel by pixel analysis. The Enterprise stent, performed in both 1.5 T and 3 T MR systems, showed mean RIS values much less than those for the Helistent for all different doses of gadolinium solution. Increased gadolinium concentration resulted in a gradual reduction in RIS values in the Enterprise group. Also, ALN in the Enterprise group showed no or little change with various gadolinium doses. The Enterprise stent demonstrated good luminal visibility regardless of gadolinium concentration. The relative in-stent signals were more predictable in the Enterprise stent with various doses of gadolinium. Therefore, the Enterprise stent has been shown to provide better in-stent visibility compared with the Helistent using various gadolinium doses. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Assessment of acute myocarditis by cardiac magnetic resonance imaging: Comparison of qualitative and quantitative analysis methods.

PubMed

Imbriaco, Massimo; Nappi, Carmela; Puglia, Marta; De Giorgi, Marco; Dell'Aversana, Serena; Cuocolo, Renato; Ponsiglione, Andrea; De Giorgi, Igino; Polito, Maria Vincenza; Klain, Michele; Piscione, Federico; Pace, Leonardo; Cuocolo, Alberto

2017-10-26

To compare cardiac magnetic resonance (CMR) qualitative and quantitative analysis methods for the noninvasive assessment of myocardial inflammation in patients with suspected acute myocarditis (AM). A total of 61 patients with suspected AM underwent coronary angiography and CMR. Qualitative analysis was performed applying Lake-Louise Criteria (LLC), followed by quantitative analysis based on the evaluation of edema ratio (ER) and global relative enhancement (RE). Diagnostic performance was assessed for each method by measuring the area under the curves (AUC) of the receiver operating characteristic analyses. The final diagnosis of AM was based on symptoms and signs suggestive of cardiac disease, evidence of myocardial injury as defined by electrocardiogram changes, elevated troponin I, exclusion of coronary artery disease by coronary angiography, and clinical and echocardiographic follow-up at 3 months after admission to the chest pain unit. In all patients, coronary angiography did not show significant coronary artery stenosis. Troponin I levels and creatine kinase were higher in patients with AM compared to those without (both P < .001). There were no significant differences among LLC, T2-weighted short inversion time inversion recovery (STIR) sequences, early (EGE), and late (LGE) gadolinium-enhancement sequences for diagnosis of AM. The AUC for qualitative (T2-weighted STIR 0.92, EGE 0.87 and LGE 0.88) and quantitative (ER 0.89 and global RE 0.80) analyses were also similar. Qualitative and quantitative CMR analysis methods show similar diagnostic accuracy for the diagnosis of AM. These findings suggest that a simplified approach using a shortened CMR protocol including only T2-weighted STIR sequences might be useful to rule out AM in patients with acute coronary syndrome and normal coronary angiography.

Active extravasation of gadolinium-based contrast agent into the subdural space following lumbar puncture.

PubMed

Kothari, Pranay D; Hanser, Evelyn M; Wang, Harrison; Farid, Nikdokht

2016-01-01

A 38year-old male presented with cauda equina syndrome following multiple lumbar puncture attempts. Lumbar spine magnetic resonance imaging (MRI) showed a subdural hematoma and an area of apparent contrast enhancement in the spinal canal on sagittal post-contrast images. Axial post-contrast images obtained seven minutes later demonstrated an increase in size and change in shape of the region of apparent contrast enhancement, indicating active extravasation of the contrast agent. This is the first reported case of active extravasation of gadolinium-based contrast agent in the spine. Copyright © 2016 Elsevier Inc. All rights reserved.

Formal consensus to identify clinically important changes in management resulting from the use of cardiovascular magnetic resonance (CMR) in patients who activate the primary percutaneous coronary intervention (PPCI) pathway.

PubMed

Pufulete, Maria; Brierley, Rachel C; Bucciarelli-Ducci, Chiara; Greenwood, John P; Dorman, Stephen; Anderson, Richard A; Harris, Jessica; McAlindon, Elisa; Rogers, Chris A; Reeves, Barnaby C

2017-06-22

To define important changes in management arising from the use of cardiovascular magnetic resonance (CMR) in patients who activate the primary percutaneous coronary intervention (PPCI) pathway. Formal consensus study using literature review and cardiologist expert opinion to formulate consensus statements and setting up a consensus panel to review the statements (by completing a web-based survey, attending a face-to-face meeting to discuss survey results and modify the survey to reflect group discussion and completing the modified survey to determine which statements were in consensus). Formulation of consensus statements: four cardiologists (two CMR and two interventional) and six non-clinical researchers. Formal consensus: seven cardiologists (two CMR and three interventional, one echocardiography and one heart failure). Forty-nine additional cardiologists completed the modified survey. Thirty-seven draft statements describing changes in management following CMR were generated; these were condensed into 12 statements and reviewed through the formal consensus process. Three of 12 statements were classified in consensus in the first survey; these related to the role of CMR in identifying the cause of out-of-hospital cardiac arrest, providing a definitive diagnosis in patients found to have unobstructed arteries on angiography and identifying patients with left ventricular thrombus. Two additional statements were in consensus in the modified survey, relating to the ability of CMR to identify patients who have a poor prognosis after PPCI and assess ischaemia and viability in patients with multivessel disease. There was consensus that CMR leads to clinically important changes in management in five subgroups of patients who activate the PPCI pathway. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Multi-atlas propagation based left atrium segmentation coupled with super-voxel based pulmonary veins delineation in late gadolinium-enhanced cardiac MRI

NASA Astrophysics Data System (ADS)

Yang, Guang; Zhuang, Xiahai; Khan, Habib; Haldar, Shouvik; Nyktari, Eva; Li, Lei; Ye, Xujiong; Slabaugh, Greg; Wong, Tom; Mohiaddin, Raad; Keegan, Jennifer; Firmin, David

2017-02-01

Late Gadolinium-Enhanced Cardiac MRI (LGE CMRI) is a non-invasive technique, which has shown promise in detecting native and post-ablation atrial scarring. To visualize the scarring, a precise segmentation of the left atrium (LA) and pulmonary veins (PVs) anatomy is performed as a first step—usually from an ECG gated CMRI roadmap acquisition—and the enhanced scar regions from the LGE CMRI images are superimposed. The anatomy of the LA and PVs in particular is highly variable and manual segmentation is labor intensive and highly subjective. In this paper, we developed a multi-atlas propagation based whole heart segmentation (WHS) to delineate the LA and PVs from ECG gated CMRI roadmap scans. While this captures the anatomy of the atrium well, the PVs anatomy is less easily visualized. The process is therefore augmented by semi-automated manual strokes for PVs identification in the registered LGE CMRI data. This allows us to extract more accurate anatomy than the fully automated WHS. Both qualitative visualization and quantitative assessment with respect to manual segmented ground truth showed that our method is efficient and effective with an overall mean Dice score of 0.91.

Three-dimensional gadolinium-enhanced magnetic resonance venography in suspected thrombo-occlusive disease of the central chest veins.

PubMed

Kroencke, T J; Taupitz, M; Arnold, R; Fritsche, L; Hamm, B

2001-11-01

To determine the usefulness of high-resolution three-dimensional (3D) gadolinium-enhanced magnetic resonance venography (MRV) in the evaluation of central venous thrombo-occlusive disease of the chest. Prospective study. University hospital. Sixteen consecutive patients with clinically suspected thrombosis of the superior vena cava, subclavian, brachiocephalic/innominate, internal jugular, or axillary veins. Thirteen patients had a neoplasm, two patients had a connective tissue disease, and one patient had a history of strenuous exercise. Twelve of 16 patients had prior central venous catheter placement. MRI was correlated with color-coded duplex sonography (CCDS) in 7 of 16 patients, digital subtraction angiography (DSA) in 3 of 16 patients, and CT in 2 of 16 patients. Contrast-enhanced MRV was performed in a total of 20 examinations. A 3D data set (gradient echo; time to repeat, 4.6 ms; time to echo, 1.8 ms; flip angle, 30 degrees; time of acquisition, 23 s; 512 matrix/64 partitions; slice thickness, 1.5 mm) was acquired in the arterial and venous phase. Overall image quality was assessed on a 5-point scale. The presence, site, and extent of thrombus, as well as presence of an intravascular device, were determined. Overall image quality was rated very good (1 point) in 7 of 16 cases (44%) and good (2 points) in 9 of 16 cases (56%). Thrombus was detected in 16 of 16 patients, and complete extent of disease could be determined in 15 of 16 patients (94%). MRV did not miss any finding obtained by CCDS, DSA, or CT, and provided additional information in 6 of 16 examinations (38%). Contrast-enhanced MRV is a fast and reliable noninvasive procedure with excellent results regarding detection and determination of the extent of thrombo-occlusive disease of the chest veins.

Impact of hyperventilation and apnea on myocardial oxygenation in patients with obstructive sleep apnea - An oxygenation-sensitive CMR study.

PubMed

Roubille, François; Fischer, Kady; Guensch, Dominik P; Tardif, Jean-Claude; Friedrich, Matthias G

2017-02-01

Oxygenation-sensitive cardiovascular magnetic resonance imaging (OS-CMR) is an emerging technique that can monitor changes in myocardial oxygenation in vivo. Obstructive sleep apnea syndrome (OSAS) is associated with endothelial and microcirculatory dysfunction and increased cardiovascular morbidity and mortality. Little is known about myocardial responses to apnea in patients with OSAS. We hypothesized that the coronary vascular response to hyperventilation and long breath-hold is diminished in patients with OSAS when compared to healthy volunteers. Twenty-nine OSAS patients and 36 healthy volunteers were prospectively enrolled. All CMR scans were performed on a clinical 3T system. Participants performed a breathing maneuver with 60s of hyperventilation followed by a maximal breath-hold. During the breath-hold, OS-CMR images were continuously acquired and signal intensity changes were measured by a blinded reader. Patients with OSAS were older than healthy volunteers (p<0.01) and presented more co-morbidities; 66% were currently treated with nocturnal positive airway pressure. Compared to healthy participants, the expected increase of myocardial oxygenation during the first 15s of the breath-hold was significantly lower in patients with OSAS (2.6±8.3% vs. 6.7±5.6%; p<0.05), and remained reduced at all time points during the breath-hold. Importantly this result was mainly driven by patients under continuous positive airway pressure (CPAP), suggesting that CPAP might have a greater impact on increase of myocardial oxygenation rather than OSAS itself. The myocardial vascular response to combined breathing maneuvers of hyperventilation followed by voluntary apnea is blunted in patients with obstructive sleep apnea. Clinical studies should now further define the clinical role of oxygenation-sensitive CMR in patients with respiratory disorders. Copyright © 2016 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Graphene oxide-gadolinium (III) oxide nanoparticle composite: a novel MR contrast agent with high longitudinal and transverse relaxivity

NASA Astrophysics Data System (ADS)

Venkatesha, N.; Poojar, Pavan; Geethanath, Sairam; Srivastava, Chandan

2014-12-01

Production of bio-compatible contrast agent materials to enhance the sensitivity of the magnetic resonance imaging (MRI) technique is a highly active area in MRI related research. This work illustrates the potential of a new material: graphene oxide-gadolinium (III) oxide nanoparticle (GO-Gd2O3) composite in yielding both transverse (16.3 mM-1 s-1) and longitudinal relaxivity (40 mM-1 s-1) values which are significantly higher than the proton relaxivity values achieved using the gadolinium based contrast agents currently used in MRI. Such high proton relaxivity values can facilitate low dosage of GO-Gd2O3 composite for obtaining both T1 and T2 weighted high signal-to-noise ratio images in MRI.

Compensated gadolinium-loaded plastic scintillators for thermal neutron detection (and counting)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dumazert, Jonathan; Coulon, Romain; Bertrand, Guillaume H. V.

2015-07-01

Plastic scintillator loading with gadolinium-rich organometallic complexes shows a high potential for the deployment of efficient and cost-effective neutron detectors. Due to the low-energy photon and electron signature of thermal neutron capture by gadolinium-155 and gadolinium-157, alternative treatment to Pulse Shape Discrimination has to be proposed in order to display a trustable count rate. This paper discloses the principle of a compensation method applied to a two-scintillator system: a detection scintillator interacts with photon radiation and is loaded with gadolinium organometallic compound to become a thermal neutron absorber, while a non-gadolinium loaded compensation scintillator solely interacts with the photon partmore » of the incident radiation. Posterior to the nonlinear smoothing of the counting signals, a hypothesis test determines whether the resulting count rate after photon response compensation falls into statistical fluctuations or provides a robust image of a neutron activity. A laboratory prototype is tested under both photon and neutron irradiations, allowing us to investigate the performance of the overall compensation system in terms of neutron detection, especially with regards to a commercial helium-3 counter. The study reveals satisfactory results in terms of sensitivity and orientates future investigation toward promising axes. (authors)« less

Tracking the Evolution of Cerebral Gadolinium-Enhancing Lesions to Persistent T1 Black Holes in Multiple Sclerosis: Validation of a Semiautomated Pipeline.

PubMed

Andermatt, Simon; Papadopoulou, Athina; Radue, Ernst-Wilhelm; Sprenger, Till; Cattin, Philippe

2017-09-01

Some gadolinium-enhancing multiple sclerosis (MS) lesions remain T1-hypointense over months ("persistent black holes, BHs") and represent areas of pronounced tissue loss. A reduced conversion of enhancing lesions to persistent BHs could suggest a favorable effect of a medication on tissue repair. However, the individual tracking of enhancing lesions can be very time-consuming in large clinical trials. We created a semiautomated workflow for tracking the evolution of individual MS lesions, to calculate the proportion of enhancing lesions becoming persistent BHs at follow-up. Our workflow automatically coregisters, compares, and detects overlaps between lesion masks at different time points. We tested the algorithm in a data set of Magnetic Resonance images (1.5 and 3T; spin-echo T1-sequences) from a phase 3 clinical trial (n = 1,272), in which all enhancing lesions and all BHs had been previously segmented at baseline and year 2. The algorithm analyzed the segmentation masks in a longitudinal fashion to determine which enhancing lesions at baseline turned into BHs at year 2. Images of 50 patients (192 enhancing lesions) were also reviewed by an experienced MRI rater, blinded to the algorithm results. In this MRI data set, there were no cases that could not be processed by the algorithm. At year 2, 417 lesions were classified as persistent BHs (417/1,613 = 25.9%). The agreement between the rater and the algorithm was > 98%. Due to the semiautomated procedure, this algorithm can be of great value in the analysis of large clinical trials, when a rater-based analysis would be time-consuming. Copyright © 2017 by the American Society of Neuroimaging.

Use of a 1.0 Tesla open scanner for evaluation of pediatric and congenital heart disease: a retrospective cohort study.

PubMed

Lu, Jimmy C; Nielsen, James C; Morowitz, Layne; Musani, Muzammil; Ghadimi Mahani, Maryam; Agarwal, Prachi P; Ibrahim, El-Sayed H; Dorfman, Adam L

2015-05-25

Open cardiovascular magnetic resonance (CMR) scanners offer the potential for imaging patients with claustrophobia or large body size, but at a lower 1.0 Tesla magnetic field. This study aimed to evaluate the efficacy of open CMR for evaluation of pediatric and congenital heart disease. This retrospective, cross-sectional study included all patients ≤18 years old or with congenital heart disease who underwent CMR on an open 1.0 Tesla scanner at two centers from 2012-2014. Indications for CMR and clinical questions were extracted from the medical record. Studies were qualitatively graded for image quality and diagnostic utility. In a subset of 25 patients, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were compared to size- and diagnosis-matched patients with CMR on a 1.5 Tesla scanner. A total of 65 patients (median 17.3 years old, 60% male) were included. Congenital heart disease was present in 32 (50%), with tetralogy of Fallot and bicuspid aortic valve the most common diagnoses. Open CMR was used due to scheduling/equipment issues in 51 (80%), claustrophobia in 7 (11%), and patient size in 3 (5%); 4 patients with claustrophobia had failed CMR on a different scanner, but completed the study on open CMR without sedation. All patients had good or excellent image quality on black blood, phase contrast, magnetic resonance angiography, and late gadolinium enhancement imaging. There was below average image quality in 3/63 (5%) patients with cine images, and 4/15 (27%) patients with coronary artery imaging. SNR and CNR were decreased in cine and magnetic resonance angiography images compared to 1.5 Tesla. The clinical question was answered adequately in all but 2 patients; 1 patient with a Fontan had artifact from an embolization coil limiting RV volume analysis, and in 1 patient the right coronary artery origin was not well seen. Open 1.0 Tesla scanners can effectively evaluate pediatric and congenital heart disease, including patients with claustrophobia

Functional, morphological and electrocardiographical abnormalities in patients with apical hypertrophic cardiomyopathy and apical aneurysm: correlation with cardiac MR

PubMed Central

Suwa, Kenichiro; Satoh, Hiroshi; Sano, Makoto; Nobuhara, Mamoru; Saitoh, Takeji; Saotome, Masao; Urushida, Tsuyoshi; Katoh, Hideki; Tawarahara, Kei; Ohtani, Hayato; Wakabayashi, Yasushi; Takase, Hiroyuki; Terada, Hajime; Takehara, Yasuo; Sakahara, Harumi; Hayashi, Hideharu

2014-01-01

Objective The prognosis of apical hypertrophic cardiomyopathy (APH) has been benign, but apical myocardial injury has prognostic importance. We studied functional, morphological and electrocardiographical abnormalities in patients with APH and with apical aneurysm and sought to find parameters that relate to apical myocardial injury. Methods Study design: a multicentre trans-sectional study. Patients: 45 patients with APH and 5 with apical aneurysm diagnosed with transthoracic echocardiography (TTE) in the database of Hamamatsu Circulation Forum. Measure: the apical contraction with cine-cardiac MR (CMR), the myocardial fibrotic scar with late gadolinium enhancement (LGE)-CMR, and QRS fragmentation (fQRS) defined when two ECG-leads exhibited RSR’s patterns. Results Cine-CMR revealed 27 patients with normal, 12 with hypokinetic and 11 with dyskinetic apical contraction. TTE misdiagnosed 11 (48%) patients with hypokinetic and dyskinetic contraction as those with normal contraction. Apical LGE was apparent in 10 (83%) and 11 (100%) patients with hypokinetic and dyskinetic contraction, whereas only in 11 patients (41%) with normal contraction (p<0.01). Patients with dyskinetic apical contraction had the lowest left ventricular ejection fraction, the highest prevalence of ventricular tachycardia, and the smallest ST depression and depth of negative T waves. The presence of fQRS was associated with impaired apical contraction and apical LGE (OR=8.32 and 8.61, p<0.05). Conclusions CMR is superior to TTE for analysing abnormalities of the apex in patients with APH and with apical aneurysm. The presence of fQRS can be a promising parameter for the early detection of apical myocardial injury. PMID:25332823

Clinical and prognostic utility of cardiovascular magnetic resonance imaging in myeloma patients with suspected cardiac amyloidosis.

PubMed

Bhatti, Sabha; Watts, Evan; Syed, Fahd; Vallurupalli, Srikanth; Pandey, Tarun; Jambekar, Kedar; Mazur, Wojciech; Hakeem, Abdul

2016-09-01

AL amyloidosis affects up to 30% of patients with multiple myeloma (MM), and cardiac involvement is associated with worse outcomes. Traditional screening modalities including EKG, echocardiography and biomarkers have limited value. The aim of this study was to evaluate the clinical and prognostic value of late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) imaging in patients with plasma cell dyscrasias and suspected cardiac amyloidosis (CA). A total of 251 consecutive patients with plasma cell dyscrasias who underwent CMR were enrolled in this study. Primary endpoint was all cause mortality. Clinical, ECG, echocardiographic, biomarker and CMR predictors of mortality were analyzed. Mean age of population was 63 ± 10 years, 36% females and 19% African Americans. During a median follow-up duration of 28 months (IQR 5-56), there were 97 deaths (39%). Patients who died were more likely to have diabetes (28% vs. 14%; P = 0.03), CAD (28% vs. 16%; P = 0.04) and CKD (33% vs. 21%; P = 0.04). With endomyocardial biopsy as the gold standard (42 (17%) patients), amyloid pattern on CMR (LGE+) had sensitivity and negative predictive values of 100%; specificity and positive predictive values of 80 and 81% with an AUC 0.9 for CA. History of CAD (HR 1.64, 95% CI 1.01-2.6; P = 0.04), brain natriuretic peptide (HR 1.0003 95% CI 1.0001-1.0006; P = 0.004) and LGE + (HR 1.72, 95% CI 1.05-2.8; P = 0.02) were independent predictors of mortality. LGE+ possessed incremental prognostic value over clinical, laboratory and echocardiographic variables for mortality prediction. CMR is a clinically useful tool for diagnosis and prognostication in myeloma patients with suspected CA. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Cardiovascular magnetic resonance assessment of ventricular function and myocardial scarring before and early after repair of anomalous left coronary artery from the pulmonary artery

PubMed Central

2014-01-01

Background In patients with anomalous left coronary artery from the pulmonary artery (ALCAPA) left ventricular (LV) dilatation and dysfunction evolves due to diminished myocardial perfusion caused by coronary steal phenomenon. Using late gadolinium enhanced cardiovascular magnetic resonance (LGE-CMR) imaging, myocardial scarring has been shown in ALCAPA patients late after repair, however the incidence of scarring before surgery and its impact on postoperative course after surgical repair remained unknown. Methods 8 ALCAPA-patients (mean age 10.0 ± 5.8 months) underwent CMR before and early after (mean 4.9 ± 2.5 months) coronary reimplantation procedures. CMR included functional analysis and LGE for detection of myocardial scars. Results LV dilatation (mean LVEDVI 171 ± 94 ml/m2) and dysfunction (mean LV-EF 22 ± 10 %) was present in all patients and improved significantly after surgery (mean LVEDV 68 ± 42 ml/m2, p = 0.02; mean LV-EF 58 ± 19 %, p < 0.001). Preoperative CMR revealed myocardial scarring in 2 of the 8 patients and did not predict postoperative course. At follow-up CMR, one LGE-positive patient showed delayed recovery of LV function while myocardial scarring was still present in both patients. In two patients new-onset transmural scarring was found, although functional recovery after operation was sufficient. One of them showed a stenosis of the left coronary artery and required resurgery. Conclusions Despite diminished myocardial perfusion and severely compromised LV function, myocardial scarring was preoperatively only infrequently present. Improvement of myocardial function was independent of new-onset scarring while the impact of preoperative scarring still needs to be defined. PMID:24387660

Comparison of triple dose versus standard dose gadolinium-DTPA for detection of MRI enhancing lesions in patients with primary progressive multiple sclerosis.

PubMed Central

Filippi, M; Campi, A; Martinelli, V; Colombo, B; Yousry, T; Canal, N; Scotti, G; Comi, G

1995-01-01

This study was performed to evaluate whether a triple dose of gadolinium-DTPA (Gd-DTPA) increases the sensitivity of brain MRI for detecting enhancing lesions in patients with primary progressive multiple sclerosis (PPMS). T1 weighted brain MRI was obtained for 10 patients with PPMS in two sessions. In the first session, one scan was obtained five to seven minutes after the injection of 0.1 mmol/kg Gd-DTPA (standard dose). In the second session, six to 24 hours later, one scan before and two scans five to seven minutes and one hour after the injection of 0.3 mmol/kg Gd-DTPA (triple dose) were obtained. Four enhancing lesions were detected in two patients when the standard dose of Gd-DTPA was used. The numbers of enhancing lesions increased to 13 and the numbers of patients with such lesions to five when the triple dose of Gd-DTPA was used and to 14 and six in the one hour delayed scans. The mean contrast ratio for enhancing lesions detected with the triple dose of Gd-DTPA was higher than those for lesions present in both the standard dose (P < 0.0009) and the one hour delayed scans (P = 0.04). These data indicate that with a triple dose of Gd-DTPA many more enhancing lesions can be detected in patients with PPMS. This is important both for planning clinical trials and for detecting the presence of inflammation in vivo in the lesions of such patients. Images PMID:8530944

Presence of non-hypervascular hypointense nodules on Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging in patients with hepatocellular carcinoma.

PubMed

Inoue, Masanori; Ogasawara, Sadahisa; Chiba, Tetsuhiro; Ooka, Yoshihiko; Wakamatsu, Toru; Kobayashi, Kazufumi; Suzuki, Eiichiro; Tawada, Akinobu; Yokosuka, Osamu

2017-04-01

Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) performed before curative therapy for hepatocellular carcinoma (HCC) can distinguish between intrahepatic distant recurrence and hypervascularization. This study aimed to retrospectively evaluate the presence of non-hypervascular hypointense nodules on hepatobiliary phase images from Gd-EOB-DTPA-enhanced MRI as a risk factor of the intrahepatic distant recurrence of early stage HCC following radiofrequency ablation (RFA). A total of 132 patients who underwent preprocedural Gd-EOB-DTPA-enhanced MRI followed by initial RFA were retrospectively analyzed. Post-RFA intrahepatic distant recurrence, which excluded the hypervascularization of non-hypervascular hypointense nodules detected by preprocedural Gd-EOB-DTPA-enhanced MRI, was evaluated according to the presence of non-hypervascular hypointense nodules on preprocedural Gd-EOB-DTPA-enhanced MRI. Intrahepatic distant recurrence rates following RFA were higher in patients with non-hypervascular hypointense nodules (1-year: 22.5%, 2-year: 52.1%, 5-year: 89.1%) compared with in patients without non-hypervascular hypointense nodules (1-year: 7.0%, 2-year: 28.8%, 5-year: 48.7%). The presence of non-hypervascular hypointense nodules was associated with markedly increased cumulative recurrence rates of both identical and different subsegment intrahepatic distant recurrence, being an independent risk factor for post-RFA identical and different subsegment intrahepatic distant recurrence (identical: HR = 2.365, P = 0.027; different: HR = 3.276, P < 0.001). The presence of non-hypervascular hypointense nodules on hepatobiliary phase images from Gd-EOB-DTPA-enhanced MRI obtained prior to RFA is an important predictive factor of intrahepatic distant recurrence following RFA of HCC. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Gadolinium-modulated 19F signals from Perfluorocarbon Nanoparticles as a New Strategy for Molecular Imaging

PubMed Central

Neubauer, Anne M.; Myerson, Jacob; Caruthers, Shelton D.; Hockett, Franklin D.; Winter, Patrick M.; Chen, Junjie; Gaffney, Patrick J.; Robertson, J. David; Lanza, Gregory M.; Wickline, Samuel A.

2008-01-01

Recent advances in the design of fluorinated nanoparticles for magnetic resonance molecular imaging have enabled specific detection of 19F nuclei, providing unique and quantifiable spectral signatures. However, a pressing need for signal enhancement exists because the total 19F in imaging voxels is often limited. By directly incorporating a relaxation agent (gadolinium) into the lipid monolayer that surrounds the perfluorocarbon, a marked augmentation of the 19F signal from 200nm nanoparticles was achieved. This design increases the magnetic relaxation rate of the 19F nuclei 4-fold at 1.5 T and effects a 125% increase in signal, an effect which is maintained when they are targeted to human plasma clots. By varying the surface concentration of gadolinium, the relaxation effect can be quantitatively modulated to tailor particle properties. This novel strategy dramatically improves the sensitivity and range of 19F MRI/MRS and forms the basis for designing contrast agents capable of sensing their surface chemistry. PMID:18956457

Application of classification trees for the qualitative differentiation of focal liver lesions suspicious for metastasis in gadolinium-EOB-DTPA-enhanced liver MR imaging.

PubMed

Schelhorn, J; Benndorf, M; Dietzel, M; Burmeister, H P; Kaiser, W A; Baltzer, P A T

2012-09-01

To evaluate the diagnostic accuracy of qualitative descriptors alone and in combination for the classification of focal liver lesions (FLLs) suspicious for metastasis in gadolinium-EOB-DTPA-enhanced liver MR imaging. Consecutive patients with clinically suspected liver metastases were eligible for this retrospective investigation. 50 patients met the inclusion criteria. All underwent Gd-EOB-DTPA-enhanced liver MRI (T2w, chemical shift T1w, dynamic T1w). Primary liver malignancies or treated lesions were excluded. All investigations were read by two blinded observers (O1, O2). Both independently identified the presence of lesions and evaluated predefined qualitative lesion descriptors (signal intensities, enhancement pattern and morphology). A reference standard was determined under consideration of all clinical and follow-up information. Statistical analysis besides contingency tables (chi square, kappa statistics) included descriptor combinations using classification trees (CHAID methodology) as well as ROC analysis. In 38 patients, 120 FLLs (52 benign, 68 malignant) were present. 115 (48 benign, 67 malignant) were identified by the observers. The enhancement pattern, relative SI upon T2w and late enhanced T1w images contributed significantly to the differentiation of FLLs. The overall classification accuracy was 91.3 % (O1) and 88.7 % (O2), kappa = 0.902. The combination of qualitative lesion descriptors proposed in this work revealed high diagnostic accuracy and interobserver agreement in the differentiation of focal liver lesions suspicious for metastases using Gd-EOB-DTPA-enhanced liver MRI. © Georg Thieme Verlag KG Stuttgart · New York.

Phenotypic expression in hypertrophic cardiomyopathy and late gadolinium enhancement on cardiac magnetic resonance.

PubMed

Caetano, Francisca; Botelho, Ana; Trigo, Joana; Silva, Joana; Almeida, Inês; Venâncio, Margarida; Pais, João; Sanches, Conceição; Leitão Marques, António

2014-05-01

The prognostic value of late gadolinium enhancement (LGE) for risk stratification of hypertrophic cardiomyopathy (HCM) patients is the subject of disagreement. We set out to examine the association between clinical and morphological variables, risk factors for sudden cardiac death and LGE in HCM patients. From a population of 78 patients with HCM, we studied 53 who underwent cardiac magnetic resonance. They were divided into two groups according to the presence or absence of LGE. Ventricular arrhythmias and morbidity and mortality during follow-up were analyzed. Patients with LGE were younger at the time of diagnosis (p=0.046) and more often had a family history of sudden death (p=0.008) and known coronary artery disease (p=0.086). On echocardiography they had greater maximum wall thickness (p=0.007) and left atrial area (p=0.037) and volume (p=0.035), and more often presented a restrictive pattern of diastolic dysfunction (p=0.011) with a higher E/É ratio (p=0.003) and left ventricular systolic dysfunction (p=0.038). Cardiac magnetic resonance supported the association between LGE and previous echocardiographic findings: greater left atrial area (p=0.029) and maximum wall thickness (p<0.001) and lower left ventricular ejection fraction (p=0.056). Patients with LGE more often had an implantable cardioverter-defibrillator (ICD) (p=0.015). At follow-up, no differences were found in the frequency of ventricular arrhythmias, appropriate ICD therapies or mortality. The presence of LGE emerges as a risk marker, associated with the classical predictors of sudden cardiac death in this population. However, larger studies are required to confirm its independent association with clinical events. Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

[Rapid imaging in orbito-ocular pathology. Contribution of gadolinium].

PubMed

Pigeau, I; Legeais, J M; D'Hermies, F; Fayet, B; Leport, M; Abenhaim, A; Guinet, C; Levy, C; Renard, G; Vadrot, D

1990-01-01

To evaluate Gradient-Echo Imaging (GEI) in orbito-ocular pathology, 15 volunteers and 34 patients (40 lesions) were examined with GEA T1 and GEA T2 (0.5 T). Results were compared with SE T1 in all cases, with SE T2 in 20 cases and with other imaging modalities (CT). 30 patients were examined before and after injection of gadolinium. Final diagnosis was obtained by surgery or biopsy in 24 cases or by combined results of imaging and clinical findings in 16 cases. Compared with SE, GEA demonstrated a better visualisation of optic nerve, orbital muscles, choroidal-retinal layer, lens capsule and episclera and a better detection of small lesions. It is very helpful for characterisation of lesions containing hemorrhages or paramagnetic components (melanine, gadolinium) or of vascular nature (angioma). Gadolinium was useful for detection of small lesions or characterisation of a few lesions. Thus GEA seems to be an efficient method for the evaluation of orbito-ocular pathology.

Target binding improves relaxivity in aptamer-gadolinium conjugates.

PubMed

Bernard, Elyse D; Beking, Michael A; Rajamanickam, Karunanithi; Tsai, Eve C; Derosa, Maria C

2012-12-01

MRI contrast agents (CA) have been heavily used over the past several decades to enhance the diagnostic value of the obtained images. From a design perspective, two avenues to improve the efficacy of contrast agents are readily evident: optimization of magnetic properties of the CA, and optimization of the pharmacokinetics and distribution of the CA in the patient. Contrast agents consisting of DNA aptamer-gadolinium(III) conjugates provide a single system in which these factors can be addressed simultaneously. In this proof-of-concept study, the 15mer thrombin aptamer was conjugated to diethylenetriaminepentaacetic (DTPA) dianhydride to form a monoamide derivative of the linear open-chain chelate present in the commonly used contrast agent Magnevist(®). The stability of the conjugated DNA aptamer-DTPA-Gd(III) chelate in a transmetallation study using Zn(II) was found to be similar to that reported for DTPA-Gd(III). Relaxivity enhancements of 35 ± 4 and 20 ± 1 % were observed in the presence of thrombin compared to a control protein at fields of 9.4 and 1.5 T, respectively. The inclusion of spacers between the aptamer and the DTPA to eliminate possible steric effects was also investigated but not found to improve the relaxation enhancement achieved in comparison to the unaltered aptamer conjugate.

Distribution and chemical forms of gadolinium in the brain: a review.

PubMed

Kanda, Tomonori; Nakai, Yudai; Hagiwara, Akifumi; Oba, Hiroshi; Toyoda, Keiko; Furui, Shigeru

2017-11-01

In the 3 years since residual gadolinium-based contrast agent (GBCA) in the brain was first reported, much has been learned about its accumulation, including the pathway of GBCA entry into the brain, the brain distribution of GBCA and its excretion. Here we review recent progress in understanding the routes of gadolinium deposition in brain structures.

The growth and evolution of cardiovascular magnetic resonance: a 20-year history of the Society for Cardiovascular Magnetic Resonance (SCMR) annual scientific sessions.

PubMed

Lee, Daniel C; Markl, Michael; Dall'Armellina, Erica; Han, Yuchi; Kozerke, Sebastian; Kuehne, Titus; Nielles-Vallespin, Sonia; Messroghli, Daniel; Patel, Amit; Schaeffter, Tobias; Simonetti, Orlando; Valente, Anne Marie; Weinsaft, Jonathan W; Wright, Graham; Zimmerman, Stefan; Schulz-Menger, Jeanette

2018-01-31

The purpose of this work is to summarize cardiovascular magnetic resonance (CMR) research trends and highlights presented at the annual Society for Cardiovascular Magnetic Resonance (SCMR) scientific sessions over the past 20 years. Scientific programs from all SCMR Annual Scientific Sessions from 1998 to 2017 were obtained. SCMR Headquarters also provided data for the number and the country of origin of attendees and the number of accepted abstracts according to type. Data analysis included text analysis (key word extraction) and visualization by 'word clouds' representing the most frequently used words in session titles for 5-year intervals. In addition, session titles were sorted into 17 major subject categories to further evaluate research and clinical CMR trends over time. Analysis of SCMR annual scientific sessions locations, attendance, and number of accepted abstracts demonstrated substantial growth of CMR research and clinical applications. As an international field of study, significant growth of CMR was documented by a strong increase in SCMR scientific session attendance (> 500%, 270 to 1406 from 1998 to 2017, number of accepted abstracts (> 700%, 98 to 701 from 1998 to 2018) and number of international participants (42-415% increase for participants from Asia, Central and South America, Middle East and Africa in 2004-2017). 'Word clouds' based evaluation of research trends illustrated a shift from early focus on 'MRI technique feasibility' to new established techniques (e.g. late gadolinium enhancement) and their clinical applications and translation (key words 'patient', 'disease') and more recently novel techniques and quantitative CMR imaging (key words 'mapping', 'T1', 'flow', 'function'). Nearly every topic category demonstrated an increase in the number of sessions over the 20-year period with 'Clinical Practice' leading all categories. Our analysis identified three growth areas 'Congenital', 'Clinical Practice', and 'Structure

Prognostic Value of Quantitative Stress Perfusion Cardiac Magnetic Resonance.

PubMed

Sammut, Eva C; Villa, Adriana D M; Di Giovine, Gabriella; Dancy, Luke; Bosio, Filippo; Gibbs, Thomas; Jeyabraba, Swarna; Schwenke, Susanne; Williams, Steven E; Marber, Michael; Alfakih, Khaled; Ismail, Tevfik F; Razavi, Reza; Chiribiri, Amedeo

2018-05-01

This study sought to evaluate the prognostic usefulness of visual and quantitative perfusion cardiac magnetic resonance (CMR) ischemic burden in an unselected group of patients and to assess the validity of consensus-based ischemic burden thresholds extrapolated from nuclear studies. There are limited data on the prognostic value of assessing myocardial ischemic burden by CMR, and there are none using quantitative perfusion analysis. Patients with suspected coronary artery disease referred for adenosine-stress perfusion CMR were included (n = 395; 70% male; age 58 ± 13 years). The primary endpoint was a composite of cardiovascular death, nonfatal myocardial infarction, aborted sudden death, and revascularization after 90 days. Perfusion scans were assessed visually and with quantitative analysis. Cross-validated Cox regression analysis and net reclassification improvement were used to assess the incremental prognostic value of visual or quantitative perfusion analysis over a baseline clinical model, initially as continuous covariates, then using accepted thresholds of ≥2 segments or ≥10% myocardium. After a median 460 days (interquartile range: 190 to 869 days) follow-up, 52 patients reached the primary endpoint. At 2 years, the addition of ischemic burden was found to increase prognostic value over a baseline model of age, sex, and late gadolinium enhancement (baseline model area under the curve [AUC]: 0.75; visual AUC: 0.84; quantitative AUC: 0.85). Dichotomized quantitative ischemic burden performed better than visual assessment (net reclassification improvement 0.043 vs. 0.003 against baseline model). This study was the first to address the prognostic benefit of quantitative analysis of perfusion CMR and to support the use of consensus-based ischemic burden thresholds by perfusion CMR for prognostic evaluation of patients with suspected coronary artery disease. Quantitative analysis provided incremental prognostic value to visual assessment and

Fuel bundle design for enhanced usage of plutonium fuel

DOEpatents

Reese, Anthony P.; Stachowski, Russell E.

1995-01-01

A nuclear fuel bundle includes a square array of fuel rods each having a concentration of enriched uranium and plutonium. Each rod of an interior array of the rods also has a concentration of gadolinium. The interior array of rods is surrounded by an exterior array of rods void of gadolinium. By this design, usage of plutonium in the nuclear reactor is enhanced.

The use of theranostic gadolinium-based nanoprobes to improve radiotherapy efficacy

PubMed Central

Sancey, L; Kotb, S; Roux, S; Dufort, S; Bianchi, A; Crémillieux, Y; Fries, P; Coll, J-L; Rodriguez-Lafrasse, C; Janier, M; Dutreix, M; Barberi-Heyob, M; Boschetti, F; Denat, F; Louis, C; Porcel, E; Lacombe, S; Le Duc, G; Deutsch, E; Perfettini, J-L; Detappe, A; Verry, C; Berbeco, R; Butterworth, K T; McMahon, S J; Prise, K M; Perriat, P; Tillement, O

2014-01-01

A new efficient type of gadolinium-based theranostic agent (AGuIX®) has recently been developed for MRI-guided radiotherapy (RT). These new particles consist of a polysiloxane network surrounded by a number of gadolinium chelates, usually 10. Owing to their small size (<5 nm), AGuIX typically exhibit biodistributions that are almost ideal for diagnostic and therapeutic purposes. For example, although a significant proportion of these particles accumulate in tumours, the remainder is rapidly eliminated by the renal route. In addition, in the absence of irradiation, the nanoparticles are well tolerated even at very high dose (10 times more than the dose used for mouse treatment). AGuIX particles have been proven to act as efficient radiosensitizers in a large variety of experimental in vitro scenarios, including different radioresistant cell lines, irradiation energies and radiation sources (sensitizing enhancement ratio ranging from 1.1 to 2.5). Pre-clinical studies have also demonstrated the impact of these particles on different heterotopic and orthotopic tumours, with both intratumoural or intravenous injection routes. A significant therapeutical effect has been observed in all contexts. Furthermore, MRI monitoring was proven to efficiently aid in determining a RT protocol and assessing tumour evolution following treatment. The usual theoretical models, based on energy attenuation and macroscopic dose enhancement, cannot account for all the results that have been obtained. Only theoretical models, which take into account the Auger electron cascades that occur between the different atoms constituting the particle and the related high radical concentrations in the vicinity of the particle, provide an explanation for the complex cell damage and death observed. PMID:24990037

Feasibility and accuracy of dual-layer spectral detector computed tomography for quantification of gadolinium: a phantom study.

PubMed

van Hamersvelt, Robbert W; Willemink, Martin J; de Jong, Pim A; Milles, Julien; Vlassenbroek, Alain; Schilham, Arnold M R; Leiner, Tim

2017-09-01

The aim of this study was to evaluate the feasibility and accuracy of dual-layer spectral detector CT (SDCT) for the quantification of clinically encountered gadolinium concentrations. The cardiac chamber of an anthropomorphic thoracic phantom was equipped with 14 tubular inserts containing different gadolinium concentrations, ranging from 0 to 26.3 mg/mL (0.0, 0.1, 0.2, 0.4, 0.5, 1.0, 2.0, 3.0, 4.0, 5.1, 10.6, 15.7, 20.7 and 26.3 mg/mL). Images were acquired using a novel 64-detector row SDCT system at 120 and 140 kVp. Acquisitions were repeated five times to assess reproducibility. Regions of interest (ROIs) were drawn on three slices per insert. A spectral plot was extracted for every ROI and mean attenuation profiles were fitted to known attenuation profiles of water and pure gadolinium using in-house-developed software to calculate gadolinium concentrations. At both 120 and 140 kVp, excellent correlations between scan repetitions and true and measured gadolinium concentrations were found (R > 0.99, P < 0.001; ICCs > 0.99, CI 0.99-1.00). Relative mean measurement errors stayed below 10% down to 2.0 mg/mL true gadolinium concentration at 120 kVp and below 5% down to 1.0 mg/mL true gadolinium concentration at 140 kVp. SDCT allows for accurate quantification of gadolinium at both 120 and 140 kVp. Lowest measurement errors were found for 140 kVp acquisitions. • Gadolinium quantification may be useful in patients with contraindication to iodine. • Dual-layer spectral detector CT allows for overall accurate quantification of gadolinium. • Interscan variability of gadolinium quantification using SDCT material decomposition is excellent.

Type of MRI contrast, tissue gadolinium, and fibrosis.

PubMed

Do, Catherine; Barnes, Jeffrey L; Tan, Chunyan; Wagner, Brent

2014-10-01

It has been presupposed that the thermodynamic stability constant (K(therm)) of gadolinium-based MRI chelates relate to the risk of precipitating nephrogenic systemic fibrosis. The present study compared low-K(therm) gadodiamide with high-K(therm) gadoteridol in cultured fibroblasts and rats with uninephrectomies. Gadolinium content was assessed using scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy in paraffin-embedded tissues. In vitro, fibroblasts demonstrated dose-dependent fibronectin generation, transforming growth factor-β production, and expression of activated myofibroblast stress fiber protein α-smooth muscle actin. There were negligible differences with respect to toxicity or proliferation between the two contrast agents. In the rodent model, gadodiamide treatment led to greater skin fibrosis and dermal cellularity than gadoteridol. In the kidney, both contrast agents led to proximal tubule vacuolization and increased fibronectin accumulation. Despite large detectable gadolinium signals in the spleen, skin, muscle, and liver from the gadodiamide-treated group, contrast-induced fibrosis appeared to be limited to the skin and kidney. These findings support the hypothesis that low-K(therm) chelates have a greater propensity to elicit nephrogenic systemic fibrosis and demonstrate that certain tissues are resistant to these effects.

Differentiation of pre-ablation and post-ablation late gadolinium-enhanced cardiac MRI scans of longstanding persistent atrial fibrillation patients

NASA Astrophysics Data System (ADS)

Yang, Guang; Zhuang, Xiahai; Khan, Habib; Haldar, Shouvik; Nyktari, Eva; Li, Lei; Ye, Xujiong; Slabaugh, Greg; Wong, Tom; Mohiaddin, Raad; Keegan, Jennifer; Firmin, David

2017-03-01

Late Gadolinium-Enhanced Cardiac MRI (LGE CMRI) is an emerging non-invasive technique to image and quantify preablation native and post-ablation atrial scarring. Previous studies have reported that enhanced image intensities of the atrial scarring in the LGE CMRI inversely correlate with the left atrial endocardial voltage invasively obtained by electro-anatomical mapping. However, the reported reproducibility of using LGE CMRI to identify and quantify atrial scarring is variable. This may be due to two reasons: first, delineation of the left atrium (LA) and pulmonary veins (PVs) anatomy generally relies on manual operation that is highly subjective, and this could substantially affect the subsequent atrial scarring segmentation; second, simple intensity based image features may not be good enough to detect subtle changes in atrial scarring. In this study, we hypothesized that texture analysis can provide reliable image features for the LGE CMRI images subject to accurate and objective delineation of the heart anatomy based on a fully-automated whole heart segmentation (WHS) method. We tested the extracted texture features to differentiate between pre-ablation and post-ablation LGE CMRI studies in longstanding persistent atrial fibrillation patients. These patients often have extensive native scarring and differentiation from post-ablation scarring can be difficult. Quantification results showed that our method is capable of solving this classification task, and we can envisage further deployment of this texture analysis based method for other clinical problems using LGE CMRI.

Comparison of Inner Ear Contrast Enhancement among Patients with Unilateral Inner Ear Symptoms in MR Images Obtained 10 Minutes and 4 Hours after Gadolinium Injection.

PubMed

Kim, T Y; Park, D W; Lee, Y J; Lee, J Y; Lee, S H; Chung, J H; Lee, S

2015-12-01

Recently 4-hour delayed-enhanced 3D-FLAIR MR imaging has been used in pathophysiologic analysis of the inner ear in many auditory diseases, including sudden sensorineural hearing loss, but comparison among different time points is not clear in patients with unilateral inner ear symptoms. We compared the signal-intensity ratios of the inner ears in patients with unilateral inner ear symptoms on 10-minute delayed-enhanced and 4-hour delayed-enhanced 3D-FLAIR MR images after IV gadolinium injection. The 10-minute delayed-enhanced and 4-hour delayed-enhanced 3D-FLAIR MR images were retrospectively analyzed. Signal-intensity ratios between the cerebellum and inner ear structures, such as the cochleae, vestibules, and vestibulocochlear nerve were assessed. Multiple comparisons were performed. Signal-intensity ratios of the affected cochleae, vestibules, and vestibulocochlear nerve were higher than those of unaffected sides in both 10-minute delayed-enhanced and 4-hour delayed-enhanced images. At the affected side, signal-intensity ratios of the vestibulocochlear nerve were higher in patients with nonsudden sensorineural hearing loss than in those with sudden sensorineural hearing loss on both 10-minute delayed-enhanced and 4-hour delayed-enhanced images. The signal-intensity ratios of some affected inner ear structures were higher than those of the unaffected sides in a group of 30 patients with sudden sensorineural hearing loss and 20 patients with nonsudden sensorineural hearing loss on 10-minute delayed-enhanced and 4-hour delayed-enhanced images. Signal-intensity ratios of the inner ear show statistically significant increases in many diseases, especially neuritis, in 10-minute delayed-enhanced and 4-hour delayed-enhanced images. The 4-hour delayed-enhanced images may be superior in neural inflammatory-dominant conditions, while 10-minute delayed-enhanced images may be superior in neural noninflammatory-dominant conditions. © 2015 by American Journal of

Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) of cadaveric shoulders: comparison of contrast dynamics in hyaline and fibrous cartilage after intraarticular gadolinium injection.

PubMed

Wiener, E; Hodler, J; Pfirrmann, C W A

2009-01-01

Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is a novel method to investigate cartilaginous and fibrocartilaginous structures. To investigate the contrast dynamics in hyaline and fibrous cartilage of the glenohumeral joint after intraarticular injection of gadopentetate dimeglumine. Transverse T(1) maps were acquired on a 1.5T scanner before and after intraarticular injection of 2.0 mmol/l gadopentetate dimeglumine in five cadaveric shoulders using a dual flip angle three-dimensional gradient echo (3D-GRE) sequence. The acquisition time for the T(1) maps was 5 min 5 s for the whole shoulder. Measurements were repeated every 15 min over 2.5 hours. Regions of interest (ROIs) covering the glenoid cartilage and the labrum were drawn to assess the temporal evolution of the relaxation parameters. T(1) of unenhanced hyaline cartilage of the glenoid was 568+/-34 ms. T(1) of unenhanced fibrous cartilage of the labrum was 552+/-38 ms. Significant differences (P=0.002 and 0.03) in the relaxation parameters were already measurable after 15 min. After 2 to 2.5 hours, hyaline and fibrous cartilage still demonstrated decreasing relaxation parameters, with a larger range of the T(1)(Gd) values in fibrous cartilage. T(1) and triangle Delta R(1) values of hyaline and fibrous cartilage after 2.5 hours were 351+/-16 ms and 1.1+/-0.09 s(-1), and 332+/-31 ms and 1.2+/-0.1 s(-1), respectively. A significant decrease in T(1)(Gd) was found 15 min after intraarticular contrast injection. Contrast accumulation was faster in hyaline than in fibrous cartilage. After 2.5 hours, contrast accumulation showed a higher rate of decrease in hyaline cartilage, but neither hyaline nor fibrous cartilage had reached equilibrium.

Delayed gadolinium-enhanced MRI of the fibrocartilage disc of the temporomandibular joint--a feasibility study.

PubMed

Pittschieler, Elisabeth; Szomolanyi, Pavol; Schmid-Schwap, Martina; Weber, Michael; Egerbacher, Monika; Traxler, Hannes; Trattnig, Siegfried

2014-12-01

To 1) test the feasibility of delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC) at 3 T in the temporomandibular joint (TMJ) and 2) to determine the optimal delay for measurements of the TMJ disc after i.v. contrast agent (CA) administration. MRI of the right and left TMJ of six asymptomatic volunteers was performed at 3 T using a dedicated coil. 2D inversion recovery (2D-IR) sequences were performed at 4 time points covering 120 minutes and 3D gradient-echo (3D GRE) dual flip-angle sequences were performed at 14 time points covering 130 minutes after the administration of 0.2 mmol/kg of Gd-diethylenetriamine pentaacetic acid ion (Gd-DTPA)(2-), i.e., 0.4 mL of Magnevist™ per kg body weight. Pair-wise tests were used to assess differences between pre-and post-contrast T1 values. 2D-IR sequences showed a statistically significant drop (p<0.001) in T1 values after i.v. CA administration. The T1 drop of 50% was reached 60 minutes after bolus injection in the TMJ disc. The 3D GRE dual flip-angle sequences confirmed these results and show plateau of T1 after 60 minutes. T1(Gd) maps calculated from dGEMRIC data allow in vivo assessment of the fibrocartilage disc of the TMJ. The recommended measurement time for dGEMRIC in the TMJ after i.v. CA administration is from 60 to 120 minutes. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Fuel bundle design for enhanced usage of plutonium fuel

DOEpatents

Reese, A.P.; Stachowski, R.E.

1995-08-08

A nuclear fuel bundle includes a square array of fuel rods each having a concentration of enriched uranium and plutonium. Each rod of an interior array of the rods also has a concentration of gadolinium. The interior array of rods is surrounded by an exterior array of rods void of gadolinium. By this design, usage of plutonium in the nuclear reactor is enhanced. 10 figs.

Monte Carlo simulation of energy absorbed in phenolic ESR dosimeters added with gadolinium exposed to thermal, epithermal and fast neutrons

NASA Astrophysics Data System (ADS)

Longo, A.; Collura, G.; Gallo, S.; Bartolotta, A.; Marrale, M.

2017-11-01

In this work analyses of the energy released per unit mass in phenolic compound exposed to neutron beams were performed with the aim of predicting the increase in dose achievable by addition of gadolinium (Gd) inside the pellets. In particular, Monte Carlo (MC) simulations were carried out for IRGANOX® 1076 phenolic compound irradiated with neutron beams with different energy spectra at various depths inside a water phantom. The addition of gadolinium increases sensitivity of phenolic ESR (electron spin resonance) dosimeters to neutrons thanks to the high gadolinium cross section for neutron capture and to the large number of secondary particles (mainly Auger and internal conversion electrons) which are able to release energy inside the sensitive material layers. For small depths in water phantom and low energy neutron spectra the increase in dose due to gadolinium is large (more than a factor 50). The enhancement is smaller in case of epithermal neutron beam, whereas the increase in dose for fast neutrons is less than 50%. In order to have a comparison with other ESR dosimeters the energy released per unit mass in phenolic compound was compared with that calculated in alanine pellets. For thermal neutron beams the energy released in phenolic compound with gadolinium is comparable to that released in alanine for small depths in phantom, whereas it is larger than in alanine for large depths. In case of epithermal and fast neutron beams the energy released in phenolic compound is larger than in alanine samples because the elastic scattering with hydrogen nuclei is more probable for high neutron energies and this phenolic compound is characterized by an higher number of 1H nuclei than alanine. All results here found suggest that these phenolic pellets could be fruitfully used for dosimetric applications in Neutron Capture Therapy.

3D Late Gadolinium Enhancement in a Single Prolonged Breath-hold using Supplemental Oxygenation and Hyperventilation

PubMed Central

Roujol, Sébastien; Basha, Tamer A.; Akçakaya, Mehmet; Foppa, Murilo; Chan, Raymond H.; Kissinger, Kraig V.; Goddu, Beth; Berg, Sophie; Manning, Warren J.; Nezafat, Reza

2013-01-01

Purpose: To evaluate the feasibility of 3D single breath-hold late gadolinium enhancement (LGE) of the left ventricle (LV) using supplemental oxygen and hyperventilation and compressed-sensing acceleration. Methods: Breath-hold metrics (breath-hold duration, diaphragmatic/LV position drift, and maximum variation of RR interval) without and with supplemental oxygen and hyperventilation were assessed in healthy adult subjects using a real time single shot acquisition. Ten healthy subjects and 13 patients then underwent assessment of the proposed 3D breath-hold LGE acquisition (FOV=320×320×100 mm3, resolution=1.6×1.6×5.0 mm3, acceleration rate of 4) and a free breathing acquisition with right hemidiaphragm navigator (NAV) respiratory gating. Semi-quantitative grading of overall image quality, motion artifact, myocardial nulling, and diagnostic value was performed by consensus of two blinded observers. Results: Supplemental oxygenation and hyperventilation increased the breath-hold duration (35±11 s to 58±21 s, p<0.0125) without significant impact on diaphragmatic/LV position drift or maximum variation of RR interval (both p>0.01). LGE images were of similar quality when compared to free breathing acquisitions but with reduced total scan time (85±22 s to 35±6 s, p<0.001). Conclusions: Supplemental oxygenation and hyperventilation allow for prolonged breath-holding and enable single breath-hold 3D accelerated LGE with similar image quality as free breathing with NAV. PMID:24186772

Scar extent as a predictive factor of ventricular tachycardia cycle length after myocardial infarction: implications for implantable cardioverter-defibrillator programming optimization.

PubMed

Alexandre, Joachim; Saloux, Eric; Lebon, Alain; Dugué, Audrey Emmanuelle; Lemaitre, Adrien; Roule, Vincent; Labombarda, Fabien; Champ-Rigot, Laure; Gomes, Sophie; Pellissier, Arnaud; Scanu, Patrice; Milliez, Paul

2014-02-01

After an old myocardial infarction (MI), patients are at risk for reentrant ventricular tachycardia (VT) due to scar tissue that can be accurately identified by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). Although the ability of LGE-CMR to predict sustained VT in implantable cardioverter-defibrillator (ICD) recipients has been well established, its use to predict monomorphic VT (sustained or not) cycle length (CL) and so, optimize ICD programming has never been investigated. We included retrospectively 49 consecutive patients with an old MI who had undergone LGE-CMR before ICD implantation over a 4-year period (2006-09). Patients with amiodarone used were excluded. Scar extent was assessed by measuring scar mass, percent scar, and transmural scar extent. The endpoint was the occurrence of monomorphic VT, requiring an ICD therapy or not. The endpoint occurred in 26 patients. The median follow-up duration was 31 months. Scar extent parameters were significantly correlated with the study endpoint. With univariate regression analysis, the scar mass had the highest correlation with the VT CL (R = 0.671, P = 0.0002). Receiver-operating characteristic curve showed that scar mass can predict VT CL (area under the curve = 0.977, P < 0.0001). For a cut-off value of scar mass at 17.6 g, there is 100% specificity and 94.4% sensitivity. In this observational and retrospective study, scar mass studied by LGE-CMR was specific and sensitive to predict VT CL and so could be a promising option to improve ICD post-implantation programming and decrease appropriate and inappropriate shocks. These conclusions must now be confirmed in a large and prospective study.

Regional convection-enhanced delivery of gadolinium-labeled albumin in the rat hippocampus in vivo.

PubMed

Astary, Garrett W; Kantorovich, Svetlana; Carney, Paul R; Mareci, Thomas H; Sarntinoranont, Malisa

2010-03-15

Convection-enhanced delivery (CED) has emerged as a promising method of targeted drug delivery for treating central nervous system (CNS) disorders, but the influence of brain structure on infusate distribution is unclear. We have utilized this approach to study extracellular transport and distribution of a contrast agent in the hippocampus, a complex structure susceptible to CNS disorders. The magnetic resonance (MR) contrast agent diethylene triamene penta-acetic acid chelated gadolinium-labeled albumin (Gd-albumin), tagged with Evans blue dye, was directly infused (V(i)=5 microl) into the dorsal and ventral hippocampus of seven male Sprague-Dawley rats. The final distribution profile of the contrast agent, a product of CED and limited diffusion, was observed in vivo using high-resolution T1-weighted MR imaging at 11.1T. Dense cell layers, such as the granule cell layer of the dentate gyrus and the pyramidal cell layer of CA1, appeared to be barriers to transport of the tracer. Three-dimensional distribution shape and volume (V(d)) differences, between the dorsal and ventral hippocampus infusions, were determined from the MR images using a semi-automatic segmentation routine (dorsal V(d)=23.4+/-1.8 microl, ventral V(d)=36.4+/-5.1 microl). Finer structural detail of the hippocampus was obtained using a combination of histological analysis and fluorescence imaging. This study demonstrates that CED has the potential to target all regions of the hippocampus and that tracer distribution is influenced by infusion site, underlying structure and circuitry, and extent of backflow. Therefore, CED, combined with high-resolution MR imaging, may be a useful strategy for delivering therapeutics for the treatment of CNS disorders affecting the hippocampus. Published by Elsevier B.V.

Anterior delayed gadolinium-enhanced MRI of cartilage values predict joint failure after periacetabular osteotomy.

PubMed

Kim, Sang Do; Jessel, Rebecca; Zurakowski, David; Millis, Michael B; Kim, Young-Jo

2012-12-01

Several available compositional MRIs seem to detect early osteoarthritis before radiographic appearance. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) has been most frequently used in clinical studies and reportedly predicts premature joint failure in patients undergoing Bernese periacetabular osteotomies (PAOs). We asked, given regional variations in biochemical composition in dysplastic hips, whether the dGEMRIC index of the anterior joint would better predict premature joint failure after PAOs than the coronal dGEMRIC index as previously reported. We retrospectively reviewed 43 hips in 41 patients who underwent Bernese PAO for hip dysplasia. Thirty-seven hips had preserved joints after PAOs and six were deemed premature failures based on pain, joint space narrowing, or subsequent THA. We used dGEMRIC to determine regional variations in biochemical composition. Preoperative demographic and clinical outcome score, radiographic measures of osteoarthritis and severity of dysplasia, and dGEMRIC indexes from different hip regions were analyzed in a multivariable regression analysis to determine the best predictor of premature joint failure. Minimum followup was 24 months (mean, 32 months; range, 24-46 months). The two cohorts were similar in age and sex distribution. Severity of dysplasia was similar as measured by lateral center-edge, anterior center-edge, and Tönnis angles. Preoperative pain, joint space width, Tönnis grade, and coronal and sagittal dGEMRIC indexes differed between groups. The dGEMRIC index in the anterior weightbearing region of the hip was lower in the prematurely failed group and was the best predictor. Success of PAO depends on the amount of preoperative osteoarthritis. These degenerative changes are seen most commonly in the anterior joint. The dGEMRIC index of the anterior joint may better predict premature joint failure than radiographic measures of hip osteoarthritis and coronal dGEMRIC index. Level II, prognostic study. See

Method of separating and purifying gadolinium-153

DOEpatents

Bray, Lane A [Richland, WA; Corneillie, Todd M [Davis, CA

2001-01-01

The present invention is an improvement to the method of separating and purifying gadolinium from a mixture of gadolinium and europium having the steps of (a) dissolving the mixture in an acid; (b) reducing europium+3 to europium+2; and (c) precipitating the europium+2 with a sulfate ion in a superstoichiometric amount; wherein the improvement is achieved by using one or more of the following: (i) the acid is an anoic acid; (ii) the reducing is with zinc metal in the absence of a second metal or with an amount of the second metal that is ineffective in the reducing; (iii) adding a group IIA element after step (c) for precipitating the excess sulfate prior to repeating step (c); (iv) the sulfate is a sulfate salt with a monovalent cation; (v) adding cold europium+3 prior to repeating step (c).

Grading of inflammatory disease activity in the sacroiliac joints with magnetic resonance imaging: comparison between short-tau inversion recovery and gadolinium contrast-enhanced sequences.

PubMed

Madsen, Karen Berenth; Egund, Niels; Jurik, Anne Grethe

2010-02-01

We investigated the potential concordance of 2 different magnetic resonance (MR) sequences - short-tau inversion recovery (STIR) and fat-saturated T1-weighted spin-echo after application of gadolinium (Gd) contrast medium to detect active bone marrow abnormalities at the sacroiliac joints (SIJ) in patients with spondyloarthritis (SpA). Blinded and using the Danish scoring method, we evaluated transaxial MR images of the 2 sequences in 40 patients with SpA with disease duration of 3-14 years. Both the cartilaginous and ligamentous portions of the SIJ were analyzed. There was a significant positive correlation between the activity scores obtained by STIR and Gd-enhanced sequences (p < 0.0001). Agreement in the detection of bone marrow abnormalities occurred in 60 of the 80 joints, 35 with and 25 without signs of active disease. Discordance with STIR-positive marrow activity scores occurred in only 11 joints; Gd-enhanced positive scores in 9 joints. The STIR sequence detected remnants of marrow activity in the periphery of chronic fatty replacement not seen or partly obscured on the Gd sequence. Small subchondral enhancing lesions may not be scored on the STIR sequence, mostly because of reduced image resolution. Active bone marrow abnormalities were detected nearly equally well with STIR and Gd-enhanced fat-suppressed T1 sequences in patients with SpA, with STIR being most sensitive to visualize active abnormalities in the periphery of chronic changes.

Low-Molecular-Weight Iron Chelates May Be an Alternative to Gadolinium-based Contrast Agents for T1-weighted Contrast-enhanced MR Imaging.

PubMed

Boehm-Sturm, Philipp; Haeckel, Akvile; Hauptmann, Ralf; Mueller, Susanne; Kuhl, Christiane K; Schellenberger, Eyk A

2018-02-01

Purpose To synthesize two low-molecular-weight iron chelates and compare their T1 contrast effects with those of a commercial gadolinium-based contrast agent for their applicability in dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging. Materials and Methods The animal experiments were approved by the local ethics committee. Two previously described iron (Fe) chelates of pentetic acid (Fe-DTPA) and of trans-cyclohexane diamine tetraacetic acid (Fe-tCDTA) were synthesized with stability constants several orders of magnitude higher than those of gadolinium-based contrast agents. The T1 contrast effects of the two chelates were compared with those of gadopentetate dimeglumine in blood serum phantoms at 1.5 T, 3 T, and 7 T. For in vivo studies, a human breast cancer cell line (MDA-231) was implanted in five mice per group. The dynamic contrast effects of the chelates were compared by performing DCE MR imaging with intravenous application of Fe-DTPA or Fe-tCDTA on day 1 and DCE MR imaging in the same tumors with gadopentetate dimeglumine on day 2. Quantitative DCE maps were generated with software and were compared by means of a one-tailed Pearson correlation test. Results Relaxivities in serum (0.94 T at room temperature) of Fe-tCDTA (r1 = 2.2 mmol -1 · sec -1 , r2 = 2.5 mmol -1 · sec -1 ) and Fe-DTPA (r1 = 0.9 mmol -1 · sec -1 , r2 = 0.9 mmol -1 · sec -1 ) were approximately twofold and fivefold lower, respectively, compared with those of gadopentetate dimeglumine (r1 = 4.1 mmol -1 · sec -1 , r2 = 4.8 mmol -1 · sec -1 ). Used at moderately higher concentrations, however, iron chelates generated similar contrast effects at T1-weighted MR imaging in vitro in serum, in vivo in blood, and for DCE MR imaging of breast cancer xenografts. The volume transfer constant values for Fe-DTPA and Fe-tCDTA in the same tumors correlated well with those observed for gadopentetate dimeglumine (Fe-tCDTA Pearson R, 0.99; P = .0003; Fe-DTPA Pearson R, 0.97; P

Gadolinium: Central Metal of the Lanthanoids

ERIC Educational Resources Information Center

Laing, Michael

2009-01-01

The physical and chemical properties of gadolinium are compared with those of the other lanthanoids. Some properties are intermediate between those of lanthanum and lutetium; some between those of barium and hafnium; and others (unexpectedly) between those of ytterbium and lutetium. Both the remarkably high molar heat capacity of the metal and the…

Gadolinium Use in Spine Pain Management Procedures for Patients with Contrast Allergies: Results in 527 Procedures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Safriel, Yair; Ang, Roberto; Ali, Muhammed

2008-03-15

Introduction. To review the safety and efficacy of gadolinium in spine pain management procedures in patients at high risk for a contrast reaction and who are not suitable candidates for the use of standard non-ionic contrast. Methods. We reviewed records over a 61-month period of all image-guided spinal pain management procedures where patients had allergies making them unsuitable candidates for standard non-ionic contrast and where gadolinium was used to confirm needle tip placement prior to injection of medication. Results. Three hundred and four outpatients underwent 527 procedures. A spinal needle was used in all but 41 procedures. Gadolinium was visualizedmore » using portable C-arm fluoroscopy in vivo allowing for confirmation of needle tip location. The gadolinium dose ranged from 0.2 to 10 ml per level. The highest dose received by one patient was 15.83 ml intradiscally during a three-level discogram. Three hundred and one patients were discharged without complication or known delayed complications. One patient had documented intrathecal injection but without sequelae and 2 patients who underwent cervical procedures experienced seizures requiring admission to the intensive care unit. Both the latter patients were discharged without any further complications. Conclusion. Based on our experience we recommend using gadolinium judiciously for needle tip confirmation. We feel more confident using gadolinium in the lumbar spine and in cervical nerve blocks. Gadolinium should probably not be used as an injectate volume expander. The indications for gadolinium use in cervical needle-guided spine procedures are less clear and use of a blunt-tipped needle should be considered.« less

Distinguishing liver haemangiomas from metastatic tumours using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced diffusion-weighted imaging at 1.5T MRI.

PubMed

Saito, Kazuhiro; Yoshimura, Nobutaka; Shirota, Natsuhiko; Saguchi, Toru; Sugimoto, Katsutoshi; Tokuuye, Koichi

2016-10-01

The aim of this study to evaluate the effectiveness of enhanced diffusion-weighted imaging (DWI) for distinguishing liver haemangiomas from metastatic tumours (mets). This study included 23 patients with 27 haemangiomas and 26 patients with 46 mets. Breath-holding diffusion-weighted imaging (DWI) (b-values of 0, 50, 100, 150, 200, 400 and 800 s/mm 2 ) were obtained before and 20 min after injection of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA). Lesion contrast-to-noise ratios (CNRs) were calculated. The data were processed using the bi-exponential model of intravoxel incoherent motion (IVIM). Receiver operating characteristic analysis was performed to compare the diagnostic performance when distinguishing haemangioma from mets. The CNRs of haemangioma and mets at post-contrast enhancement increased. All IVIM parameters for liver haemangioma and mets showed no significant differences between pre- and post-contrast enhancement. The highest A z value of CNR and IVIM parameters occurred at a post-contrast b-value of 0 s/mm 2 and true diffusion (D). The highest qualitative evaluation occurred at a b-value of 800 s/mm 2 . The sensitivity and specificity, with a CNR of 100 or higher at a post-contrast b-value of 0 s/mm 2 and considered to be haemangioma, were 89% and 67% (<10 mm, 91%, 77%) respectively. The sensitivity and specificity, when D was higher than 1.4 × 10 -3 mm 2 /s, were 74% and 83% (<10 mm, 64%, 77%) respectively. The sensitivity and specificity of qualitative evaluation by enhanced DWI were 74% and 76% (<10 mm, 64%, 80%) respectively. The accuracy of the CNR was highest with b = 0; however, examination at high b-values had advantages in the qualitative evaluation of some small-size lesions. © 2016 The Royal Australian and New Zealand College of Radiologists.

Highly automatic quantification of myocardial oedema in patients with acute myocardial infarction using bright blood T2-weighted CMR

PubMed Central

2013-01-01

Background T2-weighted cardiovascular magnetic resonance (CMR) is clinically-useful for imaging the ischemic area-at-risk and amount of salvageable myocardium in patients with acute myocardial infarction (MI). However, to date, quantification of oedema is user-defined and potentially subjective. Methods We describe a highly automatic framework for quantifying myocardial oedema from bright blood T2-weighted CMR in patients with acute MI. Our approach retains user input (i.e. clinical judgment) to confirm the presence of oedema on an image which is then subjected to an automatic analysis. The new method was tested on 25 consecutive acute MI patients who had a CMR within 48 hours of hospital admission. Left ventricular wall boundaries were delineated automatically by variational level set methods followed by automatic detection of myocardial oedema by fitting a Rayleigh-Gaussian mixture statistical model. These data were compared with results from manual segmentation of the left ventricular wall and oedema, the current standard approach. Results The mean perpendicular distances between automatically detected left ventricular boundaries and corresponding manual delineated boundaries were in the range of 1-2 mm. Dice similarity coefficients for agreement (0=no agreement, 1=perfect agreement) between manual delineation and automatic segmentation of the left ventricular wall boundaries and oedema regions were 0.86 and 0.74, respectively. Conclusion Compared to standard manual approaches, the new highly automatic method for estimating myocardial oedema is accurate and straightforward. It has potential as a generic software tool for physicians to use in clinical practice. PMID:23548176

[Gadolinium-based contrast agents for magnetic resonance imaging].

PubMed

Carrasco Muñoz, S; Calles Blanco, C; Marcin, Javier; Fernández Álvarez, C; Lafuente Martínez, J

2014-06-01

Gadolinium-based contrast agents are increasingly being used in magnetic resonance imaging. These agents can improve the contrast in images and provide information about function and metabolism, increasing both sensitivity and specificity. We describe the gadolinium-based contrast agents that have been approved for clinical use, detailing their main characteristics based on their chemical structure, stability, and safety. In general terms, these compounds are safe. Nevertheless, adverse reactions, the possibility of nephrotoxicity from these compounds, and the possibility of developing nephrogenic systemic fibrosis will be covered in this article. Lastly, the article will discuss the current guidelines, recommendations, and contraindications for their clinical use, including the management of pregnant and breast-feeding patients. Copyright © 2014 SERAM. Published by Elsevier Espana. All rights reserved.

Theoretical study of structure and stability of small gadolinium carboxylate complexes in liquid scintillator solvents.

PubMed

Huang, Pin-Wen

2014-09-01

The structural properties of three small gadolinium carboxylate complexes in three liquid scintillator solvents (pseudocumene, linear alkylbenzene, and phenyl xylylethane) were theoretically investigated using density functional theory (B3LYP/LC-RECP) and polarizable continuum model (PCM). The average interaction energy between gadolinium atom and carboxylate ligand (E(int)) and the energy difference of the highest singly occupied molecular orbital and lowest unoccupied molecular orbital (Δ(SL)) were calculated to evaluate and compare the relative stability of these complexes in solvents. The calculation results show that the larger (with a longer alkyl chain) gadolinium carboxylate complex has greater stability than the smaller one, while these gadolinium carboxylates in linear alkylbenzene were found to have greater stability than those in the other two solvents.

Prevalence of scarred and dysfunctional myocardium in patients with heart failure of ischaemic origin: A cardiovascular magnetic resonance study

PubMed Central

2011-01-01

Background Cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) can provide unique data on the transmural extent of scar/viability. We assessed the prevalence of dysfunctional myocardium, including partial thickness scar, which could contribute to left ventricular contractile dysfunction in patients with heart failure and ischaemic heart disease who denied angina symptoms. Methods We invited patients with ischaemic heart disease and a left ventricular ejection fraction < 50% by echocardiography to have LGE CMR. Myocardial contractility and transmural extent of scar were assessed using a 17-segment model. Results The median age of the 193 patients enrolled was 70 (interquartile range: 63-76) years and 167 (87%) were men. Of 3281 myocardial segments assessed, 1759 (54%) were dysfunctional, of which 581 (33%) showed no scar, 623 (35%) had scar affecting ≤50% of wall thickness and 555 (32%) had scar affecting > 50% of wall thickness. Of 1522 segments with normal contractile function, only 98 (6%) had evidence of scar on CMR. Overall, 182 (94%) patients had ≥1 and 107 (55%) patients had ≥5 segments with contractile dysfunction that had no scar or ≤50% transmural scar suggesting viability. Conclusions In this cohort of patients with left ventricular systolic dysfunction and ischaemic heart disease, about half of all segments had contractile dysfunction but only one third of these had > 50% of the wall thickness affected by scar, suggesting that most dysfunctional segments could improve in response to an appropriate intervention. PMID:21936915

Toxicological and pharmacological effects of gadolinium and samarium chlorides

PubMed Central

Haley, T. J.; Raymond, K.; Komesu, N.; Upham, H. C.

1961-01-01

A study has been made of the toxicology and pharmacology of gadolinium and samarium chlorides. The symptoms of acute toxicity following intraperitoneal injection are described. The chronic oral ingestion of both chemicals for 12 weeks produced no effects on growth or the blood picture, and only the male rats receiving gadolinium chloride showed liver damage. The pharmacological responses to both chemicals were mainly depressant on all systems studied, and death was associated with cardiovascular collapse coupled with respiratory paralysis. The greatest damage seen was on abraded skin, where non-healing ulcers were produced by both chemicals, whereas irritation of intact skin and ocular tissues was only transient in nature. PMID:13903826

CMR imaging of edema in myocardial infarction using cine balanced steady-state free precession.

PubMed

Kumar, Andreas; Beohar, Nirat; Arumana, Jain Mangalathu; Larose, Eric; Li, Debiao; Friedrich, Matthias G; Dharmakumar, Rohan

2011-12-01

The aim of this study was to investigate the capabilities of balanced steady-state free precession (bSSFP) cardiac magnetic resonance imaging as a novel cine imaging approach for characterizing myocardial edema in animals and patients after reperfused myocardial infarction. Current cardiac magnetic resonance methods require 2 separate scans for assessment of myocardial edema and cardiac function. Mini-pigs (n = 13) with experimentally induced reperfused myocardial infarction and patients with reperfused ST-segment elevation myocardial infarction (n = 26) underwent cardiac magnetic resonance scans on days 2 to 4 post-reperfusion. Cine bSSFP, T2-weighted short TI inversion recovery (T2-STIR), and late gadolinium enhancement were performed at 1.5-T. Cine bSSFP and T2-STIR images were acquired with a body coil to mitigate surface coil bias. Signal, contrast, and the area of edema were compared. Additional patients (n = 10) were analyzed for the effect of microvascular obstruction on bSSFP. A receiver-operator characteristic analysis was performed to assess the accuracy of edema detection. An area of hyperintense bSSFP signal consistent with edema was observed in the infarction zone (contrast-to-noise ratio: 37 ± 13) in all animals and correlated well with the area of late gadolinium enhancement (R = 0.83, p < 0.01). In all patients, T2-STIR and bSSFP images showed regional hyperintensity in the infarction zone. Normalized contrast-to-noise ratios were not different between T2-STIR and bSSFP. On a slice basis, the volumes of hyperintensity on T2-STIR and bSSFP images correlated well (R = 0.86, p < 0.001), and their means were not different. When compared with T2-STIR, bSSFP was positive for edema in 25 of 26 patients (96% sensitivity) and was negative in all controls (100% specificity). All patients with microvascular obstruction showed a significant reduction of signal in the subendocardial infarction zone compared with infarcted epicardial tissue without

Anti-EpCAM scFv gadolinium chelate: a novel targeted MRI contrast agent for imaging of colorectal cancer.

PubMed

Khantasup, Kannika; Saiviroonporn, Pairash; Jarussophon, Suwatchai; Chantima, Warangkana; Dharakul, Tararaj

2018-05-08

The development of targeted contrast agents for magnetic resonance imaging (MRI) facilitates enhanced cancer imaging and more accurate diagnosis. In the present study, a novel contrast agent was developed by conjugating anti-EpCAM humanized scFv with gadolinium chelate to achieve target specificity. The material design strategy involved site-specific conjugation of the chelating agent to scFv. The scFv monomer was linked to maleimide-DTPA via unpaired cysteine at the scFv C-terminus, followed by chelation with gadolinium (Gd). Successful scFv-DTPA conjugation was achieved at 1:10 molar ratio of scFv to maleimide-DTPA at pH 6.5. The developed anti-EpCAM-Gd-DTPA MRI contrast agent was evaluated for cell targeting ability, in vitro serum stability, cell cytotoxicity, relaxivity, and MR contrast enhancement. A high level of targeting efficacy of anti-EpCAM-Gd-DTPA to an EpCAM-overexpressing HT29 colorectal cell was demonstrated by confocal microscopy. Good stability of the contrast agent was obtained and no cytotoxicity was observed in HT29 cells after 48 h incubation with 25-100 µM of Gd. Favorable imaging was obtained using anti-EpCAM-Gd-DTPA, including 1.8-fold enhanced relaxivity compared with Gd-DTPA, and MR contrast enhancement observed after binding to HT29. The potential benefit of this contrast agent for in vivo MR imaging of colorectal cancer, as well as other EpCAM positive cancers, is suggested and warrants further investigation.

Proton Relaxivity and Magnetic Hyperthermia Evaluation of Gadolinium Doped Nickel Ferrite Nanoparticles as Potential Theranostic Agents.

PubMed

Yadavalli, Tejabhiram; Raja, Paradeep; Ramaswamy, Shivaraman; Chandrasekharan, Gopalakrishnan; Chennakesavulu, Ramasamy

2017-02-01

This paper outlines the preparation of gadolinium doped nickel ferrite nanoparticles as potential magnetic carriers and longitudinal magnetic resonance imaging contrast agents using hydrothermal method with gadolinium concentration varying from 10% to 40%. A concise effect on the crystal structure was observed at 10% and 20% gadolinium doping, while gadolinium oxide was observed to leach at concentrations exceeding 20%. Further, gadolinium doped nickel ferrites were analyzed for their morphological, magnetic, proton relaxation and magnetic hyperthermia heating properties to understand their potential role as magnetic carrier agents. Low temperature and room temperature magnetic studies conducted on the samples showed comparatively high magnetic saturation with low remanent magnetization. Further, relaxometry studies revealed a high relaxation rate of 6.63 s−1 at a concentration of 0.1 mg/mL. Magnetic hyperthermia studies of the samples at a concentration of 1 mg/mL, assessed that the samples attained a temperature of 68 °C in 240 seconds.

Delayed gadolinium-enhanced MRI of the fibrocartilage disc of the temporomandibular joint – a feasibility study

PubMed Central

Pittschieler, Elisabeth; Szomolanyi, Pavol; Schmid-Schwap, Martina; Weber, Michael; Egerbacher, Monika; Traxler, Hannes; Trattnig, Siegfried

2014-01-01

Objective To 1) test the feasibility of delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC) at 3 T in the temporomandibular joint (TMJ) and 2) to determine the optimal delay for measurements of the TMJ disc after i.v. contrast agent (CA) administration. Design MRI of the right and left TMJ of six asymptomatic volunteers was performed at 3 T using a dedicated coil. 2D inversion recovery (2D-IR) sequences were performed at 4 time points covering 120 minutes and 3D gradient-echo (3D GRE) dual flip-angle sequences were performed at 14 time points covering 130 minutes after the administration of 0.2 mmol/kg of Gd-diethylenetriamine pentaacetic acid ion (Gd-DTPA)2-, i.e., 0.4 mL of Magnevist™ per kg body weight. Pair-wise tests were used to assess differences between pre-and post-contrast T1 values. Results 2D-IR sequences showed a statistically significant drop (p < 0.001) in T1 values after i.v. CA administration. The T1 drop of 50% was reached 60 minutes after bolus injection in the TMJ disc. The 3D GRE dual flip-angle sequences confirmed these results and show plateau of T1 after 60 minutes. Conclusions T1(Gd) maps calculated from dGEMRIC data allow in vivo assessment of the fibrocartilage disc of the TMJ. The recommended measurement time for dGEMRIC in the TMJ after i.v. CA administration is from 60 to 120 minutes. PMID:25131629

3D late gadolinium enhancement in a single prolonged breath-hold using supplemental oxygenation and hyperventilation.

PubMed

Roujol, Sébastien; Basha, Tamer A; Akçakaya, Mehmet; Foppa, Murilo; Chan, Raymond H; Kissinger, Kraig V; Goddu, Beth; Berg, Sophie; Manning, Warren J; Nezafat, Reza

2014-09-01

To evaluate the feasibility of three-dimensional (3D) single breath-hold late gadolinium enhancement (LGE) of the left ventricle (LV) using supplemental oxygen and hyperventilation and compressed-sensing acceleration. Breath-hold metrics [breath-hold duration, diaphragmatic/LV position drift, and maximum variation of R wave to R wave (RR) interval] without and with supplemental oxygen and hyperventilation were assessed in healthy adult subjects using a real-time single shot acquisition. Ten healthy subjects and 13 patients then underwent assessment of the proposed 3D breath-hold LGE acquisition (field of view = 320 × 320 × 100 mm(3) , resolution = 1.6 × 1.6 × 5.0 mm(3) , acceleration rate of 4) and a free-breathing acquisition with right hemidiaphragm navigator (NAV) respiratory gating. Semiquantitative grading of overall image quality, motion artifact, myocardial nulling, and diagnostic value was performed by consensus of two blinded observers. Supplemental oxygenation and hyperventilation increased the breath-hold duration (35 ± 11 s to 58 ± 21 s; P < 0.0125) without significant impact on diaphragmatic/LV position drift or maximum variation of RR interval (both P > 0.01). LGE images were of similar quality when compared with free-breathing acquisitions, but with reduced total scan time (85 ± 22 s to 35 ± 6 s; P < 0.001). Supplemental oxygenation and hyperventilation allow for prolonged breath-holding and enable single breath-hold 3D accelerated LGE with similar image quality as free breathing with NAV. Copyright © 2013 Wiley Periodicals, Inc.

Evaluating the potential of chelation therapy to prevent and treat gadolinium deposition from MRI contrast agents

DOE PAGES

Rees, Julian A.; Deblonde, Gauthier J. -P.; An, Dahlia D.; ...

2018-03-13

Several MRI contrast agent clinical formulations are now known to leave deposits of the heavy metal gadolinium in the brain, bones, and other organs of patients. This persistent biological accumulation of gadolinium has been recently recognized as a deleterious outcome in patients administered Gd-based contrast agents (GBCAs) for MRI, prompting the European Medicines Agency to recommend discontinuing the use of over half of the GBCAs currently approved for clinical applications. Here, to address this problem, we find that the orally-available metal decorporation agent 3,4,3-LI(1,2-HOPO) demonstrates superior efficacy at chelating and removing Gd from the body compared to diethylenetriaminepentaacetic acid, amore » ligand commonly used in the United States in the GBCA Gadopentetate (Magnevist). Using the radiotracer 153Gd to obtain precise biodistribution data, the results herein, supported by speciation simulations, suggest that the prophylactic or post-hoc therapeutic use of 3,4,3-LI(1,2-HOPO) may provide a means to mitigate Gd retention in patients requiring contrast-enhanced MRI.« less

Evaluating the potential of chelation therapy to prevent and treat gadolinium deposition from MRI contrast agents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rees, Julian A.; Deblonde, Gauthier J. -P.; An, Dahlia D.

Several MRI contrast agent clinical formulations are now known to leave deposits of the heavy metal gadolinium in the brain, bones, and other organs of patients. This persistent biological accumulation of gadolinium has been recently recognized as a deleterious outcome in patients administered Gd-based contrast agents (GBCAs) for MRI, prompting the European Medicines Agency to recommend discontinuing the use of over half of the GBCAs currently approved for clinical applications. Here, to address this problem, we find that the orally-available metal decorporation agent 3,4,3-LI(1,2-HOPO) demonstrates superior efficacy at chelating and removing Gd from the body compared to diethylenetriaminepentaacetic acid, amore » ligand commonly used in the United States in the GBCA Gadopentetate (Magnevist). Using the radiotracer 153Gd to obtain precise biodistribution data, the results herein, supported by speciation simulations, suggest that the prophylactic or post-hoc therapeutic use of 3,4,3-LI(1,2-HOPO) may provide a means to mitigate Gd retention in patients requiring contrast-enhanced MRI.« less

Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Systolic Dysfunction: The CAMERA-MRI Study.

PubMed

Prabhu, Sandeep; Taylor, Andrew J; Costello, Ben T; Kaye, David M; McLellan, Alex J A; Voskoboinik, Aleksandr; Sugumar, Hariharan; Lockwood, Siobhan M; Stokes, Michael B; Pathik, Bhupesh; Nalliah, Chrishan J; Wong, Geoff R; Azzopardi, Sonia M; Gutman, Sarah J; Lee, Geoffrey; Layland, Jamie; Mariani, Justin A; Ling, Liang-Han; Kalman, Jonathan M; Kistler, Peter M

2017-10-17

Atrial fibrillation (AF) and left ventricular systolic dysfunction (LVSD) frequently co-exist despite adequate rate control. Existing randomized studies of AF and LVSD of varying etiologies have reported modest benefits with a rhythm control strategy. The goal of this study was to determine whether catheter ablation (CA) for AF could improve LVSD compared with medical rate control (MRC) where the etiology of the LVSD was unexplained, apart from the presence of AF. This multicenter, randomized clinical trial enrolled patients with persistent AF and idiopathic cardiomyopathy (left ventricular ejection fraction [LVEF] ≤45%). After optimization of rate control, patients underwent cardiac magnetic resonance (CMR) to assess LVEF and late gadolinium enhancement, indicative of ventricular fibrosis, before randomization to either CA or ongoing MRC. CA included pulmonary vein isolation and posterior wall isolation. AF burden post-CA was assessed by using an implanted loop recorder, and adequacy of MRC was assessed by using serial Holter monitoring. The primary endpoint was change in LVEF on repeat CMR at 6 months. A total of 301 patients were screened; 68 patients were enrolled between November 2013 and October 2016 and randomized with 33 in each arm (accounting for 2 dropouts). The average AF burden post-CA was 1.6 ± 5.0% at 6 months. In the intention-to-treat analysis, absolute LVEF improved by 18 ± 13% in the CA group compared with 4.4 ± 13% in the MRC group (p < 0.0001) and normalized (LVEF ≥50%) in 58% versus 9% (p = 0.0002). In those undergoing CA, the absence of late gadolinium enhancement predicted greater improvements in absolute LVEF (10.7%; p = 0.0069) and normalization at 6 months (73% vs. 29%; p = 0.0093). AF is an underappreciated reversible cause of LVSD in this population despite adequate rate control. The restoration of sinus rhythm with CA results in significant improvements in ventricular function, particularly in the absence of

Removal of gadolinium, a neutron poison from the moderator system of nuclear reactors.

PubMed

Rufus, A L; Kumar, Padma S; Jeena, K; Velmurugan, S

2018-01-15

Gadolinium as gadolinium nitrate is used as neutron poison in the moderator system for regulating and controlling the power generation of Pressurized Heavy Water Reactors (PHWR) and proposed to be used in Advanced Heavy Water Reactors (AHWR) owing to its high neutron absorption cross section. Removal of the added gadolinium nitrate (Gd 3+ and NO 3 - ) from the system after its intended use is done using ion exchange resins. In the present investigation, attempts have been made to optimize the ion exchange process for generation of low radioactive waste and maximize utilization of the ion exchange resins by employing different types of resins and different modes of operation. The investigations revealed that use of mixed bed (MB) resin column consisting of Strong Acid Cation (SAC) resin and Strong Base Anion (SBA) resin followed by SAC resin column is efficient in removing the Gd 3+ and NO 3 - from the system besides maintaining the pH of the moderator system in the desirable regime, where gadolinium does not get precipitated as its hydroxide. Copyright © 2017 Elsevier B.V. All rights reserved.

High Relaxivity Gadolinium Hydroxypyridonate-Viral Capsid Conjugates: Nano-sized MRI Contrast Agents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meux, Susan C.; Datta, Ankona; Hooker, Jacob M.

2007-08-29

High relaxivity macromolecular contrast agents based on the conjugation of gadolinium chelates to the interior and exterior surfaces of MS2 viral capsids are assessed. The proton nuclear magnetic relaxation dispersion (NMRD) profiles of the conjugates show up to a five-fold increase in relaxivity, leading to a peak relaxivity (per Gd{sup 3+} ion) of 41.6 mM{sup -1}s{sup -1} at 30 MHz for the internally modified capsids. Modification of the exterior was achieved through conjugation to flexible lysines, while internal modification was accomplished by conjugation to relatively rigid tyrosines. Higher relaxivities were obtained for the internally modified capsids, showing that (1) theremore » is facile diffusion of water to the interior of capsids and (2) the rigidity of the linker attaching the complex to the macromolecule is important for obtaining high relaxivity enhancements. The viral capsid conjugated gadolinium hydroxypyridonate complexes appear to possess two inner-sphere water molecules (q = 2) and the NMRD fittings highlight the differences in the local motion for the internal ({tau}{sub RI} = 440 ps) and external ({tau}{sub RI} = 310 ps) conjugates. These results indicate that there are significant advantages of using the internal surface of the capsids for contrast agent attachment, leaving the exterior surface available for the installation of tissue targeting groups.« less

Gadolinium Scandium Gallium Garnet (GSGG) as a Solid-State Laser Host

DTIC Science & Technology

1987-07-01

o*SATI CODSi1.SBEC EM (otne nrvrs fnceayad dniy nb)k ubr ~~~~~~~~ Gadolinium Scandium Gallium Garnet (GSGG)asaSldtteLerHt 17. ABSTRACT 6.SUJCTTEM...certain other garnet materials for replacement. It also addresses the solid-state laser host material Gadolinium Scandium Gal- lium Garnet (GSGG) and its...by neodymium-doped yttrium aluminum garnet (Nd:YAG) or other mate- rials for most applications. In the years after the invention of the ruby laser, in

Diagnostic accuracy for macroscopic classification of nodular hepatocellular carcinoma: comparison of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging and angiography-assisted computed tomography.

PubMed

Tada, Toshifumi; Kumada, Takashi; Toyoda, Hidenori; Ito, Takanori; Sone, Yasuhiro; Okuda, Seiji; Ogawa, Sadanobu; Igura, Takumi; Imai, Yasuharu

2015-01-01

The macroscopic type of hepatocellular carcinoma (HCC) is a predictor of prognosis. We clarified the diagnostic value of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) in the macroscopic classification of nodular hepatocellular carcinoma (HCC) as compared to angiography-assisted computed tomography (CT). A total of 71 surgically resected nodular HCCs with a maximum diameter of ≤5 cm were investigated. HCCs were evaluated preoperatively using Gd-EOB-DTPA-enhanced MRI and angiography-assisted CT. HCCs were pathologically classified as simple nodular (SN), SN with extranodular growth (SN-EG), or confluent multinodular (CMN). SN-EG and CMN were grouped as non-SN. Five readers independently reviewed the images using a five-point scale. We examined the accuracy of both imaging modalities in differentiating between SN and non-SN HCC. Overall, the area under the receiver operating characteristic curve (A z ) for the diagnosis of non-SN did not differ between Gd-EOB-DTPA-enhanced MRI and angiography-assisted CT [0.879 (95% confidence interval (CI), 0.779-0.937) and 0.845 (95% CI, 0.723-0.919), respectively]. For HCCs >2 cm, the A z for Gd-EOB-DTPA-enhanced MRI was greater than 0.9. The sensitivity, specificity, and accuracy of Gd-EOB-DTPA-enhanced MRI for identifying non-SN were equal to or higher than values with angiography-assisted CT in all three categories (all tumors, ≤2 cm, and >2 cm), but the differences were not statistically significant. Using Gd-EOB-DTPA-enhanced MRI to assess the macroscopic findings in nodular HCC was equal or superior to using angiography-assisted CT.

T1 and T2 mapping for evaluation of myocardial involvement in patients with ANCA-associated vasculitides.

PubMed

Greulich, Simon; Mayr, Agnes; Kitterer, Daniel; Latus, Joerg; Henes, Joerg; Steubing, Hannah; Kaesemann, Philipp; Patrascu, Alexandru; Greiser, Andreas; Groeninger, Stefan; Braun, Niko; Alscher, M Dominik; Sechtem, Udo; Mahrholdt, Heiko

2017-01-06

Myocardial involvement in AAV patients might be silent, presenting with no or nonspecific symptoms, normal ECG, and preserved left-ventricular ejection fraction (LV-EF). Since up to 50% of deaths in these patients may be due to myocardial involvement, a reliable diagnostic tool is warranted. In contrast to LGE-CMR, which has its strengths in detecting focal inflammatory or fibrotic processes, recent mapping techniques are able to detect even subtle, diffuse inflammatory or fibrotic processes. Our study sought to investigate ANCA (antineutrophil cytoplasmic antibody) associated vasculitides (AAV) patients for myocardial involvement by a cardiovascular magnetic resonance (CMR) protocol, including late gadolinium enhancement (LGE) and mapping sequences. Thirty seven AAV patients were prospectively enrolled and underwent CMR imaging. Twenty healthy volunteers served as controls. Mean LV-EF was 64%; LGE prevalence of the AAV patients was 43%. AAV patients had higher median native T1 (988 vs. 952 ms, p < 0.001), lower post-contrast T1 (488 vs. 524 ms, p = 0.03), expanded extracellular volume (ECV) (27.5 vs. 24.5%, p < 0.001), and higher T2 (53 vs. 49 ms, p < 0.001) compared to controls, with most parameters independent of the LGE status. Native T1 and T2 in AAV patients showed the highest prevalence of abnormally increased values beyond the 95% percentile of controls. AAV patients demonstrated increased T1, ECV, and T2 values, with native T1 and T2 showing the highest prevalence of values beyond the 95% percentile of normal. Since these findings seem to be independent of LGE, mapping techniques may provide complementary information to LGE-CMR in the assessment of myocardial involvement in patients with AAV.

Usefulness of combining gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging and contrast-enhanced ultrasound for diagnosing the macroscopic classification of small hepatocellular carcinoma.

PubMed

Kobayashi, Tomoki; Aikata, Hiroshi; Hatooka, Masahiro; Morio, Kei; Morio, Reona; Kan, Hiromi; Fujino, Hatsue; Fukuhara, Takayuki; Masaki, Keiichi; Ohno, Atsushi; Naeshiro, Noriaki; Nakahara, Takashi; Honda, Yohji; Murakami, Eisuke; Kawaoka, Tomokazu; Tsuge, Masataka; Hiramatsu, Akira; Imamura, Michio; Kawakami, Yoshiiku; Hyogo, Hideyuki; Takahashi, Shoichi; Chayama, Kazuaki

2015-11-01

Non-simple nodules in hepatocellular carcinoma (HCC) correlate with poor prognosis. Therefore, we examined the diagnostic ability of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) and contrast-enhanced ultrasound (CEUS) for diagnosing the macroscopic classification of small HCCs. A total of 85 surgically resected nodules (≤30 mm) were analyzed. HCCs were pathologically classified as simple nodular (SN) and non-SN. By evaluating hepatobiliary phase (HBP) of EOB-MRI and Kupffer phase of CEUS, the diagnostic abilities of both modalities to correctly distinguish between SN and non-SN were compared. Forty-six nodules were diagnosed as SN and the remaining 39 nodules as non-SN. The area under the ROC curve (AUROCs, 95% confidence interval) for the diagnosis of non-SN were EOB-MRI, 0.786 (0.682-0.890): CEUS, 0.784 (0.679-0.889), in combination, 0.876 (0.792-0.959). The sensitivity, specificity, and accuracy were 64.1%, 95.7%, and 81.2% in EOB-MRI, 56.4%, 97.8%, and 78.8% in CEUS, and 84.6%, 95.7%, and 90.6% in combination, respectively. High diagnostic ability was obtained when diagnosed in both modalities combined. The sensitivity was especially statistically significant compared to CEUS. Combined diagnosis by EOB-MRI and CEUS can provide high-quality imaging assessment for determining non-SN in small HCCs. • Non-SN has a higher frequency of MVI and intrahepatic metastasis than SN. • Macroscopic classification is useful to choose the treatment strategy for small HCCs. • Diagnostic ability for macroscopic findings of EOB-MRI and CEUS were statistically equal. • The diagnosis of macroscopic findings by individual modality has limitations. • Combined diagnosis of EOB-MRI and CEUS provides high diagnostic ability.

Retention of Gadolinium-Based Contrast Agents in Multiple Sclerosis: Retrospective Analysis of an 18-Year Longitudinal Study.

PubMed

Forslin, Y; Shams, S; Hashim, F; Aspelin, P; Bergendal, G; Martola, J; Fredrikson, S; Kristoffersen-Wiberg, M; Granberg, T

2017-07-01

Gadolinium-based contrast agents have been associated with lasting high T1-weighted signal intensity in the dentate nucleus and globus pallidus, with histopathologically confirmed gadolinium retention. We aimed to longitudinally investigate the relationship of multiple gadolinium-based contrast agent administrations to the Signal Intensity Index in the dentate nucleus and globus pallidus and any associations with cognitive function in multiple sclerosis. The Signal Intensity Index in the dentate nucleus and globus pallidus was retrospectively evaluated on T1-weighted MR imaging in an 18-year longitudinal cohort study of 23 patients with MS receiving multiple gadolinium-based contrast agent administrations and 23 healthy age- and sex-matched controls. Participants also underwent comprehensive neuropsychological testing. Patients with MS had a higher Signal Intensity Index in the dentate nucleus ( P < .001), but not in the globus pallidus ( P = .19), compared with non-gadolinium-based contrast agent-exposed healthy controls by an unpaired t test. Increasing numbers of gadolinium-based contrast agent administrations were associated with an increased Signal Intensity Index in the dentate nucleus (β = 0.45, P < .001) and globus pallidus (β = 0.60, P < .001). This association remained stable with corrections for the age, disease duration, and physical disability for both the dentate nucleus (β = 0.43, P = .001) and globus pallidus (β = 0.58, P < .001). An increased Signal Intensity Index in the dentate nucleus among patients with MS was associated with lower verbal fluency scores, which remained significant after correction for several aspects of disease severity (β = -0.40 P = .013). Our data corroborate previous reports of lasting gadolinium retention in brain tissues. An increased Signal Intensity Index in the dentate nucleus and globus pallidus was associated with lower verbal fluency, which does not prove causality but encourages further studies on cognition

[Combined use of contrast media containing iodine and gadolinium for imaging and intervention : A hitherto widely ignored topic in radiological practice].

PubMed

Golder, W

2012-02-01

The synchronous use of chemically different contrast media in the same body compartment is a challenge for the radiologist, whether it is scheduled or unexpected. However, to inject contrast media containing iodine and gadolinium at the same time can be a prerequisite for the examination of several organs or organ systems. Unlike other topics of contrast-enhanced imaging procedures, the difficulties encountered with double contrast injections have been widely ignored in the literature. In the absence of reliable data from experimental and clinical studies the radiologist is dependent on case reports, information provided by the contrast media manufacturers, personal communications, mostly scanty personal experiences and a skilful time management, in order to overcome the situation. Only the combination of X-ray, computed tomography and magnetic resonance arthrography can be performed without another thought. However, the more or less synchronous vascular application of contrast media containing iodine and gadolinium requires vigilance. The more seriously ill the patient is, the more caution is advised even if the decision on the combined administration has to be reached urgently. The following overview gives a description of the properties of contrast media containing iodine and gadolinium as far as interactions following simultaneous administration are concerned. Subsequently, the clinically relevant situations and constellations are outlined and analyzed.

Polydisulfide Manganese(II) Complexes as Non-Gadolinium Biodegradable Macromolecular MRI Contrast Agents

PubMed Central

Ye, Zhen; Jeong, Eun-Kee; Wu, Xueming; Tan, Mingqian; Yin, Shouyu; Lu, Zheng-Rong

2011-01-01

Purpose To develop safe and effective manganese(II) based biodegradable macromolecular MRI contrast agents. Materials and Methods In this study, we synthesized and characterized two polydisulfide manganese(II) complexes, Mn-DTPA cystamine copolymers and Mn-EDTA cystamine copolymers, as new biodegradable macromolecular MRI contrast agents. The contrast enhancement of the two manganese based contrast agents were evaluated in mice bearing MDA-MB-231 human breast carcinoma xenografts, in comparison with MnCl2. Results The T1 and T2 relaxivities were 4.74 and 10.38 mM−1s−1 per manganese at 3T for Mn-DTPA cystamine copolymers (Mn=30.50 kDa) and 6.41 and 9.72 mM−1s−1 for Mn-EDTA cystamine copolymers (Mn= 61.80 kDa). Both polydisulfide Mn(II) complexes showed significant liver, myocardium and tumor enhancement. Conclusion The manganese based polydisulfide contrast agents have a potential to be developed as alternative non-gadolinium contrast agents for MR cancer and myocardium imaging. PMID:22031457

Role of myocardial collagen degradation and fibrosis in right ventricle dysfunction in transposition of the great arteries after atrial switch.

PubMed

Ladouceur, Magalie; Baron, Stephanie; Nivet-Antoine, Valérie; Maruani, Gérard; Soulat, Gilles; Pereira, Helena; Blanchard, Anne; Boutouyrie, Pierre; Paul, Jean Louis; Mousseaux, Elie

2018-05-01

Heart failure is a serious event in patients with transposition of the great arteries (D-TGA) after atrial redirection surgery. We aimed to determine the association between myocardial fibrosis and systolic and diastolic systemic right ventricle (sRV) dysfunction. Diastolic and systolic function of sRV was prospectively assessed using echocardiography and cardiac magnetic resonance imaging (CMR) in 48 patients with atrially switched D-TGA and 26 healthy subjects. Diastolic function of the subaortic ventricle was assessed by echocardiography Doppler and DTI. In CMR, ejection fraction of sRV and wall stress defined as the product of the systolic blood pressure and volume/mass ratio were assessed. Fibrosis extent within sRV myocardium was evaluated using gadolinium-enhanced magnetic resonance and serum collagen turnover biomarkers. Late gadolinium enhancement (LGE) was found in 35% of D-TGA patients, and the collagen degradation biomarker pro-MMP1:TIMP1 ratio was significantly increased in D-TGA patients compared to healthy subjects (1.0 × 10 -2 vs. 2.5 × 10 -2 , p = 0.04). Increase in sRV wall stress was significantly associated with LGE (p = 0.01) and pro-MMP1:TIMP1 ratio (r = 0.77, p < 0.01). After adjustment for age, sex, BMI, blood pressure and cardiac treatment, pro-MMP1:TIMP1 ratio was the strongest determinant of sRVEF (R 2  = 0.85, p < 0.01). Pro-MMP1:TIMP1 ratio was also significantly correlated with the early diastolic filling parameter E/E' (r = 0.53, p = 0.02), but this was not anymore the case after adjustment. Diastolic and systolic sRV dysfunction is related to myocardial collagen degradation and fibrosis. Research in medical therapies that reduce systemic sRV afterload and limit collagen degradation is warranted in this setting. Copyright © 2018 Elsevier B.V. All rights reserved.

Assessment of aortic stiffness in patients with ankylosing spondylitis using cardiovascular magnetic resonance.

PubMed

Biesbroek, P Stefan; Heslinga, Sjoerd C; van de Ven, Peter M; Peters, Mike J L; Amier, Raquel P; Konings, Thelma C; Maroules, Christopher D; Ayers, Colby; Joshi, Parag H; van der Horst-Bruinsma, Irene E; van Halm, Vokko P; van Rossum, Albert C; Nurmohamed, Michael T; Nijveldt, Robin

2018-05-12

To evaluate aortic stiffness in patients with ankylosing spondylitis (AS) using cardiovascular magnetic resonance (CMR) and to assess its association with AS characteristics and left ventricular (LV) remodeling. In this prospective study, 14 consecutive AS patients were each matched to two controls without cardiovascular symptoms or known cardiovascular disease who underwent CMR imaging for the assessment of aortic arch pulse wave velocity (PWV) at 1.5 Tesla. To enhance comparability of the samples, matching was done with replacement resulting in 20 unique controls. Only AS patients with abnormal findings on screening echocardiography were included in this exploratory study. Cine CMR was used to assess LV geometry and systolic function, and late gadolinium enhancement was performed to determine the presence of myocardial hyperenhancement (i.e., fibrosis). Aortic arch PWV was significantly higher in the AS group compared with the control group (median 9.7 m/s, interquartile range [IQR] 7.1 to 11.8 vs. 6.1 m/s, IQR 4.6 to 7.6 m/s; p < 0.001). PWV was positively associated with functional disability as measured by BASFI (R: 0.62; p = 0.018). Three patients (21%) with a non-ischemic pattern of hyperenhancement showed increased PWV (11.7, 12.3, and 16.5 m/s) as compared to the 11 patients without hyperenhancement (9.0 m/s, IQR 6.6 to 10.5 m/s; p = 0.022). PWV was inversely associated with LV ejection fraction (R: - 0.63; p = 0.015), but was not found to be statistically correlated to LV volumes or mass. Aortic arch PWV was increased in our cohort of patients with AS. Higher PWV in the aortic arch was associated with functional disability, the presence of non-ischemic hyperenhancement, and reduced LV systolic function.

Spectrum and clinical significance of systolic function and myocardial fibrosis assessed by cardiovascular magnetic resonance in hypertrophic cardiomyopathy.

PubMed

Olivotto, Iacopo; Maron, Barry J; Appelbaum, Evan; Harrigan, Caitlin J; Salton, Carol; Gibson, C Michael; Udelson, James E; O'Donnell, Christopher; Lesser, John R; Manning, Warren J; Maron, Martin S

2010-07-15

In hypertrophic cardiomyopathy (HCM), the clinical significance attributable to the broad range of left ventricular (LV) systolic function, assessed as the ejection fraction (EF), is incompletely resolved. We evaluated the EF using cardiovascular magnetic resonance (CMR) imaging in a large cohort of patients with HCM with respect to the clinical status and evidence of left ventricular remodeling with late gadolinium enhancement (LGE). CMR imaging was performed in 310 consecutive patients, aged 42 +/- 17 years. The EF in patients with HCM was 71 +/- 10% (range 28% to 89%), exceeding that of 606 healthy controls without cardiovascular disease (66 +/- 5%, p <0.001). LGE reflecting LV remodeling showed an independent, inverse relation to the EF (B-0.69, 95% confidence interval -0.86 to -0.52; p <0.001) and was greatest in patients with an EF <50%, in whom it constituted a median value of 29% of the LV volume (interquartile range 16% to 40%). However, the substantial subgroup with low-normal EF values of 50% to 65% (n = 45; 15% of the whole cohort), who were mostly asymptomatic or mildly symptomatic (37 or 82% with New York Heart Association functional class I to II), showed substantial LGE (median 5% of LV volume, interquartile range 2% to 10%). This overlapped with the subgroup with systolic dysfunction and significantly exceeded that of patients with an EF of 66% to 75% and >75% (median 2% of the LV volume, interquartile range 1.5% to 4%; p <0.01). In conclusion, in a large cohort of patients with HCM, a subset of patients with low-normal EF values (50% to 65%) was identified by contrast-enhanced CMR imaging as having substantial degrees of LGE, suggesting a transition phase, potentially heralding advanced LV remodeling and systolic dysfunction, with implications for clinical surveillance and management. Copyright (c) 2010. Published by Elsevier Inc.

Fabrication and in vitro characterization of gadolinium-based nanoclusters for simultaneous drug delivery and radiation enhancement

NASA Astrophysics Data System (ADS)

Yoo, Shannon S.; Guo, Linghong; Sun, Xuejun; Shaw, Andrew R.; Yuan, Zhipeng; Löbenberg, Raimar; Roa, Wilson H.

2016-09-01

We report the synthesis of a gadolinium hydroxide (Gd(OH)3) nanorod based doxorubicin (Dox) delivery system that can enhance both magnetic resonance imaging contrast and radiation sensitivity. A simple and cost effective wet-chemical method was utilized in the presence of manganese (Mn) ions and Dox to produce the Gd(OH)3:Mn·Dox nanocluster structure. The Gd(OH)3:Mn·Dox nanocluster was composed of Mn-doped Gd(OH)3 nanorods arranged in parallel with Dox as a linker molecule between the adjacent nanorods. No other studies have utilized Dox as both the linker and therapeutic molecule in a nanostructure to date. The Gd(OH)3 nanorod is reported to have no significant cellular or in vivo toxicity, which makes it an ideal base material for this biomedical application. The Gd(OH)3:Mn·Dox nanocluster exhibited paramagnetic behavior and was stable in a colloidal solution. The nanocluster also enabled high Dox loading capacity and specifically released Dox in a sustained and pH-dependent manner. The positively charged Gd(OH)3:Mn·Dox nanoclusters were readily internalized into MDA-MB-231 breast cancer cells via endocytosis, which resulted in intracellular release of Dox. The released Dox in cells was effective in conferring cytotoxicity and inhibiting proliferation of cancer cells. Furthermore, a synergistic anticancer effect could be observed with radiation treatment. Overall, the Gd(OH)3:Mn·Dox nanocluster drug delivery system described herein may have potential utility in clinics as a multifunctional theranostic nanoparticle with combined benefits in both diagnosis and therapy in the management of cancer.

Pediatric Patients Demonstrate Progressive T1-Weighted Hyperintensity in the Dentate Nucleus following Multiple Doses of Gadolinium-Based Contrast Agent.

PubMed

Roberts, D R; Chatterjee, A R; Yazdani, M; Marebwa, B; Brown, T; Collins, H; Bolles, G; Jenrette, J M; Nietert, P J; Zhu, X

2016-12-01

While there have been recent reports of brain retention of gadolinium following gadolinium-based contrast agent administration in adults, a retrospective series of pediatric patients has not previously been reported, to our knowledge. We investigated the relationship between the number of prior gadolinium-based contrast agent doses and increasing T1 signal in the dentate nucleus on unenhanced T1-weighted MR imaging. We hypothesized that despite differences in pediatric physiology and the smaller gadolinium-based contrast agent doses that pediatric patients are typically administered based on weighted-adjusted dosing, the pediatric brain would also demonstrate dose-dependent increasing T1 signal in the dentate nucleus. We included children with multiple gadolinium-based contrast agent administrations at our institution. A blinded reader placed ROIs within the dentate nucleus and adjacent cerebellar white matter. To eliminate reader bias, we also performed automated ROI delineation of the dentate nucleus, cerebellar white matter, and pons. Dentate-to-cerebellar white matter and dentate-to pons ratios were compared with the number of gadolinium-based contrast agent administrations. During 20 years at our institution, 280 patients received at least 5 gadolinium-based contrast agent doses, with 1 patient receiving 38 doses. Sixteen patients met the inclusion/exclusion criteria for ROI analysis. Blinded reader dentate-to-cerebellar white matter ratios were significantly associated with gadolinium-based contrast agent doses (r s = 0.77, P = .001). The dentate-to-pons ratio and dentate-to-cerebellar white matter ratios based on automated ROI placement were also significantly correlated with gadolinium-based contrast agent doses (t = 4.98, P < .0001 and t = 2.73, P < .02, respectively). In pediatric patients, the number of prior gadolinium-based contrast agent doses is significantly correlated with progressive T1-weighted dentate hyperintensity. Definitive confirmation of

The High Radiosensitizing Efficiency of a Trace of Gadolinium-Based Nanoparticles in Tumors

NASA Astrophysics Data System (ADS)

Dufort, Sandrine; Le Duc, Géraldine; Salomé, Murielle; Bentivegna, Valerie; Sancey, Lucie; Bräuer-Krisch, Elke; Requardt, Herwig; Lux, François; Coll, Jean-Luc; Perriat, Pascal; Roux, Stéphane; Tillement, Olivier

2016-07-01

We recently developed the synthesis of ultrasmall gadolinium-based nanoparticles (GBN), (hydrodynamic diameter <5 nm) characterized by a safe behavior after intravenous injection (renal clearance, preferential accumulation in tumors). Owing to the presence of gadolinium ions, GBN can be used as contrast agents for magnetic resonance imaging (MRI) and as radiosensitizers. The attempt to determine the most opportune delay between the intravenous injection of GBN and the irradiation showed that a very low content of radiosensitizing nanoparticles in the tumor area is sufficient (0.1 μg/g of particles, i.e. 15 ppb of gadolinium) for an important increase of the therapeutic effect of irradiation. Such a promising and unexpected result is assigned to a suited distribution of GBN within the tumor, as revealed by the X-ray fluorescence (XRF) maps.

In vitro radiosensitizing effects of ultrasmall gadolinium based particles on tumour cells.

PubMed

Mowat, P; Mignot, A; Rima, W; Lux, F; Tillement, O; Roulin, C; Dutreix, M; Bechet, D; Huger, S; Humbert, L; Barberi-Heyob, M; Aloy, M T; Armandy, E; Rodriguez-Lafrasse, C; Le Duc, G; Roux, S; Perriat, P

2011-09-01

Since radiotherapy is widely used in cancer treatment, it is essential to develop strategies which lower the irradiation burden while increasing efficacy and become efficient even in radio resistant tumors. Our new strategy is relying on the development of solid hybrid nanoparticles based on rare-earth such as gadolinium. In this paper, we then evidenced that gadolinium-based particles can be designed to enter efficiently into the human glioblastoma cell line U87 in quantities that can be tuned by modifying the incubation conditions. These sub-5 nm particles consist in a core of gadolinium oxide, a shell of polysiloxane and are functionalized by diethylenetriaminepentaacetic acid (DTPA). Although photoelectric effect is maximal in the [10-100 keV] range, such particles were found to possess efficient in-vitro radiosensitizing properties at an energy of 660 keV by using the "single-cell gel electrophoresis comet assay," an assay that measures the number of DNA damage that occurs during irradiation. Even more interesting, the particles have been evidenced by MTT assays to be also efficient radiosensitizers at an energy of 6 MeV for doses comprised between 2 and 8 Gy. The properties of the gadolinium-based particles give promising opening to a particle-assisted radio-therapy by using irradiation systems already installed in the majority of hospitals.

Multifunctional Gadolinium-Doped Mesoporous TiO2 Nanobeads: Photoluminescence, Enhanced Spin Relaxation, and Reactive Oxygen Species Photogeneration, Beneficial for Cancer Diagnosis and Treatment.

PubMed

Imani, Roghayeh; Dillert, Ralf; Bahnemann, Detlef W; Pazoki, Meysam; Apih, Tomaž; Kononenko, Veno; Repar, Neža; Kralj-Iglič, Veronika; Boschloo, Gerrit; Drobne, Damjana; Edvinsson, Tomas; Iglič, Aleš

2017-05-01

Materials with controllable multifunctional abilities for optical imaging (OI) and magnetic resonant imaging (MRI) that also can be used in photodynamic therapy are very interesting for future applications. Mesoporous TiO 2 sub-micrometer particles are doped with gadolinium to improve photoluminescence functionality and spin relaxation for MRI, with the added benefit of enhanced generation of reactive oxygen species (ROS). The Gd-doped TiO 2 exhibits red emission at 637 nm that is beneficial for OI and significantly improves MRI relaxation times, with a beneficial decrease in spin-lattice and spin-spin relaxation times. Density functional theory calculations show that Gd 3+ ions introduce impurity energy levels inside the bandgap of anatase TiO 2 , and also create dipoles that are beneficial for charge separation and decreased electron-hole recombination in the doped lattice. The Gd-doped TiO 2 nanobeads (NBs) show enhanced ability for ROS monitored via • OH radical photogeneration, in comparison with undoped TiO 2 nanobeads and TiO 2 P25, for Gd-doping up to 10%. Cellular internalization and biocompatibility of TiO 2 @xGd NBs are tested in vitro on MG-63 human osteosarcoma cells, showing full biocompatibility. After photoactivation of the particles, anticancer trace by means of ROS photogeneration is observed just after 3 min irradiation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mn-Site Doped CaMnO 3: Creation of the CMR Effect

NASA Astrophysics Data System (ADS)

Raveau, B.; Zhao, Y. M.; Martin, C.; Hervieu, M.; Maignan, A.

2000-01-01

The doping of CaMnO3-δ at Mn sites with pentavalent and hexavalent d0 elements - Nb, Ta, W, Mo - modifies the resistivity behavior of this phase, extending the insulating domain and increasing significantly the resistivity at low temperature as the doping element content increases. The higher valency of the doping element introduces electrons; i.e., Mn3+ species are formed in the Mn4+ matrix. Double exchange phenomena then allow ferromagnetic interactions, by application of external magnetic fields which are similar to those observed for electron-doped manganites Ca1-xLnxMnO3 (x≤0.15), but with smaller magnetic moments. Consequently, this Mn site doping induces CMR properties with resistivity ratios considerably larger than those for CaMnO3-δ.

Gadolinium-hydrogen ion exchange of zirconium phosphate

NASA Technical Reports Server (NTRS)

Liu, D. C.; Power, J. L.

1972-01-01

The Gd(+3)/H(+) ion exchange on a commercial zirconium phosphate ion exchanger was investigated in chloride, sulfate, and phosphate solutions of Gd(+3) at gadolinium concentrations of 0.001 to 1 millimole per cc and in the pH range of 0 to 3.5. Relatively low Gd(+3) capacities, in the range of 0.01 to 0.1 millimole per g of ion exchanger were found at room temperature. A significant difference in Gd(+3) sorption was observed, depending on whether the ion exchanger was converted from initial conditions of greater or lesser Gd(+3) sorption than the specific final conditions. Correlations were found between decrease in Gd(+3) capacity and loss of exchanger phosphate groups due to hydrolysis during washing and between increase in capacity and treatment with H3PO4. Fitting of the experimental data to ideal ion exchange equilibrium expressions indicated that each Gd(+3) ion is sorbed on only one site of the ion exchanger. The selectivity quotient was determined to be 2.5 + or - 0.4 at room temperature on gadolinium desorption in chloride solutions.

T1 Measurements Identify Extracellular Volume Expansion in Hypertrophic Cardiomyopathy Sarcomere Mutation Carriers With and Without Left Ventricular Hypertrophy

PubMed Central

Ho, Carolyn Y.; Abbasi, Siddique A.; Neilan, Tomas G.; Shah, Ravi V.; Chen, Yucheng; Heydari, Bobak; Cirino, Allison L.; Lakdawala, Neal K.; Orav, E. John; González, Arantxa; López, Begoña; Díez, Javier; Jerosch-Herold, Michael; Kwong, Raymond Y.

2013-01-01

Background Myocardial fibrosis is a hallmark of hypertrophic cardiomyopathy (HCM) and a potential substrate for arrhythmias and heart failure. Sarcomere mutations appear to induce profibrotic changes before left ventricular hypertrophy (LVH) develops. To further evaluate these processes, we used cardiac magnetic resonance (CMR) with T1 measurements on a genotyped HCM population to quantify myocardial extracellular volume (ECV). Methods and Results Sarcomere mutation carriers with LVH (G+/LVH+, n = 37) and without LVH (G+/LVH−, n = 29); HCM patients without mutations (sarcomere-negative HCM, n = 11); and healthy controls (n = 11) underwent contrast CMR, measuring T1 times pre- and post-gadolinium infusion. Concurrent echocardiography and serum biomarkers of collagen synthesis, hemodynamic stress, and myocardial injury were also available in a subset. Compared to controls, ECV was increased in patients with overt HCM, as well as G+/LVH− mutation carriers (ECV= 0.36±0.01, 0.33±0.01, 0.27±0.01 in G+/LVH+, G+/LVH−, controls, respectively, P≤0.001 for all comparisons). ECV correlated with NT-proBNP levels (r = 0.58, P<0.001) and global E’ velocity (r = −0.48, P<0.001). Late gadolinium enhancement (LGE) was present in >60% of overt HCM patients but absent from G+/LVH− subjects. Both ECV and LGE were more extensive in sarcomeric HCM than sarcomere-negative HCM. Conclusions Myocardial ECV is increased in HCM sarcomere mutation carriers even in the absence of LVH. These data provide additional support that fibrotic remodeling is triggered early in disease pathogenesis. Quantifying ECV may help characterize the development myocardial fibrosis in HCM and ultimately assist in developing novel disease-modifying therapy, targeting interstitial fibrosis. PMID:23549607

Gadolinium-loaded Plastic Scintillators for Thermal Neutron Detection using Compensation

NASA Astrophysics Data System (ADS)

Dumazert, Jonathan; Coulon, Romain; Hamel, Matthieu; Carrel, Frédérick; Sguerra, Fabien; Normand, Stéphane; Méchin, Laurence; Bertrand, Guillaume H. V.

2016-06-01

Plastic scintillator loading with gadolinium-rich organometallic complexes shows a high potential for the deployment of efficient and cost-effective neutron detectors. Due to the low-energy photon and electron signature of thermal neutron capture by Gd-155 and Gd-157, alternative treatment to pulse-shape discrimination has to be proposed in order to display a count rate. This paper discloses the principle of a compensation method applied to a two-scintillator system: a detection scintillator interacts with photon and fast neutron radiation and is loaded with gadolinium organometallic compound to become a thermal neutron absorber, while a not-gadolinium loaded compensation scintillator solely interacts with the fast neutron and photon part of incident radiation. After the nonlinear smoothing of the counting signals, a hypothesis test determines whether the resulting count rate post-background response compensation falls into statistical fluctuations or provides a robust indication of neutron activity. Laboratory samples are tested under both photon and neutron irradiations, allowing the authors to investigate the performance of the overall detection system in terms of sensitivity and detection limits, especially with regards to a similar-active volume He-3 based commercial counter. The study reveals satisfactory figures of merit in terms of sensitivity and directs future investigation toward promising paths.

Phenotypic diversity identified by cardiac magnetic resonance in a large hypertrophic cardiomyopathy family with a single MYH7 mutation.

PubMed

Wang, Jie; Wan, Ke; Sun, Jiayu; Li, Weihao; Liu, Hong; Han, Yuchi; Chen, Yucheng

2018-01-17

Limited data is available on phenotypic variations with the same genotype in hypertrophic cardiomyopathy (HCM). The present study aims to explore the relationship between genotype and phenotype characterized by cardiovascular magnetic resonance (CMR) in a large Chinese family. A proband diagnosed with HCM from a multigenerational family underwent next-generation sequencing based on a custom sureSelect panel, including 117 candidate pathogenic genes associated with cardiomyopathies. All genetic results were confirmed by the Sanger sequencing method. All confirmed mutation carriers underwent CMR exam and myocardial tissue characterization using T1 mapping and late gadolinium enhancement (LGE) on a 3T scanner (Siemens Trio, Gemany). After clinical and genetic screening of 36 (including the proband) members of a large Chinese family, nineteen family members are determined to carry the single p.T1377M (c.4130C>T) mutation in the MYH7 gene. Of these 19 mutation carriers, eight are diagnosed with HCM, one was considered as borderline affected and ten are not clinically or phenotypically affected. Different HCM phenotypes are present in the nine affected individuals in this family. In addition, we have found different tissue characteristics assessed by T1 mapping and LGE in these individuals. We describe a family that demonstrates the diverse HCM phenotypes associated with a single MYH7 mutation.

Contribution of cardiovascular magnetic resonance in the evaluation of coronary arteries

PubMed Central

Mavrogeni, Sophie; Markousis-Mavrogenis, George; Kolovou, Genovefa

2014-01-01

Cardiovascular magnetic resonance (CMR) allows the nonradiating assessment of coronary arteries; to achieve better image quality cardiorespiratory artefacts should be corrected. Coronary MRA (CMRA) at the moment is indicated only for the detection of abnormal coronary origin, coronary artery ectasia and/or aneurysms (class I indication) and coronary bypass grafts (class II indication). CMRA utilisation for coronary artery disease is not yet part of clinical routine. However, the lack of radiation is of special value for the coronary artery evaluation in children and women. CMRA can assess the proximal part of coronary arteries in almost all cases. The best results have been observed in the evaluation of the left anterior descending and the right coronary artery, while the left circumflex, which is located far away from the coil elements, is frequently imaged with reduced quality, compared to the other two. Different studies detected an increase in wall thickness of the coronaries in patients with type I diabetes and abnormal renal function. Additionally, the non-contrast enhanced T1-weighed images detected the presence of thrombus in acute myocardial infarction. New techniques using delayed gadolinium enhanced imaging promise the direct visualization of inflamed plaques in the coronary arteries. The major advantage of CMR is the potential of an integrated protocol offering assessment of coronary artery anatomy, cardiac function, inflammation and stress perfusion-fibrosis in the same study, providing an individualized clinical profile of patients with heart disease. PMID:25349650

Highly transparent cerium doped gadolinium gallium aluminum garnet ceramic prepared with precursors fabricated by ultrasonic enhanced chemical co-precipitation.

PubMed

Zhang, Ji-Yun; Luo, Zhao-Hua; Jiang, Hao-Chuan; Jiang, Jun; Chen, Chun-Hua; Zhang, Jing-Xian; Gui, Zhen-Zhen; Xiao, Na

2017-11-01

Cerium doped gadolinium gallium aluminum garnet (GGAG:Ce) ceramic precursors have been synthesized with an ultrasonic chemical co-precipitation method (UCC) and for comparison with a traditional chemical co-precipitation method (TCC). The effect of ultra-sonication on the morphology of powders and the transmittance of GGAG:Ce ceramics are studied. The results indicate that the UCC method can effectively improve the homogenization and sinterability of GGAG:Ce powders, which contribute to obtain high transparent GGAG ceramic with the highest transmittance of 81%. Copyright © 2017 Elsevier B.V. All rights reserved.

Penetration and distribution of gadolinium-based contrast agents into the cerebrospinal fluid in healthy rats: a potential pathway of entry into the brain tissue.

PubMed

Jost, Gregor; Frenzel, Thomas; Lohrke, Jessica; Lenhard, Diana Constanze; Naganawa, Shinji; Pietsch, Hubertus

2017-07-01

Signal hyperintensity on unenhanced MRI in certain brain regions has been reported after multiple administrations of some, but not all, gadolinium-based contrast agents (GBCAs). One potential initial pathway of GBCA entry into the brain, infiltration from blood into the cerebrospinal fluid (CSF), was systematically evaluated in this preclinical study. GBCA infiltration and distribution in the CSF were investigated in healthy rats using repeated fluid-attenuated MRI up to 4 h after high-dose (1.8 mmol/kg) administration of six marketed and one experimental GBCA. Additionally, gadolinium measurements in CSF, blood and brain tissue samples (after 24 h) were performed using inductively coupled plasma mass spectrometry. Enhanced MRI signals in the CSF spaces with similar distribution kinetics were observed for all GBCAs. No substantial differences in the gadolinium concentrations among the marketed GBCAs were found in the CSF, blood or brain tissue. After 4.5 h, the concentration in the CSF was clearly higher than in blood but was almost completely cleared and lower than the brain tissue concentration after 24 h. In contrast to the brain signal hyperintensities, no differences in penetration and distribution into the CSF of healthy rats exist among the marketed GBCAs. • Gadolinium-based contrast agents can cross the blood-CSF barrier. • Fluid-attenuated MRI shows GBCA distribution with CSF flow. • GBCA structure and physicochemical properties do not impact CSF penetration and distribution. • GBCA clearance from CSF was almost complete within 24 h in rats. • CSF is a potential pathway of GBCA entry into the brain.

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

PubMed

Semelka, Richard C; Ramalho, Joana; Vakharia, Ami; AlObaidy, Mamdoh; Burke, Lauren M; Jay, Michael; Ramalho, Miguel

2016-12-01

To describe the clinical manifestations of presumed gadolinium toxicity in patients with normal renal function. Participants 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. 42 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. Gadolinium 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. Copyright © 2016 Elsevier Inc. All rights reserved.

Gadolinium-based Contrast Media, Cerebrospinal Fluid and the Glymphatic System: Possible Mechanisms for the Deposition of Gadolinium in the Brain.

PubMed

Taoka, Toshiaki; Naganawa, Shinji

2018-04-10

After Kanda's first report in 2014 on gadolinium (Gd) deposition in brain tissue, a considerable number of studies have investigated the explanation for the observation. Gd deposition in brain tissue after repeated administration of gadolinium-based contrast medium (GBCM) has been histologically proven, and chelate stability has been shown to affect the deposition. However, the mechanism for this deposition has not been fully elucidated. Recently, a hypothesis was introduced that involves the 'glymphatic system', which is a coined word that combines 'gl' for glia cell and 'lymphatic' system. According to this hypothesis, the perivascular space functions as a conduit for cerebrospinal fluid to flow into the brain parenchyma. The perivascular space around the arteries allows cerebrospinal fluid to enter the interstitial space of the brain tissue through water channels controlled by aquaporin 4. The cerebrospinal fluid entering the interstitial space clears waste proteins from the tissue. It then flows into the perivascular space around the vein and is discharged outside the brain. In addition to the hypothesis regarding the glymphatic system, some reports have described that after GBCM administration, some of the GBCM distributes through systemic blood circulation and remains in other compartments including the cerebrospinal fluid. It is thought that the GBCM distributed into the cerebrospinal fluid cavity via the glymphatic system may remain in brain tissue for a longer duration compared to the GBCM in systemic circulation. Glymphatic system may of course act as a clearance system for GBCM from brain tissue. Based on these findings, the mechanism for Gd deposition in the brain will be discussed in this review. The authors speculate that the glymphatic system may be the major contributory factor to the deposition and clearance of gadolinium in brain tissue.

Gadolinium-based Contrast Media, Cerebrospinal Fluid and the Glymphatic System: Possible Mechanisms for the Deposition of Gadolinium in the Brain

PubMed Central

Taoka, Toshiaki; Naganawa, Shinji

2018-01-01

After Kanda’s first report in 2014 on gadolinium (Gd) deposition in brain tissue, a considerable number of studies have investigated the explanation for the observation. Gd deposition in brain tissue after repeated administration of gadolinium-based contrast medium (GBCM) has been histologically proven, and chelate stability has been shown to affect the deposition. However, the mechanism for this deposition has not been fully elucidated. Recently, a hypothesis was introduced that involves the ‘glymphatic system’, which is a coined word that combines ‘gl’ for glia cell and ‘lymphatic’ system. According to this hypothesis, the perivascular space functions as a conduit for cerebrospinal fluid to flow into the brain parenchyma. The perivascular space around the arteries allows cerebrospinal fluid to enter the interstitial space of the brain tissue through water channels controlled by aquaporin 4. The cerebrospinal fluid entering the interstitial space clears waste proteins from the tissue. It then flows into the perivascular space around the vein and is discharged outside the brain. In addition to the hypothesis regarding the glymphatic system, some reports have described that after GBCM administration, some of the GBCM distributes through systemic blood circulation and remains in other compartments including the cerebrospinal fluid. It is thought that the GBCM distributed into the cerebrospinal fluid cavity via the glymphatic system may remain in brain tissue for a longer duration compared to the GBCM in systemic circulation. Glymphatic system may of course act as a clearance system for GBCM from brain tissue. Based on these findings, the mechanism for Gd deposition in the brain will be discussed in this review. The authors speculate that the glymphatic system may be the major contributory factor to the deposition and clearance of gadolinium in brain tissue. PMID:29367513

Image-guided convection-enhanced delivery of muscimol to the primate brain

PubMed Central

Heiss, John D.; Walbridge, Stuart; Asthagiri, Ashok R.; Lonser, Russell R.

2009-01-01

Object Muscimol is a potent γ-aminobutyric acid-A receptor agonist (GABAA) that temporarily and selectively suppresses neurons. Targeted muscimol-suppression of neuronal structures could provide insight into the pathophysiology and treatment of a variety of neurologic disorders. To determine if muscimol delivered to the brain by convection-enhanced delivery (CED) could be monitored using a co-infused surrogate magnetic resonance (MR)-imaging tracer, we perfused the striata of primates with tritiated muscimol and gadolinium-DTPA. Methods Three primates underwent convective co-infusion of 3H-muscimol (0.8 μM) and gadolinium-DTPA (−5 mM) into the bilateral striata. Primates underwent serial MR-imaging during infusion and animals were sacrificed immediately after infusion. Post-mortem quantitative autoradiography and histological analysis was performed. Results MR-imaging revealed that infusate (tritiated muscimol and gadolinium-DTPA) distribution was clearly discernible from the non-infused parenchyma. Real-time MR-imaging of the infusion revealed the precise region of anatomic perfusion in each animal. Imaging analysis during infusion revealed that the distribution volume of infusate linearly increased (R=0.92) with volume of infusion. Overall, the mean (±S.D.) volume of distribution to volume of infusion ratio was 8.2±1.3. Autoradiographic analysis revealed that MR-imaging of gadolinium-DTPA closely correlated with the distribution of 3H-muscimol and precisely estimated its volume of distribution (mean difference in volume of distribution, 7.4%). Quantitative autoradiograms revealed that muscimol was homogeneously distributed over the perfused region in a square-shaped concentration profile. Conclusions Muscimol can be effectively delivered to clinically relevant volumes of the primate brain. Moreover, the distribution of muscimol can be tracked by co-infusion of gadolinium-DTPA using MR-imaging. The ability to accurately monitor and control the anatomic

Identifying the Etiology: A Systematic Approach Using Delayed Enhancement Cardiovascular Magnetic Resonance

PubMed Central

Senthilkumar, Annamalai; Majmudar, Maulik D.; Shenoy, Chetan; Kim, Han W.; Kim, Raymond J.

2009-01-01

SYNOPSIS In patients with heart failure, treatment and survival are directly related to the etiology. Clinically, as a practical first step, patients are classified as having either ischemic or nonischemic cardiomyopathy and this delineation is usually based on the presence or absence of epicardial coronary artery disease. However, this approach does not account for patients with nonischemic cardiomyopathy who also have coronary artery disease, which may be either incidental or partly contributing to myocardial dysfunction (mixed cardiomyopathy). By allowing direct assessment of the myocardium, delayed enhancement cardiovascular magnetic resonance (DE-CMR) may aid in addressing these conundrums. In this article we explore how DE-CMR may be helpful in identifying ischemic and nonischemic myopathic processes and detail a systematic approach using this technique to determine the etiology of cardiomyopathy. PMID:19564013

Serial cardiac MRIs in adult Fontan patients detect progressive hepatic enlargement and congestion.

PubMed

Lewis, Matthew J; Hecht, Elizabeth; Ginns, Jonathan; Benton, Joshua; Prince, Martin; Rosenbaum, Marlon S

2017-03-01

The progression of hepatic disease in adult Fontan patients is not well understood. They reviewed the experience with serial cardiac MRIs (CMR) in adult Fontan patients to determine if hepatic anatomic markers of prolonged Fontan exposure were present and if clinical predictors of progressive hepatic congestion could be identified. A retrospective cohort study of all adult Fontan patients who had undergone at least two CMRs was performed. Hepatic dimensions, inferior vena cava (IVC) size, right hepatic vein (RHV) size and spleen diameter were determined from images acquired at the time of clinically guided CMR. Two radiologists with expertise in hepatic imaging graded congestion and liver size independently using post-gadolinium contrast sequences. Twenty-seven patients met inclusion criteria. Over a mean time of 5.1 years between CMRs, there was a significant increase in mean lateral-medial hepatic dimension (P = .005), mean RHV diameter (P = .004), and mean splenic diameter (P = .001). Serial post-gadolinium imaging was available in 25/27 (93%) patients of which 15/27 (55%) showed evidence of progressive hepatic congestion across serial studies. Progressive hepatic congestion was associated with single ventricle ejection fraction (SVEF) less than 50% (P = .008), and larger indexed end-diastolic (EDVI) and end-systolic volume (ESVI). RHV diameter was the only anatomic variable significantly correlated with time from Fontan completion (P = .004). Serial CMRs detected progressive liver and hepatic vein enlargement in our cohort of adult Fontan patients over a mean time of 5.2 years. Progressive hepatic congestion occurs in a significant number of adult Fontan patients and may be associated with ventricular enlargement and decreased ventricular function by CMR. © 2016 Wiley Periodicals, Inc.

Contrast-enhanced magnetic resonance angiography: first-pass arterial enhancement as a function of gadolinium-chelate concentration, and the saline chaser volume and injection rate.

PubMed

Husarik, Daniela B; Bashir, Mustafa R; Weber, Paul W; Nichols, Eli B; Howle, Laurens E; Merkle, Elmar M; Nelson, Rendon C

2012-02-01

To evaluate the effect of the contrast medium (CM) concentration and the saline chaser volume and injection rate on first-pass aortic enhancement characteristics in contrast-enhanced magnetic resonance angiography using a physiologic flow phantom. Imaging was performed on a 3.0-T magnetic resonance system (MAGNETOM Trio, Siemens Healthcare Solutions, Inc, Erlangen, Germany) using a 2-dimensional fast low angle shot T1-weighted sequence (repetition time, 500 milliseconds; echo time, 1.23 milliseconds; flip angle, 8 degrees; 1 frame/s × 60 seconds). The following CM concentrations injected at 2 mL/s were used with 3 different contrast agents (gadolinium [Gd]-BOPTA, Gd-HP-DO3A, Gd-DTPA): 20 mL of undiluted CM (100%) and 80%, 40%, 20%, 10%, 5%, and 2.5% of the full amount, all diluted in saline to a volume of 20 mL to ensure equal bolus volume. The CM was followed by saline chasers of 20 to 60 mL injected at 2 mL/s and 6 mL/s. Aortic signal intensity (SI) was measured, and normalized SI versus time (SI/Tn) curves were generated. The maximal SI (SI(max)), bolus length, and areas under the SI/Tn curve were calculated. Decreasing the CM concentration from 100% to 40% resulted in a decrease of SI(max) to 86.1% (mean). Further decreasing the CM concentration to 2.5% decreased SI(max) to 5.1% (mean). Altering the saline chaser volume had no significant effect on SI(max). Increasing the saline chaser injection rate had little effect (mean increase, 2.2%) on SI(max) when using ≥40% of CM. There was a larger effect (mean increase, 19.6%) when ≤20% of CM were used. Bolus time length was significantly shorter (P < 0.001), and area under the SI/T(n) curve was significantly smaller (P < 0.01) for the CM protocols followed by a saline chaser injected at 6 mL/s compared with a saline chaser injected at 2 mL/s. With 40% of CM and a fast saline chaser, SImax close to that with undiluted CM can be achieved. An increased saline chaser injection rate has a more pronounced effect on

Improved dark blood late gadolinium enhancement (DB-LGE) imaging using an optimized joint inversion preparation and T2 magnetization preparation.

PubMed

Basha, Tamer A; Tang, Maxine C; Tsao, Connie; Tschabrunn, Cory M; Anter, Elad; Manning, Warren J; Nezafat, Reza

2018-01-01

To develop a dark blood-late gadolinium enhancement (DB-LGE) sequence that improves scar-blood contrast and delineation of scar region. The DB-LGE sequence uses an inversion pulse followed by T 2 magnetization preparation to suppress blood and normal myocardium. Time delays inserted after preparation pulses and T 2 -magnetization-prep duration are used to adjust tissue contrast. Selection of these parameters was optimized using numerical simulations and phantom experiments. We evaluated DB-LGE in 9 swine and 42 patients (56 ± 14 years, 33 male). Improvement in scar-blood contrast and overall image quality was subjectively evaluated by two independent readers (1 = poor, 4 = excellent). The signal ratios among scar, blood, and myocardium were compared. Simulations and phantom studies demonstrated that simultaneous nulling of myocardium and blood can be achieved by selecting appropriate timing parameters. The scar-blood contrast score was significantly higher for DB-LGE (P < 0.001) with no significant difference in overall image quality (P > 0.05). Scar-blood signal ratios for DB-LGE versus LGE were 5.0 ± 2.8 versus 1.5 ± 0.5 (P < 0.001) for patients, and 2.2 ± 0.7 versus 1.0 ± 0.4 (P = 0.0023) for animals. Scar-myocardium signal ratios were 5.7 ± 2.9 versus 6.3 ± 2.6 (P = 0.35) for patients, and 3.7 ± 1.1 versus 4.1 ± 2.0 (P = 0.60) for swine. The DB-LGE sequence simultaneously reduces normal myocardium and blood signal intensity, thereby enhancing scar-blood contrast while preserving scar-myocardium contrast. Magn Reson Med 79:351-360, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Measurement of gamma-ray production from thermal neutron capture on gadolinium for neutrino experiments

NASA Astrophysics Data System (ADS)

Yano, Takatomi; 2012B0025 Collaboration; 2014B0126 Collaboration

2017-02-01

Recently, several scientific applications of gadolinium are found in neutrino physics experiments. Gadolinium-157 is the nucleus, which has the largest thermal neutron capture cross-section among all stable nuclei. Gadolinium-155 also has the large cross-section. These neutron capture reactions provide the gamma-ray cascade with the total energy of about 8 MeV. This reaction is applied for several neutrino experiments, e.g. reactor neutrino experiments and Gd doped large water Cherenkov detector experiments, to recognize inverse-beta-decay reaction. A good Gd(n,γ) simulation model is needed to evaluate the detection efficiency of the neutron capture reaction, i.e. the efficiency of IBD detection. In this presentation, we will report the development and study status of a Gd(n,γ) calculation model and comparison with our experimental data taken at ANNRI/MLF beam line, J-PARC.

Critical Questions Regarding Gadolinium Deposition in the Brain and Body After Injections of the Gadolinium-Based Contrast Agents, Safety, and Clinical Recommendations in Consideration of the EMA's Pharmacovigilance and Risk Assessment Committee Recommendation for Suspension of the Marketing Authorizations for 4 Linear Agents.

PubMed

Runge, Val M

2017-06-01

For magnetic resonance, the established class of intravenous contrast media is the gadolinium-based contrast agents. In the 3 decades since initial approval, these have proven in general to be very safe for human administration. However, in 2006, a devastating late adverse reaction to administration of the less stable gadolinium-based contrast agents was identified, nephrogenic systemic fibrosis. The result of actions taken by the European Medicines Agency and the US Food and Drug Administration, stratifying the agents by risk and contraindicating specific agents in severe renal dysfunction, has led to no new cases being identified in North America or Europe. Subsequently, in 2014, long-term deposition in the brain of gadolinium was first shown, after administration of 2 nonionic linear chelates, gadodiamide, and gadopentetate dimeglumine. This has led to an intense focus on the question of in vivo distribution, possible dechelation, and subsequent deposition of gadolinium, together with substantial clarification of the phenomenon as well as stratification of the agents on this basis. This review focuses on 8 critical questions regarding gadolinium deposition in the brain and body, with the answers and discussion therein important for future regulatory decisions and clinical practice. It is now clear that dechelation of gadolinium occurs in vivo with the linear agents and is responsible for this phenomenon, with key experts in the field recommending, except where there is no suitable alternative, a shift in clinical practice from the linear to macrocyclic agents. In addition, on March 10, 2017, the Pharmacovigilance and Risk Assessment Committee of the European Medicines Agency recommended suspension of the marketing authorization for 4 linear gadolinium contrast agents-specifically Omniscan, Optimark, Magnevist, and MultiHance (gadodiamide, gadoversetamide, gadopentetate dimeglumine, and gadobenate dimeglumine)-for intravenous injection. Cited in the report was

Type-II domains in ferroelectric gadolinium molybdate (in German)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bohm, J.; Kuersten, H.D.

Etching (001)-faces of gadolinium molybdate (GMO) reveals new kinds of domains. They are created by a translation, that leaves the spontaneous polarization and the transition parameter invariant. The translation vector is a part of a lattice vector, similar to stacking faults. (auth)

The Effect of Pressure and Temperature on Separation of Free Gadolinium(III) From Gd-DTPA Complex by Nanofiltration-Complexation Method

NASA Astrophysics Data System (ADS)

Rahayu, Iman; Anggraeni, Anni; Ukun, MSS; Bahti, Husein H.

2017-05-01

Nowdays, the utilization of rare earth elements has been carried out widely in industry and medicine, one of them is gadolinium in Gd-DTPA complex is used as a contrast agent in a magnetic resonance imaging (MRI) diagnostic to increase the visual contrast between normal tissue and diseased. Although the stability of a given complex may be high enough, the complexation step couldnot have been completed, so there is possible to gadolinium(III) in the complex compound. Therefore, the function of that compounds should be dangerous because of the toxicity of gadolinium(III) in human body. So, it is necessarry to separate free gadolinium(III) from Gd-DTPA complex by nanofiltration-complexation. The method of this study is complexing of Gd2O3 with DTPA ligand by reflux and separation of Gd-DTPA complex from gadolinium(III) with a nanofiltration membrane on the variation of pressures(2, 3, 4, 5, 6 bars) and temperature (25, 30, 35, 40 °C) and determined the flux and rejection. The results of this study are the higher of pressures and temperatures, permeation flux are increasing and ion rejections are decreasing and gave the free gadolinium(III) rejection until 86.26%.

Use of a 3-Telsa magnet to perform delayed gadolinium-enhanced magnetic resonance imaging of the distal interphalangeal joint of horses with and without naturally occurring osteoarthritis.

PubMed

Bischofberger, Andrea S; Fürst, Anton E; Torgerson, Paul R; Carstens, Ann; Hilbe, Monika; Kircher, Patrick

2018-03-01

OBJECTIVE To characterize delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) features of healthy hyaline cartilage of the distal interphalangeal joint (DIPJ) of horses, to determine whether dGEMRIC can be used to differentiate various stages of naturally occurring osteoarthritis of the DIPJ, and to correlate relaxation times determined by dGEMRIC with the glycosaminoglycan concentration, water content, and macroscopic and histologic findings of hyaline cartilage of DIPJs with and without osteoarthritis. SAMPLE 1 cadaveric forelimb DIPJ from each of 12 adult warmblood horses. PROCEDURES T1-weighted cartilage relaxation times were obtained for predetermined sites of the DIPJ before (T1 preGd ) and after (T1 postGd ) intra-articular gadolinium administration. Corresponding cartilage sites underwent macroscopic, histologic, and immunohistochemical evaluation, and cartilage glycosaminoglycan concentration and water content were determined. Median T1 preGd and T1 postGd were correlated with macroscopic, histologic, and biochemical data. Mixed generalized linear models were created to evaluate the effects of cartilage site, articular surface, and macroscopic and histologic scores on relaxation times. RESULTS 122 cartilage specimens were analyzed. Median T1 postGd was lower than the median T1 preGd for normal and diseased cartilage. Both T1 preGd and T1 postGd were correlated with macroscopic and histologic scores, whereby T1 preGd increased and T1 postGd decreased as osteoarthritis progressed. There was topographic variation of T1 preGd and T1 postGd within the DIPJ. Cartilage glycosaminoglycan concentration and water content were significantly correlated with T1 preGd and macroscopic and histologic scores but were not correlated with T1 postGd . CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that dGEMRIC relaxation times varied for DIPJs with various degrees of osteoarthritis. These findings may help facilitate early detection of osteoarthritis.

A tight binding model study of tunneling conductance spectra of spin and orbitally ordered CMR manganites

NASA Astrophysics Data System (ADS)

Panda, Saswati; Sahoo, D. D.; Rout, G. C.

2018-04-01

We report here a tight binding model for colossal magnetoresistive (CMR) manganites to study the pseudo gap (PG) behavior near Fermi level. In the Kubo-Ohata type DE model, we consider first and second nearest neighbor interactions for transverse spin fluctuations in core band and hopping integrals in conduction band, in the presence of static band Jahn-Teller distortion. The model Hamiltonian is solved using Zubarev's Green's function technique. The electron density of states (DOS) is found out from the Green's functions. We observe clear PG near Fermi level in the electron DOS.

Biocompatible Polyhydroxyethylaspartamide-based Micelles with Gadolinium for MRI Contrast Agents

PubMed Central

2010-01-01

Biocompatible poly-[N-(2-hydroxyethyl)-d,l-aspartamide]-methoxypoly(ethyleneglycol)-hexadecylamine (PHEA-mPEG-C16) conjugated with 1,4,7,10-tetraazacyclododecan-1,4,7,10-tetraacetic acid-gadolinium (DOTA-Gd) via ethylenediamine (ED) was synthesized as a magnetic resonance imaging (MRI) contrast agent. Amphiphilic PHEA-mPEG-C16-ED-DOTA-Gd forms micelle in aqueous solution. All the synthesized materials were characterized by proton nuclear magnetic resonance (1H NMR). Micelle size and shape were examined by dynamic light scattering (DLS) and atomic force microscopy (AFM). Micelles with PHEA-mPEG-C16-ED-DOTA-Gd showed higher relaxivities than the commercially available gadolinium contrast agent. Moreover, the signal intensity of a rabbit liver was effectively increased after intravenous injection of PHEA-mPEG-C16-ED-DOTA-Gd. PMID:21170410

Biocompatible Polyhydroxyethylaspartamide-based Micelles with Gadolinium for MRI Contrast Agents

NASA Astrophysics Data System (ADS)

Jeong, Sang Young; Kim, Hyo Jeong; Kwak, Byung-Kook; Lee, Ha-Young; Seong, Hasoo; Shin, Byung Cheol; Yuk, Soon Hong; Hwang, Sung-Joo; Cho, Sun Hang

2010-12-01

Biocompatible poly-[ N-(2-hydroxyethyl)- d, l-aspartamide]-methoxypoly(ethyleneglycol)-hexadecylamine (PHEA-mPEG-C16) conjugated with 1,4,7,10-tetraazacyclododecan-1,4,7,10-tetraacetic acid-gadolinium (DOTA-Gd) via ethylenediamine (ED) was synthesized as a magnetic resonance imaging (MRI) contrast agent. Amphiphilic PHEA-mPEG-C16-ED-DOTA-Gd forms micelle in aqueous solution. All the synthesized materials were characterized by proton nuclear magnetic resonance (1H NMR). Micelle size and shape were examined by dynamic light scattering (DLS) and atomic force microscopy (AFM). Micelles with PHEA-mPEG-C16-ED-DOTA-Gd showed higher relaxivities than the commercially available gadolinium contrast agent. Moreover, the signal intensity of a rabbit liver was effectively increased after intravenous injection of PHEA-mPEG-C16-ED-DOTA-Gd.

Electron magnetic resonance investigation of gadolinium diffusion in zircon powders

NASA Astrophysics Data System (ADS)

de Biasi, R. S.; Grillo, M. L. N.

2011-11-01

The electron magnetic resonance (EMR) technique was used to investigate the diffusion of gadolinium in zircon (ZrSiO4) powders. The EMR absorption intensity was measured for several annealing times and three different temperatures of isothermal annealing: 1273, 1323 and 1373 K. The activation energy for diffusion, calculated from the experimental data using a theoretical model based on the Fick equation, was found to be EA=506±5 kJ mol-1. This value is close to the ones for the diffusion of Gd in UO2 and CeO2, but much larger than for the diffusion of gadolinium in a compound with the same crystal structure as zircon, YVO4. This is attributed to a difference in the relative sizes of the ions involved in the diffusion process.

Gadolinium concentration analysis in brain phantom by X-ray fluorescence.

PubMed

Almalki, Musaed; Majid, Samir Abdul; Butler, Philip H; Reinisch, Lou

2010-06-01

We have measured the X-ray fluorescence from gadolinium as a function of concentration and position in tumors of different sizes and shapes in a head phantom. The gadolinium fluorescence was excited with a 36 GBq Am-241 source. The fluorescence signal was detected with a CdTe detector and a multi-channel analyzer. The fluorescence peak was clearly separated from the scattered X-rays. Concentrations of 5.62-78.63 mg/ml of Gd ion were used in 1, 2, and 3 cm diameter spherical tumors and a 2x4 cm oblate spheroid tumor. The data show trends approaching saturation for the highest concentrations, probably due to reabsorption in the tumor. A comparison of X-ray photographic imaging and densitometer measurements to determine concentration is also presented.

Criticality Safety Evaluation for Small Sample Preparation and Non-Destructive Assay (NDA) Operations in Wing 7 Basement of the CMR Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kunkle, Paige Elizabeth; Zhang, Ning

Nuclear Criticality Safety (NCS) has reviewed the fissionable material small sample preparation and NDA operations in Wing 7 Basement of the CMR Facility. This is a Level-1 evaluation conducted in accordance with NCS-AP-004 [Reference 1], formerly NCS-GUIDE-01, and the guidance set forth on use of the Standard Criticality Safety Requirements (SCSRs) [Reference 2]. As stated in Reference 2, the criticality safety evaluation consists of both the SCSR CSED and the SCSR Application CSED. The SCSR CSED is a Level-3 CSED [Reference 3]. This Level-1 CSED is the SCSR Application CSED. This SCSR Application (Level-1) evaluation does not derive controls, itmore » simply applies controls derived from the SCSR CSED (Level-3) for the application of operations conducted here. The controls derived in the SCSR CSED (Level-3) were evaluated via the process described in Section 6.6.5 of SD-130 (also reproduced in Section 4.3.5 of NCS-AP-004 [Reference 1]) and were determined to not meet the requirements for consideration of elevation into the safety basis documentation for CMR. According to the guidance set forth on use of the SCSRs [Reference 2], the SCSR CSED (Level-3) is also applicable to the CMR Facility because the process and the normal and credible abnormal conditions in question are bounded by those that are described in the SCSR CSED. The controls derived in the SCSR CSED include allowances for solid materials and solution operations. Based on the operations conducted at this location, there are less-than-accountable (LTA) amounts of 233U. Based on the evaluation documented herein, the normal and credible abnormal conditions that might arise during the execution of this process will remain subcritical with the following recommended controls.« less

Spectral presaturation inversion recovery MR imaging sequence after gadolinium injection to differentiate fibrotic scar tissue and neoplastic strands in the mesorectal fat in patients undergoing restaging of rectal carcinoma after neoadjuvant chemo- and radiation therapy.

PubMed

Quaia, Emilio; Ulcigrai, Veronica; Coss, Matteo; De Paoli, Luca; Ukmar, Maja; Zanconati, Fabrizio; De Pellegrin, Alessandro; De Manzini, Nicolò; Cova, Maria Assunta

2011-11-01

To retrospectively assess the value of spectral presaturation by inversion-recovery (SPIR) magnetic resonance (MR) imaging sequence after gadolinium injection to differentiate fibrotic scar tissue and tumoral infiltration within the mesorectal fat in patients with rectal carcinoma undergoing MR restaging after neoadjuvant chemo- and radiation therapy (CRT). Forty-three consecutive patients (mean age, 65.8 years; range, 46-85 years; male:female, 29:14) with locally advanced rectal carcinoma underwent CRT followed by surgery. MR imaging was performed before and after completion of CRT by using T2-weighted turbo spin-echo and T1-weighted SPIR sequences before and after gadolinium injection, and MR images were assessed by two radiologists in consensus. Logistic regression was conducted to test the significance of the MR image findings with histology. After CRT the disease was either limited to the rectal wall (n = 18 patients) or presented perirectal infiltration (n = 25) on histology. In 21 patients, mesorectal enhancing strands were observed. Reticular-shaped enhancing strands reaching the mesorectal fascia presented the highest correlation with tumor infiltration of the mesorectal fat (OR 130.33, 95% CI: 4.1-4220.29; logistic regression), whereas linear-shaped enhancing strands either reaching or not reaching the mesorectal fascia (OR 0.25 or 0.1, 95% CI: 0.024-2.6 or 0.01-1.07) revealed the lowest correlation. Reticular-shaped enhancing strands on SPIR MR imaging after gadolinium injection are associated with tumor infiltration of the mesorectal fat. Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.

Infarct characterization using CT

PubMed Central

Toia, Patrizia; Maffei, Erica; Cademartiri, Filippo; Lagalla, Roberto; Midiri, Massimo

2017-01-01

Myocardial infarction (MI) is a major cause of death and disability worldwide. The incidence is not expected to diminish, despite better prevention, diagnosis and treatment, because of the ageing population in industrialized countries and unhealthy lifestyles in developing countries. Nowadays it is highly requested an imaging tool able to evaluate MI and viability. Technology improvements determined an expansion of clinical indications from coronary plaque evaluation to functional applications (perfusion, ischemia and viability after MI) integrating additional phases and information in the mainstream examination. Cardiac computed tomography (CCT) and cardiac MR (CMR) employ different contrast media, but may characterize MI with overlapping imaging findings due to the similar kinetics and tissue distribution of gadolinium and iodinated contrast media. CCT may detect first-pass perfusion defects, dynamic perfusion after pharmacological stress, and delayed enhancement (DE) of non-viable territories. PMID:28540212

Multifunctional gadolinium-based dendritic macromolecules as liver targeting imaging probes.

PubMed

Luo, Kui; Liu, Gang; He, Bin; Wu, Yao; Gong, Qingyong; Song, Bin; Ai, Hua; Gu, Zhongwei

2011-04-01

The quest for highly efficient and safe contrast agents has become the key factor for successful application of magnetic resonance imaging (MRI). The gadolinium (Gd) based dendritic macromolecules, with precise and tunable nanoscopic sizes, are excellent candidates as multivalent MRI probes. In this paper, a novel series of Gd-based multifunctional peptide dendritic probes (generation 2, 3, and 4) possessing highly controlled structures and single molecular weight were designed and prepared as liver MRI probes. These macromolecular Gd-ligand agents exhibited up to 3-fold increase in T(1) relaxivity comparing to Gd-DTPA complexes. No obvious in vitro cytotoxicity was observed from the measured concentrations. These dendritic probes were further functionalized with multiple galactosyl moieties and led to much higher cell uptake in vitro as demonstrated in T(1)-weighted scans. During in vivo animal studies, the probes provided better signal intensity (SI) enhancement in mouse liver, especially at 60 min post-injection, with the most efficient enhancement from the galactosyl moiety decorated third generation dendrimer. The imaging results were verified with analysis of Gd content in liver tissues. The design strategy of multifunctional Gd-ligand peptide dendritic macromolecules in this study may be used for developing other sensitive MRI probes with targeting capability. Copyright © 2011 Elsevier Ltd. All rights reserved.

Acute side effects of three commonly used gadolinium contrast agents in the paediatric population.

PubMed

Neeley, Chris; Moritz, Michael; Brown, Jeffrey J; Zhou, Yihua

2016-07-01

To determine the incidence of acute side effects of three commonly used gadolinium contrast agents in the paediatric population. A retrospective review of medical records was performed to determine the incidence of acute adverse side effects of i.v. gadolinium contrast agents [MultiHance(®) (Bracco Diagnostics Inc., Princeton, NJ), Magnevist(®) (Bayer Healthcare Pharmaceuticals, Wayne, NJ) or Gadavist(®) (Bayer HealthCare Pharmaceuticals)] in paediatric patients. 40 of the 2393 patients who received gadolinium contrast agents experienced acute side effects, representing an incidence of 1.7%. The majority of the acute side effects (in 30 patients) were nausea and vomiting. The incidence was significantly higher in non-sedated patients (2.37% vs 0.7%; p = 0.0018). Furthermore, without sedation, the incidence of both nausea and vomiting was significantly higher in children receiving MultiHance, with a 4.48% incidence of nausea when compared with Magnevist (0.33%, p < 0.0001) and Gadavist (0.28%, p < 0.0001) and a 2.36% incidence of vomiting compared with those for Magnevist (0.50%, p = 0.0054) and Gadavist (0.28%, p = 0.014), whereas no difference was observed between Magnevist and Gadavist within the power of the study. In addition, there was no apparent difference between any of the three contrast agents for the incidence of allergy or other acute side effects detected, given the sample size. The gadolinium contrast agents MultiHance, Magnevist and Gadavist have a low incidence of acute side effects in the paediatric population, a rate that is further reduced in moderately sedated patients. MultiHance demonstrated significantly increased incidence of gastrointestinal symptoms compared with Magnevist and Gadavist. The incidence of acute side effects of three commonly used gadolinium contrast agents was determined in the paediatric population, which can have clinical implications.

Layered gadolinium hydroxides for low-temperature magnetic cooling.

PubMed

Abellán, Gonzalo; Espallargas, Guillermo Mínguez; Lorusso, Giulia; Evangelisti, Marco; Coronado, Eugenio

2015-09-28

Layered gadolinium hydroxides have revealed to be excellent candidates for cryogenic magnetic refrigeration. These materials behave as pure 2D magnetic systems with a Heisenberg-Ising critical crossover, induced by dipolar interactions. This 2D character and the possibility offered by these materials to be delaminated open the possibility of rapid heat dissipation upon substrate deposition.

Gadolinium-148 and other spallation production cross section measurements for accelerator target facilities

NASA Astrophysics Data System (ADS)

Kelley, Karen Corzine

At the Los Alamos Neutron Science Center accelerator complex, protons are accelerated to 800 MeV and directed to two tungsten targets, Target 4 at the Weapons Neutron Research facility and the 1L target at the Lujan Center. The Department of Energy requires hazard classification analyses to be performed on these targets and places limits on certain radionuclide inventories in the targets to avoid characterizing the facilities as "nuclear facilities." Gadolinium-148 is a radionuclide created from the spallation of tungsten. Allowed isotopic inventories are particularly low for this isotope because it is an alpha-particle emitter with a 75-year half-life. The activity level of Gadolinium-148 is low, but it encompasses almost two-thirds of the total dose burden for the two tungsten targets based on present yield estimates. From a hazard classification standpoint, this severely limits the lifetime of these tungsten targets. The cross section is not well-established experimentally and this is the motivation for measuring the Gadolinium-148 production cross section from tungsten. In a series of experiments at the Weapons Neutron Research facility, Gadolinium-148 production was measured for 600- and 800-MeV protons on tungsten, tantalum, and gold. These experiments used 3 mum thin tungsten, tantalum, and gold foils and 10 mum thin aluminum activation foils. In addition, spallation yields were determined for many short-lived and long-lived spallation products with these foils using gamma and alpha spectroscopy and compared with predictions of the Los Alamos National Laboratory codes CEM2k+GEM2 and MCNPX. The cumulative Gadolinium-148 production cross section measured from tantalum, tungsten, and gold for incident 600-MeV protons were 15.2 +/- 4.0, 8.31 +/- 0.92, and 0.591 +/- 0.155, respectively. The average production cross sections measured at 800 MeV were 28.6 +/- 3.5, 19.4 +/- 1.8, and 3.69 +/- 0.50 for tantalum, tungsten, and gold, respectively. These cumulative

High Spatial Resolution Cardiovascular Magnetic Resonance at 7.0 Tesla in Patients with Hypertrophic Cardiomyopathy - First Experiences: Lesson Learned from 7.0 Tesla.

PubMed

Prothmann, Marcel; von Knobelsdorff-Brenkenhoff, Florian; Töpper, Agnieszka; Dieringer, Matthias A; Shahid, Etham; Graessl, Andreas; Rieger, Jan; Lysiak, Darius; Thalhammer, C; Huelnhagen, Till; Kellman, Peter; Niendorf, Thoralf; Schulz-Menger, Jeanette

2016-01-01

Cardiovascular Magnetic Resonance (CMR) provides valuable information in patients with hypertrophic cardiomyopathy (HCM) based on myocardial tissue differentiation and the detection of small morphological details. CMR at 7.0T improves spatial resolution versus today's clinical protocols. This capability is as yet untapped in HCM patients. We aimed to examine the feasibility of CMR at 7.0T in HCM patients and to demonstrate its capability for the visualization of subtle morphological details. We screened 131 patients with HCM. 13 patients (9 males, 56 ±31 years) and 13 healthy age- and gender-matched subjects (9 males, 55 ±31years) underwent CMR at 7.0T and 3.0T (Siemens, Erlangen, Germany). For the assessment of cardiac function and morphology, 2D CINE imaging was performed (voxel size at 7.0T: (1.4x1.4x2.5) mm3 and (1.4x1.4x4.0) mm3; at 3.0T: (1.8x1.8x6.0) mm3). Late gadolinium enhancement (LGE) was performed at 3.0T for detection of fibrosis. All scans were successful and evaluable. At 3.0T, quantification of the left ventricle (LV) showed similar results in short axis view vs. the biplane approach (LVEDV, LVESV, LVMASS, LVEF) (p = 0.286; p = 0.534; p = 0.155; p = 0.131). The LV-parameters obtained at 7.0T where in accordance with the 3.0T data (pLVEDV = 0.110; pLVESV = 0.091; pLVMASS = 0.131; pLVEF = 0.182). LGE was detectable in 12/13 (92%) of the HCM patients. High spatial resolution CINE imaging at 7.0T revealed hyperintense regions, identifying myocardial crypts in 7/13 (54%) of the HCM patients. All crypts were located in the LGE-positive regions. The crypts were not detectable at 3.0T using a clinical protocol. CMR at 7.0T is feasible in patients with HCM. High spatial resolution gradient echo 2D CINE imaging at 7.0T allowed the detection of subtle morphological details in regions of extended hypertrophy and LGE.

Blood-threshold CMR volume analysis of functional univentricular heart.

PubMed

Secchi, Francesco; Alì, Marco; Petrini, Marcello; Pluchinotta, Francesca Romana; Cozzi, Andrea; Carminati, Mario; Sardanelli, Francesco

2018-05-01

To validate a blood-threshold (BT) segmentation software for cardiac magnetic resonance (CMR) cine images in patients with functional univentricular heart (FUH). We evaluated retrospectively 44 FUH patients aged 25 ± 8 years (mean ± standard deviation). For each patient, the epicardial contour of the single ventricle was manually segmented on cine images by two readers and an automated BT algorithm was independently applied to calculate end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and cardiac mass (CM). Aortic flow analysis (AFA) was performed on through-plane images to obtain forward volumes and used as a benchmark. Reproducibility was tested in a subgroup of 24 randomly selected patients. Wilcoxon, Spearman, and Bland-Altman statistics were used. No significant difference was found between SV (median 57.7 ml; interquartile range 47.9-75.6) and aortic forward flow (57.4 ml; 48.9-80.4) (p = 0.123), with a high correlation (r = 0.789, p < 0.001). Intra-reader reproducibility was 86% for SV segmentation, and 96% for AFA. Inter-reader reproducibility was 85 and 96%, respectively. The BT segmentation provided an accurate and reproducible assessment of heart function in FUH patients.

Solid solutions of gadolinium doped zinc oxide nanorods by combined microwave-ultrasonic irradiation assisted crystallization

NASA Astrophysics Data System (ADS)

Kiani, Armin; Dastafkan, Kamran; Obeydavi, Ali; Rahimi, Mohammad

2017-12-01

Nanocrystalline solid solutions consisting of un-doped and gadolinium doped zinc oxide nanorods were fabricated by a modified sol-gel process utilizing combined ultrasonic-microwave irradiations. Polyvinylpyrrolidone, diethylene glycol, and triethylenetetramine respectively as capping, structure directing, and complexing agents were used under ultrasound dynamic aging and microwave heating to obtain crystalline nanorods. Crystalline phase monitoring, lattice parameters and variation, morphology and shape, elemental analysis, functional groups, reducibility, and the oxidation state of emerged species were examined by PXRD, FESEM, TEM, EDX, FTIR, micro Raman, H2-TPR, and EPR techniques. Results have verified that irradiation mechanism of gelation and crystallization reduces the reaction time, augments the crystal quality, and formation of hexagonal close pack structure of Wurtzite morphology. Besides, dissolution of gadolinium within host lattice involves lattice deformation, unit cell distortion, and angular position variation. Structure related shape and growth along with compositional purity were observed through microscopic and spectroscopic surveys. Furthermore, TPR and EPR studies elucidated more detailed behavior upon exposure to the exerted irradiations and subsequent air-annealing including the formed oxidation states and electron trapping centers, presence of gadolinium, zinc, and oxygen disarrays and defects, as well as alteration in the host unit cell via gadolinium addition.

The network formers role of gadolinium(III) ions in some zinc-borate glass ceramics

NASA Astrophysics Data System (ADS)

Bosca, Maria; Pop, Lidia; Pascuta, Petru

2017-12-01

EPR and magnetic susceptibility measurements were performed on glass ceramics from the (Gd2O3)x.(B2O3)(60-x).(ZnO)40 system, with 0 ≤ x ≤ 15 mol%, in order to determine the role of gadolinium ions on structural and magnetic properties. At low Gd2O3 contents (x ≤ 1 mol%) the EPR spectra show four resonance lines with effective g-values of ˜ 6, 4.8, 2.8 and 2, typical for Gd3+ ions uniformly distributed in the glass and glass ceramic samples. For higher contents of gadolinium ions (x ≥ 3 mol%) the EPR spectra are dominated by a single broad line centered at g ˜ 2, which can be due to the magnetic clusters containing Gd3+ ions. The magnetic susceptibility data show that the gadolinium ions are involved in superexchange interactions in all the investigated glass ceramics, being antiferromagnetically coupled.

Role of MRI and added value of diffusion-weighted and gadolinium-enhanced MRI for the diagnosis of local recurrence from rectal cancer.

PubMed

Molinelli, Valeria; Angeretti, Maria Gloria; Duka, Ejona; Tarallo, Nicola; Bracchi, Elena; Novario, Raffaele; Fugazzola, Carlo

2018-03-14

To evaluate whether the addition of gadolinium-enhanced MRI and diffusion-weighted imaging (DWI) improves T2 sequence performance for the diagnosis of local recurrence (LR) from rectal cancer and to assess which approach is better at formulating this diagnosis among readers with different experience. Forty-three patients with suspected LR underwent pelvic MRI with T2 weighted (T2) sequences, gadolinium fat-suppressed T1 weighted sequences (post-contrast T1), and DWI sequences. Three readers (expert: G, intermediate: E, resident: V) scored the likelihood of LR on T2, T2 + post-contrast T1, T2 + DWI, and T2 + post-contrast T1 + DWI. In total, 18/43 patients had LR; on T2 images, the expert reader achieved an area under the ROC curve (AUC) of 0.916, sensitivity of 88.9%, and specificity of 76%; the intermediate reader achieved values of 0.890, 88.9%, and 48%, respectively, and the resident achieved values of 0.852, 88.9%, and 48%, respectively. DWI significantly improved the AUC value for the expert radiologist by up to 0.999 (p = 0.04), while post-contrast T1 significantly improved the AUC for the resident by up to 0.950 (p = 0.04). For the intermediate reader, both the T2 + DWI AUC and T2 + post-contrast T1 AUC were better than the T2 AUC (0.976 and 0.980, respectively), but with no statistically significant difference. No statistically significant difference was achieved by any of the three readers by comparing either the T2 + DWI AUCs to the T2 + post-contrast T1 AUCs or the AUCs of the two pairs of sequences to those of the combined three sequences. Furthermore, using the T2 sequences alone, all of the readers achieved a fair number of "equivocal" cases: they decreased with the addition of either DWI or post-contrast T1 sequences and, for the two less experienced readers, they decreased even more with the three combined sequences. Both DWI and T1 post-contrast MRI increased diagnostic performance for LR diagnosis compared to T2; however, no

Sensitive and transportable gadolinium-core plastic scintillator sphere for neutron detection and counting

NASA Astrophysics Data System (ADS)

Dumazert, Jonathan; Coulon, Romain; Carrel, Frédérick; Corre, Gwenolé; Normand, Stéphane; Méchin, Laurence; Hamel, Matthieu

2016-08-01

Neutron detection forms a critical branch of nuclear-related issues, currently driven by the search for competitive alternative technologies to neutron counters based on the helium-3 isotope. The deployment of plastic scintillators shows a high potential for efficient detectors, safer and more reliable than liquids, more easily scalable and cost-effective than inorganic. In the meantime, natural gadolinium, through its 155 and mostly 157 isotopes, presents an exceptionally high interaction probability with thermal neutrons. This paper introduces a dual system including a metal gadolinium core inserted at the center of a high-scale plastic scintillator sphere. Incident fast neutrons are thermalized by the scintillator shell and then may be captured with a significant probability by gadolinium 155 and 157 nuclei in the core. The deposition of a sufficient fraction of the capture high-energy prompt gamma signature inside the scintillator shell will then allow discrimination from background radiations by energy threshold, and therefore neutron detection. The scaling of the system with the Monte Carlo MCNPX2.7 code was carried out according to a tradeoff between the moderation of incident fast neutrons and the probability of slow neutron capture by a moderate-cost metal gadolinium core. Based on the parameters extracted from simulation, a first laboratory prototype for the assessment of the detection method principle has been synthetized. The robustness and sensitivity of the neutron detection principle are then assessed by counting measurement experiments. Experimental results confirm the potential for a stable, highly sensitive, transportable and cost-efficient neutron detector and orientate future investigation toward promising axes.

T1 relaxivity of core-encapsulated gadolinium liposomal contrast agents--effect of liposome size and internal gadolinium concentration.

PubMed

Ghaghada, Ketan; Hawley, Catherine; Kawaji, Keigo; Annapragada, Ananth; Mukundan, Srinivasan

2008-10-01

Long circulating core-encapsulated gadolinium (CE-Gd) liposomal nanoparticles that have surface conjugated polyethylene glycol are a promising platform technology for use as blood pool T1-based magnetic resonance (MR) contrast agents. The objective of this study was to investigate the effect of liposome size and internal (core) Gd concentration on the T1 relaxivity of CE-Gd liposomes. Twelve different liposomal formulations were synthesized and characterized, resulting in a size (50, 100, 200, and 400 nm) and core Gd-concentration (200, 350, and 500 mM) "matrix" of test samples. Subsequently, CE-Gd liposomes were diluted in deionized water (four diluted samples) and molar T1 relaxivity (r1) measurements were performed at 2- and 7-T MR field strengths. The r1 of CE-Gd liposomes was inversely related to the liposome size. The largest change in r1 was observed between liposomes that were extruded through 50- and 100-nm filter membranes. At both field strengths, the variation in internal gadolinium concentration did not show any significant correlation (alpha < or = 0.05) with r1. The size of CE-Gd liposomal nanoparticles significantly affects the T1 relaxivity. An inverse relation was observed between liposome size and T1 relaxivity. The T1 relaxivity did not change significantly with core Gd concentration over the measured concentration range.

Magnetization reversal and inverted magnetoresistance of exchange-biased spin valves with a gadolinium layer

NASA Astrophysics Data System (ADS)

Milyaev, M.; Naumova, L.; Chernyshova, T.; Proglyado, V.; Kamensky, I.; Krinitsina, T.; Ryabukhina, M.; Ustinov, V.

2017-03-01

FeMn-based spin valves with a gadolinium layer have been fabricated by magnetron sputtering. The magnetoresistive properties of the spin valves have been investigated at temperatures of 80-293 K. Temperature-induced switching between low- and high-resistance magnetic states has been revealed. Realization of the low- or high-resistance states depends on which magnetic moment dominates in the exchange-coupled Gd/CoFe, of Gd or CoFe. It has been shown that the switching temperature depends on the thickness of the gadolinium layer.

Synthesis of gadolinium doped titanium(IV) oxide and their photocatalytic activity to decrease chemical oxygen demand (COD) value of water pollutants

NASA Astrophysics Data System (ADS)

Eddy, Diana Rakhmawaty; Dwiyanti, Dina; Rahayu, Iman; Hastiawan, Iwan; Bahti, Husein H.

2017-05-01

Pesticides are widely used for the control of plant disease. Unfortunately they are highly toxic to terraneous and aquatic life; this is a particular problem in agricultural areas. TiO2 is widely used for pesticide control because of its photocatalytic activity, but it still has inadequacy in its wide band gap. Alternatively, the wide band gap of TiO2 could be narrowed by modification with rare earth element such as gadolinium, so the photocatalytic activity of TiO2could be significantly enhanced. The purpose of this experiment is to synthesize Gd/TiO2 and its application to reduce COD of water pollutants such as carbosulfan pesticide. This experiment is done by doping gadolinium oxide into titanium tetra isopropoxide by sol-gel method. The crystal structure is characterized by using XRD, shown anatase successfully obtained with the smallest crystallite size is 37.655 nm, indicated optimum calcination time is 4 hours. SEM-EDX result shown morphology of crystal is big aggregates. Photocatalytic activity is tested to carbosulfan pesticide, obtained the COD percent decreases up to 87.88%.

Midregional pro-atrial natriuretic peptide: a novel marker of myocardial fibrosis in patients with hypertrophic cardiomyopathy.

PubMed

Elmas, Elif; Doesch, Christina; Fluechter, Stephan; Freundt, Miriam; Weiss, Christel; Lang, Siegfried; Kälsch, Thorsten; Haghi, Dariush; Papassotiriou, Jana; Kunde, Jan; Schoenberg, Stefan O; Borggrefe, Martin; Papavassiliu, Theano

2011-04-01

We aimed to determine the diagnostic performance of biomarkers in predicting myocardial fibrosis assessed by late gadolinium enhancement (LGE) cardiovascular magnetic resonance imaging (CMR) in patients with hypertrophic cardiomyopathy (HCM). LGE CMR was performed in 40 consecutive patients with HCM. Left and right ventricular parameters, as well as the extent of LGE were determined and correlated to the plasma levels of midregional pro-atrial natriuretic peptide (MR-proANP), midregional pro-adrenomedullin (MR-proADM), carboxy-terminal pro-endothelin-1 (CT-proET-1), carboxy-terminal pro-vasopressin (CT-proAVP), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1) and interleukin-8 (IL-8). Myocardial fibrosis was assumed positive, if CMR indicated LGE. LGE was present in 26 of 40 patients with HCM (65%) with variable extent (mean: 14%, range: 1.3-42%). The extent of LGE was positively associated with MR-proANP (r = 0.4; P = 0.01). No correlations were found between LGE and MR-proADM (r = 0.1; P = 0.5), CT-proET-1 (r = 0.07; P = 0.66), CT-proAVP (r = 0.16; P = 0.3), MMP-9 (r = 0.01; P = 0.9), TIMP-1 (r = 0.02; P = 0.85), and IL-8 (r = 0.02; P = 0.89). After adjustment for confounding factors, MR-proANP was the only independent predictor associated with the presence of LGE (P = 0.007) in multivariate analysis. The area under the ROC curve (AUC) indicated good predictive performance (AUC = 0.882) of MR-proANP with respect to LGE. The odds ratio was 1.268 (95% confidence interval 1.066-1.508). The sensitivity of MR-proANP at a cut-off value of 207 pmol/L was 69%, the specificity 94%, the positive predictive value 90% and the negative predictive value 80%. The results imply that MR-proANP serves as a novel marker of myocardial fibrosis assessed by LGE CMR in patients with HCM.

Cardiac involvement in genotype-positive Fabry disease patients assessed by cardiovascular MR.

PubMed

Kozor, Rebecca; Grieve, Stuart M; Tchan, Michel C; Callaghan, Fraser; Hamilton-Craig, Christian; Denaro, Charles; Moon, James C; Figtree, Gemma A

2016-02-15

Cardiac magnetic resonance (CMR) has the potential to provide early detection of cardiac involvement in Fabry disease. We aimed to gain further insight into this by assessing a cohort of Fabry patients using CMR. Fifty genotype-positive Fabry subjects (age 45±2 years; 50% male) referred for CMR and 39 matched controls (age 40±2 years; 59% male) were recruited. Patients had a mean Mainz severity score index of 15±2 (range 0-46), reflecting an overall mild degree of disease severity. Compared with controls, Fabry subjects had a 34% greater left ventricular mass (LVM) index (82±5 vs 61±2 g/m(2), p=0.001) and had a significantly greater papillary muscle contribution to total LVM (13±1 vs 6±0.5%, p<0.001), even in the absence of left ventricular hypertrophy (LVH). Late gadolinium enhancement (LGE) was present in 15 Fabry subjects (9/21 males and 6/23 females). The most common site for LGE was the basal inferolateral wall (93%, 14/15). There was a positive association between LVM index and LGE. Despite this, there were two males and three females with no LVH that displayed LGE. Of Fabry subjects who were not on enzyme replacement therapy at enrolment (n=28), six were reclassified as having cardiac involvement (four LVH-negative/LGE-positive, one LVH-positive/LGE-positive and one LVH-positive/LGE-negative). CMR was able to detect cardiac involvement in 48% of this Fabry cohort, despite the overall mild disease phenotype of the cohort. Of those not on ERT, 21% were reclassified as having cardiac involvement allowing improved risk stratification and targeting of therapy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Cardiac T1 mapping in congenital heart disease: bolus vs. infusion protocols for measurements of myocardial extracellular volume fraction.

PubMed

Al-Wakeel-Marquard, Nadya; Rastin, Sanaz; Muench, Frédéric; O H-Ici, Darach; Yilmaz, Sevim; Berger, Felix; Kuehne, Titus; Messroghli, Daniel R

2017-12-01

Myocardial extracellular volume fraction (ECV) reflecting diffuse myocardial fibrosis can be measured with T1 mapping cardiovascular magnetic resonance (CMR) before and after the application of a gadolinium-based extracellular contrast agent. The equilibrium between blood and myocardium contrast concentration required for ECV measurements can be obtained with a primed contrast infusion (equilibrium contrast-CMR). We hypothesized that equilibrium can also be achieved with a single contrast bolus to accurately measure diffuse myocardial fibrosis in patients with congenital heart disease (CHD). Healthy controls (n = 17; median age 24.0 years) and patients with CHD (n = 19; 25.0 years) were prospectively enrolled. Using modified Look-Locker inversion recovery T1 mapping before, 15 min after bolus injection, and during constant infusion of gadolinium-DOTA, T1 values were obtained for blood pool and myocardium of the left ventricle (LV), the interventricular septum (IVS), and the right ventricle (RV) in a single midventricular plane in short axis or in transverse orientation. ECV of LV, IVS and RV by bolus-only and bolus-infusion correlated significantly in CHD patients (r = 0.94, 0.95, and 0.74; p < 0.01, respectively) and healthy controls (r = 0.96, 0.89, and 0.64; p < 0.05, respectively). Bland-Altman plots revealed no significant bias between the techniques for any of the analyzed regions. ECV of LV and RV myocardium measured by bolus-only T1 mapping agrees well with bolus-infusion measurements in patients with CHD. The use of a bolus-only approach facilitates the integration of ECV measurements into existing CMR imaging protocols, allowing for assessment of diffuse myocardial fibrosis in CHD in clinical routine.

Gadolinium-based nanoparticles for highly efficient T1-weighted magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Lim, Eun-Kyung; Kang, Byunghoon; Choi, Yuna; Jang, Eunji; Han, Seungmin; Lee, Kwangyeol; Suh, Jin-Suck; Haam, Seungjoo; Huh, Yong-Min

2014-06-01

We developed Pyrene-Gadolinium (Py-Gd) nanoparticles as pH-sensitive magnetic resonance imaging (MRI) contrast agents capable of showing a high-Mr signal in cancer-specific environments, such as acidic conditions. Py-Gd nanoparticles were prepared by coating Py-Gd, which is a complex of gadolinium with pyrenyl molecules, with pyrenyl polyethyleneglycol PEG using a nano-emulsion method. These particles show better longitudinal relaxation time (T1) MR signals in acidic conditions than they do in neutral conditions. Furthermore, the particles exhibit biocompatibility and MR contrast effects in both in vitro and in vivo studies. From these results, we confirm that Py-Gd nanoparticles have the potential to be applied for accurate cancer diagnosis and therapy.

Gadolinium oxide nanoplates with high longitudinal relaxivity for magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Cho, Minjung; Sethi, Richa; Ananta Narayanan, Jeyarama Subramanian; Lee, Seung Soo; Benoit, Denise N.; Taheri, Nasim; Decuzzi, Paolo; Colvin, Vicki L.

2014-10-01

Molecular-based contrast agents for magnetic resonance imaging (MRI) are often characterized by insufficient relaxivity, thus requiring the systemic injection of high doses to induce sufficient contrast enhancement at the target site. In this work, gadolinium oxide (Gd2O3) nanoplates are produced via a thermal decomposition method. The nanoplates have a core diameter varying from 2 to 22 nm, a thickness of 1 to 2 nm and are coated with either an oleic acid bilayer or an octylamine modified poly(acrylic acid) (PAA-OA) polymer layer. For the smaller nanoplates, longitudinal relaxivities (r1) of 7.96 and 47.2 (mM s)-1 were measured at 1.41 T for the oleic acid bilayer and PAA-OA coating, respectively. These values moderately reduce as the size of the Gd2O3 nanoplates increases, and are always larger for the PAA-OA coating. Cytotoxicity studies on human dermal fibroblast cells documented no significant toxicity, with 100% cell viability preserved up to 250 μM for the PAA-OA coated Gd2O3 nanoplates. Given the 10 times increase in longitudinal relaxivity over the commercially available Gd-based molecular agents and the favorable toxicity profile, the 2 nm PAA-OA coated Gd2O3 nanoplates could represent a new class of highly effective T1 MRI contrast agents.Molecular-based contrast agents for magnetic resonance imaging (MRI) are often characterized by insufficient relaxivity, thus requiring the systemic injection of high doses to induce sufficient contrast enhancement at the target site. In this work, gadolinium oxide (Gd2O3) nanoplates are produced via a thermal decomposition method. The nanoplates have a core diameter varying from 2 to 22 nm, a thickness of 1 to 2 nm and are coated with either an oleic acid bilayer or an octylamine modified poly(acrylic acid) (PAA-OA) polymer layer. For the smaller nanoplates, longitudinal relaxivities (r1) of 7.96 and 47.2 (mM s)-1 were measured at 1.41 T for the oleic acid bilayer and PAA-OA coating, respectively. These values

Characterization of the reaction products and precipitates at the interface of carbon fiber reinforced magnesium–gadolinium composite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yaping; Jiang, Longtao, E-mail: longtaojiang@163.com; Chen, Guoqin

2016-03-15

In the present work, carbon fiber reinforced magnesium-gadolinium composite was fabricated by pressure infiltration method. The phase composition, micro-morphology, and crystal structure of reaction products and precipitates at the interface of the composite were investigated. Scanning electron microscopy and energy dispersive spectroscopy analysis revealed the segregation of gadolinium element at the interface between carbon fiber and matrix alloy. It was shown that block-shaped Gd4C5, GdC2 and nano-sized Gd2O3 were formed at the interface during the fabrication process due to the interfacial reaction. Furthermore, magnesium-gadolinium precipitates including needle-like Mg5Gd (or Mg24Gd5) and thin plate-shaped long period stacking-ordered phase, were also observedmore » at the interface and in the matrix near the interface. The interfacial microstructure and bonding mode were influenced by these interfacial products, which were beneficial for the improvement of the interfacial bonding strength. - Highlights: • Gadolinium element segregated on the surface of carbon fibers. • Block-shaped Gd{sub 4}C{sub 5} and GdC{sub 2} were formed at the interface via chemical reaction. • Gadolinium and oxygen reacted at the interface and formed nano-scaled Gd{sub 2}O{sub 3}. • The precipitates formed in the interface were identified to be Mg{sub 5}Gd (or Mg{sub 24}Gd{sub 5}) and plate-shaped long period stacking-ordered phase.« less

Compressed sensing for rapid late gadolinium enhanced imaging of the left atrium: A preliminary study.

PubMed

Kamesh Iyer, Srikant; Tasdizen, Tolga; Burgon, Nathan; Kholmovski, Eugene; Marrouche, Nassir; Adluru, Ganesh; DiBella, Edward

2016-09-01

Current late gadolinium enhancement (LGE) imaging of left atrial (LA) scar or fibrosis is relatively slow and requires 5-15min to acquire an undersampled (R=1.7) 3D navigated dataset. The GeneRalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) based parallel imaging method is the current clinical standard for accelerating 3D LGE imaging of the LA and permits an acceleration factor ~R=1.7. Two compressed sensing (CS) methods have been developed to achieve higher acceleration factors: a patch based collaborative filtering technique tested with acceleration factor R~3, and a technique that uses a 3D radial stack-of-stars acquisition pattern (R~1.8) with a 3D total variation constraint. The long reconstruction time of these CS methods makes them unwieldy to use, especially the patch based collaborative filtering technique. In addition, the effect of CS techniques on the quantification of percentage of scar/fibrosis is not known. We sought to develop a practical compressed sensing method for imaging the LA at high acceleration factors. In order to develop a clinically viable method with short reconstruction time, a Split Bregman (SB) reconstruction method with 3D total variation (TV) constraints was developed and implemented. The method was tested on 8 atrial fibrillation patients (4 pre-ablation and 4 post-ablation datasets). Blur metric, normalized mean squared error and peak signal to noise ratio were used as metrics to analyze the quality of the reconstructed images, Quantification of the extent of LGE was performed on the undersampled images and compared with the fully sampled images. Quantification of scar from post-ablation datasets and quantification of fibrosis from pre-ablation datasets showed that acceleration factors up to R~3.5 gave good 3D LGE images of the LA wall, using a 3D TV constraint and constrained SB methods. This corresponds to reducing the scan time by half, compared to currently used GRAPPA methods. Reconstruction of 3D LGE images

Functional valve assessment: the emerging role of cardiovascular magnetic resonance.

PubMed

Shah, Dipan J

2010-01-01

insufficiency are threefold: 1) to provide insight into the mechanism of mitral insufficiency, and 3) to discern the consequences of the lesions including the effects on left ventricular (LV) volume, LV systolic function, and left atrial volumes. In most instances this information can be obtained without the need for intravenous contrast agents (gadolinium). Therefore, CMR can be performed even in patients with severe renal failure.

Simple method for quantification of gadolinium magnetic resonance imaging contrast agents using ESR spectroscopy.

PubMed

Takeshita, Keizo; Kinoshita, Shota; Okazaki, Shoko

2012-01-01

To develop an estimation method of gadolinium magnetic resonance imaging (MRI) contrast agents, the effect of concentration of Gd compounds on the ESR spectrum of nitroxyl radical was examined. A solution of either 4-oxo-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPONE) or 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPOL) was mixed with a solution of Gd compound and the ESR spectrum was recorded. Increased concentration of gadolinium-diethylenetriamine pentaacetic acid chelate (Gd-DTPA), an MRI contrast agent, increased the peak-to-peak line widths of ESR spectra of the nitroxyl radicals, in accordance with a decrease of their signal heights. A linear relationship was observed between concentration of Gd-DTPA and line width of ESR signal, up to approximately 50 mmol/L Gd-DTPA, with a high correlation coefficient. Response of TEMPONE was 1.4-times higher than that of TEMPOL as evaluated from the slopes of the lines. The response was slightly different among Gd compounds; the slopes of calibration curves for acua[N,N-bis[2-[(carboxymethyl)[(methylcarbamoyl)methyl]amino]ethyl]glycinato(3-)]gadolinium hydrate (Gd-DTPA-BMA) (6.22 μT·L/mmol) and gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid chelate (Gd-DOTA) (6.62 μT·L/mmol) were steeper than the slope for Gd-DTPA (5.45 μT·L/mmol), whereas the slope for gadolinium chloride (4.94 μT·L/mmol) was less steep than that for Gd-DTPA. This method is simple to apply. The results indicate that this method is useful for rough estimation of the concentration of Gd contrast agents if calibration is carried out with each standard compound. It was also found that the plot of the reciprocal square root of signal height against concentrations of contrast agents could be useful for the estimation if a constant volume of sample solution is taken and measured at the same position in the ESR cavity every time.

Quantification and significance of diffuse myocardial fibrosis and diastolic dysfunction in childhood hypertrophic cardiomyopathy.

PubMed

Hussain, Tarique; Dragulescu, Andreea; Benson, Lee; Yoo, Shi-Joon; Meng, Howard; Windram, Jonathan; Wong, Derek; Greiser, Andreas; Friedberg, Mark; Mertens, Luc; Seed, Michael; Redington, Andrew; Grosse-Wortmann, Lars

2015-06-01

The purpose of this study was to evaluate the presence of diffuse myocardial fibrosis in children and adolescents with hypertrophic cardiomyopathy (HCM) and to assess associations with echocardiographic and clinical parameters of disease. While a common end point in adults with HCM, it is unclear whether diffuse myocardial fibrosis occurs early in the disease. Cardiac magnetic resonance (CMR) estimation of myocardial post-contrast longitudinal relaxation time (T1) is an increasingly used method to estimate diffuse fibrosis. T1 measurements were taken using standard multi-breath-hold spoiled gradient echo phase-sensitive inversion-recovery CMR before and 15 min after the injection of gadolinium. The tissue-blood partition coefficient was calculated as a function of the ratio of T1 change of myocardium compared with blood. An echocardiogram and blood brain natriuretic peptide (BNP) levels were obtained on the day of the CMR. Twelve controls (mean age 12.8 years; 7 male) and 28 patients with HCM (mean age 12.8 years; 21 male) participated. The partition coefficient for both septal (0.27 ± 0.17 vs. 0.13 ± 0.09; p = 0.03) and lateral walls (0.22 ± 0.09 vs. 0.07 ± 0.10; p < 0.001) was increased in patients compared with controls. Eight patients had overt areas of late gadolinium enhancement (LGE). These patients did not show increased partition coefficient compared with those without LGE (0.27 ± 0.15 vs. 0.27 ± 0.19 and 0.22 ± 0.09 vs. 0.22 ± 0.09; p = 0.95 and 0.98, respectively). However, patients who were symptomatic (dyspnea, arrhythmia and/or chest pain) had higher lateral wall partition coefficient than asymptomatic HCM patients (0.27 ± 0.08 vs. 0.17 ± 0.08; p = 0.006). Similarly, patients with raised BNP (>100 pg/ml) had raised lateral wall coefficients (0.27 ± 0.07 vs. 0.20 ± 0.07; p = 0.03), as did those with traditional risk factors for sudden death (0.27 ± 0.06 vs. 0.18 ± 0.08; p = 0.007). Diffuse fibrosis, measured by the partition coefficient

Cardiovascular magnetic resonance physics for clinicians: part II

PubMed Central

2012-01-01

This is the second of two reviews that is intended to cover the essential aspects of cardiovascular magnetic resonance (CMR) physics in a way that is understandable and relevant to clinicians using CMR in their daily practice. Starting with the basic pulse sequences and contrast mechanisms described in part I, it briefly discusses further approaches to accelerate image acquisition. It then continues by showing in detail how the contrast behaviour of black blood fast spin echo and bright blood cine gradient echo techniques can be modified by adding rf preparation pulses to derive a number of more specialised pulse sequences. The simplest examples described include T2-weighted oedema imaging, fat suppression and myocardial tagging cine pulse sequences. Two further important derivatives of the gradient echo pulse sequence, obtained by adding preparation pulses, are used in combination with the administration of a gadolinium-based contrast agent for myocardial perfusion imaging and the assessment of myocardial tissue viability using a late gadolinium enhancement (LGE) technique. These two imaging techniques are discussed in more detail, outlining the basic principles of each pulse sequence, the practical steps required to achieve the best results in a clinical setting and, in the case of perfusion, explaining some of the factors that influence current approaches to perfusion image analysis. The key principles of contrast-enhanced magnetic resonance angiography (CE-MRA) are also explained in detail, especially focusing on timing of the acquisition following contrast agent bolus administration, and current approaches to achieving time resolved MRA. Alternative MRA techniques that do not require the use of an endogenous contrast agent are summarised, and the specialised pulse sequence used to image the coronary arteries, using respiratory navigator gating, is described in detail. The article concludes by explaining the principle behind phase contrast imaging techniques

Accuracy of Area at Risk Quantification by Cardiac Magnetic Resonance According to the Myocardial Infarction Territory.

PubMed

Fernández-Friera, Leticia; García-Ruiz, José Manuel; García-Álvarez, Ana; Fernández-Jiménez, Rodrigo; Sánchez-González, Javier; Rossello, Xavier; Gómez-Talavera, Sandra; López-Martín, Gonzalo J; Pizarro, Gonzalo; Fuster, Valentín; Ibáñez, Borja

2017-05-01

Area at risk (AAR) quantification is important to evaluate the efficacy of cardioprotective therapies. However, postinfarction AAR assessment could be influenced by the infarcted coronary territory. Our aim was to determine the accuracy of T 2 -weighted short tau triple-inversion recovery (T 2 W-STIR) cardiac magnetic resonance (CMR) imaging for accurate AAR quantification in anterior, lateral, and inferior myocardial infarctions. Acute reperfused myocardial infarction was experimentally induced in 12 pigs, with 40-minute occlusion of the left anterior descending (n = 4), left circumflex (n = 4), and right coronary arteries (n = 4). Perfusion CMR was performed during selective intracoronary gadolinium injection at the coronary occlusion site (in vivo criterion standard) and, additionally, a 7-day CMR, including T 2 W-STIR sequences, was performed. Finally, all animals were sacrificed and underwent postmortem Evans blue staining (classic criterion standard). The concordance between the CMR-based criterion standard and T 2 W-STIR to quantify AAR was high for anterior and inferior infarctions (r = 0.73; P = .001; mean error = 0.50%; limits = -12.68%-13.68% and r = 0.87; P = .001; mean error = -1.5%; limits = -8.0%-5.8%, respectively). Conversely, the correlation for the circumflex territories was poor (r = 0.21, P = .37), showing a higher mean error and wider limits of agreement. A strong correlation between pathology and the CMR-based criterion standard was observed (r = 0.84, P < .001; mean error = 0.91%; limits = -7.55%-9.37%). T 2 W-STIR CMR sequences are accurate to determine the AAR for anterior and inferior infarctions; however, their accuracy for lateral infarctions is poor. These findings may have important implications for the design and interpretation of clinical trials evaluating the effectiveness of cardioprotective therapies. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Measurement of gadolinium retention: current status and review from an applied radiation physics perspective.

PubMed

Gräfe, James L; McNeill, Fiona E

2018-06-28

This article briefly reviews the main measurement techniques for the non-invasive detection of residual gadolinium (Gd) in those exposed to gadolinium-based contrast agents (GBCAs). Approach and Main results: The current status of in vivo Gd measurement is discussed and is put into the context of concerns within the radiology community. The main techniques are based on applied atomic/nuclear medicine utilizing the characteristic atomic and nuclear spectroscopic signature of Gd. The main emission energies are in the 40-200 keV region and require spectroscopic detectors with good energy resolution. The two main techniques, prompt gamma neutron activation analysis and x-ray fluorescence, provide adequate detection limits for in vivo measurement, whilst delivering a low effective radiation dose on the order of a few µSv. Gadolinium is being detected in measureable quantities in people with healthy renal function who have received FDA approved GBCAs. The applied atomic/nuclear medicine techniques discussed in this review will be useful in determining the significance of this retention, and will help on advising future administration protocols.

CMR reference values for left ventricular volumes, mass, and ejection fraction using computer-aided analysis: the Framingham Heart Study.

PubMed

Chuang, Michael L; Gona, Philimon; Hautvast, Gilion L T F; Salton, Carol J; Breeuwer, Marcel; O'Donnell, Christopher J; Manning, Warren J

2014-04-01

To determine sex-specific reference values for left ventricular (LV) volumes, mass, and ejection fraction (EF) in healthy adults using computer-aided analysis and to examine the effect of age on LV parameters. We examined data from 1494 members of the Framingham Heart Study Offspring cohort, obtained using short-axis stack cine SSFP CMR, identified a healthy reference group (without cardiovascular disease, hypertension, or LV wall motion abnormality) and determined sex-specific upper 95th percentile thresholds for LV volumes and mass, and lower 5th percentile thresholds for EF using computer-assisted border detection. In secondary analyses, we stratified participants by age-decade and tested for linear trend across age groups. The reference group comprised 685 adults (423F; 61 ± 9 years). Men had greater LV volumes and mass, before and after indexation to common measures of body size (all P = 0.001). Women had greater EF (73 ± 6 versus 71 ± 6%; P = 0.0002). LV volumes decreased with greater age in both sexes, even after indexation. Indexed LV mass did not vary with age. LV EF and concentricity increased with greater age in both sexes. We present CMR-derived LV reference values. There are significant age and sex differences in LV volumes, EF, and geometry, whereas mass differs between sexes but not age groups. Copyright © 2013 Wiley Periodicals, Inc.

CMR Reference Values for Left Ventricular Volumes, Mass and Ejection Fraction Using Computer-Aided Analysis: The Framingham Heart Study

PubMed Central

Chuang, Michael L.; Gona, Philimon; Hautvast, Gilion L.T.F.; Salton, Carol J.; Breeuwer, Marcel; O’Donnell, Christopher J.; Manning, Warren J.

2013-01-01

Purpose To determine sex-specific reference values for left ventricular (LV) volumes, mass and ejection fraction (EF) in healthy adults using computer-aided analysis and to examine the effect of age on LV parameters. Methods and Methods We examined data from 1494 members of the Framingham Heart Study Offspring cohort, obtained using short-axis stack cine SSFP CMR, identified a healthy reference group (without cardiovascular disease, hypertension, or LV wall motion abnormality) and determined sex-specific upper 95th percentile thresholds for LV volumes and mass, and lower 5th percentile thresholds for EF using computer-assisted border detection. In secondary analyses we stratified participants by age-decade and tested for linear trend across age groups. Results The reference group comprised 685 adults (423F; 61±9 years). Men had greater LV volumes and mass, before and after indexation to common measures of body size (all p<0.001). Women had greater EF (73±6 vs. 71±6%, p=0.0002). LV volumes decreased with greater age in both sexes, even after indexation. Indexed LV mass did not vary with age. LV EF and concentricity increased with greater age in both sexes. Conclusion We present CMR-derived LV reference values. There are significant age and sex differences in LV volumes, EF and geometry, while mass differs between sexes but not age groups. PMID:24123369

Heavy metal staining, a comparative assessment of gadolinium chloride and osmium tetroxide for inner ear labyrinthine contrast enhancement using X-ray microtomography.

PubMed

Wong, Christopher C; Curthoys, Ian S; O'Leary, Stephen J; Jones, Allan S

2013-01-01

The use of both gadolinium chloride (GdCl(3)) and osmium tetroxide (OsO(4)) allowed for the visualization of the membranous labyrinth and other intralabyrinthine structures, at different intensities, as compared with the control sample. This initial comparison shows the advantages of GdCl(3) in radiological assessments and OsO(4) in more detailed anatomical studies and pathways of labyrinthine pathogenesis using X-ray microtomography (microCT). To assess an improved OsO(4) staining protocol and compare the staining affinities against GdCl(3). Guinea pig temporal bones were stained with either GdCl(3) (2% w/v) for 7 days or OsO(4) (2% w/v) for 3 days, and scanned in a microCT system. The post-scanned datasets were then assessed in a 3D rendering program. The enhanced soft tissue contrast as presented in the temporal bones stained with either GdCl(3) or OsO(4) allowed for the membranous labyrinth to be visualized throughout the whole specimen. GdCl(3)-stained specimens presented more defined contours of the bone profile in the radiographs, while OsO(4)-stained specimens provided more anatomical detail of individual intralabyrinthine structures, hence allowing spatial relationships to be visualized with ease in a 3D rendering context and 2D axial slice images.

Revisiting the Pharmacokinetic Profiles of Gadolinium-Based Contrast Agents: Differences in Long-Term Biodistribution and Excretion.

PubMed

Lancelot, Eric

2016-11-01

Gadolinium-based contrast agents (GBCAs) have been used for years for magnetic resonance imaging examinations. Because of their rapid blood clearance, they were considered as very safe products until some of them were shown to induce nephrogenic systemic fibrosis in patients with renal failure and hypersignals on T1-weighted unenhanced brain scans of patients with normal renal function. To date, these adverse effects have been related almost exclusively to the use of low-stability linear agents, which are more prone to release free gadolinium. The aim of the present meta-analysis was to ascertain the existence of a deep compartment for gadolinium storage in the body and to assess whether all the GBCAs present the same toxicokinetic profile. Applying a systematic literature search methodology, all clinical and preclinical studies reporting time-dependent plasma concentrations and renal excretion data of gadolinium were identified and analyzed. Since the individual data were not available, the analysis focused on the average values per groups of subjects or animals, which had received a given GBCA at a given dose. The rate constants of the distribution phase (α), rapid elimination phase (β), and residual excretion phase (γ) of gadolinium were determined in each group from the plasma concentration (Cp) time curves and the relative urinary excretion rate (rER) time curves, taking the 2-hour time point as a reference. Moreover, as bone may represent a reservoir for long-term gadolinium accumulation and slow release into the blood stream, the time curves of the relative concentration in the bone (rCB) of Gd-labeled GBCAs in mice or rats were analyzed taking day 1 concentrations as a reference. The ratio of gadolinium concentrations in the bone marrow (CBM) as compared with the bone (CB) was also calculated. The relative urinary excretion rate (rER) plots revealed a prolonged residual excretion phase of gadolinium in healthy volunteers, consistent with the existence of

The feasibility of in vivo quantification of bone-gadolinium in humans by prompt gamma neutron activation analysis (PGNAA) following gadolinium-based contrast-enhanced MRI

NASA Astrophysics Data System (ADS)

Mostafaei, F.; McNeill, F. E.; Chettle, D. R.; Noseworthy, M. D.; Prestwich, W. V.

2015-11-01

The feasibility of using a 238Pu/Be-based in vivo prompt γ-ray neutron activation analysis (IVNAA) system, previously successfully used for measurements of muscle, for the detection of gadolinium (Gd) in bone was presented. Gd is extensively used in contrast agents in MR imaging. We present phantom measurement data for the measurement of Gd in the tibia. Gd has seven naturally occurring isotopes, of which two have extremely large neutron capture cross sections; 155Gd (14.8% natural abundance (NA), σ= 60,900 barns) and 157Gd (15.65% NA, σ= 254,000 barns). Our previous work focused on muscle but this only informs about the short term kinetics of Gd. We studied the possibility of measuring bone, as it may be a long term storage site for Gd. A human simulating bone phantom set was developed. The phantoms were doped with seven concentrations of Gd of concentrations 0.0, 25, 50, 75, 100, 120 and 150 ppm. Additional elements important for neutron activation analysis, Na, Cl and Ca, were also included to create an overall elemental composition consistent with Reference Man. The overall conclusion is that the potential application of this Pu-Be-based prompt in vivo NAA for the monitoring of the storage and retention of Gd in bone is not feasible.

Diverse patterns of perilymphatic space enhancement in the rat inner ear after intratympanic injection of two different types of gadolinium: a 9.4-tesla magnetic resonance study.

PubMed

Park, Mina; Lee, Ho Sun; Choi, Jun-Jae; Kim, Hyeonjin; Lee, Jun Ho; Oh, Seung Ha; Suh, Myung-Whan

2015-01-01

To compare the quality of perilymphatic enhancement in the rat inner ear after intratympanic injection of two types of gadolinium with a 9.4-tesla micro-MRI. Gadolinium was injected into the middle ear in 6 Sprague-Dawley rats via the transtympanic route. The left ear was injected with Gd-DO3A-butrol first, and then the right ear was injected with Gd-DOTA. MR images of the inner ear were acquired 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, and 4 h after intratympanic (IT) injection using an Agilent MRI system 9.4T/160/AS. The normalized signal intensity was quantitatively analyzed at the scala vestibuli (SV), scala media, and scala tympani (ST) using a Marosis M-view system. Then the normalized signal intensities (SIs) were compared between the two contrast agents. For Gd-DO3A-butrol, the SI was as low as 1.0-1.5 throughout 1-4 h at the SV and ST of the basal turn. The maximum SI was 1.5 ± 0.5 at the SV (2 h) and 1.3 ± 0.5 at the ST (2 h). For Gd-DOTA, the 1-hour postinjection SI at the basal turn was 2.5 ± 0.5 at the SV, 1.6 ± 0.3 at the ST, and 1.2 ± 0.3 at the scala media. In the apical turn, the maximum SI was reached after 2.5 h. The maximum SI in the apical turn was 1.8 ± 0.4 at the SV (3.5 h), 1.8 ± 0.4 at the ST (4 h), and 1.4 ± 0.3 at the scala media (4 h). We were able to clearly visualize and separate the ST and SV using IT Gd and 9.4-tesla micro-MRI. We recommend using Gd-DO3A-butrol over Gd-DOTA and to perform the MRI 2.5 h after using IT Gd in the rat inner ear. © 2015 S. Karger AG, Basel.

Non-Hypervascular Hypointense Hepatic Nodules during the Hepatobiliary Phase of Gadolinium-Ethoxybenzyl-Diethylenetriamine Pentaacetic Acid-Enhanced MRI as a Risk Factor of Intrahepatic Distant Recurrence after Radiofrequency Ablation of Hepatocellular Carcinoma.

PubMed

Iwamoto, Takayuki; Imai, Yasuharu; Igura, Takumi; Kogita, Sachiyo; Sawai, Yoshiyuki; Fukuda, Kazuto; Yamaguchi, Yoshitaka; Matsumoto, Yasushi; Nakahara, Masanori; Morimoto, Osakuni; Ohashi, Hiroshi; Fujita, Norihiko; Kudo, Masatoshi; Takehara, Tetsuo

2017-01-01

Non-hypervascular hypointense hepatic nodules during the hepatobiliary phase of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI have been reported to be associated with intrahepatic distant recurrence (IDR) after hepatectomy or radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). IDR is categorized into hypervascular transformation of non-hypervascular hypointense hepatic nodules and new intrahepatic recurrence. The aim of this study was to evaluate the relationship between non-hypervascular hypointense hepatic nodules on Gd-EOB-DTPA-enhanced MRI and IDR after RFA, focusing on new intrahepatic recurrence. Ninety-one consecutive patients with 115 HCCs undergoing pretreatment Gd-EOB-DTPA-enhanced MRI and RFA for treatment of HCC were enrolled. Of the 91 patients who underwent RFA for HCC, 24 had non-hypervascular hypointense hepatic nodules on pretreatment Gd-EOB-DTPA-enhanced MRI. Recurrences were observed in 15 and 19 patients with and without non-hypervascular hypointense hepatic nodules, respectively. Of the 15 recurrences in patients with non-hypervascular hypointense hepatic nodules, 10 patients had new intrahepatic recurrences. The cumulative incidence of new intrahepatic recurrence was significantly higher in patients with non-hypervascular hypointense hepatic nodules than in those without non-hypervascular hypointense hepatic nodules (p < 0.0001). Multivariate analysis revealed that the presence of non-hypervascular hypointense hepatic nodules and Child-Pugh score were independent risk factors for new intrahepatic recurrence. Non-hypervascular hypointense hepatic nodules during the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI were a useful predictive factor for IDR, particularly for new intrahepatic recurrence, after RFA. © 2017 S. Karger AG, Basel.

Gadolinium prevents high airway pressure-induced permeability increases in isolated rat lungs.

PubMed

Parker, J C; Ivey, C L; Tucker, J A

1998-04-01

To determine the initial signaling event in the vascular permeability increase after high airway pressure injury, we compared groups of lungs ventilated at different peak inflation pressures (PIPs) with (gadolinium group) and without (control group) infusion of 20 microM gadolinium chloride, an inhibitor of endothelial stretch-activated cation channels. Microvascular permeability was assessed by using the capillary filtration coefficient (Kfc), a measure of capillary hydraulic conductivity. Kfc was measured after ventilation for 30-min periods with 7, 20, and 30 cmH2O PIP with 3 cmH2O positive end-expiratory pressure and with 35 cmH2O PIP with 8 cmH2O positive end-expiratory pressure. In control lungs, Kfc increased significantly to 1.8 and 3.7 times baseline after 30 and 35 cmH2O PIP, respectively. In the gadolinium group, Kfc was unchanged from baseline (0.060 +/- 0.010 ml . min-1 . cmH2O-1 . 100 g-1) after any PIP ventilation period. Pulmonary vascular resistance increased significantly from baseline in both groups before the last Kfc measurement but was not different between groups. These results suggest that microvascular permeability is actively modulated by a cellular response to mechanical injury and that stretch-activated cation channels may initiate this response through increases in intracellular calcium concentration.

Gadolinium Ethoxybenzyl Diethylenetriamine Pentaacetic Acid (Gd-EOB-DTPA)-Enhanced Magnetic Resonance Imaging and Multidetector-Row Computed Tomography for the Diagnosis of Hepatocellular Carcinoma: A Systematic Review and Meta-analysis.

PubMed

Ye, Feng; Liu, Jun; Ouyang, Han

2015-08-01

The purpose of this meta-analysis was to compare the diagnostic accuracy of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and multidetector-row computed tomography (MDCT) for hepatocellular carcinoma (HCC).Medline, Cochrane, EMBASE, and Google Scholar databases were searched until July 4, 2014, using combinations of the following terms: gadoxetic acid disodium, Gd-EOB-DTPA, multidetector CT, contrast-enhanced computed tomography, and magnetic resonance imaging. Inclusion criteria were as follows: confirmed diagnosis of primary HCC by histopathological examination of a biopsy specimen; comparative study of MRI using Gd-EOB-DTPA and MDCT for diagnosis of HCC; and studies that provided quantitative outcome data. The pooled sensitivity and specificity of the 2 methods were compared, and diagnostic accuracy was assessed with alternative-free response receiver-operating characteristic analysis.Nine studies were included in the meta-analysis, and a total of 1439 lesions were examined. The pooled sensitivity and specificity for 1.5T MRI were 0.95 and 0.96, respectively, for 3.0T MRI were 0.91 and 0.96, respectively, and for MDCT were 0.74 and 0.93, respectively. The pooled diagnostic odds ratio for 1.5T and 3.0T MRI was 242.96, respectively, and that of MDCT was 33.47. To summarize, Gd-EOB-DTPA-enhanced MRI (1.5T and 3.0T) has better diagnostic accuracy for HCC than MDCT.

Gadolinium-enhanced versus time-of-flight magnetic resonance angiography: what is the benefit of contrast enhancement in evaluating carotid stenosis?

PubMed

Muhs, Bart E; Gagne, Paul; Wagener, Jael; Baker, Jessica; Ortega, Marta Ramirez; Adelman, Mark A; Cayne, Neal S; Rockman, Caron B; Maldonado, Thomas

2005-11-01

Accurate patient selection based on preoperative imaging is imperative to good risk reduction in patients undergoing carotid endarterectomy (CEA). The goal of this study was to assess the accuracy of gadolinium-enhanced magnetic resonance angiography (GE MRA) versus time-of-flight (TOF) MRA in the work-up of patients undergoing CEA. Patients undergoing CEA between 1999 and 2001 were identified from a prospectively maintained institutional database. GE or TOF MRA was obtained on extracranial carotid arteries (n = 319) in patients undergoing CEA. Stenosis on MRA images was graded as moderate (n = 76) or severe (n = 243) by an attending radiologist who was blind to duplex results. Duplex imaging was performed in an Intersocietal Commission for the Accreditation of Vascular Labs (ICAVL) accredited lab, and stenosis was stratified as moderate (50-79%, n = 76) or high (80-99%, n = 243) grade using University of Washington criteria. For each patient, the degree of stenosis as determined by MRA (GE versus TOF) was compared to percent stenosis on duplex. For moderate-grade lesions, GE MRA concurred with duplex in 11.1% (4/36), underestimated in 2.8% (1/36), and overestimated in 86.1% (31/36) of carotid arteries imaged. TOF MRA concurred with duplex in 35% (14/40), underestimated in 0% (0/40), and overestimated in 65% (26/40) of carotid arteries. High-grade lesions demonstrated improved concordance between MRA and duplex. For these lesions, GE MRA concurred with duplex in 95.6% (130/136) of carotid arteries imaged, never overestimated stenosis (0/136), and underestimated in 4.4% (6/136). TOF MRA concurred with duplex 96.3% (103/107), overestimated stenosis as an occlusion in 0.9% (1/107), and underestimated in 2.8% (3/107). In addition to neck visualization, the GE technique allowed simultaneous aortic arch imaging. This was accomplished in 79.1% (136/172) of all GE MRAs. Simultaneous aortic arch imaging was not technically feasible with TOF MRA. For moderate-grade lesions

GADOLINIUM(Gd)-BASED and Ion Oxide Nanoparticle Contrast Agents for Pre-Clinical and Clinical Magnetic Resonance Imaging (mri) Research

NASA Astrophysics Data System (ADS)

Ng, Thian C.

2012-06-01

It is known that one strength of MRI is its excellent soft tissue discrimination. It naturally provides sufficient contrast between the structural differences of normal and pathological tissues, their spatial extent and progression. However, to further extend its applications and enhance even more contrast for clinical studies, various Gadolinium (Gd)-based contrast agents have been developed for different organs (brain strokes, cancer, cardio-MRI, etc). These Gd-based contrast agents are paramagnetic compounds that have strong T1-effect for enhancing the contrast between tissue types. Gd-contrast can also enhance magnetic resonance angiography (CE-MRA) for studying stenosis and for measuring perfusion, vascular susceptibility, interstitial space, etc. Another class of contrast agents makes use of ferrite iron oxide nanoparticles (including Superparamagnetic Ion Oxide (SPIO) and Ultrasmall Superparamagnetic Iron Oxide (USPIO)). These nanoparticles have superior magnetic susceptibility effect and produce a drop in signal, namely in T2*-weighted images, useful for the determination of lymph nodes metastases, angiogenesis and arteriosclerosis plaques.

Evaluation of the vascular anatomy in potential living kidney donors with gadolinium-enhanced magnetic resonance angiography: comparison with digital subtraction angiography and intraoperative findings.

PubMed

Asgari, Majid A; Dadkhah, Farid; Ghadian, Ali R; Razzaghi, Mohammad R; Noorbala, Mohammad H; Amini, Erfan

2011-01-01

X-ray contrast arteriography has traditionally been used for pre-operative evaluation in living kidney donors. However, magnetic resonance angiography (MRA) offers a non-invasive alternative, which has been considered to be less accurate. This study was performed to determine whether MRA in the pre-operative investigation of living kidney donors provides sufficient information. From December 2005 to December 2007, 173 potential live donors were evaluated in this study. Donors performed digital subtraction angiography (DSA) and those with one or more accessory arteries at least on one side recruited for further evaluation with three-dimensional gadolinium-enhanced MRA. A total of 30 donors constituted the study population. When compared with DSA as the reference method, MRA detected 20 of 36 renal accessory arteries which indicates a sensitivity of 55.6%. The difference between MRA and DSA in identifying accessory renal arteries was significant (p-value <0.001). Considering intraoperative findings as the standard of reference, MRA depicted correctly four of six (66.7%) accessory arteries on the transplanted kidneys. MRA has the advantage of avoiding exposure to ionizing radiation and is non-invasive. These are important considerations in pre-operative evaluation of a generally healthy donor population. However, MRA provides suboptimal accuracy in detecting small accessory arteries. © 2010 John Wiley & Sons A/S.

Cardiac profile of asymptomatic children with Becker and Duchenne muscular dystrophy under treatment with steroids and with/without perindopril.

PubMed

Mavrogeni, Sophie; Giannakopoulou, Aikaterini; Papavasiliou, Antigoni; Markousis-Mavrogenis, George; Pons, Roser; Karanasios, Evangelos; Noutsias, Michel; Kolovou, Genovefa; Papadopoulos, George

2017-07-24

To evaluate cardiovascular function in boys with Duchenne (DMD) and Becker (BMD) muscular dystrophy, using cardiac magnetic resonance (CMR). This is a single point cross sectional study of twenty-four boys with genetically ascertained DMD, and 10 with BMD, aged 10.5 ± 1.5 years (range 9-13), were prospectively evaluated by a 1.5 T system and compared with those of age-sex matched controls. The DMD patients were divided in 2 groups. Group A (N = 12) were under treatment with both deflazacort and perindopril, while Group B (n = 12) were under treatment with deflazacort, only. BMD patients did not take any medication. Biventricular function was assessed using a standard SSFP sequence. Late gadolinium enhancement (LGE) was assessed from T1 images taken 15 min after injection of 0.2 mg/Kg gadolinium DTPA using a 3D-T1-TFE sequence. Group A and BMDs were asymptomatic with normal ECG, 24 h ECG recording and echocardiogram. Group B were asymptomatic but 6/12 had abnormal ECG and mildly impaired LVEF. Their 24 h ECG recording revealed supraventricular and ventricular extrasystoles (all at 12-13 yrs). LV indices in Group A and BMD did not differ from those of controls. However, LV indices in Group B were significantly impaired compared with controls, Group A and BMDs (p < 0.001). An epicardial LGE area = 3 ± 0.5% of LV mass was identified in the posterolateral wall of LV only in 6/12 patients of Group B, but in not in any BMD or Group A. Children with either BMD or DMD under treatment with both deflazacort and perindopril present preserved LV function and lack of LGE. However, further large scale multicenter studies are warranted to confirm these data, including further CMR mapping approaches.

Contrast enhanced liver MRI in patients with primary sclerosing cholangitis: inverse appearance of focal confluent fibrosis on delayed phase MR images with hepatocyte specific versus extracellular gadolinium based contrast agents.

PubMed

Husarik, Daniela B; Gupta, Rajan T; Ringe, Kristina I; Boll, Daniel T; Merkle, Elmar M

2011-12-01

To assess the enhancement pattern of focal confluent fibrosis (FCF) on contrast-enhanced hepatic magnetic resonance imaging (MRI) using hepatocyte-specific (Gd-EOB-DTPA) and extracellular (ECA) gadolinium-based contrast agents in patients with primary sclerosing cholangitis (PSC). After institutional review board approval, 10 patients with PSC (6 male, 4 female; 33-61 years) with 13 FCF were included in this retrospective study. All patients had a Gd-EOB-DTPA-enhanced liver MRI exam, and a comparison ECA-enhanced MRI. On each T1-weighted dynamic dataset, the signal intensity (SI) of FCF and the surrounding liver as well as the paraspinal muscle (M) were measured. In the Gd-EOB-DTPA group, hepatocyte phase images were also included. SI FCF/SI M, SI liver/SI M, and [(SI liver - SI FCF)/SI liver] were compared between the different contrast agents for each dynamic phase using the paired Student's t-test. There was no significant difference in SI FCF/SI M in all imaging phases. SI liver/SI M was significantly higher for the Gd-EOB-DTPA group in the delayed phase (P < .001), whereas there was no significant difference in all other imaging phases. In the Gd-EOB-DTPA group, mean [(SI liver - SI FCF)/SI liver] were as follows (values for ECA group in parentheses): unenhanced phase: 0.26 (0.26); arterial phase: 0.01 (-0.31); portal venous phase (PVP): -0.05 (-0.26); delayed phase (DP): 0.14 (-0.54); and hepatocyte phase: 0.26. Differences were significant for the DP (P < .001). On delayed phase MR images the FCF-to-liver contrast is reversed with the lesions appearing hyperintense on ECA enhanced images and hypointense on Gd-EOB-DTPA-enhanced images. Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.

Helium defectoscopy of cerium gadolinium ceramics Ce0.8Gd0.2O1.9 with a submicrocrystalline structure in the impurity disorder region

NASA Astrophysics Data System (ADS)

Koromyslov, A. V.; Zhiganov, A. N.; Kovalenko, M. A.; Kupryazhkin, A. Ya.

2013-12-01

The concentration of impurity anion vacancies formed upon the dissociation of gadolinium-vacancy complexes has been determined using helium defectoscopy of the cerium gadolinium ceramics Ce0.8Gd0.2O1.9 with a submicrocrystalline structure in the temperature range T = 740-1123 K and at saturation pressures ranging from 0.05 to 15 MPa. It has been found that the energy of dissociation of gadoliniumvacancy complexes is E {eff/ D }= 0.26 ± 0.06 eV, and the energy of dissolution of helium in anion vacancies in the impurity disorder region is E P = -0.31 ± 0.09 eV. The proposed mechanism of dissolution has been confirmed by the investigation of the electrical conductivity of the cerium gadolinium ceramics, as well as by the high-speed molecular dynamics simulation of the dissociation of gadolinium-vacancy complexes. It has been assumed that a decrease in the effective dissolution energy in comparison with the results of the previously performed low-temperature investigations is caused by the mutual repulsion of vacancies formed upon the dissociation of gadolinium-vacancy complexes in highly concentrated solutions of gadolinium in CeO2 with increasing temperature.

Electrocardiography based prediction of hypertrophy pattern and fibrosis amount in hypertrophic cardiomyopathy: comparative study with cardiac magnetic resonance imaging.

PubMed

Park, Chul Hwan; Chung, Hyemoon; Kim, Yoonjung; Kim, Jong-Youn; Min, Pil-Ki; Lee, Kyung-A; Yoon, Young Won; Kim, Tae Hoon; Lee, Byoung Kwon; Hong, Bum-Kee; Rim, Se-Joong; Kwon, Hyuck Moon; Choi, Eui-Young

2018-05-04

Although, cardiac magnetic resonance imaging (CMR) is a gold standard for risk stratification of hypertrophic cardiomyopathy (HCM), is limited in some situations. We sought to evaluate the predictive power of quantitative electrocardiography in assessing hypertrophy pattern and fibrosis in HCM. Eighty-eight patients with HCM were studied. Voltage of R-S-T waves, number of fragmented QRS (fQRS) complexes, and T wave morphology were measured by 12-lead electrocardiography. Sixteen segmental thickness, late gadolinium enhancement (LGE), native T1, extracellular volume fraction (ECV), and T2, left ventricular (LV) mass and %LGE were measured by CMR. Patterns of LV hypertrophy were classified as pure apical, mixed, or asymmetrical septal hypertrophy. Positive and negative predictive values of biphasic T wave for pure apical type were 70.4 and 63.9%, and the predictive values of precordial negative T wave sums [Formula: see text] 12.5 mm were 69.2 and 79.6%. Precordial S waves, especially Cornell voltage index, were significantly correlated to LV mass index and maximal thickness (p [Formula: see text]0.001). The number of fQRS leads was significantly correlated to %LGE, average ECV, and T2 (all p [Formula: see text]0.001). More than one lead with fQRS could predict [Formula: see text]5% of LGE mass with 58% sensitivity and 63% specificity (p = 0.049, area under the curve = 0.627). However, degree of correlation between maximal thickness and precordial S was poor in cases with fQRS more two leads. T wave morphology and precordial S helps discriminate hypertrophy pattern and maximal hypertrophy, however, in cases with more than two leads of concomitant fQRS, CMR defines fibrosis amount and hypertrophy more accurately.

Light deflection in gadolinium molybdate ferroelastic crystals

NASA Astrophysics Data System (ADS)

Staniorowski, Piotr; Bornarel, Jean

2000-02-01

The deflection of a He-Ne light beam by polydomain gadolinium molybdate (GMO) crystals has been studied with respect to incidence angle icons/Journals/Common/alpha" ALT="alpha" ALIGN="TOP"/> i on the sample at room temperature. The A and B deflected beams do not cross each other during the icons/Journals/Common/alpha" ALT="alpha" ALIGN="TOP"/> i variation, in contrast to results and calculations previously published. The model using the Fresnel equation confirms this result. The model presented is more accurate for numerical calculation than that using the Huygens construction.

Controlled intracellular self-assembly of gadolinium nanoparticles as smart molecular MR contrast agents.

PubMed

Cao, Chun-Yan; Shen, Ying-Ying; Wang, Jian-Dong; Li, Li; Liang, Gao-Lin

2013-01-01

Herein we developed a new "smart" Gd-based MR contrast agent (i.e., 1) which is susceptive to furin, a protease overexpressed in tumor. Under the action of furin, 1 condenses to form dimers (1-Ds) and the latter self-assemble into gadolinium nanparticles (Gd-NPs). Relaxivity of 1-D is more than 2 folds of those of 1 and magnevist at 1.5 T, and 1.4 folds of that of 1 at 3 T. Intracellular condensation of 1 in furin-overexpressed MDA-MB-468 cells was proven with direct two-photon laser microscopy (TPLM) fluorescence imaging of the cells incubated with the europium analog of 1 (i.e., 2). Intracellular Gd-NPs of 1 were uncovered and characterized for the first time. MRI of MDA-MB-468 tumors showed that 1 has enhanced MR contrast within the tumors than that of its scrambled control 1-Scr.

T1 mapping using saturation recovery single-shot acquisition at 3-tesla magnetic resonance imaging in hypertrophic cardiomyopathy: comparison to late gadolinium enhancement.

PubMed

Ogawa, Ryo; Kido, Tomoyuki; Nakamura, Masashi; Kido, Teruhito; Kurata, Akira; Uetani, Teruyoshi; Ogimoto, Akiyoshi; Miyagawa, Masao; Mochizuki, Teruhito

2017-03-01

We evaluated the T1 values of segments and slices and the reproducibility in healthy controls, using saturation recovery single-shot acquisition (SASHA) at 3T magnetic resonance imaging. Moreover, we examined the difference in T1 values between hypertrophic cardiomyopathy (HCM) and healthy controls, and compared those with late gadolinium enhancement (LGE). Twenty-one HCM patients and 10 healthy controls underwent T1 mapping before and after contrast administration. T1 values were measured in 12 segments. Native T1 values were significantly longer in HCM than in healthy controls [1373 ms (1312-1452 ms) vs. 1279 ms (1229-1326 ms); p < 0.0001]. Even in HCM segments without LGE, native T1 values were significantly longer than in healthy control segments [1366 ms (1300-1439 ms) vs. 1279 ms (1229-1326 ms); p < 0.0001]. Using a cutoff value of 1327 ms for septal native T1 values, we differentiated between HCM and healthy controls with 95% sensitivity, 90% specificity, 94% accuracy, and an area under the curve of 0.95. Native T1 values using a SASHA at 3T could differentiate HCM from healthy controls. Moreover, native T1 values have the potential to detect abnormal myocardium that cannot be identified adequately by LGE in HCM.

Suppression of Rabbit VX‐2 Subcutaneous Tumor Growth by Gadolinium Neutron Capture Therapy

PubMed Central

Tokita, Nobuhiko; Tokuuye, Koichi; Satoh, Michinao; Churei, Hisahiko; Pechoux, Cécile Le; Kobayashi, Tooru; Kanda, Keiji

1993-01-01

VX‐2 tumors growing in hind legs of New Zealand White rabbits (n=4) were exposed to thermal neutrons for 40 min (2.1 × 1012 neutrons cm−2) while one of two hind leg tumors of each rabbit was infused continuously with meglumine gadopentetate through a branch of the left femoral artery. The contralateral (uninfused) tumors served as controls. Although no differential distribution of gadolinium was achieved between the tumor and its adjacent normal tissue, the gadolinium concentration in the infused tumor was approximately 5–6 fold higher than that in the contralateral tumor. Growth of gadolinium‐infused tumors was significantly inhibited compared to that of control tumors (P<0.05) between the 16th and 23rd days after treatment. PMID:8407547

Gadolinium sulfate modified by formate to obtain optimized magneto-caloric effect.

PubMed

Xu, Long-Yang; Zhao, Jiong-Peng; Liu, Ting; Liu, Fu-Chen

2015-06-01

Three new Gd(III) based coordination polymers [Gd2(C2H6SO)(SO4)3(H2O)2]n (1), {[Gd4(HCOO)2(SO4)5(H2O)6]·H2O}n (2), and [Gd(HCOO)(SO4)(H2O)]n (3) were obtained by modifying gadolinium sulfate. With the gradual increase of the volume ratio of HCOOH and DMSO in synthesis, the formate anions begin to coordinate with metal centers; this results in the coordination numbers of sulfate anion increasing and the contents of water and DMSO molecules decreasing in target complexes. Accordingly, spin densities both per mass and per volume were enhanced step by step, which are beneficial for the magneto-caloric effect (MCE). Magnetic studies reveal that with the more formate anions present, the larger the negative value of magnetic entropy change (-ΔSm) is. Complex 3 exhibits the largest -ΔSm = 49.91 J kg(-1) K(-1) (189.51 mJ cm(-3) K(-1)) for T = 2 K and ΔH = 7 T among three new complexes.

Pharmacological stress, rest perfusion and delayed enhancement cardiac magnetic resonance identifies very early cardiac involvement in systemic sclerosis patients of recent onset.

PubMed

Giacomelli, Roberto; Di Cesare, Ernesto; Cipriani, Paola; Ruscitti, Piero; Di Sibio, Alessandra; Liakouli, Vasiliki; Gennarelli, Antonio; Carubbi, Francesco; Splendiani, Alessandra; Berardicurti, Onorina; Di Benedetto, Paola; Ciccia, Francesco; Guggino, Giuliana; Radchenko, Ganna; Triolo, Giovanni; Masciocchi, Carlo

2017-09-01

To evaluate occult cardiac involvement in asymptomatic systemic sclerosis (SSc) patients by pharmacological stress, rest perfusion and delayed enhancement cardiac magnetic resonance (CMR), for a very early identification of patients at higher risk of cardiac-related mortality. Sixteen consecutive patients with definite SSc, fulfilling the American College of Rheumatology/European League Against Rheumatism 2013 classification criteria in less than 1 year from the onset of Raynaud's phenomenon, underwent pharmacological stress, rest perfusion and delayed enhancement CMR. At enrollment, no patient showed signs and/or symptoms suggestive for cardiac involvement. No patient showed traditional cardiovascular risk factors. Both the 12-lead electrocardiogram examination and echocardiographic evaluation did not show any alterations in our cohort. Stress perfusion defects of left ventricle were detected in six out of 16 (37.5%) patients and these defects did not match with the coronary flow distribution. The results showed the presence of two different patterns of stress perfusion defects: sub-endocardial and/or a midmyocardial. The presence of stress perfusion defects did not correlate with any clinical feature of enrolled patients. Myocardial stress perfusion defects may be detected early by pharmacological stress perfusion CMR, a reliable and sensitive technique for the noninvasive evaluation of SSc heart disease, in patients with SSc of recent onset. These defects seem to be independent from traditional risk factors and associated comorbidities, suggesting they are a specific hallmark of the disease. © 2017 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.

Triple dose of gadolinium-DTPA and delayed MRI in patients with benign multiple sclerosis.

PubMed Central

Filippi, M; Capra, R; Campi, A; Colombo, B; Prandini, F; Marcianò, N; Gasparotti, R; Comi, G

1996-01-01

OBJECTIVES--To evaluate whether a triple dose of gadolinium-DTPA (Gd-DTPA) or delayed MRI increase the number, size, and conspicuousness of enhancing lesions in patients with benign multiple sclerosis. METHODS--T1 weighted brain MRI was carried out on 20 patients with benign multiple sclerosis (expanded disability status scale < 3 with a disease duration > 10 years) in two sessions. In the first session, one scan was obtained before and two scans five to seven minutes and 20-30 minutes after the injection of 0.1 mmol/kg Gd-DTPA (standard dose). In the second session, six to 24 hours later, the same procedure was repeated with 0.3 mmol/kg Gd-DTPA (triple dose). RESULTS--Nine enhancing lesions were found in seven patients (35%) using the standard dose of Gd-DTPA. The numbers of enhancing lesions increased to 13 (P = 0.03) and the number of patients with such lesions to eight (40%) on the delayed standard dose scans. On the early triple dose scans, we found 19 enhancing lesions in 10 patients (50%). The number of enhancing lesions was significantly higher (P = 0.01) than that obtained with the early standard dose. The number of enhancing lesions was 18 and the number of "active" patients 11 (55%) on the delayed triple dose scans. The enhancing areas increased progressively from the early standard dose scans to the delayed triple dose scans. The contrast ratios of the lesions detected in early standard dose scans was lower than those of lesions present in the early (P = 0.01) and delayed (P = 0.04) triple dose scans. CONCLUSIONS--More enhancing lesions were detected in patients with benign multiple sclerosis with both delay of MRI and the use of triple dose of Gd-DTPA suggesting that the amount of inflammation in the lesions of such patients is mild and heterogeneous. Images PMID:8778257

Survey of gadolinium-based contrast agent utilization among the members of the Society for Pediatric Radiology: a Quality and Safety Committee report.

PubMed

Blumfield, Einat; Moore, Michael M; Drake, Mary K; Goodman, Thomas R; Lewis, Kristopher N; Meyer, Laura T; Ngo, Thang D; Sammet, Christina; Stanescu, Arta Luana; Swenson, David W; Slovis, Thomas L; Iyer, Ramesh S

2017-05-01

Gadolinium-based contrast agents (GBCAs) have been used for magnetic resonance (MR) imaging over the last three decades. Recent reports demonstrated gadolinium retention in patients' brains following intravenous administration. Since gadolinium is a highly toxic heavy metal, there is a potential for adverse effects from prolonged retention or deposition, particularly in children. For this reason, the Society (SPR) for Pediatric Radiology Quality and Safety committee conducted a survey to evaluate the current status of GBCAs usage among pediatric radiologists. To assess the usage of GBCAs among SPR members. An online 15-question survey was distributed to SPR members. Survey questions pertained to the type of GBCAs used, protocoling workflow, requirement of renal function or pregnancy tests, and various clinical indications for contrast-enhanced MRI examinations. A total of 163 survey responses were compiled (11.1% of survey invitations), the majority of these from academic institutions in the United States. Ninety-four percent reported that MR studies are always or usually protocoled by pediatric radiologists. The most common GBCA utilized by survey respondents were Eovist (60.7%), Ablavar (45.4%), Gadovist (38.7%), Magnevist (34.4%) and Dotarem (32.5%). For several clinical indications, survey responses regarding GBCA administration were concordant with American College of Radiology (ACR) Appropriateness Criteria, including seizures, headache and osteomyelitis. For other indications, including growth hormone deficiency and suspected vascular ring, survey responses revealed potential overutilization of GBCAs when compared to ACR recommendations. Survey results demonstrate that GBCAs are administered judiciously in children, yet there is an opportunity to improve their utilization with the goal of reducing potential future adverse effects.

Study of the Photon Strength Functions for Gadolinium Isotopes with the DANCE Array

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dashdorj, D.; Mitchell, G. E.; Baramsai, B.

2009-03-10

The gadolinium isotopes are interesting for reactor applications as well as for medicine and astrophysics. The gadolinium isotopes have some of the largest neutron capture cross sections. As a consequence they are used in the control rod in reactor fuel assembly. From the basic science point of view, there are seven stable isotopes of gadolinium with varying degrees of deformation. Therefore they provide a good testing ground for the study of deformation dependent structure such as the scissors mode. Decay gamma rays following neutron capture on Gd isotopes are detected by the DANCE array, which is located at flight pathmore » 14 at the Lujan Neutron Scattering Center at Los Alamos National Laboratory. The high segmentation and close packing of the detector array enable gamma-ray multiplicity measurements. The calorimetric properties of the DANCE array coupled with the neutron time-of-flight technique enables one to gate on a specific resonance of a specific isotope in the time-of-flight spectrum and obtain the summed energy spectrum for that isotope. The singles gamma-ray spectrum for each multiplicity can be separated by their DANCE cluster multiplicity. Various photon strength function models are used for comparison with experimentally measured DANCE data and provide insight for understanding the statistical decay properties of deformed nuclei.« less

Role of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging in the management of hepatocellular carcinoma: consensus at the Symposium of the 48th Annual Meeting of the Liver Cancer Study Group of Japan.

PubMed

Kudo, Masatoshi; Matsui, Osamu; Sakamoto, Michiie; Kitao, Azusa; Kim, Tonsok; Ariizumi, Shun-ichi; Ichikawa, Tomoaki; Kobayashi, Satoshi; Imai, Yasuharu; Izumi, Namiki; Fujinaga, Yasunari; Arii, Shigeki

2013-01-01

We summarize here the consensus reached at the Symposium of the 48th Annual Meeting of the Liver Cancer Study Group of Japan held in Kanazawa on July 20th and 21st, 2012, on the role of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) in the management of hepatocellular carcinoma (HCC). Currently, dynamic CT is the first choice of imaging modality when HCC is suspected. EOB-MRI is useful for differentiation and definitive diagnosis of HCC when dynamic CT/MRI does not show conclusive findings for HCC. In addition, contrast- enhanced ultrasound with Sonazoid is useful for making a decision on whether or not to treat a hypovascular lesion <1 cm when the nodules are shown with low intensity in the hepatocyte phase of EOB-MRI. Furthermore, EOB-MRI should be performed in selected cases of HCC ultrahigh-risk groups every 3-4 months, or EOB-MRI should be performed at least once at the first visit in all HCC ultrahigh-risk groups. Copyright © 2013 S. Karger AG, Basel.

Recurrent medulloblastoma: Frequency of tumor enhancement on Gd-DTPA MR imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rollins, N.; Mendelsohn, D.; Mulne, A.

1990-05-01

Thirty-two children with medulloblastoma were evaluated postoperatively with conventional and gadolinium-enhanced MR imaging. Eleven patients had abnormal cranial MR studies; nine of these had recurrent tumor. In six patients recurrent tumor enhanced with Gd, while in the other three patients recurrent tumor did not enhance. The remaining two patients had areas of abnormal Gd enhancement that were caused by radiation-induced breakdown of the blood-brain barrier rather than by recurrent tumor. This study shows that not all recurrent medulloblastoma enhances and that the absence of Gd enhancement does not necessarily indicate the absence of recurrent tumor.

Recurrent medulloblastoma: Frequency of tumor enhancement on Gd-DTPA MR imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rollins, N.; Mendelsohn, D.; Mulne, A.

1990-07-01

Thirty-two children with medulloblastoma were evaluated postoperatively with conventional and gadolinium-enhanced MR imaging. Eleven patients had abnormal cranial MR studies; nine of these had recurrent tumor. In six patients recurrent tumor enhanced with Gd, while in the other three patients recurrent tumor did not enhance. The remaining two patients had areas of abnormal Gd enhancement that were caused by radiation-induced breakdown of the blood-brain barrier rather than by recurrent tumor. This study shows that not all recurrent medulloblastoma enhances and that the absence of Gd enhancement does not necessarily indicate the absence of recurrent tumor.

[Comparing the activity of multiple sclerosis (MS) at the minute and at 20 minutes of gadolinium application in magnetic resonance imaging (MRI) of the brain?

PubMed

Saldívar-Uribe, Christina; de la Portilla-Villanueva, Mario Alberto; Esau-Mendoza-García, Alberto

2017-01-01

The aim was to compare active disease in patients diagnosed with multiple sclerosis, brain by MRI after gadolinium application at one minute and 20 minutes. A longitudinal, prospective, observational, analytical and comparative study was conducted in 18 patients over 18 years of age diagnosed with multiple sclerosis (MS). An analysis was made for each patient, watching for inflammatory activity in MS lesions, comparing the results to one minute and 20 minutes after the application of gadolinium. For the descriptive analysis, absolute frequencies and percentages were used, as well as means and standard deviations or medians with ranges for the inferential analysis comparing the presence or absence of enhancement in lesions at one minute and 20 minutes; the exact probability test used was Fisher. Finally, the results were analyzed, looking at the gender distribution: 14 (77.8%) were female. The average age was 36.2 ± 9.5 years, with a minimum age of 18 years and a maximum of 55 years; four patients (22.2%) presented further highlight active lesions at 20 minutes, and two patients (11.1%) presented enhancement at one minute. Concluding that MRI in the diagnosis of MS is very important for the detection of activity in lesions caused by the disease, it is evident that the optimum time for evaluation of postcontrast sequences is 20 minutes.

Pericortical Enhancement on Delayed Postgadolinium Fluid-Attenuated Inversion Recovery Images in Normal Aging, Mild Cognitive Impairment, and Alzheimer Disease.

PubMed

Freeze, W M; Schnerr, R S; Palm, W M; Jansen, J F; Jacobs, H I; Hoff, E I; Verhey, F R; Backes, W H

2017-09-01

Breakdown of BBB integrity occurs in dementia and may lead to neurodegeneration and cognitive decline. We assessed whether extravasation of gadolinium chelate could be visualized on delayed postcontrast FLAIR images in older individuals with and without cognitive impairment. Seventy-four individuals participated in this study (15 with Alzheimer disease, 33 with mild cognitive impairment, and 26 with normal cognition). We assessed the appearance of pericortical enhancement after contrast administration, MR imaging markers of cerebrovascular damage, and medial temporal lobe atrophy. Three participants who were positive for pericortical enhancement (1 with normal cognition and 2 with mild cognitive impairment) were followed up for approximately 2 years. In vitro experiments with a range of gadolinium concentrations served to elucidate the mechanisms underlying the postcontrast FLAIR signals. Postcontrast pericortical enhancement was observed in 21 participants (28%), including 6 individuals with Alzheimer disease (40%), 10 with mild cognitive impairment (30%), and 5 with normal cognition (19%). Pericortical enhancement was positively associated with age ( P < .02) and ischemic stroke ( P < .05), but not with cognitive status ( P = .3). Foci with enhanced signal remained stable across time in all follow-up cases. The in vitro measurements confirmed that FLAIR imaging is highly sensitive for the detection of low gadolinium concentrations in CSF, but not in cerebral tissue. Postcontrast pericortical enhancement on FLAIR images occurs in older individuals with normal cognition, mild cognitive impairment, and dementia. It may represent chronic focal superficial BBB leakage. Future longitudinal studies are needed to determine its clinical significance. © 2017 by American Journal of Neuroradiology.

Kinetic characteristics of the luminescence decay for industrial yttrium-gadolinium-aluminium garnet based phosphors

NASA Astrophysics Data System (ADS)

Lisitsyn, V. M.; Stepanov, S. A.; Valiev, D. T.; Vishnyakova, E. A.; Abdullin, H. A.; Marhabaeva, A. A.; Tulegenova, A. T.

2016-02-01

The spectral and decay kinetic characteristics of pulse cathodoluminescence and photoluminescence of phosphors based on yttrium-gadolinium-aluminum garnet were investigated using pulsed optical time resolved spectroscopy.

Tumor Xenograft Response to Redox-Active Therapies Assessed by Magnetic Resonance Imaging Using a Thiol-Bearing DOTA Complex of Gadolinium1

PubMed Central

Guntle, Gerald P; Jagadish, Bhumasamudram; Mash, Eugene A; Powis, Garth; Dorr, Robert T; Raghunand, Natarajan

2012-01-01

Gd-LC6-SH is a thiol-bearing DOTA complex of gadolinium designed to bind plasma albumin at the conserved Cys34 site. The binding of Gd-LC6-SH shows sensitivity to the presence of competing thiols. We hypothesized that Gd-LC6-SH could provide magnetic resonance imaging (MRI) enhancement that is sensitive to tumor redox state and that the prolonged retention of albumin-bound Gd-LC6-SH in vivo can be exploited to identify a saturating dose above which the shortening of MRI longitudinal relaxation time (T1) of tissue is insensitive to the injected gadolinium dose. In the Mia-PaCa-2 pancreatic tumor xenograft model in SCID mice, both the small-molecule Gd-DTPA-BMA and the macromolecule Galbumin MRI contrast agents produced dose-dependent decreases in tumor T1. By contrast, the decreases in tumor T1 provided by Gd-LC6-SH at 0.05 and 0.1 mmol/kg were not significantly different at longer times after injection. SCID mice bearing Mia-PaCa-2 or NCI-N87 tumor xenografts were treated with either the glutathione synthesis inhibitor buthionine sulfoximine or the thiol-oxidizing anticancer drug Imexon, respectively. In both models, there was a significantly greater increase in tumor R1 (=1/T1) 60 minutes after injection of Gd-LC6-SH in drug-treated animals relative to saline-treated controls. In addition, Mercury Orange staining for nonprotein sulfhydryls was significantly decreased by drug treatment relative to controls in both tumor models. In summary, these studies show that thiol-bearing complexes of gadolinium such as Gd-LC6-SH can serve as redox-sensitive MRI contrast agents for detecting differences in tumor redox status and can be used to evaluate the effects of redox-active drugs. PMID:22741038

Synthesis route and three different core-shell impacts on magnetic characterization of gadolinium oxide-based nanoparticles as new contrast agents for molecular magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Azizian, Gholamreza; Riyahi-Alam, Nader; Haghgoo, Soheila; Moghimi, Hamid Reza; Zohdiaghdam, Reza; Rafiei, Behrooz; Gorji, Ensieh

2012-10-01

Despite its good resolution, magnetic resonance imaging intrinsically has low sensitivity. Recently, contrast agent nanoparticles have been used as sensitivity and contrast enhancer. The aim of this study was to investigate a new controlled synthesis method for gadolinium oxide-based nanoparticle preparation. For this purpose, diethyleneglycol coating of gadolinium oxide (Gd2O3-DEG) was performed using new supervised polyol route, and small particulate gadolinium oxide (SPGO) PEGylation was obtained with methoxy-polyethylene-glycol-silane (550 and 2,000 Da) coatings as SPGO-mPEG-silane550 and 2,000, respectively. Physicochemical characterization and magnetic properties of these three contrast agents in comparison with conventional Gd-DTPA were verified by dynamic light scattering transmission electron microscopy, Fourier transform infrared spectroscopy, inductively coupled plasma, X-ray diffraction, vibrating sample magnetometer, and the signal intensity and relaxivity measurements were performed using 1.5-T MRI scanner. As a result, the nanoparticle sizes of Gd2O3-DEG, SPGO-mPEG-silane550, and SPGO-mPEG-silane2000 could be reached to 5.9, 51.3, 194.2 nm, respectively. The image signal intensity and longitudinal ( r 1) and transverse relaxivity ( r 2) measurements in different concentrations (0.3 to approximately 2.5 mM), revealed the r 2/ r 1 ratios of 1.13, 0.89, 33.34, and 33.72 for Gd-DTPA, Gd2O3-DEG, SPGO-mPEG-silane550, and SPGO-mPEG-silane2000, respectively. The achievement of new synthesis route of Gd2O3-DEG resulted in lower r 2/ r 1 ratio for Gd2O3-DEG than Gd-DTPA and other previous synthesized methods by this and other groups. The smaller r 2/ r 1 ratios of two PEGylated-SPGO contrast agents in our study in comparison with r 2/ r 1 ratio of previous PEGylation ( r 2/ r 1 = 81.9 for mPEG-silane 6,000 MW) showed that these new three introduced contrast agents could potentially be proper contrast enhancers for cellular and molecular MR imaging.

Nephrogenic systemic fibrosis and class labeling of gadolinium-based contrast agents by the Food and Drug Administration.

PubMed

Yang, Lucie; Krefting, Ira; Gorovets, Alex; Marzella, Louis; Kaiser, James; Boucher, Robert; Rieves, Dwaine

2012-10-01

In 2007, the Food and Drug Administration requested that manufacturers of all approved gadolinium-based contrast agents (GBCAs), drugs widely used in magnetic resonance imaging, use nearly identical text in their product labeling to describe the risk of nephrogenic systemic fibrosis (NSF). Accumulating information about NSF risks led to revision of the labeling text for all of these drugs in 2010. The present report summarizes the basis and purpose of this class-labeling approach and describes some of the related challenges, given the evolutionary nature of the NSF risk evidence. The class-labeling approach for presentation of product risk is designed to decrease the occurrence of NSF and to enhance the safe use of GBCAs in radiologic practice. © RSNA, 2012.

Assessment of local pulse wave velocity distribution in mice using k-t BLAST PC-CMR with semi-automatic area segmentation.

PubMed

Herold, Volker; Herz, Stefan; Winter, Patrick; Gutjahr, Fabian Tobias; Andelovic, Kristina; Bauer, Wolfgang Rudolf; Jakob, Peter Michael

2017-10-16

Local aortic pulse wave velocity (PWV) is a measure for vascular stiffness and has a predictive value for cardiovascular events. Ultra high field CMR scanners allow the quantification of local PWV in mice, however these systems are yet unable to monitor the distribution of local elasticities. In the present study we provide a new accelerated method to quantify local aortic PWV in mice with phase-contrast cardiovascular magnetic resonance imaging (PC-CMR) at 17.6 T. Based on a k-t BLAST (Broad-use Linear Acquisition Speed-up Technique) undersampling scheme, total measurement time could be reduced by a factor of 6. The fast data acquisition enables to quantify the local PWV at several locations along the aortic blood vessel based on the evaluation of local temporal changes in blood flow and vessel cross sectional area. To speed up post processing and to eliminate operator bias, we introduce a new semi-automatic segmentation algorithm to quantify cross-sectional areas of the aortic vessel. The new methods were applied in 10 eight-month-old mice (4 C57BL/6J-mice and 6 ApoE (-/-) -mice) at 12 adjacent locations along the abdominal aorta. Accelerated data acquisition and semi-automatic post-processing delivered reliable measures for the local PWV, similiar to those obtained with full data sampling and manual segmentation. No statistically significant differences of the mean values could be detected for the different measurement approaches. Mean PWV values were elevated for the ApoE (-/-) -group compared to the C57BL/6J-group (3.5 ± 0.7 m/s vs. 2.2 ± 0.4 m/s, p < 0.01). A more heterogeneous PWV-distribution in the ApoE (-/-) -animals could be observed compared to the C57BL/6J-mice, representing the local character of lesion development in atherosclerosis. In the present work, we showed that k-t BLAST PC-MRI enables the measurement of the local PWV distribution in the mouse aorta. The semi-automatic segmentation method based on PC-CMR data allowed rapid determination of

Improved multimodality data fusion of late gadolinium enhancement MRI to left ventricular voltage maps in ventricular tachycardia ablation.

PubMed

Roujol, Sebastien; Basha, Tamer A; Tan, Alex; Khanna, Varun; Chan, Raymond H; Moghari, Mehdi H; Rayatzadeh, Hussein; Shaw, Jaime L; Josephson, Mark E; Nezafat, Reza

2013-05-01

Electroanatomical voltage mapping (EAVM) is commonly performed prior to catheter ablation of scar-related ventricular tachycardia (VT) to locate the arrhythmic substrate and to guide the ablation procedure. EAVM is used to locate the position of the ablation catheter and to provide a 3-D reconstruction of left-ventricular anatomy and scar. However, EAVM measurements only represent the endocardial scar with no transmural or epicardial information. Furthermore, EAVM is a time-consuming procedure, with a high operator dependence and has low sampling density, i.e., spatial resolution. Late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) allows noninvasive assessment of scar morphology that can depict 3-D scar architecture. Despite the potential use of LGE as a roadmap for VT ablation for identification of arrhythmogenic substrate, its utility has been very limited. To allow for identification of VT substrate, a correlation is needed between the substrates identified by EAVM as the gold standard and LGE-MRI scar characteristics. To do so, a system must be developed to fuse the datasets from these modalities. In this study, a registration pipeline for the fusion of LGE-MRI and EAVM data is presented. A novel surface registration algorithm is proposed, integrating the matching of global scar areas as an additional constraint in the registration process. A preparatory landmark registration is initially performed to expedite the convergence of the algorithm. Numerical simulations were performed to evaluate the accuracy of the registration in the presence of errors in identifying landmarks in EAVM or LGE-MRI datasets as well as additional errors due to respiratory or cardiac motion. Subsequently, the accuracy of the proposed fusion system was evaluated in a cohort of ten patients undergoing VT ablation where both EAVM and LGE-MRI data were available. Compared to landmark registration and surface registration, the presented method achieved significant

Polythermal investigation of viscosity of solution of metal carboxylates in VIK-grade mixed carboxylic acids: Yttrium and gadolinium carboxylates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mezhov, E.A.; Samatov, A.V.; Troyanovskii, L.V.

Kinematic viscosities have been measured for solutions of yttrium and gadolinium carboxylates in grade VIK mixed carboxylic acids (MCA). It has been established that the optimal fluidity of these metal carboxylate solutions for application to articles is reached at 333 K. A regression model has been developed to describe the concentration and temperature dependences of the viscosity of yttrium- and gadolinium-containing MCA solutions. 2 refs., 3 tabs.

The performance of hafnium and gadolinium self powered neutron detectors in the TREAT reactor

NASA Astrophysics Data System (ADS)

Imel, G. R.; Hart, P. R.

1996-05-01

The use of gadolinium and hafnium self powered neutron detectors in a transient reactor is described in this paper. The detectors were calibrated to the fission rate of U-235 using calibrated fission chambers; the calibration factors were tested in two reactors in steady state and found to be consistent. Calibration of the detectors in transient reactor conditions was done by using uranium wires that were analyzed by radiochemistry techniques to determine total fissions during the transient. This was correlated to the time-integrated current of the detectors during the transient. A temperature correction factor was derived to account for self-shielding effects in the hafnium and gadolinium detectors. The dynamic response of the detectors under transient conditions was studied, and found to be excellent.

The tight binding model study of the role of anisotropic AFM spin ordering in the charge ordered CMR manganites

NASA Astrophysics Data System (ADS)

Kar, J. K.; Panda, Saswati; Rout, G. C.

2017-05-01

We propose here a tight binding model study of the interplay between charge and spin orderings in the CMR manganites taking anisotropic effect due to electron hoppings and spin exchanges. The Hamiltonian consists of the kinetic energies of eg and t2g electrons of manganese ion. It further includes double exchange and Heisenberg interactions. The charge density wave interaction (CDW) describes an extra mechanism for the insulating character of the system. The CDW gap and spin parameters are calculated using Zubarev's Green's function technique and computed self-consistently. The results are reported in this communication.

Metabolomic Analysis of N-acetylcysteine Protection of Injury from Gadolinium-DTPA Contrast Agent in Rats with Chronic Renal Failure.

PubMed

Wan, Chuanling; Xue, Rong; Zhan, Youyang; Wu, Yijie; Li, Xiaojing; Pei, Fengkui

2017-09-01

Gadolinium-based contrast agents (GBCAs) are frequently used to enhance the diagnostic efficacy of magnetic resonance imaging. On the other hand, the association between GBCA administration in patients with advanced renal disease and nephrogenic systemic fibrosis (NSF) was also noted. NSF is a systemic disorder characterized by widespread tissue fibrosis that may lead to death. N-acetylcysteine (NAC) protects rats from injury induced by gadolinium-based contrast agents, but the underlying mechanisms remain unclear. In this study, a nuclear magnetic resonance-based metabolomic approach was used to systematically investigate the protective effects of NAC on Gd-DTPA-induced injury. Thirty-two male Sprague-Dawley rats were given adenine (200 mg·kg -1 body weight) by oral gavage once a day for 3 weeks to induce chronic renal failure (CRF). NAC (600 mg/L in drinking water for 9 days) pretreatment was initiated 2 days before Gd-DTPA injection (a single tail vein injection, 2 mmol/kg body weight). Serum and liver samples were collected on day 7 after Gd-DTPA injection. By study design, the serum and hepatic metabolic changes of rats were measured in four groups of eight each: CRF, CRF-Gd, CRF-Gd-NAC, and CRF-NAC. Gd-DTPA administration to rats with CRF resulted in disturbances of several metabolic pathways, including glucose, lipid, glutamate, choline, gut microbiota, one-carbon, and purine metabolism. NAC pretreatment reversed the abundance changes of high-density lipoprotein, low-density lipoprotein, very low-density lipoprotein, glutamate, glutamine, oxidized glutathione, choline, phosphocholine, glycerophosphocholine, trimethylamine, and trimethylamine-N-oxide induced by Gd-DTPA. It is noteworthy, however, that the ameliorating effects of NAC on the disturbance of glutamate, choline, and gut microbiota metabolism may be specific to Gd-DTPA. In all, these findings could be potentially useful to decipher the underlying mechanisms of NAC protective effects from the

Effect of Cu2+ substitution on the structural, magnetic and electrical properties of gadolinium orthoferrite

NASA Astrophysics Data System (ADS)

Sai Vandana, C.; Hemalatha Rudramadevi, B.

2018-04-01

The pure and copper (Cu) substituted Gadolinium orthoferrites, GdFeO3, GdCu0.1Fe0.9O3, GdCu0.2Fe0.8O3 and GdCu0.3Fe0.7O3 were synthesized by conventional solid state method. The structural, morphological, dielectric, magnetic and impedance properties of Cu substituted Gadolinium orthoferrites have been investigated. The crystallographic phase as well as the substitution of Cu2+ ions in the lattice of GdFeO3 is confirmed from the x-ray diffraction patterns. The Fourier transform infrared spectra exhibit two prominent fundamental absorption peaks at ∼417 cm‑1 and 545 cm‑1. These bands are related to inherent stretching vibrations of metals at octahedral and tetrahedral sites respectively. The coercivity (Hc) and saturation magnetization (Ms) of the synthesized samples at different temperatures were determined from the hysteresis plots. Higher coercive values, 598 Oe and 600 Oe were achieved in GdCu0.1Fe0.9O3 ferrites compared to 527 Oe and 360 Oe in pure GdFeO3 at room temperature (300 K) and low temperature (20 k) respectively. Dielectric dispersion has been observed for gadolinium ferrite samples with Maxwell–Wagner type interfacial polarization. The decrease of dielectric constant and dielectric loss tangent with an increase in frequency was observed. The conduction due to charge hopping between localized states was confirmed from AC conductivity measurements. The composition dependent cationic distributions estimated from XRD, magnetic and electrical studies are in good agreement with each other. The achieved results indicate that the substitution of Cu in gadolinium orthoferrite strongly influences the crystal structure, magnetic and electrical properties thereby making them suitable as multiple state memory devices, transducers, electronic field controlled ferromagnetic resonance devices and spintronic devices.

Cardiac involvement in female Duchenne and Becker muscular dystrophy carriers in comparison to their first-degree male relatives: a comparative cardiovascular magnetic resonance study.

PubMed

Florian, Anca; Rösch, Sabine; Bietenbeck, Michael; Engelen, Markus; Stypmann, Jörg; Waltenberger, Johannes; Sechtem, Udo; Yilmaz, Ali

2016-03-01

Duchenne (DMD) and Becker (BMD) muscular dystrophies are X-linked recessive disorders associated with both skeletal myopathy and progressive cardiomyopathy in males. Female DMD/BMD carriers (DMDc/BMDc) are mostly free of skeletal muscle symptoms, but they are also prone to cardiomyopathy. The aim of the current study was to characterize the frequency, pattern, and extent of cardiomyopathy in female DMD/BMD carriers (DMDc/BMDc) in comparison to their first-degree male MD relatives. Thirty-six (age 44 ± 14 years) female MD carriers (20 DMDc and 16 BMDc) constituted the 'MD carrier group' and were prospectively enrolled. All MD carriers underwent a complete CMR study comprising cine- and late gadolinium enhancement (LGE) imaging. In 22 of these women ('female MD carrier comparison group', 7 DMD and 15 BMD), at least one first-degree male relative with a previously established diagnosis of MD underwent the same CMR protocol and was assigned to the 'male MD comparison group' (n = 24, 6 DMD and 18 BMD). In the total MD carrier group, 17 (47%) MD carriers had at least one pathological CMR finding [5 (14%) with a reduced left ventricular ejection fraction (LV-EF) and 16 (44%) with the presence of LGE]. All LGE-positive patients (n = 16) showed non-ischaemic LGE with subepicardial involvement of the LV lateral free wall being the most frequent pattern (13/16, 81%). Compared with BMDc, DMDc demonstrated more frequently a pathological CMR result (65 vs. 19%; P = 0.008)--in spite of being significantly younger (40 ± 11 vs. 50 ± 16 years, P = 0.038). In the male MD comparison group, the same LGE pattern as in female carriers was seen, but with a significantly higher prevalence of cardiac abnormalities compared with their female carrier relatives constituting the female MD comparison group (75 vs. 27%; P = 0.003). Cardiac involvement is a frequent finding in female carriers of DMD, but less frequently observed in carriers of BMD. Those DMDc and BMDc with cardiac involvement

Structural studies on the substitution of Ag, Na doped LCSMO CMR manganites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Subhashini, P., E-mail: subhashinisvu@gmail.com; Krishnaiah, M.; Munirathinam, B.

2016-05-06

Synthesis and characterization of colossal magnetoresistance (CMR) materials has been a subject of scientific research due to the unique transport, magnetotransport, and magnetic properties. The single phase polycrystalline La{sub 0.7}Ca{sub 0.1}Sr{sub 0.1}M{sub 0.1}MnO{sub 3} (LCSMO) (M=Ag and Na) samples prepared using nitrate route method. The structural properties are studied at different dopants by X-ray diffraction. The surface morphology and elemental analysis of both samples were carried out by scanning electron microscopy (SEM) and energy dispersive X-ray technique (EDAX) respectively. The structural analysis shows that the LCSMO is crystallized in an orthorhombic perovskite structure belonging to Pnma space group. The crystalmore » size of the sample is calculated using Scherrer formula. The SEM images show that the polycrystalline grains are observed to be near spherical shape and uniform in size. EDAX spectra taken from the surface of the synthesized powders show a nominal composition near the desired one for M=Na sample where as some vacancies are present in the A-site in the case of Ag substitution as will be discussed in this paper.« less

Fiber architecture in remodeled myocardium revealed with a quantitative diffusion CMR tractography framework and histological validation.

PubMed

Mekkaoui, Choukri; Huang, Shuning; Chen, Howard H; Dai, Guangping; Reese, Timothy G; Kostis, William J; Thiagalingam, Aravinda; Maurovich-Horvat, Pal; Ruskin, Jeremy N; Hoffmann, Udo; Jackowski, Marcel P; Sosnovik, David E

2012-10-12

The study of myofiber reorganization in the remote zone after myocardial infarction has been performed in 2D. Microstructural reorganization in remodeled hearts, however, can only be fully appreciated by considering myofibers as continuous 3D entities. The aim of this study was therefore to develop a technique for quantitative 3D diffusion CMR tractography of the heart, and to apply this method to quantify fiber architecture in the remote zone of remodeled hearts. Diffusion Tensor CMR of normal human, sheep, and rat hearts, as well as infarcted sheep hearts was performed ex vivo. Fiber tracts were generated with a fourth-order Runge-Kutta integration technique and classified statistically by the median, mean, maximum, or minimum helix angle (HA) along the tract. An index of tract coherence was derived from the relationship between these HA statistics. Histological validation was performed using phase-contrast microscopy. In normal hearts, the subendocardial and subepicardial myofibers had a positive and negative HA, respectively, forming a symmetric distribution around the midmyocardium. However, in the remote zone of the infarcted hearts, a significant positive shift in HA was observed. The ratio between negative and positive HA variance was reduced from 0.96 ± 0.16 in normal hearts to 0.22 ± 0.08 in the remote zone of the remodeled hearts (p < 0.05). This was confirmed histologically by the reduction of HA in the subepicardium from -52.03° ± 2.94° in normal hearts to -37.48° ± 4.05° in the remote zone of the remodeled hearts (p < 0.05). A significant reorganization of the 3D fiber continuum is observed in the remote zone of remodeled hearts. The positive (rightward) shift in HA in the remote zone is greatest in the subepicardium, but involves all layers of the myocardium. Tractography-based quantification, performed here for the first time in remodeled hearts, may provide a framework for assessing regional changes in the left ventricle following

The Use of Gadolinium-Carbon Nanostructures to Magnetically Enhance Stem Cell Retention for Cellular Cardiomyoplasty

PubMed Central

Tran, Lesa A.; Hernández-Rivera, Mayra; Berlin, Ari N.; Zheng, Yi; Sampaio, Luiz; Bové, Christina; Cabreira-Hansen, Maria da Graça; Willerson, James T.; Perin, Emerson C.; Wilson, Lon J.

2014-01-01

In this work, the effectiveness of using Gadonanotubes (GNTs) with an external magnetic field to improve retention of transplanted adult mesenchymal stem cells (MSCs) during cellular cardiomyoplasty was evaluated. As a high-performance T1-weighted magnetic resonance imaging (MRI) cell tracking label, the GNTs are gadolinium-loaded carbon nanotube capsules that render MSCs magnetic when internalized. MSCs were internally labeled with either superparamagnetic GNTs or colloidal diamagnetic lutetium (Lu). In vitro cell rolling assays and ex vivo cardiac perfusion experiments qualitatively demonstrated increased magnetic-assisted retention of GNT-labeled MSCs. Subsequent in vivo epicardial cell injections were performed around a 1.3 T NdFeB ring magnet sutured onto the left ventricle of female juvenile pigs (n = 21). Cell dosage, magnet exposure time, and endpoints were varied to evaluate the safety and efficacy of the proposed therapy. Quantification of retained cells in collected tissues by elemental analysis (Gd or Lu) showed that the external magnet helped retain nearly three times more GNT-labeled MSCs than Lu-labeled cells. The sutured magnet was tolerated for up to 168 hours; however, an inflammatory response to the magnet was noted after 48 hours. These proof-of-concept studies support the feasibility and value of using GNTs as a magnetic nanoparticle facilitator to improve cell retention during cellular cardiomyoplasty. PMID:24148239

Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and T2 mapping of talar osteochondral lesions: Indicators of clinical outcomes.

PubMed

Rehnitz, Christoph; Kuni, Benita; Wuennemann, Felix; Chloridis, Dimitrios; Kirwadi, Anand; Burkholder, Iris; Kauczor, Hans-Ulrich; Weber, Marc-André

2017-12-01

To evaluate the utility of delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) and T 2 mapping in evaluation of type II osteochondral lesions (OCLs) of the talus and define cutoff values for identifying patients with good/poor clinical outcomes. 28 patients (mean age, 42.3 years) underwent T 2 mapping and dGEMRIC at least 1.5 years (mean duration, 3.5 years) after microfracture (n = 12) or conservative (n = 16) treatment for type II OCL. Clinical outcomes were considered good with an American Orthopedic Foot and Ankle Society score ≥80. The T 1 /T 2 -values and indices of repair tissue (RT; cartilage above the OCL) were compared to those of the adjacent normal cartilage (NC) by region-of-interest analysis. The ability of the two methods to discriminate RT from NC was determined by area under the receiver operating characteristics curve (AUC) analysis. The Youden index was maximized for T 1 /T 2 measures for identifying cutoff values indicative of good/poor clinical outcomes. Repair tissue exhibited lower dGEMRIC values (629.83 vs. 738.51 msec) and higher T 2 values (62.07 vs. 40.69 msec) than NC (P < 0.001). T 2 mapping exhibited greater AUC than dGEMRIC (0.88 vs. 0.69; P = 0.0398). All T 1 measures exhibited higher maximized Youden indices than the corresponding T 2 measures. The highest maximized Youden index for T 1difference was observed at a cutoff value of 84 msec (sensitivity, 78%; specificity, 83%). While T 2 mapping is superior to dGEMRIC in discriminating RT, the latter better identifies good/poor clinical outcomes in patients with type II talar OCL. 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017;46:1601-1610. © 2017 International Society for Magnetic Resonance in Medicine.

Automatic classification of scar tissue in late gadolinium enhancement cardiac MRI for the assessment of left-atrial wall injury after radiofrequency ablation

PubMed Central

Morris, Alan; Burgon, Nathan; McGann, Christopher; MacLeod, Robert; Cates, Joshua

2013-01-01

Radiofrequency ablation is a promising procedure for treating atrial fibrillation (AF) that relies on accurate lesion delivery in the left atrial (LA) wall for success. Late Gadolinium Enhancement MRI (LGE MRI) at three months post-ablation has proven effective for noninvasive assessment of the location and extent of scar formation, which are important factors for predicting patient outcome and planning of redo ablation procedures. We have developed an algorithm for automatic classification in LGE MRI of scar tissue in the LA wall and have evaluated accuracy and consistency compared to manual scar classifications by expert observers. Our approach clusters voxels based on normalized intensity and was chosen through a systematic comparison of the performance of multivariate clustering on many combinations of image texture. Algorithm performance was determined by overlap with ground truth, using multiple overlap measures, and the accuracy of the estimation of the total amount of scar in the LA. Ground truth was determined using the STAPLE algorithm, which produces a probabilistic estimate of the true scar classification from multiple expert manual segmentations. Evaluation of the ground truth data set was based on both inter- and intra-observer agreement, with variation among expert classifiers indicating the difficulty of scar classification for a given a dataset. Our proposed automatic scar classification algorithm performs well for both scar localization and estimation of scar volume: for ground truth datasets considered easy, variability from the ground truth was low; for those considered difficult, variability from ground truth was on par with the variability across experts. PMID:24236224

Automatic classification of scar tissue in late gadolinium enhancement cardiac MRI for the assessment of left-atrial wall injury after radiofrequency ablation

NASA Astrophysics Data System (ADS)

Perry, Daniel; Morris, Alan; Burgon, Nathan; McGann, Christopher; MacLeod, Robert; Cates, Joshua

2012-03-01

Radiofrequency ablation is a promising procedure for treating atrial fibrillation (AF) that relies on accurate lesion delivery in the left atrial (LA) wall for success. Late Gadolinium Enhancement MRI (LGE MRI) at three months post-ablation has proven effective for noninvasive assessment of the location and extent of scar formation, which are important factors for predicting patient outcome and planning of redo ablation procedures. We have developed an algorithm for automatic classification in LGE MRI of scar tissue in the LA wall and have evaluated accuracy and consistency compared to manual scar classifications by expert observers. Our approach clusters voxels based on normalized intensity and was chosen through a systematic comparison of the performance of multivariate clustering on many combinations of image texture. Algorithm performance was determined by overlap with ground truth, using multiple overlap measures, and the accuracy of the estimation of the total amount of scar in the LA. Ground truth was determined using the STAPLE algorithm, which produces a probabilistic estimate of the true scar classification from multiple expert manual segmentations. Evaluation of the ground truth data set was based on both inter- and intra-observer agreement, with variation among expert classifiers indicating the difficulty of scar classification for a given a dataset. Our proposed automatic scar classification algorithm performs well for both scar localization and estimation of scar volume: for ground truth datasets considered easy, variability from the ground truth was low; for those considered difficult, variability from ground truth was on par with the variability across experts.

Myocardial impairment detected by late gadolinium enhancement in hypertrophic cardiomyopathy: comparison with 99mTc-MIBI/tetrofosmin and 123I-BMIPP SPECT.

PubMed

Hashimura, Hiromi; Kiso, Keisuke; Yamada, Naoaki; Kono, Atsushi; Morita, Yoshiaki; Fukushima, Kazuto; Higashi, Masahiro; Noguchi, Teruo; Ishibashi-Ueda, Hatsue; Naito, Hiroaki; Sugimura, Kazuro

2013-06-17

Myocardial fibrosis is considered to be an important factor in myocardial dysfunction and sudden cardiac death in hypertrophic cardiomyopathy (HCM). The purpose of this study was to compare myocardial fibrosis detected by late gadolinium enhancement (LGE) on cardiac MRI with myocardial perfusion and fatty acid metabolism assessed by single photon emission computed tomography in HCM. We retrospectively evaluated 20 consecutive HCM patients (female, 7; mean age, 53.4 years) who underwent LGE, technetium-99m methoxyisobutylisonitrile/tetrofosmin (99mTc-MIBI/tetrofosmin), and iodine-123 beta-methyl-iodophenylpentadecanoic acid (123I-BMIPP) imaging. We calculated the myocardium-to-lumen signal ratio (M/L) for LGE in 17 segments based on the American Heart Association statement. Scoring of 99mTc-MIBI/tetrofosmin (PI) and 123I-BMIPP (BM) was performed for each segment using a 5-point scale (0, normal; 4, highly decreased). Nineteen of 20 patients (95%) and 153 of 340 segments (45%) showed LGE. M/Ls were 0.42±0.16, 0.55±0.17, and 0.65±0.24 in PI0/BM0, PI0/BM1-4 and PI1-4/BM1-4, respectively. All M/Ls were significantly higher than that of a normal control (0.34±0.14) (p<0.001). Myocardial fibrosis in HCM can occur despite normal perfusion and fatty acid metabolism, and is more strongly associated with disorders of fatty acid metabolism than with perfusion abnormalities. M/L may be a useful indicator of disease severity.

Influence of delayed gadolinium enhanced MRI of cartilage (dGEMRIC) protocol on T2-mapping: is it possible to comprehensively assess knee cartilage composition in one post-contrast MR examination at 3 Tesla?

PubMed

Verschueren, J; van Tiel, J; Reijman, M; Bron, E E; Klein, S; Verhaar, J A N; Bierma-Zeinstra, S M A; Krestin, G P; Wielopolski, P A; Oei, E H G

2017-09-01

To evaluate the possibility of assessing knee cartilage with T2-mapping and delayed gadolinium enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) in one post-contrast MR examination at 3 Tesla (T). T2 mapping was performed in 10 healthy volunteers at baseline; directly after baseline; after 10 min of cycling; and after 90 min delay, and in 16 osteoarthritis patients before and after intravenous administration of a double dose gadolinium dimeglumine contrast agent, reflecting key dGEMRIC protocol elements. Differences in T2 relaxation times between each timepoint and baseline were calculated for 6 cartilage regions using paired t tests or Wilcoxon signed-rank tests and the smallest detectable change (SDC). After cycling, a significant change in T2 relaxation times was found in the lateral weight-bearing tibial plateau (+1.0 ms, P = 0.04). After 90 min delay, significant changes were found in the lateral weight-bearing femoral condyle (+1.2 ms, P = 0.03) and the lateral weight-bearing tibial plateau (+1.3 ms, P = 0.01). In these regions of interests (ROIs), absolute differences were small and lower than the corresponding SDCs. T2-mapping after contrast administration only showed statistically significantly lower T2 relaxation times in the medial posterior femoral condyle (-2.4 ms, P < 0.001) with a change exceeding the SDC. Because dGEMRIC protocol elements resulted in only small differences in T2 relaxation times that were not consistent and lower than the SDC in the majority of regions, our results suggest that T2-mapping and dGEMRIC can be performed reliably in a single imaging session to assess cartilage biochemical composition in knee osteoarthritis (OA) at 3 T. Copyright © 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Speckle tracking imaging in inflammatory heart diseases.

PubMed

Leitman, Marina; Vered, Zvi; Tyomkin, Vladimir; Macogon, Boris; Moravsky, Gil; Peleg, Eli; Copel, Laurian

2018-05-01

Accurate diagnosis of acute myocarditis is important for the prognosis and risk stratification of these patients. Cardiac magnetic resonance (CMR) has become a major modality for diagnosis of myocarditis, but not widely available. In this study, we tried to evaluate regional and global longitudinal strain by speckle tracking echocardiography in patients with acute inflammatory myocardial diseases in correlation with CMR. Patients with suspected acute myocarditis were recruited prospectively. Clinical diagnosis was established based on clinical, electrocardiographic, laboratory and conventional echocardiographic data. All patients underwent CMR and repeat echocardiographic examination within 24 h of CMR. Echocardiographic examinations were analyzed offline with speckle tracking imaging software. Thirty-two patients with acute perimyocarditis and myopericarditis were included. Mean age was 29 ± 8, 30 males. All patients presented with chest pain and an abnormal electrocardiogram, in 28 ST elevation was found. Troponin was elevated in 30 and was 0.7 ± 0.5 ng/ml. Creatine kinase was 487 ± 319 U. LVEF was 56 ± 5%. Wall motion abnormalities were present in postero-lateral (53%), and inferior wall (21%). Delayed enhancement on CMR was found in 29 patients. Echocardiographic EF based on speckle tracking imaging correlated with CMR calculated EF. There was a positive correlation between the amplitude of regional strain and delayed enhancement, r = 0.52. Sensitivity and specificity of regional strain for prediction of delayed enhancement was 85 and 73% respectively. Speckle tracking imaging can help in the diagnosis of acute myocarditis when CMR is not readily available. Speckle tracking imaging based EF correlates with CMR calculated LVEF and with global strain.

RV Fractional Area Change and TAPSE as Predictors of Severe Right Ventricular Dysfunction in Pulmonary Hypertension: A CMR Study.

PubMed

Hoette, Susana; Creuzé, Nicolas; Günther, Sven; Montani, David; Savale, Laurent; Jaïs, Xavier; Parent, Florence; Sitbon, Olivier; Rochitte, Carlos Eduardo; Simonneau, Gerald; Humbert, Marc; Souza, Rogerio; Chemla, Denis

2018-04-01

The right ventricular ejection fraction (RVEF) is a surrogate marker of right ventricular function in pulmonary hypertension (PH), but its measurement is complicated and time consuming. The tricuspid annular plane systolic excursion (TAPSE) measures only the longitudinal component of RV contraction while the right ventricular fractional area change (RVFAC) takes into account both the longitudinal and the transversal components. The aim of our study was to evaluate the relationship between RVEF, RVFAC, and TAPSE according to hemodynamic severity in two groups of patients with PH: pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). Fifty-four patients with PAH (n = 15) and CTEPH (n = 39) underwent right heart catheterization and cardiac magnetic resonance (CMR). The ventricular volumes and areas, TAPSE, and eccentricity index were measured. The RVFAC was more strongly correlated with the RVEF (r = 0.81, p < 0.0001) than the TAPSE (r = 0.63, p < 0.0001). RVEF < 35% was better predicted by the RVFAC than the TAPSE (TAPSE: AUC = 0.77 and RVFAC: AUC = 0.91; p = 0.042). In the group with the worse hemodynamic status, the RVFAC correlated much better with the RVEF than the TAPSE. There were no significant differences in the CMR data analyzed between the groups of PAH and CETPH patients. The RVFAC is a good index to estimate RVEF in PH patients; even better than the TAPSE in patients with more severe hemodynamic profile, possibly for including the transversal component of right ventricular function in its measurement. Furthermore, RVFAC performance was similar in the two PH groups (PAH and CTEPH).

Tungsten-encapsulated gadolinium nanoislands with enhanced magnetocaloric response

DOE PAGES

Logan, Jonathan M.; Rosenmann, Daniel; Sangpo, Tenzin; ...

2017-07-03

Here, we report a method for growing chemically pure, oxide-free, air-stable Gd nanoislands with enhanced magnetic properties. These nanoislands are grown by solid-state dewetting and are fully encapsulated in tungsten such that they remain stable in ambient environments. They display good crystalline properties with hexagonally close-packed crystal structure and strong preferential orientation. We show that the choice of substrate strongly affects their shape, crystal orientation, and magnetic properties. The temperature-dependent magnetic coercivity and remanence of the Gd islands can vary by as much as a factor of three depending on the substrate used. The magneto- caloric properties of Gd islandsmore » grown on a sapphire substrate exceed those of high-quality Gd thin films.« less

Assessing the effect of football play on knee articular cartilage using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC).

PubMed

Wei, Wenbo; Lambach, Becky; Jia, Guang; Flanigan, David; Chaudhari, Ajit M W; Wei, Lai; Rogers, Alan; Payne, Jason; Siston, Robert A; Knopp, Michael V

2017-06-01

The prevalence of cartilage lesions is much higher in football athletes than in the general population. Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) has been shown to quantify regional variations of glycosaminoglycan (GAG) concentrations which is an indicator of early cartilage degeneration. The goal of this study is to determine whether dGEMRIC can be used to assess the influence in cartilage GAG concentration due to college level football play. Thirteen collegiate football players with one to four years of collegiate football play experience were recruited and both knee joints were scanned using a dedicated 8-channel phased array knee coil on a 3T MRI system. The contrast concentrations within cartilage were calculated based on the T 1 values from dGEMRIC scans. No substantial differences were found in the contrast concentrations between the pre- and post-season across all the cartilage compartments. One year collegiate football players presented an average contrast concentration at the pre-season of 0.116±0.011mM and post-season of 0.116±0.011mM. In players with multiple years of football play, contrast uptake was elevated to 0.141±0.012mM at the pre-season and 0.139±0.012mM at the post-season. The pre-season 0.023±0.016mM and post-season 0.025±0.016mM increase in contrast concentration within the group with multiple years of experience presented with a >20% increase in contrast uptake. This may indicate the gradual, cumulative damage of football play to the articular cartilage over years, even though the effect may not be noticeable after a season of play. Playing collegiate football for a longer period of time may lead to cartilage microstructural alterations, which may be linked to early knee cartilage degeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

Cross-linkable liposomes stabilize a magnetic resonance contrast-enhancing polymeric fastener.

PubMed

Smith, Cartney E; Kong, Hyunjoon

2014-04-08

Liposomes are commonly used to deliver drugs and contrast agents to their target site in a controlled manner. One of the greatest obstacles in the performance of such delivery vehicles is their stability in the presence of serum. Here, we demonstrate a method to stabilize a class of liposomes that load gadolinium, a magnetic resonance (MR) contrast agent, as a model cargo on their surfaces. We hypothesized that the sequential adsorption of a gadolinium-binding chitosan fastener on the liposome surface followed by covalent cross-linking of the lipid bilayer would provide enhanced stability and improved MR signal in the presence of human serum. To investigate this hypothesis, liposomes composed of diyne-containing lipids were assembled and functionalized via chitosan conjugated with a hydrophobic anchor and diethylenetriaminepentaacetic acid (DTPA). This postadsorption cross-linking strategy served to stabilize the thermodynamically favorable association between liposome and polymeric fastener. Furthermore, the chitosan-coated, cross-linked liposomes proved more effective as delivery vehicles of gadolinium than uncross-linked liposomes due to the reduced liposome degradation and chitosan desorption. Overall, this study demonstrates a useful method to stabilize a broad class of particles used for systemic delivery of various molecular payloads.

Cross-Linkable Liposomes Stabilize a Magnetic Resonance Contrast-Enhancing Polymeric Fastener

PubMed Central

2015-01-01

Liposomes are commonly used to deliver drugs and contrast agents to their target site in a controlled manner. One of the greatest obstacles in the performance of such delivery vehicles is their stability in the presence of serum. Here, we demonstrate a method to stabilize a class of liposomes that load gadolinium, a magnetic resonance (MR) contrast agent, as a model cargo on their surfaces. We hypothesized that the sequential adsorption of a gadolinium-binding chitosan fastener on the liposome surface followed by covalent cross-linking of the lipid bilayer would provide enhanced stability and improved MR signal in the presence of human serum. To investigate this hypothesis, liposomes composed of diyne-containing lipids were assembled and functionalized via chitosan conjugated with a hydrophobic anchor and diethylenetriaminepentaacetic acid (DTPA). This postadsorption cross-linking strategy served to stabilize the thermodynamically favorable association between liposome and polymeric fastener. Furthermore, the chitosan-coated, cross-linked liposomes proved more effective as delivery vehicles of gadolinium than uncross-linked liposomes due to the reduced liposome degradation and chitosan desorption. Overall, this study demonstrates a useful method to stabilize a broad class of particles used for systemic delivery of various molecular payloads. PMID:24635565

Daclizumab high-yield process reduced the evolution of new gadolinium-enhancing lesions to T1 black holes in patients with relapsing-remitting multiple sclerosis.

PubMed

Radue, E-W; Sprenger, T; Vollmer, T; Giovannoni, G; Gold, R; Havrdova, E; Selmaj, K; Stefoski, D; You, X; Elkins, J

2016-02-01

In the SELECT study, treatment with daclizumab high-yield process (DAC HYP) versus placebo reduced the frequency of gadolinium-enhancing (Gd(+) ) lesions in patients with relapsing-remitting multiple sclerosis (RRMS). The objective of this post hoc analysis of SELECT was to evaluate the effect of DAC HYP on the evolution of new Gd(+) lesions to T1 hypointense lesions (T1 black holes). SELECT was a randomized double-blind study of subcutaneous DAC HYP 150 or 300 mg or placebo every 4 weeks. Magnetic resonance imaging (MRI) scans were performed at baseline and weeks 24, 36 and 52 in all patients and monthly between weeks 4 and 20 in a subset of patients. MRI scans were evaluated for new Gd(+) lesions that evolved to T1 black holes at week 52. Data for the DAC HYP groups were pooled for analysis. Daclizumab high-yield process reduced the number of new Gd(+) lesions present at week 24 (P = 0.005) or between weeks 4 and 20 (P = 0.014) that evolved into T1 black holes at week 52 versus placebo. DAC HYP treatment also reduced the percentage of patients with Gd(+) lesions evolving to T1 black holes versus placebo. Treatment with DAC HYP reduced the evolution of Gd(+) lesions to T1 black holes versus placebo, suggesting that inflammatory lesions that evolved during DAC HYP treatment are less destructive than those evolving during placebo treatment. © 2016 EAN.

MO-FG-BRA-07: Theranostic Gadolinium-Based AGuIX Nanoparticles for MRI-Guided Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Detappe, A; Institut Lumiere-Matiere, Villeurbanne; Nano-H, St-Quentin Fallavier

2015-06-15

Purpose: AGuIX are gadolinium-based nanoparticles, initially developed for MRI, that have a potential role in radiation therapy as a radiosensitizer. Our goal is to demonstrate that these nanoparticles can both be used as an MRI contrast agent, as well as to obtain local dose enhancement in a pancreatic tumor when delivered in combination with an external beam irradiation. Methods: We performed in vitro cell uptake and radiosensitization studies of a pancreatic cancer cell line in a low energy (220kVp) beam, a standard clinical 6MV beam (STD) and a flattening filter free clinical 6MV beam (FFF). After injection of 40mM ofmore » nanoparticles, a biodistribution study was performed in vivo on mice with subcutaneous xenograft pancreatic tumors. In vivo radiation therapy studies were performed at the time point of maximum tumor uptake. Results: The concentration of AGuIX nanoparticles in Panc-1 pancreatic cancer cells, determined in vitro by MRI and ICPMS, peaks after 30 minutes with 0.3% of the initial concentration (5mg/g). Clonogenic assays show a significant effect (p<0.05) when the AGuIX are coupled with MV photon irradiation (DEF20%=1.31). Similar AGuIX tumor uptake is found in vivo by both MRI and ICPMS 30 minutes after intravenous injection. For long term survival studies, the choice of the radiation dose is determined with 5 control groups (3mice/group) irradiated with 0, 5, 10, 15, and 20Gy. Afterwards, 4 groups (8mice/group) are used to evaluate the effect of the nanoparticles. A Logrank test is performed as a statistical test to evaluate the effect of the nanoparticles. Conclusion: The combination of the MRI contrast and radiosensitization properties of gadolinium nanoparticles reveals a strong potential for usage with MRI-guided radiation therapy.« less

Impact of Impaired Renal Function on Gadolinium Retention After Administration of Gadolinium-Based Contrast Agents in a Mouse Model.

PubMed

Kartamihardja, A Adhipatria P; Nakajima, Takahito; Kameo, Satomi; Koyama, Hiroshi; Tsushima, Yoshito

2016-10-01

The aim of this study was to investigate the impact of impaired renal function on gadolinium (Gd) retention in various organs after Gd-based contrast agent injection. After local animal care and review committee approval, 23 normal mice and 26 with renal failure were divided into 4 treatment groups (Gd-DTPA-BMA, 5 mmol/kg; Gd-DOTA, 5 mmol/kg; GdCl3, 0.02 mmol/kg; and saline, 250 μL). Each agent was intravenously administered on weekdays for 4 weeks. Samples were collected on days 3 (short-term) and 45 (long-term) after the last injection. Gadolinium concentrations were quantified by inductively coupled plasma-mass spectrometry. Three mice with renal failure and 2 normal mice in the GdCl3 group and 1 mouse with renal failure in the Gd-DTPA-BMA group died. In the Gd-DTPA-BMA group, impaired renal function increased short-term Gd retention in the liver, bone, spleen, skin, and kidney (P < 0.01) but did not affect long-term Gd retention. Gd-DTPA-BMA showed higher Gd retention than Gd-DOTA. Although Gd retention in the Gd-DOTA group was generally low, impaired renal function increased only long-term hepatic Gd retention. Hepatic and splenic Gd retentions were significantly higher than other organs' Gd retention in the GdCl3 group (P < 0.01). Renal function did not affect brain Gd retention, regardless of the Gd compound used. The tendency of Gd retention varied according to the agent, regardless of renal function. Although renal impairment increased short-term Gd retention after Gd-DTPA-BMA administration, long-term Gd retention for Gd-based contrast agents was almost unaffected by renal function, suggesting that the chemical structures of retained Gd may not be consistent and some Gd is slowly eliminated after initially being retained.

Engineered gadolinium-doped carbon dots for magnetic resonance imaging-guided radiotherapy of tumors.

PubMed

Du, Fengyi; Zhang, Lirong; Zhang, Li; Zhang, Miaomiao; Gong, Aihua; Tan, Youwen; Miao, Jiawen; Gong, Yuhua; Sun, Mingzhong; Ju, Huixiang; Wu, Chaoyang; Zou, Shenqiang

2017-03-01

The effectiveness of radiotherapy can decrease due to inaccurate positioning of machinery and inherent radioresistance of tumors. To address this issue, we present a novel theranostic nanoplatform based on gadolinium-doped carbon dots (Gd-doped CDs) designed specifically for magnetic resonance imaging (MRI)-guided radiotherapy of tumors. The Gd-doped CDs (∼18 nm) with dispersibility in water and stable photoluminescence were synthesized via a one-step hydrothermal approach. After tail vein injection of the Gd-doped CDs, they exhibited a relatively long circulation time (∼6 h), enabled efficient passive tumor targeting. Gd-doped CDs accumulate in the kidney and could be cleared out of the body from bladder. Importantly, they exhibited favorable biocompatibility with excellent performance in longitudinal relaxivity rate (r 1 ) of 6.45 mM -1 S -1 and radiosensitization enhancements. These results show that Gd-doped CDs are excellent T 1 contrast agents and radiosensitizers, possessing great promise for MRI-guided radiotherapy of tumors. Copyright © 2016 Elsevier Ltd. All rights reserved.

High-pressure high-temperature phase diagram of gadolinium studied using a boron-doped heater anvil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Montgomery, J. M.; Samudrala, G. K.; Vohra, Y. K.

A boron-doped designer heater anvil is used in conjunction with powder x-ray diffraction to collect structural information on a sample of quasi-hydrostatically loaded gadolinium metal up to pressures above 8 GPa and 600 K. The heater anvil consists of a natural diamond anvil that has been surface modified with a homoepitaxially grown chemical-vapor-deposited layer of conducting boron-doped diamond, and is used as a DC heating element. Internally insulating both diamond anvils with sapphire support seats allows for heating and cooling of the high-pressure area on the order of a few tens of seconds. This device is then used to scan the phasemore » diagram of the sample by oscillating the temperature while continuously increasing the externally applied pressure and collecting in situ time-resolved powder diffraction images. In the pressure-temperature range covered in this experiment, the gadolinium sample is observed in its hcp, αSm, and dhcp phases. Under this temperature cycling, the hcp → αSm transition proceeds in discontinuous steps at points along the expected phase boundary. From these measurements (representing only one hour of synchrotron x-ray collection time), a single-experiment equation of state and phase diagram of each phase of gadolinium is presented for the range of 0–10 GPa and 300–650 K.« less

High-pressure high-temperature phase diagram of gadolinium studied using a boron-doped heater anvil

NASA Astrophysics Data System (ADS)

Montgomery, J. M.; Samudrala, G. K.; Velisavljevic, N.; Vohra, Y. K.

2016-04-01

A boron-doped designer heater anvil is used in conjunction with powder x-ray diffraction to collect structural information on a sample of quasi-hydrostatically loaded gadolinium metal up to pressures above 8 GPa and 600 K. The heater anvil consists of a natural diamond anvil that has been surface modified with a homoepitaxially grown chemical-vapor-deposited layer of conducting boron-doped diamond, and is used as a DC heating element. Internally insulating both diamond anvils with sapphire support seats allows for heating and cooling of the high-pressure area on the order of a few tens of seconds. This device is then used to scan the phase diagram of the sample by oscillating the temperature while continuously increasing the externally applied pressure and collecting in situ time-resolved powder diffraction images. In the pressure-temperature range covered in this experiment, the gadolinium sample is observed in its hcp, αSm, and dhcp phases. Under this temperature cycling, the hcp → αSm transition proceeds in discontinuous steps at points along the expected phase boundary. From these measurements (representing only one hour of synchrotron x-ray collection time), a single-experiment equation of state and phase diagram of each phase of gadolinium is presented for the range of 0-10 GPa and 300-650 K.

Disparate ultrafast dynamics of itinerant and localized magnetic moments in gadolinium metal

PubMed Central

Frietsch, B.; Bowlan, J.; Carley, R.; Teichmann, M.; Wienholdt, S.; Hinzke, D.; Nowak, U.; Carva, K.; Oppeneer, P. M.; Weinelt, M.

2015-01-01

The Heisenberg–Dirac intra-atomic exchange coupling is responsible for the formation of the atomic spin moment and thus the strongest interaction in magnetism. Therefore, it is generally assumed that intra-atomic exchange leads to a quasi-instantaneous aligning process in the magnetic moment dynamics of spins in separate, on-site atomic orbitals. Following ultrashort optical excitation of gadolinium metal, we concurrently record in photoemission the 4f magnetic linear dichroism and 5d exchange splitting. Their dynamics differ by one order of magnitude, with decay constants of 14 versus 0.8 ps, respectively. Spin dynamics simulations based on an orbital-resolved Heisenberg Hamiltonian combined with first-principles calculations explain the particular dynamics of 5d and 4f spin moments well, and corroborate that the 5d exchange splitting traces closely the 5d spin-moment dynamics. Thus gadolinium shows disparate dynamics of the localized 4f and the itinerant 5d spin moments, demonstrating a breakdown of their intra-atomic exchange alignment on a picosecond timescale. PMID:26355196

A Manganese Alternative to Gadolinium for MRI Contrast

PubMed Central

Gale, Eric M.; Atanasova, Iliyana P.; Blasi, Francesco; Ay, Ilknur; Caravan, Peter

2016-01-01

Contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) are routinely used to diagnose soft tissue and vascular abnormalities. However safety concerns limit the use of iodinated and gadolinium- (Gd) based CT and MRI contrast media in renally compromised patients. With an estimated 14% of the US population suffering from chronic kidney disease (CKD), contrast media compatible with renal impairment is sorely needed. We present the new manganese(II) complex [Mn(PyC3A)(H2O)]- as a Gd alternative. [Mn(PyC3A)(H2O)]- is amongst the most stable Mn(II) complexes at pH 7.4 (log KML = 11.40). In the presence of 25 mol equiv. Zn at pH 6.0, 37 °C, [Mn(PyC3A)(H2O)]- is 20-fold more resistant to dissociation than [Gd(DTPA)(H2O)]2-. Relaxivity of [Mn(PyC3A)(H2O)]- in blood plasma is comparable to commercial Gd contrast agents. Biodistribution analysis confirms that [Mn(PyC3A)(H2O)]- clears via a mixed renal/ hepatobiliary pathway with >99% elimination by 24h. [Mn(PyC3A)(H2O)]- was modified to form a bifunctional chelator and 4 chelates were conjugated to a fibrin-specific peptide to give Mn-FBP. Mn-FBP binds the soluble fibrin fragment DD(E) with Kd = 110 nM. Per Mn relaxivity of Mn-FBP is 4-fold greater than [Mn(PyC3A)(H2O)]- and increases 60% in the presence of fibrin, consistent with binding. Mn-FBP provided equivalent thrombus enhancement to the state of the art Gd analog, EP-2104R, in a rat model of arterial thrombosis. Mn metabolite analysis reveals no evidence of dechelation and the probe was >99% eliminated after 24 hr. [Mn(PyC3A)(H2O)]- is a lead development candidate for an imaging probe that is compatible with renally compromised patients. PMID:26588204

K3 Li3 Gd7 (BO3 )9 : A New Gadolinium-Rich Orthoborate for Cryogenic Magnetic Cooling.

PubMed

Xia, Mingjun; Shen, Shipeng; Lu, Jun; Sun, Young; Li, Rukang

2018-03-02

Magnetic cooling technology based on magnetocaloric effect (MCE) has attracted great interest in obtaining extremely low temperatures, for example, for space exploration. Here, we grew a new gadolinium-rich orthoborate K 3 Li 3 Gd 7 (BO 3 ) 9 (1) as a promising cryogenic magnetic coolant. It exhibits a complicated three dimensional framework constructed from BO 3 groups and gadolinium-oxygen chains. The Gd-O chain consists of two types of clusters of Gd 3 O 20 and Gd 3 O 19 interconnection by Gd(4)O 8 polyhydron. Due to its high gadolinium concentration, a large -ΔS m of 56.6 J kg -1  K -1 for 1 was obtained at 2 K and ΔH=7 T, much larger than that of the commercial benchmark Gd 3 Ga 5 O 12 (GGG) crystal (38.4 J kg -1  K -1 ), suggesting it to be an excellent MCE material. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Transient arterial phase respiratory motion-related artifact in MR imaging of the liver: an analysis of four different gadolinium-based contrast agents.

PubMed

Shah, Mansi R; Flusberg, Milana; Paroder, Viktoriya; Rozenblit, Alla M; Chernyak, Victoria

The purpose was to compare hepatic arterial phase (HAP) respiratory motion artifact (RMA) between gadoxetate, gadobutrol, gadopentetate, and gadobenate. Two hundred cases of each gadolinium agent were included. RMA was assigned using 5-point Likert scale (1=no motion, 5=extreme motion) on precontrast and HAP. RMA increase (increase ≥1 on HAP from precontrast) was the outcome in logistic regression. Odds of RMA increase for gadoxetate were 5.5 (P<.001), 3.6 (P=.034), and 9.5 (P<.001) times higher than gadobutrol, gadopentetate, and gadobenate, respectively. Gadolinium volume and dose were not independent predictors of RMA increase. Gadoxetate has increased odds of RMA compared with other gadolinium agents; tight contrast bolus is not a contributor. Copyright © 2016 Elsevier Inc. All rights reserved.

Incremental prognostic value of the SYNTAX score to late gadolinium-enhanced magnetic resonance images for patients with stable coronary artery disease.

PubMed

Kato, Shingo; Saito, Naka; Kirigaya, Hidekuni; Gyotoku, Daiki; Iinuma, Naoki; Kusakawa, Yuka; Iguchi, Kohei; Nakachi, Tatsuya; Fukui, Kazuki; Futaki, Masaaki; Iwasawa, Tae; Taguri, Masataka; Kimura, Kazuo; Umemura, Satoshi

2016-06-01

The prognostic significance of the SYNTAX (Synergy between PCI with Taxus and cardiac surgery) score has recently been demonstrated in patients with stable multivessel or left main coronary artery disease (CAD). The present study determines whether adding the SYNTAX score to Framingham risk score (FRS), left ventricular ejection fraction (LVEF) and presence of myocardial infarction (MI) by late gadolinium enhancement (LGE) magnetic resonance imaging can improve the risk stratification in patients with stable CAD. We calculated the SYNTAX score in 161 patients with stable CAD (mean age: 66 ± 10 years old). During a mean follow-up of 2.3 years, 56 (35 %) of 161 patients developed cardiovascular events defined as cardiovascular death, non-fatal MI, cerebral infarction, unstable angina pectoris, hospitalization due to heart failure and revascularization. Multivariate Cox regression analysis selected triglycerides [hazard ratio (HR): 1.005 (95 % confidence interval (CI): 1.001-1.008), p < 0.008], presence of LGE [HR: 6.329 (95 % CI: 2.662-15.05), p < 0.001] and the SYNTAX score [HR: 1.085 (95 % CI: 1.044-1.127), p < 0.001] as risk factors for future cardiovascular events. Adding the SYNTAX score to FRS, EF and LGE significantly improved the net reclassification index (NRI) [40.4 % (95 % CI: 18.1-54.8 %), p < 0.05] with an increase in C-statistics of 0.089 (from 0.707 to 0.796). An increase in C-statistics and significant improvement of NRI showed that adding the SYNTAX score to the FRS, LVEF and LGE incrementally improved risk stratification in patient with stable CAD.

Evaluation of focal cartilage lesions of the knee using MRI T2 mapping and delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC).

PubMed

Årøen, Asbjørn; Brøgger, Helga; Røtterud, Jan Harald; Sivertsen, Einar Andreas; Engebretsen, Lars; Risberg, May Arna

2016-02-11

Assessment of degenerative changes of the cartilage is important in knee cartilage repair surgery. Magnetic Resonance Imaging (MRI) T2 mapping and delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC) are able to detect early degenerative changes. The hypothesis of the study was that cartilage surrounding a focal cartilage lesion in the knee does not possess degenerative changes. Twenty-eight consecutive patients included in a randomized controlled trial on cartilage repair were evaluated using MRI T2 mapping and dGEMRIC before cartilage treatment was initiated. Inclusion was based on disabling knee problems (Lysholm score of ≤ 75) due to an arthroscopically verified focal femoral condyle cartilage lesion. Furthermore, no major malalignments or knee ligament injuries were accepted. Mean patient age was 33 ± 9.6 years, and the mean duration of knee symptoms was 49 ± 60 months. The MRI T2 mapping and the dGEMRIC measurements were performed at three standardized regions of interest (ROIs) at the medial and lateral femoral condyle, avoiding the cartilage lesion The MRI T2 mapping of the cartilage did not demonstrate significant differences between condyles with or without cartilage lesions. The dGEMRIC results did not show significantly lower values of the affected condyle compared with the opposite condyle and the contra-lateral knee in any of the ROIs. The intraclass correlation coefficient (ICC) of the dGEMRIC readings was 0.882. The MRI T2 mapping and the dGEMRIC confirmed the arthroscopic findings that normal articular cartilage surrounded the cartilage lesion, reflecting normal variation in articular cartilage quality. NCT00885729 , registered April 17 2009.

Reference ranges of left ventricular structure and function assessed by contrast-enhanced cardiac MR and changes related to ageing and hypertension in a population-based study.

PubMed

Bülow, Robin; Ittermann, Till; Dörr, Marcus; Poesch, Axel; Langner, Sönke; Völzke, Henry; Hosten, Norbert; Dewey, Marc

2018-03-14

Reference ranges of left ventricular (LV) parameters from cardiac magnetic resonance (CMR) were established to investigate the impact of ageing and hypertension as important determinants of cardiac structure and function. One thousand five hundred twenty-five contrast-enhanced CMRs were conducted in the Study of Health in Pomerania. LV end-diastolic volume (LVEDV), end-systolic volume (LVESV), stroke volume (LVSV), ejection fraction (LVEF), and myocardial mass (LVMM) were determined using long- and short-axis steady-state free-precession sequences. The reference population was defined as participants without late enhancement, hypertension, and prior cardiovascular diseases. Reference ranges were established by quantile regression (5th and 95th percentile) and compared with an additional sample of treated and untreated hypertensives. LV volumes in the reference population (n = 634, 300 males, 334 females, 52.1 ± 13.3 years) aged between 20-69 years were lower with higher age (p = 0.001), whereas LVEFs were higher (p ≤ 0.020). LVMM was lower only in males (p = 0.002). Compared with the reference population, hypertension was associated with lower LVEDV in males (n = 258, p ≤ 0.032). Antihypertensive therapy was associated with higher LVEF in males (n = 258, +2.5%, p = 0.002) and females (n = 180, +2.1%, p = 0.001). Population-based LV reference ranges were derived from contrast-enhanced CMR. Hypertension-related changes were identified by comparing these values with those of hypertensives, and they might be used to monitor cardiac function in these patients. • Left ventricular function changed slightly but significantly between 20-69 years. • Reference values of BSA-indexed myocardial mass decreased with age in males. • Hypertension was associated with lower LV end-diastolic volume only in males. • CMR may allow assessing remodelling related to hypertension or antihypertensive treatment.

Renal function, nephrogenic systemic fibrosis and other adverse reactions associated with gadolinium-based contrast media.

PubMed

Canga, Ana; Kislikova, Maria; Martínez-Gálvez, María; Arias, Mercedes; Fraga-Rivas, Patricia; Poyatos, Cecilio; de Francisco, Angel L M

2014-01-01

Nephrogenic systemic fibrosis is a fibrosing disorder that affects patients with impaired renal function and is associated with the administration of gadolinium-based contrast media used in MRI. Despite being in a group of drugs that were considered safe, report about this potentially serious adverse reaction was a turning point in the administration guidelines of these contrast media. There has been an attempt to establish safety parameters to identify patients with risk factors of renal failure. The close pharmacovigilance and strict observation of current regulations, with special attention being paid to the value of glomerular filtration, have reduced the published cases involving the use of gadolinium-based contrast media. In a meeting between radiologists and nephrologists we reviewed the most relevant aspects currently and recommendations for its prevention.

Antimicrobial and Insecticidal: Cyclic Lipopeptides and Hydrogen Cyanide Produced by Plant-Beneficial Pseudomonas Strains CHA0, CMR12a, and PCL1391 Contribute to Insect Killing

PubMed Central

Flury, Pascale; Vesga, Pilar; Péchy-Tarr, Maria; Aellen, Nora; Dennert, Francesca; Hofer, Nicolas; Kupferschmied, Karent P.; Kupferschmied, Peter; Metla, Zane; Ma, Zongwang; Siegfried, Sandra; de Weert, Sandra; Bloemberg, Guido; Höfte, Monica; Keel, Christoph J.; Maurhofer, Monika

2017-01-01

Particular groups of plant-beneficial fluorescent pseudomonads are not only root colonizers that provide plant disease suppression, but in addition are able to infect and kill insect larvae. The mechanisms by which the bacteria manage to infest this alternative host, to overcome its immune system, and to ultimately kill the insect are still largely unknown. However, the investigation of the few virulence factors discovered so far, points to a highly multifactorial nature of insecticidal activity. Antimicrobial compounds produced by fluorescent pseudomonads are effective weapons against a vast diversity of organisms such as fungi, oomycetes, nematodes, and protozoa. Here, we investigated whether these compounds also contribute to insecticidal activity. We tested mutants of the highly insecticidal strains Pseudomonas protegens CHA0, Pseudomonas chlororaphis PCL1391, and Pseudomonas sp. CMR12a, defective for individual or multiple antimicrobial compounds, for injectable and oral activity against lepidopteran insect larvae. Moreover, we studied expression of biosynthesis genes for these antimicrobial compounds for the first time in insects. Our survey revealed that hydrogen cyanide and different types of cyclic lipopeptides contribute to insecticidal activity. Hydrogen cyanide was essential to full virulence of CHA0 and PCL1391 directly injected into the hemolymph. The cyclic lipopeptide orfamide produced by CHA0 and CMR12a was mainly important in oral infections. Mutants of CMR12a and PCL1391 impaired in the production of the cyclic lipopeptides sessilin and clp1391, respectively, showed reduced virulence in injection and feeding experiments. Although virulence of mutants lacking one or several of the other antimicrobial compounds, i.e., 2,4-diacetylphloroglucinol, phenazines, pyrrolnitrin, or pyoluteorin, was not reduced, these metabolites might still play a role in an insect background since all investigated biosynthetic genes for antimicrobial compounds of strain

Bioconjugation of luminescent silicon quantum dots to gadolinium ions for bioimaging applications

NASA Astrophysics Data System (ADS)

Erogbogbo, Folarin; Chang, Ching-Wen; May, Jasmine L.; Liu, Liwei; Kumar, Rajiv; Law, Wing-Cheung; Ding, Hong; Yong, Ken Tye; Roy, Indrajit; Sheshadri, Mukund; Swihart, Mark T.; Prasad, Paras N.

2012-08-01

Luminescent imaging agents and MRI contrast agents are desirable components in the rational design of multifunctional nanoconstructs for biological imaging applications. Luminescent biocompatible silicon quantum dots (SiQDs) and gadolinium chelates can be applied for fluorescence microscopy and MRI, respectively. Here, we report the first synthesis of a nanocomplex incorporating SiQDs and gadolinium ions (Gd3+) for biological applications. The nanoconstruct is composed of a PEGylated micelle, with hydrophobic SiQDs in its core, covalently bound to DOTA-chelated Gd3+. Dynamic light scattering reveals a radius of 85 nm for these nanoconstructs, which is consistent with the electron microscopy results depicting radii ranging from 25 to 60 nm. Cellular uptake of the probes verified that they maintain their optical properties within the intracellular environment. The magnetic resonance relaxivity of the nanoconstruct was 2.4 mM-1 s-1 (in terms of Gd3+ concentration), calculated to be around 6000 mM-1 s-1 per nanoconstruct. These desirable optical and relaxivity properties of the newly developed probe open the door for use of SiQDs in future multimodal applications such as tumour imaging.Luminescent imaging agents and MRI contrast agents are desirable components in the rational design of multifunctional nanoconstructs for biological imaging applications. Luminescent biocompatible silicon quantum dots (SiQDs) and gadolinium chelates can be applied for fluorescence microscopy and MRI, respectively. Here, we report the first synthesis of a nanocomplex incorporating SiQDs and gadolinium ions (Gd3+) for biological applications. The nanoconstruct is composed of a PEGylated micelle, with hydrophobic SiQDs in its core, covalently bound to DOTA-chelated Gd3+. Dynamic light scattering reveals a radius of 85 nm for these nanoconstructs, which is consistent with the electron microscopy results depicting radii ranging from 25 to 60 nm. Cellular uptake of the probes verified that they

Removal of gadolinium nitrate from heavy water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilde, E.W.

2000-03-22

Work was conducted to develop a cost-effective process to purify 181 55-gallon drums containing spent heavy water moderator (D2O) contaminated with high concentrations of gadolinium nitrate, a chemical used as a neutron poison during former nuclear reactor operations at the Savannah River Site (SRS). These drums also contain low level radioactive contamination, including tritium, which complicates treatment options. Presently, the drums of degraded moderator are being stored on site. It was suggested that a process utilizing biological mechanisms could potentially lower the total cost of heavy water purification by allowing the use of smaller equipment with less product loss andmore » a reduction in the quantity of secondary waste materials produced by the current baseline process (ion exchange).« less

Image-based reconstruction of three-dimensional myocardial infarct geometry for patient-specific modeling of cardiac electrophysiology

PubMed Central

Ukwatta, Eranga; Arevalo, Hermenegild; Rajchl, Martin; White, James; Pashakhanloo, Farhad; Prakosa, Adityo; Herzka, Daniel A.; McVeigh, Elliot; Lardo, Albert C.; Trayanova, Natalia A.; Vadakkumpadan, Fijoy

2015-01-01

Purpose: Accurate three-dimensional (3D) reconstruction of myocardial infarct geometry is crucial to patient-specific modeling of the heart aimed at providing therapeutic guidance in ischemic cardiomyopathy. However, myocardial infarct imaging is clinically performed using two-dimensional (2D) late-gadolinium enhanced cardiac magnetic resonance (LGE-CMR) techniques, and a method to build accurate 3D infarct reconstructions from the 2D LGE-CMR images has been lacking. The purpose of this study was to address this need. Methods: The authors developed a novel methodology to reconstruct 3D infarct geometry from segmented low-resolution (Lo-res) clinical LGE-CMR images. Their methodology employed the so-called logarithm of odds (LogOdds) function to implicitly represent the shape of the infarct in segmented image slices as LogOdds maps. These 2D maps were then interpolated into a 3D image, and the result transformed via the inverse of LogOdds to a binary image representing the 3D infarct geometry. To assess the efficacy of this method, the authors utilized 39 high-resolution (Hi-res) LGE-CMR images, including 36 in vivo acquisitions of human subjects with prior myocardial infarction and 3 ex vivo scans of canine hearts following coronary ligation to induce infarction. The infarct was manually segmented by trained experts in each slice of the Hi-res images, and the segmented data were downsampled to typical clinical resolution. The proposed method was then used to reconstruct 3D infarct geometry from the downsampled images, and the resulting reconstructions were compared with the manually segmented data. The method was extensively evaluated using metrics based on geometry as well as results of electrophysiological simulations of cardiac sinus rhythm and ventricular tachycardia in individual hearts. Several alternative reconstruction techniques were also implemented and compared with the proposed method. Results: The accuracy of the LogOdds method in reconstructing 3D

Image-based reconstruction of three-dimensional myocardial infarct geometry for patient-specific modeling of cardiac electrophysiology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ukwatta, Eranga, E-mail: eukwatt1@jhu.edu; Arevalo, Hermenegild; Pashakhanloo, Farhad

Purpose: Accurate three-dimensional (3D) reconstruction of myocardial infarct geometry is crucial to patient-specific modeling of the heart aimed at providing therapeutic guidance in ischemic cardiomyopathy. However, myocardial infarct imaging is clinically performed using two-dimensional (2D) late-gadolinium enhanced cardiac magnetic resonance (LGE-CMR) techniques, and a method to build accurate 3D infarct reconstructions from the 2D LGE-CMR images has been lacking. The purpose of this study was to address this need. Methods: The authors developed a novel methodology to reconstruct 3D infarct geometry from segmented low-resolution (Lo-res) clinical LGE-CMR images. Their methodology employed the so-called logarithm of odds (LogOdds) function to implicitlymore » represent the shape of the infarct in segmented image slices as LogOdds maps. These 2D maps were then interpolated into a 3D image, and the result transformed via the inverse of LogOdds to a binary image representing the 3D infarct geometry. To assess the efficacy of this method, the authors utilized 39 high-resolution (Hi-res) LGE-CMR images, including 36 in vivo acquisitions of human subjects with prior myocardial infarction and 3 ex vivo scans of canine hearts following coronary ligation to induce infarction. The infarct was manually segmented by trained experts in each slice of the Hi-res images, and the segmented data were downsampled to typical clinical resolution. The proposed method was then used to reconstruct 3D infarct geometry from the downsampled images, and the resulting reconstructions were compared with the manually segmented data. The method was extensively evaluated using metrics based on geometry as well as results of electrophysiological simulations of cardiac sinus rhythm and ventricular tachycardia in individual hearts. Several alternative reconstruction techniques were also implemented and compared with the proposed method. Results: The accuracy of the LogOdds method in

Insights into the use of gadolinium and gadolinium/boron-based agents in imaging-guided neutron capture therapy applications.

PubMed

Deagostino, Annamaria; Protti, Nicoletta; Alberti, Diego; Boggio, Paolo; Bortolussi, Silva; Altieri, Saverio; Crich, Simonetta Geninatti

2016-05-01

Gadolinium neutron capture therapy (Gd-NCT) is currently under development as an alternative approach for cancer therapy. All of the clinical experience to date with NCT is done with (10)B, known as boron neutron capture therapy (BNCT), a binary treatment combining neutron irradiation with the delivery of boron-containing compounds to tumors. Currently, the use of Gd for NCT has been getting more attention because of its highest neutron cross-section. Although Gd-NCT was first proposed many years ago, its development has suffered due to lack of appropriate tumor-selective Gd agents. This review aims to highlight the recent advances for the design, synthesis and biological testing of new Gd- and B-Gd-containing compounds with the task of finding the best systems able to improve the NCT clinical outcome.

Computer-based assessment of left ventricular regional ejection fraction in patients after myocardial infarction

NASA Astrophysics Data System (ADS)

Teo, S.-K.; Su, Y.; Tan, R. S.; Zhong, L.

2014-03-01

After myocardial infarction (MI), the left ventricle (LV) undergoes progressive remodeling which adversely affects heart function and may lead to development of heart failure. There is an escalating need to accurately depict the LV remodeling process for disease surveillance and monitoring of therapeutic efficacy. Current practice of using ejection fraction to quantitate LV function is less than ideal as it obscures regional variation and anomaly. Therefore, we sought to (i) develop a quantitative method to assess LV regional ejection fraction (REF) using a 16-segment method, and (ii) evaluate the effectiveness of REF in discriminating 10 patients 1-3 months after MI and 9 normal control (sex- and agematched) based on cardiac magnetic resonance (CMR) imaging. Late gadolinium enhancement (LGE) CMR scans were also acquired for the MI patients to assess scar extent. We observed that the REF at the basal, mid-cavity and apical regions for the patient group is significantly lower as compared to the control group (P < 0.001 using a 2-tail student t-test). In addition, we correlated the patient REF over these regions with their corresponding LGE score in terms of 4 categories - High LGE, Low LGE, Border and Remote. We observed that the median REF decreases with increasing severity of infarction. The results suggest that REF could potentially be used as a discriminator for MI and employed to measure myocardium homogeneity with respect to degree of infarction. The computational performance per data sample took approximately 25 sec, which demonstrates its clinical potential as a real-time cardiac assessment tool.

The DD genotype of the angiotensin converting enzyme gene independently associates with CMR-derived abnormal microvascular perfusion in patients with a first anterior ST-segment elevation myocardial infarction treated with thrombolytic agents.

PubMed

Bodi, Vicente; Sanchis, Juan; Nunez, Julio; Aliño, Salvador F; Herrero, Maria J; Chorro, Francisco J; Mainar, Luis; Lopez-Lereu, Maria P; Monmeneu, Jose V; Oltra, Ricardo; Chaustre, Fabian; Forteza, Maria J; Husser, Oliver; Riegger, Günter A; Llacer, Angel

2009-12-01

The role of the angiotensin converting enzyme (ACE) gene on the result of thrombolysis at the microvascular level has not been addressed so far. We analyzed the implications of the insertion/deletion (I/D) polymorphism of the ACE gene on the presence of abnormal cardiovascular magnetic resonance (CMR)-derived microvascular perfusion after ST-segment elevation myocardial infarction (STEMI). We studied 105 patients with a first anterior STEMI treated with thrombolytic agents and an open left anterior descending artery. Microvascular perfusion was assessed using first-pass perfusion CMR at 7+/-1 days. CMR studies were repeated 184+/-11 days after STEMI. The ACE gene insertion/deletion (I/D) polymorphism was determined using polymerase chain reaction amplification. Overall genotype frequencies were II-ID 58% and DD 42%. Abnormal perfusion (> or = 1 segment) was detected in 56% of patients. The DD genotype associated to a higher risk of abnormal microvascular perfusion (68% vs. 47%, p=0.03) and to a larger extent of perfusion deficit (median [percentile 25 - percentile 75]: 4 [0-6] vs. 0 [0-4] segments, p=0.003). Once adjusted for baseline characteristics, the DD genotype independently increased the risk of abnormal microvascular perfusion (odds ratio [95% confidence intervals]: 2.5 [1.02-5.9], p=0.04). Moreover, DD patients displayed a larger infarct size (35+/-17 vs. 27+/-15 g, p=0.01) and a lower ejection fraction at 6 months (48+/-14 vs. 54+/-14%, p=0.03). The DD genotype associates to a higher risk of abnormal microvascular perfusion after STEMI.

Convection-enhanced delivery of MANF--volume of distribution analysis in porcine putamen and substantia nigra.

PubMed

Barua, N U; Bienemann, A S; Woolley, M; Wyatt, M J; Johnson, D; Lewis, O; Irving, C; Pritchard, G; Gill, S

2015-10-15

Mesencephalic astrocyte-derived neurotrophic factor (MANF) is a 20kDa human protein which has both neuroprotective and neurorestorative activity on dopaminergic neurons and therefore may have application for the treatment of Parkinson's Disease. The aims of this study were to determine the translational potential of convection-enhanced delivery (CED) of MANF for the treatment of PD by studying its distribution in porcine putamen and substantia nigra and to correlate histological distribution with co-infused gadolinium-DTPA using real-time magnetic resonance imaging. We describe the distribution of MANF in porcine putamen and substantia nigra using an implantable CED catheter system using co-infused gadolinium-DTPA to allow real-time MRI tracking of infusate distribution. The distribution of gadolinium-DTPA on MRI correlated well with immunohistochemical analysis of MANF distribution. Volumetric analysis of MANF IHC staining indicated a volume of infusion (Vi) to volume of distribution (Vd) ratio of 3 in putamen and 2 in substantia nigra. This study confirms the translational potential of CED of MANF as a novel treatment strategy in PD and also supports the co-infusion of gadolinium as a proxy measure of MANF distribution in future clinical studies. Further study is required to determine the optimum infusion regime, flow rate and frequency of infusions in human trials. Copyright © 2015 Elsevier B.V. All rights reserved.

High-pressure high-temperature phase diagram of gadolinium studied using a boron-doped heater anvil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Montgomery, J. M.; Samudrala, G. K.; Velisavljevic, N.

A boron-doped designer heater anvil is used in conjunction with powder x-ray diffraction to collect structural information on a sample of quasi-hydrostatically loaded gadolinium metal up to pressures above 8 GPa and 600 K. The heater anvil consists of a natural diamond anvil that has been surface modified with a homoepitaxially-grown chemical-vapor-deposited layer of conducting boron-doped diamond, and is used as a DC heating element. Internally insulating both diamond anvils with sapphire support seats allows for heating and cooling of the high pressure area on the order of a few tens of seconds. This device is then used to scanmore » the phase diagram of the sample by oscillating the temperature while continuously increasing the externally applied pressure and collecting in situ time-resolved powder diffraction images. In the pressure-temperature range covered in the experiment the gadolinium sample is observed in its hcp, αSm, and dhcp phases. Under this temperature cycling, the hcp→αSm transition proceeds in discontinuous steps at points along the expected phase boundary. Additionally, the unit cell volumes of each phase deviate from the expected thermal expansion behavior just before each transition is observed from the diffraction data. From these measurements (representing only one hour of synchrotron x-ray collection time), a single-experiment equation of state and phase diagram of each phase of gadolinium is presented for the range of 0 - 10 GPa and 300 - 650 K.« less

High-pressure high-temperature phase diagram of gadolinium studied using a boron-doped heater anvil

DOE PAGES

Montgomery, J. M.; Samudrala, G. K.; Velisavljevic, N.; ...

2016-04-07

A boron-doped designer heater anvil is used in conjunction with powder x-ray diffraction to collect structural information on a sample of quasi-hydrostatically loaded gadolinium metal up to pressures above 8 GPa and 600 K. The heater anvil consists of a natural diamond anvil that has been surface modified with a homoepitaxially-grown chemical-vapor-deposited layer of conducting boron-doped diamond, and is used as a DC heating element. Internally insulating both diamond anvils with sapphire support seats allows for heating and cooling of the high pressure area on the order of a few tens of seconds. This device is then used to scanmore » the phase diagram of the sample by oscillating the temperature while continuously increasing the externally applied pressure and collecting in situ time-resolved powder diffraction images. In the pressure-temperature range covered in the experiment the gadolinium sample is observed in its hcp, αSm, and dhcp phases. Under this temperature cycling, the hcp→αSm transition proceeds in discontinuous steps at points along the expected phase boundary. Additionally, the unit cell volumes of each phase deviate from the expected thermal expansion behavior just before each transition is observed from the diffraction data. From these measurements (representing only one hour of synchrotron x-ray collection time), a single-experiment equation of state and phase diagram of each phase of gadolinium is presented for the range of 0 - 10 GPa and 300 - 650 K.« less

Are gadolinium contrast agents suitable for gadolinium neutron capture therapy?

PubMed

De Stasio, Gelsomina; Rajesh, Deepika; Casalbore, Patrizia; Daniels, Matthew J; Erhardt, Robert J; Frazer, Bradley H; Wiese, Lisa M; Richter, Katherine L; Sonderegger, Brandon R; Gilbert, Benjamin; Schaub, Sebastien; Cannara, Rachel J; Crawford, John F; Gilles, Mary K; Tyliszczak, Tolek; Fowler, John F; Larocca, Luigi M; Howard, Steven P; Mercanti, Delio; Mehta, Minesh P; Pallini, Roberto

2005-06-01

Gadolinium neutron capture therapy (GdNCT) is a potential treatment for malignant tumors based on two steps: (1) injection of a tumor-specific (157)Gd compound; (2) tumor irradiation with thermal neutrons. The GdNC reaction can induce cell death provided that Gd is proximate to DNA. Here, we studied the nuclear uptake of Gd by glioblastoma (GBM) tumor cells after treatment with two Gd compounds commonly used for magnetic resonance imaging, to evaluate their potential as GdNCT agents. Using synchrotron X-ray spectromicroscopy, we analyzed the Gd distribution at the subcellular level in: (1) human cultured GBM cells exposed to Gd-DTPA or Gd-DOTA for 0-72 hours; (2) intracerebrally implanted C6 glioma tumors in rats injected with one or two doses of Gd-DOTA, and (3) tumor samples from GBM patients injected with Gd-DTPA. In cell cultures, Gd-DTPA and Gd-DOTA were found in 84% and 56% of the cell nuclei, respectively. In rat tumors, Gd penetrated the nuclei of 47% and 85% of the tumor cells, after single and double injection of Gd-DOTA, respectively. In contrast, in human GBM tumors 6.1% of the cell nuclei contained Gd-DTPA. Efficacy of Gd-DTPA and Gd-DOTA as GdNCT agents is predicted to be low, due to the insufficient number of tumor cell nuclei incorporating Gd. Although multiple administration schedules in vivo might induce Gd penetration into more tumor cell nuclei, a search for new Gd compounds with higher nuclear affinity is warranted before planning GdNCT in animal models or clinical trials.

Gadolinium based contrast agents in current practice: Risks of accumulation and toxicity in patients with normal renal function

PubMed Central

Ranga, Anju; Agarwal, Yatish; Garg, Kanika J

2017-01-01

Despite being decked as the most prized compounds in the nugget box of contrast agents for clinical radiologists, and carrying an indisputable tag of safety of the US Food and Drug Administration for close to three decades, all may not be seemingly well with the family of gadolinium compounds. If the first signs of violations of primum non nocere in relation to gadolinium-based contrast agents (GBCAs) appeared in the millennium year with the first published report of skin fibrosis in patients with compromised renal function, the causal relationship between the development of nephrogenic systemic fibrosis (NSF) and GBCAs, first proposed by two European groups in 2006, further precluded their use in renocompromised patients. The toxicity, pharmacokinetics, and pharmacodynamics of GBCAs, however, has come under hawk-eyed scrutiny with recent reports that gadolinium tends to deposit cumulatively in the brain of patients with normal hepatobiliary function and intact blood–brain barrier. While the jury on the long-term hazard significance of this critical scientific finding is still out, the use of GBCAs must be guided by due clinical diligence, avoidance of repeated doses, and preferring GBCAs with the best safety profiles. PMID:28744073

Reaction of gadolinium chelates with ozone and hydroxyl radicals.

PubMed

Cyris, Maike; Knolle, Wolfgang; Richard, Jessica; Dopp, Elke; von Sonntag, Clemens; Schmidt, Torsten C

2013-09-03

Gadolinium chelates are used in increasing amounts as contrast agents in magnetic resonance imaging, and their fate in wastewater treatment has recently become the focus of research. Oxidative processes, in particular the application of ozone, are currently discussed or even implemented for advanced wastewater treatment. However, reactions of the gadolinium chelates with ozone are not yet characterized. In this study, therefore, rate constants with ozone were determined for the three commonly used chelates Gd-DTPA, Gd-DTPA-BMA, and Gd-BT-DO3A, which were found to be 4.8 ± 0.88, 46 ± 2.5, and 24 ± 1.5 M(-1) s(-1), respectively. These low rate constants indicate that a direct reaction with ozone in wastewater is negligible. However, application of ozone in wastewater leads to substantial yields of (•)OH. Different methods have been applied and compared for determination of k((•)OH+Gd chelate). From rate constants determined by pulse radiolysis experiments (k((•)OH+Gd-DTPA) = 2.6 ± 0.2 × 10(9) M(-1) s(-1), k((•)OH+Gd-DTPA-BMA) = 1.9 ± 0.7 × 10(9) M(-1) s(-1), k((•)OH+Gd-BT-DO3A) = 4.3 ± 0.2 × 10(9) M(-1) s(-1)), it is concluded that a reaction in wastewater via (•)OH radicals is feasible. Toxicity has been tested for educt and product mixtures of both reactions. Cytotoxicity (MTT test) and genotoxicity (micronuclei assay) were not detectable.

Neuroprotective effect of gadolinium: a stretch-activated calcium channel blocker in mouse model of ischemia-reperfusion injury.

PubMed

Gulati, Puja; Muthuraman, Arunachalam; Jaggi, Amteshwar S; Singh, Nirmal

2013-03-01

The present study was designed to investigate the potential of gadolinium, a stretch-activated calcium channel blocker in ischemic reperfusion (I/R)-induced brain injury in mice. Bilateral carotid artery occlusion of 12 min followed by reperfusion for 24 h was given to induce cerebral injury in male Swiss mice. Cerebral infarct size was measured using triphenyltetrazolium chloride staining. Memory was assessed using Morris water maze test and motor incoordination was evaluated using rota-rod, lateral push, and inclined beam walking tests. In addition, total calcium, thiobarbituric acid reactive substance (TBARS), reduced glutathione (GSH), and acetylcholinesterase (AChE) activity were also estimated in brain tissue. I/R injury produced a significant increase in cerebral infarct size. A significant loss of memory along with impairment of motor performance was also noted. Furthermore, I/R injury also produced a significant increase in levels of TBARS, total calcium, AChE activity, and a decrease in GSH levels. Pretreatment of gadolinium significantly attenuated I/R-induced infarct size, behavioral and biochemical changes. On the basis of the present findings, we can suggest that opening of stretch-activated calcium channel may play a critical role in ischemic reperfusion-induced brain injury and that gadolinium has neuroprotective potential in I/R-induced injury.

Analytical Interference in Serum Iron Determination Reveals Iron Versus Gadolinium Transmetallation With Linear Gadolinium-Based Contrast Agents

PubMed Central

Fretellier, Nathalie; Poteau, Nathalie; Factor, Cécile; Mayer, Jean-François; Medina, Christelle; Port, Marc; Idée, Jean-Marc; Corot, Claire

2014-01-01

Objectives The purposes of this study were to evaluate the risk for analytical interference with gadolinium-based contrast agents (GBCAs) for the colorimetric measurement of serum iron (Fe3+) and to investigate the mechanisms involved. Materials and Methods Rat serum was spiked with several concentrations of all molecular categories of GBCAs, ligands, or “free” soluble gadolinium (Gd3+). Serum iron concentration was determined by 2 different colorimetric methods at pH 4.0 (with a Vitros DT60 analyzer or a Cobas Integra 400 analyzer). Secondly, the cause of interference was investigated by (a) adding free soluble Gd3+ or Mn2+ to serum in the presence of gadobenic acid or gadodiamide and (b) electrospray ionization mass spectrometry. Results Spurious decrease in serum Fe3+ concentration was observed with all linear GBCAs (only with the Vitros DT60 technique occurring at pH 4.0) but not with macrocyclic GBCAs or with free soluble Gd3+. Spurious hyposideremia was also observed with the free ligands present in the pharmaceutical solutions of the linear GBCAs gadopentetic acid and gadodiamide (ie, diethylene triamine pentaacetic acid and calcium-diethylene triamine pentaacetic acid bismethylamide, respectively), suggesting the formation of Fe-ligand chelate. Gadobenic acid-induced interference was blocked in a concentration-dependent fashion by adding a free soluble Gd3+ salt. Conversely, Mn2+, which has a lower affinity than Gd3+ and Fe3+ for the ligand of gadobenic acid (ie, benzyloxypropionic diethylenetriamine tetraacetic acid), was less effective (interference was only partially blocked), suggesting an Fe3+ versus Gd3+ transmetallation phenomenon at pH 4.0. Similar results were observed with gadodiamide. Mass spectrometry detected the formation of Fe-ligand with all linear GBCAs tested in the presence of Fe3+ and the disappearance of Fe-ligand after the addition of free soluble Gd3+. No Fe-ligand chelate was found in the case of the macrocyclic GBCA gadoteric

Evaluation of liver function using gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid enhanced magnetic resonance imaging based on a three-dimensional volumetric analysis system.

PubMed

Kudo, Masashi; Gotohda, Naoto; Sugimoto, Motokazu; Kobayashi, Tatsushi; Kojima, Motohiro; Takahashi, Shinichiro; Konishi, Masaru; Hayashi, Ryuichi

2018-06-02

Magnetic resonance imaging with gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (EOB-MRI) is a diagnostic modality for liver tumors. Three-dimensional (3D) volumetric analysis systems using EOB-MRI data are used to simulate liver anatomy for surgery. This study was conducted to investigate clinical utility of a 3D volumetric analysis system on EOB-MRI to evaluate liver function. Between August 2014 and December 2015, 181 patients underwent laboratory and radiological exams as standardized preoperative evaluation for liver surgery. The liver-spleen contrast-enhanced ratio (LSR) was measured by a semi-automated 3D volumetric analysis system on EOB-MRI. First, the inter-evaluator variability of the calculated LSR was evaluated. Additionally, a subset of liver surgical specimens was evaluated histologically by using immunohistochemical staining. Finally, the correlations between the LSR and grading systems of liver function, laboratory data, or histological findings were analyzed. The inter-evaluator correlation coefficient of the measured LSR was 0.986. The mean LSR was significantly correlated with the Child-Pugh score (p = 0.014) and the ALBI score (p < 0.001). Significant correlations were also observed between the LSR and indocyanine green retention rate at 15 min (r = - 0.601, p < 0.001), between the LSR and liver fibrosis stage (r = - 0.556, p < 0.001), and between the LSR and liver steatosis grade (r = - 0.396, p < 0.001). The LSR calculated by a 3D volumetric analysis system on EOB-MRI was highly reproducible and was shown to be correlated with liver function parameters and liver histology. These data suggest that this imaging modality can be a reliable tool to evaluate liver function.

T2* mapping and delayed gadolinium-enhanced magnetic resonance imaging in cartilage (dGEMRIC) of humeral articular cartilage--a histologically controlled study.

PubMed

Bittersohl, Bernd; Kircher, Jörn; Miese, Falk R; Dekkers, Christin; Habermeyer, Peter; Fröbel, Julia; Antoch, Gerald; Krauspe, Rüdiger; Zilkens, Christoph

2015-10-01

Cartilage biochemical imaging modalities that include the magnetic resonance imaging (MRI) techniques of T2* mapping (sensitive to water content and collagen fiber network) and delayed gadolinium-enhanced MRI of cartilage (dGEMRIC, sensitive to the glycosaminoglycan content) can be effective instruments for early diagnosis and reliable follow-up of cartilage damage. The purpose of this study was to provide T2* mapping and dGEMRIC values in various histologic grades of cartilage degeneration in humeral articular cartilage. A histologically controlled in vitro study was conducted that included human humeral head cartilage specimens with various histologic grades of cartilage degeneration. High-resolution, 3-dimensional (3D) T2* mapping and dGEMRIC were performed that enabled the correlation of MRI and histology data. Cartilage degeneration was graded according to the Mankin score, which evaluates surface morphology, cellularity, toluidine blue staining, and tidemark integrity. SPSS software was used for statistical analyses. Both MRI mapping values decreased significantly (P < .001) with increasing cartilage degeneration. Spearman rank analysis revealed a significant correlation (correlation coefficients ranging from -0.315 to 0.784; P < .001) between the various histologic parameters and the T2* and T1Gd mapping values. This study demonstrates the feasibility of 3D T2* and dGEMRIC to identify various histologic grades of cartilage damage of humeral articular cartilage. With regard to the advantages of these mapping techniques with high image resolution and the ability to accomplish a 3D biochemically sensitive imaging, we consider that these imaging techniques can make a positive contribution to the currently evolving science and practice of cartilage biochemical imaging. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Magnetic Resonance Imaging-Based Assessment of Gadolinium-Conjugated Diethylenetriamine Penta-Acetic Acid Test-Infusion in Detecting Dysfunction of Convection-Enhanced Delivery Catheters.

PubMed

van Putten, Erik H P; Wembacher-Schröder, Eva; Smits, Marion; Dirven, Clemens M F

2016-05-01

In a phase 1 trial conducted at our institute, convection-enhanced delivery (CED) was used to administrate the Delta-24-RGD adenovirus in patients with a recurrent glioblastoma multiforme. Infusion of the virus was preceded by a gadolinium-conjugated diethylenetriamine penta-acetic acid (Gd-DTPA) test-infusion. In the present study, we analyzed the results of Gd-DTPA test infusion through 50 catheters. Thirteen adults with a recurrent glioblastoma multiforme were enrolled in a larger phase 1 multicenter, dose-finding study, in which a conditionally replication-competent adenovirus was administered by CED. Up to 4 infusion catheters per patient were placed intra- and/or peritumorally. Before infusion of the virus, a Gd-DTPA infusion was performed for 6 hours, directly followed by a MRI scan. The MRIs were evaluated for catheter position, Gd-DTPA distribution outcome, and contrast leakage. Leakage of Gd-DTPA into the cerebrospinal fluid was detected in 17 of the 50 catheters (34%). Sulcus crossing was the most frequent cause of leakage. In 8 cases, leakage could only be detected on the fluid-attenuated inversion recovery sequence. Nonleaking catheters showed a significantly larger Gd-DTPA distribution fraction (volume of distribution/volume of infusion) than leaking catheters (P = 0.009). A significantly lower volume of distribution/volume of infusion was observed in intratumoral catheters, compared with peritumoral catheters (P = 0.004). Gd-DTPA test infusion did not result in significant changes in Karnofsky Performance Score and Neurological Status. Pre-CED treatment infusion of Gd-DTPA is an adequate and safe method to identify dysfunctional catheters. The use of an optimized drug delivery catheter is necessary to reduce leakage and improve the efficacy of intracerebral drug infusion. Copyright © 2016 Elsevier Inc. All rights reserved.

Stability of Gadolinium-Doped Liquid Organic Scintillators

NASA Astrophysics Data System (ADS)

Gromov, M. B.; Kuznetsov, D. S.; Murchenko, A. E.; Novikova, G. Ya.; Obinyakov, B. A.; Oralbaev, A. Yu.; Plakitina, K. V.; Skorokhvatov, M. D.; Sukhotin, S. V.; Chepurnov, A. S.; Etenko, A. V.

2018-03-01

The technology of preparing a linear-alkylbenzene-based gadolinium-doped liquid organic scintillator (Gd-LOS) as a target material in reactor antineutrino detectors has been developed. Results of longterm measurements of the light yield of Gd-LOS in contact with acryl and stainless steel are presented, which confirm the compatibility of Gd-LOS with these materials. The measurements were performed for two otherwise identical LOS detectors only differing in wall materials of the sensitive volume: acryl versus stainless steel. The results of measurements over about one year showed almost the same, relatively small decreases in the light yield of both detectors. It is concluded that both structural materials can be used in detector parts contacting with Gd-doped scintillator. Such a long-term parallel comparative test was carried out for the first time.

Analysis of Blood Gadolinium in an Isotope Geochemist Following Contrast MRI

NASA Astrophysics Data System (ADS)

Wasylenki, L. E.

2011-12-01

Normal brain tissue does not have blood flowing throughout it; instead oxygen diffuses across a blood-brain barrier in order to oxygenate brain cells. Brain tumors, however, do grow blood supplies, so an abnormal distribution of blood in the brain is a key indicator of abnormal cell growth. But how is the distribution of blood in inside the brain observed? The lanthanide ion gadolinium(III) has unpaired 5f-shell electrons and is thus paramagnetic. As such, the presence of Gd causes the nuclei of nearby atoms to relax more quickly when excited to high-energy spin states by pulses of radio-frequency energy than they would without Gd nearby. The signal in magnetic resonance imaging correlates with this nuclear spin relaxation time, so gadolinium's presence in certain body tissues makes those tissues appear as bright areas on MRI images. Gadolinium is therefore commonly injected intravenously just prior to MRI imaging, so that the distribution of blood in and around the brain can be mapped. Gadolinium as a free ion is toxic, so it is injected in a relatively inert form, often as gadoversetamide, in which Gd is tightly bound in nine-fold coordination with N, C, and O. This compound is removed from the blood by the kidneys at a rate that is fast compared to the rate of breakdown of this compound in the blood, thus preventing release of toxic Gd in the bloodstream. But how quickly can the kidneys of an isotope geochemist remove Gd from blood? In this experiment, a single isotope geochemist's wristwatch was synchronized with that of the MRI technician and then left in a dressing room with all other magnetically susceptible objects until after the MRI. The time of intravenous injection of gadoversetamide into the isotopist was recorded by the technician and later transmitted verbally to the isotopist. Following the MRI session, blood samples were collected by self-fingerprick, in a Class 100 trace metal clean lab, from 47 to 281 minutes after intravenous injection. For each

Differences in perilymphatic space enhancement and adverse inflammatory reaction after intratympanic injection of two different gadolinium agents: A 9.4-T magnetic resonance imaging study.

PubMed

Park, Mina; Lee, Ho Sun; Kim, Hyeonjin; Oh, Seung Ha; Lee, Jun Ho; Suh, Myung-Whan

2016-03-01

To compare the inner ear enhancement after intratympanic injection of two widely used gadolinium (Gd) agents by 9.4 T micro-magnetic resonance imaging (MRI) and to investigate the effects of Gd on the inner ear. Twelve ears of six rats received intratympanic administration of 1/5 diluted Gd agents: gadoterate meglumine (Gd-DTPA) for the left ear and gadodiamide (Gd-DTPA-BMA) for the right ear. MRI was performed every 30 min from 1 to 4 h after administration. The normalized signal intensity was evaluated by quantitative analysis at each cochlear fluid compartment. Eight, six, and seven ears treated with Gd-DTPA, Gd-DPTA-BMA, and nothing as controls, respectively, were processed for histological evaluation after MRI. After hematoxylin & eosin staining, adverse inflammatory reactions were evaluated for turbid aggregation and lymphocytes. The perilymphatic enhancement of Gd-DTPA was superior to that of Gd-DTPA-BMA regardless of cochlear turn, compartment, and time point. Inflammatory reactions were found in 4/8 (50.0%) and 4/6 (66.6%) ears administered Gd-DTPA and Gd-DTPA-BMA, respectively. Regardless of the contrast agent used, inflammatory reactions were most definite in the scala tympani of the basal turn, i.e., near the round window. Slightly greater inflammatory reactions were observed in ears injected with Gd-DTPA-BMA compared to Gd-DTPA although the difference was not statistically significant. No inflammatory reaction was observed in any of the seven controls. The auditory brainstem response threshold was 11.8 ± 2.5 dB SPL before IT Gd injection and it did not change for up to 5 days (15.4 ± 6.6 dB SPL) post-injection. Gd-DTPA was superior to Gd-DTPA-BMA for visualization of the inner ear. Administration of diluted Gd agents intratympanically may induce considerable inflammatory reactions in the inner ear. Copyright © 2015 Elsevier B.V. All rights reserved.

Dramatic impact of the giant local magnetic fields on spin-dependent recombination processes in gadolinium based garnets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Romanov, N. G., E-mail: nikolai.romanov@mail.ioffe.ru; Tolmachev, D. O.; Gurin, A. S.

2015-06-29

A giant magnetic field effect on spin-dependent recombination of the radiation-induced defects has been found in cerium doped gadolinium based garnet crystals and ceramics, promising materials for scintillator applications. A sharp and strong increase in the afterglow intensity stimulated by external magnetic field and an evidence of the magnetic field memory have been discovered. The effect was ascribed to huge Gd-induced internal magnetic fields, which suppress the recombination, and cross-relaxation with Gd{sup 3+} ions leading to reorientation of the spins of the electron and hole centers. Thus, the spin system of radiation-induced defects in gadolinium garnet based scintillator materials wasmore » shown to accumulate significant energy which can be released in external magnetic fields.« less

Quantification of fibrosis in infarcted swine hearts by ex vivo late gadolinium-enhancement and diffusion-weighted MRI methods

NASA Astrophysics Data System (ADS)

Pop, Mihaela; Ghugre, Nilesh R.; Ramanan, Venkat; Morikawa, Lily; Stanisz, Greg; Dick, Alexander J.; Wright, Graham A.

2013-08-01

Many have speculated that MRI signal characteristics can be used to identify regions of heterogeneous infarct associated with an arrhythmogenic substrate; however, direct evidence of this relationship is limited. The aim of this study was to demonstrate the remodelling characteristics of fibrosis by means of histology and high-resolution MR imaging. For this purpose, we performed whole-mount histology in heart samples (n = 9) collected from five swine at six weeks post-infarction and compared the extent of fibrosis in the infarcted areas delineated in these histological images with that obtained ex vivo by MRI using late gadolinium-enhancement (LGE) and diffusion-weighted imaging (DWI) methods. All MR images were obtained at a submillimetre resolution (i.e., voxel size of 0.6×0.6×1.2 mm3). Specifically, in the histology images, we differentiated moderate fibrosis (consisting of a mixture of viable and non-viable myocytes, known as border zone, BZ) from severe fibrosis (i.e., the dense scar). Correspondingly, tissue heterogeneities in the MR images were categorized by a Gaussian mixture model into healthy, BZ and scar. Our results showed that (a) both MRI methods were capable of qualitatively distinguishing sharp edges between dense scar and healthy tissue from regions of heterogeneous BZ; (b) the BZ and dense scar areas had intermediate-to-high increased values of signal intensity in the LGE images and of apparent diffusion coefficient in the DWI, respectively. In addition, as demonstrated by the Picrosirius Red and immunohistochemistry stains, the viable bundles in the BZ were clearly separated by thin collagen strands and had reduced expression of Cx43, whereas the core scar was composed of dense fibrosis. A quantitative analysis demonstrated that the comparison between BZ/scar extent in LGE and DWI to the corresponding areas identified in histology yielded very good correlations (i.e., for the scar identified by LGE, R2 was 0.96 compared to R2 = 0.93 for the

The association of lesion eccentricity with plaque morphology and components in the superficial femoral artery: a high-spatial-resolution, multi-contrast weighted CMR study.

PubMed

Li, Feiyu; McDermott, Mary McGrae; Li, Debiao; Carroll, Timothy J; Hippe, Daniel S; Kramer, Christopher M; Fan, Zhaoyang; Zhao, Xihai; Hatsukami, Thomas S; Chu, Baocheng; Wang, Jinnan; Yuan, Chun

2010-07-01

Atherosclerotic plaque morphology and components are predictors of subsequent cardiovascular events. However, associations of plaque eccentricity with plaque morphology and plaque composition are unclear. This study investigated associations of plaque eccentricity with plaque components and morphology in the proximal superficial femoral artery using cardiovascular magnetic resonance (CMR). Twenty-eight subjects with an ankle-brachial index less than 1.00 were examined with 1.5 T high-spatial-resolution, multi-contrast weighted CMR. One hundred and eighty diseased locations of the proximal superficial femoral artery (about 40 mm) were analyzed. The eccentric lesion was defined as [(Maximum wall thickness- Minimum wall thickness)/Maximum wall thickness] >or= 0.5. The arterial morphology and plaque components were measured using semi-automatic image analysis software. One hundred and fifteen locations were identified as eccentric lesions and sixty-five as concentric lesions. The eccentric lesions had larger wall but similar lumen areas, larger mean and maximum wall thicknesses, and more calcification and lipid rich necrotic core, compared to concentric lesions. For lesions with the same lumen area, the degree of eccentricity was associated with an increased wall area. Eccentricity (dichotomous as eccentric or concentric) was independently correlated with the prevalence of calcification (odds ratio 3.78, 95% CI 1.47-9.70) after adjustment for atherosclerotic risk factors and wall area. Plaque eccentricity is associated with preserved lumen size and advanced plaque features such as larger plaque burden, more lipid content, and increased calcification in the superficial femoral artery.

Switching of the polarization of ferroelectric-ferroelastic gadolinium molybdate in a magnetic field

NASA Astrophysics Data System (ADS)

Yakushkin, E. D.

2017-10-01

A change in the character of the electric switching of polydomain ferroelectric-ferroelastic gadolinium molybdate in an external magnetic field has been detected. This change has been attributed to a magnetically stimulated increase in the pinning of domain walls. Under certain conditions, the loop of switchable polarization is degenerated into an ellipse characteristic of a linear insulator with leakage current.

Quantitative comparison of 2D and 3D late gadolinium enhancement MR imaging in patients with Fabry disease and hypertrophic cardiomyopathy.

PubMed

Morsbach, F; Gordic, S; Gruner, C; Niemann, M; Goetti, R; Gotschy, A; Kozerke, S; Alkadhi, H; Manka, R

2016-08-15

This study aims to determine whether the quantification of myocardial fibrosis in patients with Fabry disease (FD) and hypertrophic cardiomyopathy (HCM) using a late gadolinium enhancement (LGE) singlebreath-hold three-dimensional (3D) inversion recovery magnetic resonance (MR) imaging sequence is comparable with a clinically established two-dimensional (2D) multi-breath-hold sequence. In this retrospective, IRB-approved study, 40 consecutive patients (18 male; mean age 50±17years) with Fabry disease (n=18) and HCM (n=22) underwent MR imaging at 1.5T. Spatial resolution was the same for 3D and 2D images (field-of-view, 350×350mm(2); in-plane-resolution, 1.2×1.2mm(2); section-thickness, 8mm). Datasets were analyzed for subjective image quality; myocardial and fibrotic mass, and total fibrotic tissue percentage were quantified. There was no significant difference in subjective image quality between 3D and 2D acquisitions (P=0.1 and P=0.3) for either disease. In patients with Fabry disease there were no significant differences between 3D and 2D acquisitions for myocardial mass (P=0.55), fibrous tissue mass (P=0.89), and total fibrous percentage (P=0.67), with good agreement between acquisitions according to Bland-Altman analyses. In patients with HCM there were also no significant differences between acquisitions for myocardial mass (P=0.48), fibrous tissue mass (P=0.56), and total fibrous percentage (P=0.67), with good agreement according to Bland-Altman analyses. Acquisition time was significantly shorter for 3D (25±5s) as compared to the 2D sequence (349±62s, P<0.001). In patients with Fabry disease and HCM, 3D LGE imaging provides equivalent diagnostic information in regard to quantification of myocardial fibrosis as compared with a standard 2D sequence, but at superior acquisition speed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Impact of agglomeration on the relaxometric properties of paramagnetic ultra-small gadolinium oxide nanoparticles

NASA Astrophysics Data System (ADS)

Faucher, Luc; Gossuin, Yves; Hocq, Aline; Fortin, Marc-André

2011-07-01

Ultra-small gadolinium oxide nanoparticles (US-Gd2O3) are used to provide 'positive' contrast effects in magnetic resonance imaging (MRI), and are being considered for molecular and cellular imaging applications. However, these nanoparticles can aggregate over time in aqueous medium, as well as when internalized into cells. This study is aimed at measuring in vitro, in aqueous medium, the impact of aggregation on the relaxometric properties of paramagnetic US-Gd2O3 particles. First, the nanoparticle core size as well as aggregation behaviour was assessed by HRTEM. DLS (hydrodynamic diameter) was used to measure the hydrodynamic diameter of nanoparticles and nanoaggregates. The relaxometric properties were measured by NMRD profiling, as well as with 1H NMR relaxometers. Then, the positive contrast enhancement effect was assessed by using magnetic resonance scanners (at 1.5 and 7 T). At every magnetic field, the longitudinal relaxivity (r1) decreased upon agglomeration, while remaining high enough to provide positive contrast. On the other hand, the transverse relaxivity (r2) slightly decreased at 0.47 and 1.41 T, but it was enhanced at higher fields (7 and 11.7 T) upon agglomeration. All NMRD profiles revealed a characteristic relaxivity peak in the range 60-100 MHz, suggesting the possibility to use US-Gd2O3 as an efficient 'positive-T1' contrast agent at clinical magnetic fields (1-3 T), in spite of aggregation.

Graphene Oxide and Gadolinium-Chelate Functionalized Poly(lactic acid) Nanocapsules Encapsulating Perfluorooctylbromide for Ultrasound/Magnetic Resonance Bimodal Imaging Guided Photothermal Ablation of Cancer.

PubMed

Li, Zhenglin; Ke, Hengte; Wang, Jinrui; Miao, Zhaohua; Yue, Xiuli

2016-03-01

This paper successfully fabricated a novel multifunctional theranostic agent (PFOB@PLA/GO/Gd-DTPA NCs) by loading perfluorooctylbromide (PFOB) into poly(lactic acid) (PLA) nanocapsules (NCs) followed by surface functionalization with graphene oxide (GO) and gadolinium-chelate (Gd-DTPA). It was found that the resulting nanoagent could serve as a contrast agent simultaneously to enhance ultrasound (US) and magnetic resonance imaging (MRI). Benefiting from the strong absorption in the near infrared (NIR) region, the nanocapsules could efficiently kill cancer cells under NIR laser irradiation. Thus, such a single theranostic agent with the combination of realtime US imaging and high-resolution MR imaging could achieve great therapeutic effectiveness without systemic damage to the body. In addition, the cytotoxicity assay on HUVEC cells revealed a good biocompatibility of PFOB@PLA/GO/Gd-DTPA NCs, showing that the versatile nanocapsule system may hold great potential as an effective nanoplatform for contrast enhanced imaging guided photothermal therapy.

Effect of solid-phase amorphization on the spectral characteristics of europium-doped gadolinium molybdate

NASA Astrophysics Data System (ADS)

Shmurak, S. Z.; Kiselev, A. P.; Kurmasheva, D. M.; Red'Kin, B. S.; Sinitsyn, V. V.

2010-05-01

A method is proposed for detecting spectral characteristics of optically inactive molybdates of rare-earth elements by their doping with rare-earth ions whose luminescence lies in the transparency region of all structural modifications of the sample. Gadolinium molybdate is chosen as the object of investigations, while europium ions are used as an optically active and structurally sensitive admixture. It is shown that after the action of a high pressure under which gadolinium molybdate passes to the amorphous state, the spectral characteristics of Gd1.99Eu0.01(MoO4)3 (GMO:Eu) change radically; namely, considerable line broadening is observed in the luminescence spectra and the luminescence excitation spectra, while the long-wave threshold of optical absorption is shifted considerably (by approximately 1.1 eV) towards lower energies. It is found that by changing the structural state of GMO:Eu by solid-state amorphization followed by annealing, the spectral characteristics of the sample can be purposefully changed. This is extremely important for solving the urgent problem of designing high-efficiency light-emitting diodes producing “white” light.

Feasibility of quantification of the distribution of blood flow in the normal human fetal circulation using CMR: a cross-sectional study.

PubMed

Seed, Mike; van Amerom, Joshua F P; Yoo, Shi-Joon; Al Nafisi, Bahiyah; Grosse-Wortmann, Lars; Jaeggi, Edgar; Jansz, Michael S; Macgowan, Christopher K

2012-11-26

We present the first phase contrast (PC) cardiovascular magnetic resonance (CMR) measurements of the distribution of blood flow in twelve late gestation human fetuses. These were obtained using a retrospective gating technique known as metric optimised gating (MOG). A validation experiment was performed in five adult volunteers where conventional cardiac gating was compared with MOG. Linear regression and Bland Altman plots were used to compare MOG with the gold standard of conventional gating. Measurements using MOG were then made in twelve normal fetuses at a median gestational age of 37 weeks (range 30-39 weeks). Flow was measured in the major fetal vessels and indexed to the fetal weight. There was good correlation between the conventional gated and MOG measurements in the adult validation experiment (R=0.96). Mean flows in ml/min/kg with standard deviations in the major fetal vessels were as follows: combined ventricular output (CVO) 540 ± 101, main pulmonary artery (MPA) 327 ± 68, ascending aorta (AAo) 198 ± 38, superior vena cava (SVC) 147 ± 46, ductus arteriosus (DA) 220 ± 39,pulmonary blood flow (PBF) 106 ± 59,descending aorta (DAo) 273 ± 85, umbilical vein (UV) 160 ± 62, foramen ovale (FO)107 ± 54. Results expressed as mean percentages of the CVO with standard deviations were as follows: MPA 60 ± 4, AAo37 ± 4, SVC 28 ± 7, DA 41 ± 8, PBF 19 ± 10, DAo50 ± 12, UV 30 ± 9, FO 21 ± 12. This study demonstrates how PC CMR with MOG is a feasible technique for measuring the distribution of the normal human fetal circulation in late pregnancy. Our preliminary results are in keeping with findings from previous experimental work in fetal lambs.

Magnetic resonance evaluation of cardiac thrombi and masses by T1 and T2 mapping: an observational study.

PubMed

Caspar, Thibault; El Ghannudi, Soraya; Ohana, Mickaël; Labani, Aïssam; Lawson, Aubrietia; Ohlmann, Patrick; Morel, Olivier; De Mathelin, Michel; Roy, Catherine; Gangi, Afshin; Germain, Philippe

2017-04-01

The purpose of this work was to evaluate CMR T1 and T2 mapping sequences in patients with intracardiac thrombi and masses in order to assess T1 and T2 relaxometry usefulness and to allow better etiological diagnosis. This observational study of patients scheduled for routine CMR was performed from September 2014 to August 2015. All patients referred to our department for a 1.5 T CMR were screened to participate. T1 mapping were acquired before and after Gadolinium injection; T2 mapping images were obtained before injection. 41 patients were included. 22 presented with cardiac thrombi and 19 with cardiac masses. The native T1 of thrombi was 1037 ± 152 ms (vs 1032 ± 39 ms for myocardium, p = 0.88; vs 1565 ± 88 ms for blood pool, p < 0.0001). T2 were 74 ± 13 ms (vs 51 ± 3 ms for myocardium, p < 0.0001; vs 170 ± 32 ms for blood pool, p < 0.0001). Recent thrombi had a native T1 shorter than old thrombi (911 ± 177 vs 1169 ± 107 ms, p = 0.01). The masses having a shorter T1 than the myocardium were lipomas (278 ± 29 ms), calcifications (621 ± 218 ms), and melanoma (736 ms). All other masses showed T1 values higher than myocardial T1, with T2 consistently >70 ms. T1 and T2 mapping CMR sequences can be useful and represent a new approach for the evaluation of cardiac thrombi and masses.

A comparison of the COG and MCNP codes in computational neutron capture therapy modeling, Part II: gadolinium neutron capture therapy models and therapeutic effects.

PubMed

Wangerin, K; Culbertson, C N; Jevremovic, T

2005-08-01

The goal of this study was to evaluate the COG Monte Carlo radiation transport code, developed and tested by Lawrence Livermore National Laboratory, for gadolinium neutron capture therapy (GdNCT) related modeling. The validity of COG NCT model has been established for this model, and here the calculation was extended to analyze the effect of various gadolinium concentrations on dose distribution and cell-kill effect of the GdNCT modality and to determine the optimum therapeutic conditions for treating brain cancers. The computational results were compared with the widely used MCNP code. The differences between the COG and MCNP predictions were generally small and suggest that the COG code can be applied to similar research problems in NCT. Results for this study also showed that a concentration of 100 ppm gadolinium in the tumor was most beneficial when using an epithermal neutron beam.

Indirect MR lymphangiography of the head and neck using conventional gadolinium contrast: A pilot study in humans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loo, Billy W.; Draney, Mary T.; Sivanandan, Ranjiv

2006-10-01

Purpose: To evaluate indirect magnetic resonance lymphangiography (MR-LAG) using interstitial injection of conventional gadolinium contrast (gadoteridol and gadopentetate dimeglumine) for delineating the primary lymphatic drainage of head-and-neck sites. Methods and Materials: We performed head-and-neck MR-LAG in 5 healthy volunteers, with injection of dermal and mucosal sites. We evaluated the safety of the procedure, the patterns of enhancement categorized by injection site and nodal level, the time course of enhancement, the optimal concentration and volume of contrast, and the optimal imaging sequence. Results: The worst side effects of interstitial contrast injection were brief, mild pain and swelling at the injected sitesmore » that were self-limited. MR-LAG resulted in consistent visualization of the primary lymphatic drainage pattern specific to each injected site, which was reproducible on repeated examinations. The best enhancement was obtained with injection of small volumes (0.3-0.5 mL) of either agent diluted, imaging within 5-15 min of injection, and a three-dimensional fast spoiled gradient echo sequence with magnetization transfer. Conclusions: We found head-and-neck MR-LAG to be a safe, convenient imaging method that provides functional information about the lymphatic drainage of injected sites. Applied to head-and-neck cancer, it has the potential to identify sites at highest risk of occult metastatic spread for radiotherapy or surgical planning, and possibly to visualize micrometastases.« less

Gadolinium oxide decorated multiwalled carbon nanotube/tridoped titania nanocomposites for improved dye degradation under simulated solar light irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mamba, Gcina; Nanotechnology and Water Sustainability Research Unit, College of Engineering, Science and Technology, University of South Africa Florida Science Campus, 1709 Florida; Mbianda, Xavier Yangkou

2016-03-15

Graphical abstract: Illustration of the collaborative effect between MWCNT-Gd and Gd,N,S-TiO{sub 2} towards degradation of AB 74. - Highlights: • MWCNT-Gd/tridoped titania was successfully prepared via a sol-gel method. • XPS revealed the presence of Ti, C, O, S, N and Gd in MWCNT-Gd/Gd,N,S-TiO{sub 2}. • MWCNT-Gd/Gd,N,S-TiO{sub 2} displayed 100% degradation of acid blue 74 in 150 min. • Over 60% TOC removal by MWCNT-Gd/Gd,N,S-TiO{sub 2}. - Abstract: Neodymium/gadolinium/europium, nitrogen and sulphur tridoped titania (Nd/Gd/Eu, N,S-TiO{sub 2}) was hybridised with pre-synthesised gadolinium oxide decorated multiwalled carbon nanotubes (MWCNT-Gd) using a sol–gel method. Subsequent to drying and calcination, composite photocatalysts: MWCNT-Gd/Nd,N,S-TiO{submore » 2}, MWCNT-Gd/Gd,N,S-TiO{sub 2} and MWCNT-Gd/Eu,N,S-TiO{sub 2}, were obtained and characterised using TEM, SEM-EDX, UV–vis, XPS, XRD and FT-IR. Acid blue 74 (AB74) was used as a model dye to investigate the photocatalytic degradation properties of the prepared materials under simulated solar light irradiation. Coupling the different tridoped titania with MWCNT-Gd enhanced their activity compared to MWCNT/TiO{sub 2}, MWCNT-Gd/TiO{sub 2} and MWCNT/Gd,N,S-TiO{sub 2}. MWCNT-Gd/Gd,N,S-TiO{sub 2} showed the highest activity towards AB74 degradation reaching 100% decolourisation after 150 min of irradiation. Total organic carbon analysis revealed that over 50% of the AB74 molecules were completely mineralised after 180 min of irradiation in the presence of MWCNT-Gd/Gd,N,S-TiO{sub 2}.« less

Primed infusion with delayed equilibrium of Gd.DTPA for enhanced imaging of small pulmonary metastases.

PubMed

Kalber, Tammy L; Campbell-Washburn, Adrienne E; Siow, Bernard M; Sage, Elizabeth; Price, Anthony N; Ordidge, Katherine L; Walker-Samuel, Simon; Janes, Sam M; Lythgoe, Mark F

2013-01-01

To use primed infusions of the magnetic resonance imaging (MRI) contrast agent Gd.DTPA (Magnevist), to achieve an equilibrium between blood and tissue (eqMRI). This may increase tumor Gd concentrations as a novel cancer imaging methodology for the enhancement of small tumor nodules within the low signal-to-noise background of the lung. A primed infusion with a delay before equilibrium (eqMRI) of the Gd(III) chelator Gd.DTPA, via the intraperitoneal route, was used to evaluate gadolinium tumor enhancement as a function of a bolus injection, which is applied routinely in the clinic, compared to gadolinium maintained at equilibrium. A double gated (respiration and cardiac) spin-echo sequence at 9.4T was used to evaluate whole lungs pre contrast and then at 15 (representative of bolus enhancement), 25 and 35 minutes (representative of eqMRI). This was carried out in two lung metastasis models representative of high and low tumor cell seeding. Lungs containing discrete tumor nodes where inflation fixed and taken for haematoxylin and eosin staining as well as CD34 staining for correlation to MRI. We demonstrate that sustained Gd enhancement, afforded by Gd equilibrium, increases the detection of pulmonary metastases compared to bolus enhancement and those tumors which enhance at equilibrium are sub-millimetre in size (<0.7 mm(2)) with a similar morphology to early bronchoalveolar cell carcinomas. As Gd-chelates are routinely used in the clinic for detecting tumors by MRI, this methodology is readily transferable to the clinic and advances MRI as a methodology for the detection of small pulmonary tumors.

Early Implantation of Primary Prevention Implantable Cardioverter Defibrillators for Patients with Newly Diagnosed Severe Nonischemic Cardiomyopathy.

PubMed

Voskoboinik, Aleksandr; Bloom, Jason; Taylor, Andrew; Mariani, Justin

2016-09-01

Primary prevention implantable cardioverter defibrillators (ICDs) reduce mortality in selected patients with severe systolic dysfunction. Current guidelines suggest a 3- to 6-month waiting period before implantation. We retrospectively studied 29 consecutive patients with newly diagnosed nonischemic cardiomyopathy (NICM) who underwent primary prevention ICD implantation within 6 months of diagnosis between January 2008 and April 2014. Cardiac MRI (CMR) evaluated left ventricular ejection fraction (LVEF) and regional fibrosis preimplant. The primary end point was "failure to qualify for an ICD at 12 months postimplant," either due to LVEF ≥ 35% or deterioration necessitating mechanical support or transplantation, without appropriate ICD therapy. Secondary end points were appropriate and inappropriate ICD therapy. Baseline mean age was 44.2 ± 14.8 years and median LVEF 16.4%. Median time from diagnosis to implant was 32 days. At 12 months, 17 patients (58.6%) no longer qualified for an ICD, mainly due to LVEF improvement. At follow-up (mean 32.0 ± 20.6 months), three patients received appropriate therapy (one for ventricular fibrillation). All three had CMR late gadolinium enhancement (LGE) and nonsustained ventricular tachycardia (NSVT) preimplant. Cardiac resynchronization at implant predicted LVEF improvement. Early appropriate therapy, particularly for ventricular fibrillation, is infrequent for patients with very severe NICM who have ICDs implanted within 6 months of diagnosis. The majority of these patients would not qualify for an ICD at 12 months postinsertion. In the absence of a multimodality risk score, early ICD insertion should only be considered in selected cases (presence of LGE and NSVT). Wearable cardioverter defibrillators may have a role as a bridge to ICD decision. © 2016 Wiley Periodicals, Inc.

Regional heterogeneity in cardiac sympathetic innervation in acute myocardial infarction: relationship with myocardial oedema on magnetic resonance.

PubMed

Gimelli, Alessia; Masci, Pier Giorgio; Liga, Riccardo; Grigoratos, Chrysanthos; Pasanisi, Emilio Maria; Lombardi, Massimo; Marzullo, Paolo

2014-09-01

To assess the relationships between myocardial structure and function on cardiac magnetic resonance (CMR) imaging and sympathetic tone on (123)I-metaiodobenzylguanidine ((123)I-MIBG) scintigraphy early after myocardial infarction (MI). Ten patients underwent (123)I-MIBG and (99m)Tc-tetrofosmin rest cadmium zinc telluride scintigraphy 4 ± 1 days after MI. The segmental left ventricular (LV) relative radiotracer uptake of both (99m)Tc-tetrofosmin and early (123)I-MIBG was calculated. The day after scintigraphy, on CMR imaging, the extent of ischaemia-related oedema and of myocardial fibrosis (late gadolinium enhancement, LGE) was assessed. Accordingly, the extent of oedema and LGE was evaluated for each segment and segmental wall thickening determined. Based on LGE distribution, LV segments were categorized as "infarcted" (56 segments), "adjacent" (66 segments) or "remote" (48 segments). Infarcted segments showed a more depressed systolic wall thickening and greater extent of oedema than adjacent segments (p < 0.001) and remote segments (p < 0.001). Interestingly, while uptake of (99m)Tc-tetrofosmin was significantly depressed only in infarcted segments (p < 0.001 vs. both adjacent and remote segments), uptake of (123)I-MIBG was impaired not only in infarcted segments (p < 0.001 vs. remote) but also in adjacent segments (p = 0.024 vs. remote segments). At the regional level, after correction for (99m)Tc-tetrofosmin and LGE distribution, segmental (123)I-MIBG uptake (p < 0.001) remained an independent predictor of ischaemia-related oedema. After acute MI the regional impairment of sympathetic tone extends beyond the area of altered myocardial perfusion and is associated with myocardial oedema.

Strategies for the preparation of bifunctional gadolinium(III) chelators

PubMed Central

Frullano, Luca; Caravan, Peter

2012-01-01

The development of gadolinium chelators that can be easily and readily linked to various substrates is of primary importance for the development high relaxation efficiency and/or targeted magnetic resonance imaging (MRI) contrast agents. Over the last 25 years a large number of bifunctional chelators have been prepared. For the most part, these compounds are based on ligands that are already used in clinically approved contrast agents. More recently, new bifunctional chelators have been reported based on complexes that show a more potent relaxation effect, faster complexation kinetics and in some cases simpler synthetic procedures. This review provides an overview of the synthetic strategies used for the preparation of bifunctional chelators for MRI applications. PMID:22375102

The structural response of gadolinium phosphate to pressure

DOE PAGES

Heffernan, Karina M.; Ross, Nancy L.; Spencer, Elinor C.; ...

2016-06-16

In this study, accurate elastic constants for gadolinium phosphate (GdPO 4) have been measured by single-crystal high-pressure diffraction methods. The bulk modulus of GdPO 4 determined under hydrostatic conditions, 128.1(8) GPa (K'=5.8(2)), is markedly different from that obtained with GdPO 4 under non-hydrostatic conditions (160(2) GPa), which indicates the importance of shear stresses on the elastic response of this phosphate. Finally, high pressure Raman and diffraction analysis indicate that the PO 4 tetrahedra behave as rigid units in response to pressure and that contraction of the GdPO 4 structure is facilitated by bending/twisting of the Gd–O–P links that result inmore » increased distortion in the GdO 9 polyhedra.« less

Dielectric properties and activation behavior of gadolinium doped nanocrystalline yttrium chromite

NASA Astrophysics Data System (ADS)

Sinha, R.; Basu, S.; Meikap, A. K.

2018-04-01

Gadolinium doped Yttrium Chromite nanoparticles are synthesized following sol-gel method. The formation of the nanoparticles are confirmed by XRD and TEM measurements. Dielectric permittivity and dielectric loss are estimated within the temperature range 298K to 523K and in the frequency range 20 Hz to 1 MHz. Dielectric permittivity follows the power law ɛ'(f) ∝ Tm. It is observed that the temperature exponent m increases with the decreasing frequency. The temperature variation of resistivity shows that the samples have semiconducting behavior. The activation energy is also measured.

Preparation of 152Gd targets from a small quantity of gadolinium oxide in a pyrochemical reaction