Comparison of the Relaxivities of Macrocyclic Gadolinium-Based Contrast Agents in Human Plasma at 1.5, 3, and 7 T, and Blood at 3 T

Szomolányi, Pavol; Rohrer, Martin; Frenzel, Thomas; Noebauer-Huhmann, Iris; Jošt, Gregor; Endrikat, Jan; Trattnig, Siegfried; Pietsch, Hubertus

doi:10.1097/rli.0000000000000577

Cited by 48 publications

(46 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When we plotted SI against the dilution of the GBCA formulations (right columns of Figs. 3 and 4), the SI differences were due to two features: (i) the different relaxivities of the GBCAs (14); and (ii) the different concentrations of the formulations in what is meant to reflect first-pass bolus imaging, as in angiography. As gadobutrol is formulated as a 1 molar and the two other GBCAs as 0.5 molar solutions, the SI differences were more pronounced in the dilution experiments.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Impact of concentration and dilution of three macrocyclic gadolinium-based contrast agents on MRI signal intensity at 1.5T and 3T and different pulse sequences: results of a phantom study in human plasma

et al. 2020

Self Cite

View full text Add to dashboard Cite

Background Many factors influence the increase in signal intensity (SI) provided by magnetic resonance imaging (MRI) contrast media. Purpose To assess the impact of different gadolinium concentrations and dilutions of three macrocyclic gadolinium-based contrast agents (GBCA) on SI. Material and Methods This phantom study investigated gadobutrol, gadoteridol, and gadoterate in human plasma of a healthy donor pool at 37 °C. Different molar concentrations served to mimic conditions typically relevant for steady-state imaging; different dilutions served to mimic influence on first-pass bolus imaging. For SI measurement at 1.5T and 3T, we used two Magnetom Scanners (Siemens), applying the T1-weighted sequences Flash 2D/3D and VIBE. Regions of interest were placed on the central slice of the test vials. Results In the concentration series, gadobutrol showed the highest SI of all three GBCAs up to 2 mM, followed by gadoteridol and gadoterate. No major differences were seen between 1.5T and 3T. In the dilution series, gadobutrol showed the highest SI of all three GBCAs up to 10 mL/L. The highest effect was recorded with Flash 3D and VIBE at 3T. Conclusion SIs measured in phantoms using three macrocyclic GBCAs strongly depend on their relaxivity and on the local concentration. The latter can be influenced—when comparing dilutions—by their initial concentration in their formulation. Furthermore, the pulse sequences and the chosen parameters have essential influence. At steady-state concentrations (≤2 mM) and first-pass bolus dilutions (up to 10 ml/L), gadobutrol showed highest SIs, followed by gadoterate and gadoteridol.

show abstract

Section: Discussionmentioning

confidence: 99%

“…(13) and published by Szomolanyi et al. (14). However, here we focus on SI enhancement, a more clinically tangible parameter than relaxivity.…”

Section: Introductionmentioning

confidence: 91%

Impact of concentration and dilution of three macrocyclic gadolinium-based contrast agents on MRI signal intensity at 1.5T and 3T and different pulse sequences: results of a phantom study in human plasma

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…To date, there is no standard protocol for how to best design and analyze a relaxivity experiment . Similar problems have been addressed previously in UV‐Vis spectroscopy and liquid chromatography‐mass spectrometry (LC‐MS) through weighted least squares (WLS), which has also been applied on occasion to relaxivity . Although WLS is a potential solution, the GGLM approach proposed in this work is more flexible as it assigns weights empirically by an iterative reweighted least squares algorithm .…”

Section: Introductionmentioning

confidence: 88%

“…Compared to traditional MRI imaging based on T 1 ‐ or T 2 ‐weighted signal intensity, MRI relaxometry is more robust for quantitative comparison as it is less sensitive to nuisance parameters such as coil positioning or scanner variabilities . Among other applications, relaxometry has been used to detect brain abnormalities and myocardial fibrosis or evaluate metabolic imaging, liver iron content (LIC), and contrast agent (CA) properties …”

Section: Introductionmentioning

confidence: 99%

“…

normalϵ

corresponds to the residual error term in the fit . Relaxivity studies are prime examples of heteroscedasticity where the error bars tend to increase in size with the relaxation rate . Currently, statistically suspect comparisons of relaxivities under different experimental conditions (e.g., field strength) or between CAs are regularly performed and displayed in bar charts or tables .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A novel gamma GLM approach to MRI relaxometry comparisons

Kapre

Zhou

et al. 2020

Magnetic Resonance in Med

View full text Add to dashboard Cite

Purpose:To demonstrate that constant coefficient of variation (CV), but nonconstant absolute variance in MRI relaxometry (T 1 , T 2 , R 1 , R 2 ) data leads to erroneous conclusions based on standard linear models such as ordinary least squares (OLS).We propose a gamma generalized linear model identity link (GGLM-ID) framework that factors the inherent CV into parameter estimates. We first examined the effects on calculations of contrast agent relaxivity before broadening to other applications such as analysis of variance (ANOVA) and liver iron content (LIC). Methods: Eight models including OLS and GGLM-ID were initially fit to data obtained on sulfated dextran iron oxide (SDIO) nanoparticles. Both a resampling simulation on the data as well as two separate Monte Carlo simulations (with and without concentration error) were performed to determine mean square error (MSE) and type I error rate. We then evaluated the performance of OLS/GGLM-ID on R 1 repeatability and LIC data sets. Results: OLS had an MSE of 4-5× that of GGLM-ID as well as a type I error rate of 20-30%, whereas GGLM-ID was near the nominal 5% level in the relaxivity study.Only OLS found statistically significant effects of MRI facility on relaxivity in an R 1 repeatability study, but no significant differences were found in a resampling, whereas GGLM was more consistent. GGLM-ID was also superior to OLS for modeling LIC. Conclusions: OLS leads to erroneous conclusions when analyzing MRI relaxometry data. GGLM-ID factors in the inherent CV of an MRI experiment, leading to more reproducible conclusions. K E Y W O R D S coefficient of variation, gamma GLM, MRI relaxometry, relaxivity, repeatability | 1593 KAPRE Et Al.

show abstract

Using Adaptive Imaging Parameters to Improve PEGylated Ultrasmall Iron Oxide Nanoparticles‐Enhanced Magnetic Resonance Angiography

Li,

Shan,

Chen

et al. 2024

Advanced Science

View full text Add to dashboard Cite

The PEGylated ultrasmall iron oxide nanoparticles (PUSIONPs) exhibit longer blood residence time and better biodegradability than conventional gadolinium‐based contrast agents (GBCAs), enabling prolonged acquisitions in contrast‐enhanced magnetic resonance angiography (CE‐MRA) applications. The image quality of CE‐MRA is dependent on the contrast agent concentration and the parameters of the pulse sequences. Here, a closed‐form mathematical model is demonstrated and validated to automatically optimize the concentration, echo time (TE), repetition time (TR) and flip angle (FA). The pharmacokinetic studies are performed to estimate the dynamic intravascular concentrations within 12 h postinjection, and the adaptive concentration‐dependent sequence parameters are determined to achieve optimal signal enhancement during a prolonged measurement window. The presented model is tested on phantom and in vivo rat images acquired from a 3T scanner. Imaging results demonstrate excellent agreement between experimental measurements and theoretical predictions, and the adaptive sequence parameters obtain better signal enhancement than the fixed ones. The low‐dose PUSIONPs (0.03 mmol kg−1 and 0.05 mmol kg−1) give a comparable signal intensity to the high‐dose one (0.10 mmol kg−1) within 2 h postinjection. The presented mathematical model provides guidance for the optimization of the concentration and sequence parameters in PUSIONPs‐enhanced MRA, and has great potential for further clinical translation.

show abstract

Comparison of the Relaxivities of Macrocyclic Gadolinium-Based Contrast Agents in Human Plasma at 1.5, 3, and 7 T, and Blood at 3 T

Cited by 48 publications

References 34 publications

Impact of concentration and dilution of three macrocyclic gadolinium-based contrast agents on MRI signal intensity at 1.5T and 3T and different pulse sequences: results of a phantom study in human plasma

Impact of concentration and dilution of three macrocyclic gadolinium-based contrast agents on MRI signal intensity at 1.5T and 3T and different pulse sequences: results of a phantom study in human plasma

A novel gamma GLM approach to MRI relaxometry comparisons

Using Adaptive Imaging Parameters to Improve PEGylated Ultrasmall Iron Oxide Nanoparticles‐Enhanced Magnetic Resonance Angiography

Contact Info

Product

Resources

About