Gadolinium-based contrast agents aggravate mechanical and thermal hyperalgesia in a nitroglycerine-induced migraine model in male mice

In the diagnosis of migraine, which is a neurovascular disease, gadolinium-based contrast agents (GBCAs) are used to rule out more serious conditions. On the other hand, it remains unclear as a scientific gap whether GBCAs may trigger migraine-related pain. The aim of this study was to investigate the effect of GBCAs on mechanical and thermal pain behaviour in a nitroglycerin (NTG)-induced migraine model in mice. NTG (10 mg/kg) was administered intraperitoneally to adult (6-8weeks old) BALB/c mice 2 h before behavioral tests 5 times every other day on days 1st, 3rd, 5th and 9th to induce migraine model (N = 50). As GBCAs, gadobenate dimeglumine (linear-ionic), Gadodiamide (linear-nonionic), and gadobutrol (macrocyclic-nonionic) were delivered intravenously through the tail vein of mice for 5 days on test days. Mechanical pain threshold (plantar and facial withdrawal threshold) was evaluated by plantar von Frey and periorbital von Frey tests on days 1st, 5th, and 9th, and thermal pain threshold (latency) was evaluated by hot plate and cold plate tests on days 3rd and 7th. There was a statistically significant increase in mechanical and thermal hyperalgesia in NTG administered groups compared to the control group. Gadodiamide, gadobutrol and gadobenate dimeglumine administration significantly decreased latency, paw and facial withdrawal threshold (0.18 ± 0.05, 0.17 ± 0.07, 0.16 ± 0.09; 9th day values respectively) compared to NTG group (0.27 ± 0.05). The results of this in vivo study show that GBCAs produce effects that may trigger migraine attacks in migraine. It is recommended that these effects be further investigated and supported by further clinical studies.

The effect of delay time after injecting gadobutrol on the diagnosis of endolymphatic hydrops

OBJECTIVES

The aim of this study was to reduce the time delay between gadolinium injection and 3D-FLAIR (three-dimensional fluid-attenuated inversion recovery) MRI by using a single dose of intravenous gadobutrol in Menière's disease patients.

METHODS

17 patients diagnosed with definite unilateral Meniere's disease underwent 3D-FLAIR MRI scans at 2, 4, and 6 h post-intravenous administration of a single-dose of gadobutrol. The signal intensity ratio of bilateral inner ear, cochlear and vestibular hydrops was measured at 2 h, 4 h and 6 h, while the differences in signal intensity ratio and endolymphatic hydrops were evaluated at three time points.

RESULTS

The cochlea, vestibule, and semicircular canal exhibit clear structural features with distinct perilymph-endolymph boundaries at 2 h, 4 h, and 6 h. The signal intensity ratio of the affected ear was significantly higher than that of the unaffected ear at 2 h, 4 h, and 6 h. The signal intensity ratio at 4 h and 6 h in both the affected and unaffected ears was significantly higher than that at 2 h, but there was no significant difference between 4 h and 6 h. Cochlear hydrops and vestibular hydrops show no significant differences at these time points, demonstrating excellent consistency.

CONCLUSIONS

We have demonstrated that 3D-FLAIR images acquired 2 h after intravenous administration of a single-dose gadobutrol are of high quality and equally effective as those obtained at the conventional 4-h time point for diagnosing endolymphatic hydrops in Menière's disease. In clinical practice, the delay time can be safely shortened to 2 h.

Investigation of imaging features in contrast-enhanced magnetic resonance imaging of benign and malignant breast lesions

PURPOSE

This study aimed to enhance the diagnostic accuracy of contrast-enhanced breast magnetic resonance imaging (MRI) using gadobutrol for differentiating benign breast lesions from malignant ones. Moreover, this study sought to address the limitations of current imaging techniques and criteria based on the Breast Imaging Reporting and Data System (BI-RADS).

MATERIALS AND METHODS

In a multicenter retrospective study conducted in Japan, 200 women were included, comprising 100 with benign lesions and 100 with malignant lesions, all classified under BI-RADS categories 3 and 4. The MRI protocol included 3D fast gradient echo T1- weighted images with fat suppression, with gadobutrol as the contrast agent. The analysis involved evaluating patient and lesion characteristics, including age, size, location, fibroglandular tissue, background parenchymal enhancement (BPE), signal intensity, and the findings of mass and non-mass enhancement. In this study, univariate and multivariate logistic regression analyses were performed, along with decision tree analysis, to identify significant predictors for the classification of lesions.

RESULTS

Differences in lesion characteristics were identified, which may influence malignancy risk. The multivariate logistic regression model revealed age, lesion location, shape, and signal intensity as significant predictors of malignancy. Decision tree analysis identified additional diagnostic factors, including lesion margin and BPE level. The decision tree models demonstrated high diagnostic accuracy, with the logistic regression model showing an area under the curve of 0.925 for masses and 0.829 for non-mass enhancements.

CONCLUSION

This study underscores the importance of integrating patient age, lesion location, and BPE level into the BI-RADS criteria to improve the differentiation between benign and malignant breast lesions. This approach could minimize unnecessary biopsies and enhance clinical decision-making in breast cancer diagnostics, highlighting the effectiveness of gadobutrol in breast MRI evaluations.

Evaluating blood supply changes in the osteonecrosis of the femoral head using gadobutrol-based steady-state MR angiography

OBJECTIVES

Assess the feasibility of using gadobutrol-based steady-state (SS) MR angiography (MRA) to evaluate the blood supply changes of osteonecrosis of the femoral head (ONFH).

MATERIALS AND METHODS

Participants were recruited in this prospective study from December 2021 to May 2022 in a single center. The number of superior retinacular arteries (SRAs), inferior retinacular arteries (IRAs), anterior retinacular arteries (ARAs), and overall retinacular arteries (ORAs), as well as the affected rates of SRA and IRA, were determined and compared between healthy and ONFH hips and between hips across the Association Research Circulation Osseous (ARCO) staging I-IV.

RESULTS

Twenty healthy and 64 ONFH hips were evaluated in 54 participants. There were significant differences between ARCO I-IV for the number of ORAs (mean of 3.5, 2.3, 1.7, and 0.8 for ARCO I-IV, respectively; p < .001), SRAs (median of 2.5, 1, 0.5, and 0 for ARCO I-IV, respectively; p < .001), and the affected rate of SRAs (20.00%, 65.22%, 77.78%, 92.31% for ARCO I-IV, respectively, p = 0.002). There were significant differences between ONFH and healthy hips for the number of ORAs (median of 5 vs. 2; p < .001), SRAs (median of 3 vs. 1; p < .001), IRAs (median of 1 vs. 1; p < .001), ARAs (median of 0 vs. 0; p = 0.04), and also the affected rate of SRAs (5.00% vs. 67.20%, p < .001) and IRAs (30% vs. 84.4%, p < .001).

CONCLUSION

Gadobutrol-enhanced SS MRA is a feasible method for evaluation of hemodynamics in ONFH.

CLINICAL RELEVANCE STATEMENT

Gadobutrol-enhanced magnetic resonance angiography can evaluate blood supply changes of ONFH and therefore helps to aid in the diagnosis and guide treatment of ONFH.

KEY POINTS

• Gadobutrol-enhanced magnetic resonance angiography showed changes in the retinacular artery related to the severity of femoral osteonecrosis. • Gadobutrol-enhanced magnetic resonance angiography revealed a reduced blood supply to the ischemic necrotic femoral head compared to the healthy counterparts.

Interval between contrast administration and T1-weighted MRI for cerebral adrenoleukodystrophy: a single-case observation

In adrenoleukodystrophy (ALD), contrast enhancement (CE) is a disease activity marker, but there is uncertainty about the optimal delay, if any, between contrast injection and magnetic resonance imaging (MRI) acquisition to avoid false-negative results. We acquired axial two-dimensional (2D) and three-dimensional (3D) T1-weighted gradient-echo every 6 min from 0 to 36 min after contrast administration (gadobutrol 0.1 mmol/kg) in an ALD patient with enlarging white matter lesions and progressive neuropsychological symptoms, using a 3-T magnet. The image signal over time was qualitatively assessed and measured in two regions of interest. On 3D sequences, no definite CE was appreciated, whereas on 2D sequences, CE was noticed after 6 min and definitely evident after 12 min, when 73% of the maximum signal intensity was measured. In ALD subjects, contrast-enhanced 2D T1-weighted gradient-echo sequences acquired at least 10 min after contrast injection may be considered to reduce false negative results.Relevance statementOur report is the first attempt to find an optimal delay between contrast administration and T1-weighted acquisition in cALD patients in order to correctly detect disease activity and avoid false negative results.Key points• The optimal time between contrast injection and image acquisition for MRI of adrenoleukodystrophy is unknown.• Contrast enhancement predicts adrenoleukodystrophy progression and could help patient's selection for the therapy.• We acquired two post-contrast T1-GRE-2D/3D sequences several times to find the best injection-time.• T1-weighted 2D GRE resulted more sensitive than T1-weighted 3D GRE even after long intervals from injection.• A delay of about 10 min may minimize false negatives.

Prospective T1 mapping to assess gadolinium retention in brain after intrathecal gadobutrol

PURPOSE

A possible pathway behind gadolinium retention in brain is leakage of contrast agents from blood to cerebrospinal fluid and entry into brain along perivascular (glymphatic) pathways. The object of this study was to assess for signs of gadolinium retention in brain 4 weeks after intrathecal contrast enhanced MRI.

METHODS

We prospectively applied standardized T1 mapping of the brain before and 4 weeks after intrathecal administration of 0.5 mmol gadobutrol in patients under work-up of cerebrospinal fluid circulation disorders. Due to methodological limitations, a safety margin for percentage change in T1 time was set to 3%. Region-wise differences were assessed by pairwise comparison using t-tests and forest plots, and statistical significance was accepted at .05 level (two-tailed).

RESULTS

In a cohort of 76 participants (mean age 47.2 years ± 17.9 [standard deviation], 47 women), T1 relaxation times remained unchanged in cerebral cortex and basal ganglia 4 weeks after intrathecal gadobutrol. T1 was reduced from 1082 ± 46.7 ms to 1070.6 ± 36.5 ms (0.98 ±2.9%) (mean [standard deviation]) (p=0.001) in white matter, thus within the pre-defined 3% safety margin. The brain stem and cerebellum could not be assessed due to poor alignment of posterior fossa structures at scans from different time points.

CONCLUSION

Gadolinium retention was not detected in the cerebral hemispheres 4 weeks after an intrathecal dose of 0.5 mmol gadobutrol, implying that presence of contrast agents in cerebrospinal fluid is of minor importance for gadolinium retention in brain.

Gadolinium retention in a rat model of subtotal renal failure: are there differences among macrocyclic GBCAs?

BACKGROUND

Gd levels are higher in tissues of animals with compromised renal function, but studies to compare levels after exposure to different macrocyclic gadolinium-based contrast agents (GBCAs) are lacking. We compared Gd levels in tissues of subtotally nephrectomised (SN) rats after repeated exposure to macrocyclic GBCAs.

METHODS

Sprague-Dawley SN male rats (19 per group) received 16 injections of gadoteridol, gadobutrol, or gadoterate meglumine at 0.6 mmol Gd/kg 4 times/weeks over 4 weeks. A control group of healthy male rats (n = 10) received gadoteridol at the same dosage. Plasma urea and creatinine levels were monitored. Blood, cerebrum, cerebellum, liver, femur, kidney(s), skin and peripheral nerves were harvested for Gd determination by inductively coupled plasma-mass spectrometry at 28 and 56 days after the end of treatment.

RESULTS

Plasma urea and creatinine levels were roughly twofold higher in SN rats than in healthy rats at all timepoints. At day 28, Gd levels in the peripheral nerves of gadobutrol- or gadoterate-treated SN animals were 5.4 or 7.2 times higher than in gadoteridol-treated animals (p < 0.001). Higher Gd levels after administration of gadobutrol or gadoterate versus gadoteridol were also determined in kidneys (p ≤ 0.002), cerebrum (p ≤ 0.001), cerebellum (p ≤ 0.003), skin (p ≥ 0.244), liver (p ≥ 0.053), and femur (p ≥ 0.271). At day 56, lower Gd levels were determined both in SN and healthy rats for all GBCAs and tissues, except the femur.

CONCLUSIONS

Gd tissue levels were lower following gadoteridol exposure than following gadobutrol or gadoterate exposure.

Time optimization of gadobutrol-enhanced brain MRI for metastases and primary tumors using a dynamic contrast-enhanced imaging

BACKGROUND

Recent advances in rapid imaging techniques necessitate the reconsideration of the optimal imaging delay time for contrast-enhanced T1-weighted imaging. The aim of our study was to determine the optimal contrast-enhanced T1-weighted imaging delay time from the obtained time-signal intensity curve (TIC) using gadobutrol in patients with brain metastases, primary brain tumors, and meningiomas.

METHODS

This prospective study enrolled 78 patients with brain metastases (n = 39), primary brain tumors (n = 22), or meningiomas (n = 17) who underwent 7-min dynamic contrast-enhanced imaging with single-dose gadobutrol. Based on the time-to-peak (TTP) derived from the TIC, we selected four different time points for analysis. Lesion conspicuity, enhanced rate (ER) and contrast rate (CR) of 116 index lesions were evaluated. Statistical comparisons were made for the four different time points using the Friedman test.

RESULTS

Maximum TTP (305.20 ± 63.47 s) was similar across all three groups (p = 0.342). Lesion conspicuity, CR and ER increased over time in all index lesions; however, no significant difference between the 5- and 7-min images was observed. The longest diameter in all groups differed significantly among time points (p < 0.001); the perpendicular diameter did not differ between the 5- and 7-min images.

CONCLUSIONS

Maximum contrast enhancement and lesion conspicuity was achieved 5-7 min after a single gadobutrol injection for brain metastases detection and for primary brain tumor/meningioma evaluation. Acquiring images 5 min after gadobutrol injection is the optimal timing for brain tumor detection during MRI work-up.

Population pharmacokinetic modeling of CSF to blood clearance: prospective tracer study of 161 patients under work-up for CSF disorders

Background

Quantitative measurements of cerebrospinal fluid to blood clearance has previously not been established for neurological diseases. Possibly, variability in cerebrospinal fluid clearance may affect the underlying disease process and may possibly be a source of under- or over-dosage of intrathecally administered drugs. The aim of this study was to characterize the cerebrospinal fluid to blood clearance of the intrathecally administered magnetic resonance imaging contrast agent gadobutrol (Gadovist, Bayer Pharma AG, GE). For this, we established a population pharmacokinetic model, hypothesizing that cerebrospinal fluid to blood clearance differs between cerebrospinal fluid diseases.

Methods

Gadobutrol served as a surrogate tracer for extra-vascular pathways taken by several brain metabolites and drugs in cerebrospinal fluid. We estimated cerebrospinal fluid to blood clearance in patients with different cerebrospinal fluid disorders, i.e. symptomatic pineal and arachnoid cysts, as well as tentative spontaneous intracranial hypotension due to cerebrospinal fluid leakage, idiopathic intracranial hypertension, or different types of hydrocephalus (idiopathic normal pressure hydrocephalus, communicating- and non-communicating hydrocephalus). Individuals with no verified cerebrospinal fluid disturbance at clinical work-up were denoted references.

Results

Population pharmacokinetic modelling based on 1,140 blood samples from 161 individuals revealed marked inter-individual variability in pharmacokinetic profiles, including differences in absorption half-life (time to 50% of tracer absorbed from cerebrospinal fluid to blood), time to maximum concentration in blood and the maximum concentration in blood as well as the area under the plasma concentration time curve from zero to infinity. In addition, the different disease categories of cerebrospinal fluid diseases demonstrated different profiles.

Conclusions

The present observations of considerable variation in cerebrospinal fluid to blood clearance between individuals in general and across neurological diseases, may suggest that defining cerebrospinal fluid to blood clearance can become a useful diagnostic adjunct for work-up of cerebrospinal fluid disorders. We also suggest that it may become useful for assessing clearance capacity of endogenous brain metabolites from cerebrospinal fluid, as well as measuring individual cerebrospinal fluid to blood clearance of intrathecal drugs.

Optimized 3D-FLAIR sequences to shorten the delay between intravenous administration of gadolinium and MRI acquisition in patients with Menière's disease

OBJECTIVES

The aim of this study was to shorten the 4-h delay between the intravenous administration of gadolinium and MRI acquisition for hydrops evaluation using an optimized 3D-FLAIR sequence in patients with Menière's disease.

METHODS

This was a single-center prospective study including 29 patients (58 ears), recruited between November 2020 and February 2021. All patients underwent a 3-T MRI with an optimized 3D-FLAIR sequence without contrast then at 1 h, 2 h, and 4 h after intravenous administration of gadobutrol. The signal intensity ratio was quantitatively assessed with the region of interest method. We also evaluated the volume of endolymphatic structures (saccule, utricle) then the presence of endolymphatic hydrops and blood-labyrinthine barrier impairment at each acquisition time.

RESULTS

For all ears, the signal intensity ratio was significantly non-inferior at 2 h compared to 4 h, with a mean geometric signal intensity ratio at 0.83 (95% CI: 0.76 to 0.90, one-sided p < .001 for non-inferiority at -30% margin). Mean volume equivalence of saccule and utricle between 2 and 4 h was proven at a ± 0.20 standardized deviation equivalence margin. Intra-rater agreements (Cohen's kappa) were all greater than 0.90 for all endolymphatic hydrops location and blood-labyrinthine-barrier impairment between the 2- and 4-h assessments.

CONCLUSIONS

We demonstrated that using an optimized 3D-FLAIR sequence we could shorten the acquisition from 4 to 2 h with a high reliability for the diagnosis of endolymphatic hydrops and blood-labyrinthine-barrier impairment.

CLINICAL TRIAL REGISTRATION

Clinical trial no: 38RC15.173 KEY POINTS: • Magnetic resonance imaging with delayed 3D-FLAIR sequences allows the diagnosis of endolymphatic hydrops in patients with definite Menière's disease. • An optimized 3D-FLAIR sequence with a long TR of 16000 ms and a constant flip angle allows for reducing the delay between intravenous injection of gadobutrol and MRI acquisition from 4 to 2 h to diagnose endolymphatic hydrops. • Reducing this delay between intravenous injection and MRI acquisition could have implications for clinical practice for both patients and imaging departments.

The TRUTH confirmed: validation of an intraindividual comparison of gadobutrol and gadoteridol for imaging of glioblastoma using quantitative enhancement analysis

BACKGROUND

Previous intraindividual comparative studies evaluating gadobutrol and gadoteridol for contrast-enhanced magnetic resonance imaging (MRI) of brain tumours have relied on subjective image assessment, potentially leading to misleading conclusions. We used artificial intelligence algorithms to objectively compare the enhancement achieved with these contrast agents in glioblastoma patients.

METHODS

Twenty-seven patients from a prior study who received identical doses of 0.1 mmol/kg gadobutrol and gadoteridol (with appropriate washout in between) were evaluated. Quantitative enhancement (QE) maps of the normalised enhancement of voxels, derived from computations based on the comparison of contrast-enhanced T1-weighted images relative to the harmonised intensity on unenhanced T1-weighted images, were compared. Bland-Altman analysis, linear regression analysis and Pearson correlation coefficient (r) determination were performed to compare net QE and per-region of interest (per-ROI) average QE (net QE divided by the number of voxels).

RESULTS

No significant differences were observed for comparisons performed on net QE (mean difference -24.37 ± 620.8, p = 0.840, r = 0.989) or per-ROI average QE (0.0043 ± 0.0218, p = 0.313, r = 0.958). Bland-Altman analysis revealed better per-ROI average QE for gadoteridol-enhanced MRI in 19/27 (70.4%) patients although the mean difference (0.0043) was close to zero indicating high concordance and the absence of fixed bias.

CONCLUSIONS

The enhancement of glioblastoma achieved with gadoteridol and gadobutrol at 0.1 mmol/kg bodyweight is similar indicating that these agents have similar contrast efficacy and can be used interchangeably, confirming the results of a prior double-blind, randomised, intraindividual, crossover study.

Dynamic susceptibility MR perfusion imaging of the brain: not a question of contrast agent molarity

PURPOSE

Dynamic susceptibility contrast (DSC) perfusion-weighted MR imaging (PWI) is increasingly used in clinical neuroimaging for a range of conditions. More highly concentrated GBCAs (e.g., gadobutrol) are often preferred for DSC imaging because it is thought that more Gd is present in the volume of interest during first pass for a given equivalent injection rate. However, faster injection of a less viscous GBCA (e.g., gadoteridol) might generate a more compact and narrower contrast bolus thus obviating any perceived benefit of higher Gd concentration. This preliminary study aimed to analyze and compare DSC examinations in the healthy brain hemisphere of patients with brain tumors using gadobutrol and gadoteridol administered at injection rates of 4 and 6 mL/s.

METHODS

Thirty-nine brain tumor patients studied with DSC-PWI were evaluated. A simplified gamma-variate model function was applied to calculate the mean peak, area under the curve (AUC), and full-width at half-maximum (FHWM) of concentration-time curves derived from ΔR2* signals at four different regions-of-interest (ROIs). Qualitative assessment of the derived CBV maps was also performed independently by 2 neuroradiologists.

RESULTS

No qualitative or quantitative differences between the two GBCAs were observed when administered at a flow rate of 4 mL/s. At a flow rate of 6 mL/s, gadoteridol showed lower FWHM values.

CONCLUSION

Gadobutrol and gadoteridol are equivalent for clinical assessment of qualitative CBV maps and quantitative perfusion parameters (FHWM) at a flow rate of 4 mL/s. At 6 mL/s, gadoteridol produces a narrower bolus shape and potentially improves quantitative assessment of perfusion parameters.

Clinical Efficacy of Reduced Dose Gadobutrol Versus Standard Dose Gadoterate for Contrast-Enhanced MRI of the CNS: An International Multicenter Prospective Crossover Trial (LEADER-75)

Background: Gadobutrol and gadoterate are widely used macrocyclic gadolinium-based contrast agents. Given gadobutrol's higher T1 relaxivity, reduced gadobutrol dose should achieve essentially equivalent diagnostic efficacy as standard gadoterate dose. Objective: To demonstrate that efficacy of 25%-reduced dose of gadobutrol (rd-gadobutrol) is non-inferior to 100%-standard-dose of gadoterate (sd-gadoterate) for contrast-enhanced MRI of the CNS. Methods: In this international, prospective, multicenter, open-label, cross-over trial (LEADER-75), adult patients with known or suspected CNS pathology underwent contrast-enhanced brain MRI with sd-gadoterate (0.1 mmol/kg); if an enhancing lesion was identified, a second MRI with rd-gadobutrol (0.075 mmol/kg) was performed within 15 days. Three radiologists independently reviewed images to score three primary efficacy measures (subjective lesion enhancement, lesion border delineation, lesion internal morphology); primary non-inferiority analysis used readers' mean scores. Non-inferiority of rd-gadobutrol to sd-gadoterate for primary efficacy measures was defined as difference in score between rd-gadobutrol and unenhanced images achieving at least 80% of difference in score between sd-gadoterate and unenhanced images. Post-hoc analysis was performed to directly compare contrast-enhanced images for equivalence. Secondary efficacy variables included number of lesions detected, reader confidence, diagnostic performance for malignancy, and reader preference in side-by-side comparison. Results: The efficacy analysis included 141 patients (78 men, 63 women; mean age, 58.5±13.5 years). Improvement of rd-gadobutrol over unenhanced images was non-inferior to improvement of sd-gadoterate over unenhanced images using 20% non-inferiority margin for all three primary efficacy measures using mean readings (p≤.025). In post-hoc analysis, mean reading for the three primary efficacy measures differed by less than 1% between rd-gadobutrol and sd-gadoterate, supporting equivalence of all measures using a narrow ±5% margin (p≤.025). Total lesions detected by mean reading was 301 for rd-gadobutrol versus 291 for sd-gadoterate. Mean confidence was 3.3±0.6 for rd-gadobutrol versus 3.3±0.6 for sd-gadoterate. Sensitivity (58.7%), specificity (91.8%), and accuracy (70.2%) for malignancy from majority reading were identical for rd-gadobutrol and sd-gadoterate. Reader preference was not different (95% CI [-0.10, 0.11]). Conclusion: A 25%-reduced dose of gadobutrol is non-inferior to sd-gadoterate for contrast-enhanced brain MRI. Clinical Impact: Use of rd-gadobutrol should be considered for brain MRI, particularly in patients undergoing multiple contrast-enhanced examinations.

Repeated gadoteric acid and gadobutrol exposure causes deterioration of behavior and memory functions in rats: MRI, histopathological and biochemical evidence

Gadolinium-based contrast agents (GBCAs) exert effects in different regions of the brain; however, studies on this topic are mostly focused on radiological outcomes of GBCA exposure. This paper is a preliminary attempt to identify whether there are changes in behavioral, cognitive, histopathological, radiological and biochemical characteristics with repeated exposure to gadobutrol and gadoteric acid. The effects of GBCAs were tested with the assessment of 4 groups -each comprised of 6 rats [controls, gadobutrol, gadoteric acid (Doteram), and gadoteric acid (Clariscan)]. Respective treatments of 0.1 ml/kg were administered for 3 weeks, followed by a recovery period of 1 week without any treatment. At the end of this regimen, behavioral tests (open field and passive learning test) were performed. Additionally, histopathological analysis of the hippocampal CA1 and CA3 regions (GFAP measurement and total neuron count), biochemical measurements [TNF-a, Malondialdehyde (MDA), Superoxide dismutase (SOD), homovalinic acid (HVA) and choline acetyl transferase (ChAT) levels], and radiological findings (MRI-region of interest) were carried out in each group. There was a significant impairment in all groups that had received gadolinium in open field and passive avoidance learning tests. Oxidative stress and inflammation markers were significantly elevated in all gadolinium groups. Additionally, increased hippocampal gliosis and decreased MRI-ROIs were observed in rats exposed to gadolinium. Chronic gadoteric acid and gadobutrol exposure causes hippocampal gliosis and elevates oxidative stress and inflammation in rats. Radiological outcomes are also consistent with these findings. Long-term studies might be required to conclude whether gadolinium deposition in the brain causes subtle neurological deficits.

Biliary excretion of gadobenate dimeglumine causing degradation of magnetic resonance cholangiopancreatography (MRCP)

PURPOSE

To assess the effect of gadobenate dimeglumine on magnetic resonance cholangiopancreatography (MRCP) and determine an appropriate time frame for performing MRCP sequences.

MATERIALS AND METHODS

2D MRCP sequences obtained after intravenous administration of gadobenate dimeglumine or gadobutrol over 14 months were reviewed retrospectively in randomized order by five abdominal radiologists, using a 3-point scale to rate biliary and pancreatic duct clarity (1 = no-, 2 = limited-, 3 = good visualization). Intraclass correlation coefficients were computed and mean scores were compared for both agents. For gadobenate dimeglumine exams, time delays between arterial phase and MRCP acquisition times were analyzed concerning duct clarity. For gadobutrol, only exams with delays ≥ 15 min were included.

RESULTS

134 exams (107 gadobenate dimeglumine, 27 gadobutrol) were included. Moderate reliability for pancreatic duct visualization and excellent reliability for visualization of intrahepatic bile ducts and upper and lower extrahepatic bile ducts were noted. No difference in mean scores was noted for pancreatic duct visualization (p = 0.66). Bile duct segment scores were lower with gadobenate dimeglumine (mean: 2.1-2.6) compared with gadobutrol (mean: 2.8-2.9) (p ≤ 0.006). For gadobenate dimeglumine, visualization scores varied depending on the delay between the arterial phase and MRCP acquisition (p ≤ 0.047). Good visualization for all bile duct segments was noted with delays of 7.2-9.4 min (95% confidence interval; mean 8.3 min).

CONCLUSION

Bile duct clarity degraded on MRCP images with an increasing delay following gadobenate dimeglumine injection. 2D MRCP, thus, should be performed within 7.2 min after obtaining the arterial phase sequence to ensure good visualization of the entire biliary system.

Transient respiratory motion artifacts in multiple arterial phases on abdominal dynamic magnetic resonance imaging: a comparison using gadoxetate disodium and gadobutrol

PURPOSE

To compare the occurrence of transient respiratory motion artifacts (TRMAs) in multiple arterial phases on abdominal magnetic resonance (MR) images between those obtained using gadobutrol and gadoxetate disodium.

MATERIALS AND METHODS

Two hundred and fourteen abdominal MR examinations (101 with gadoxetate disodium, 113 with gadobutrol) were evaluated. Dynamic three-dimensional contrast-enhanced T1-weighted imaging (CAIPIRINHA-Dixon-TWIST-VIBE) including single-breath-hold six arterial phase acquisitions was performed on a 3.0-T MRI scanner. The TRMAs frequency and the mean TRMA scores were compared between patients assessed with gadoxetate disodium and those assessed with gadobutrol. In addition, the timing of TRMAs appearing for the first time was also recorded and compared between the two groups.

RESULTS

The mean TRMA scores in all arterial phases using gadoxetate disodium were significantly worse than in those using gadobutrol (1.49 ± 0.78 vs. 1.18 ± 0.53, P < .001). Regarding the timing of the occurrence of TRMAs, the severe TRMAs frequency after the third arterial phase was significantly higher in patients using gadoxetate disodium (10/101, 10%) than in those using gadobutrol (0/113, 0%) (P < .001).

CONCLUSION

In multiple-arterial-phase dynamic MRI, the TRMAs frequency when using gadoxetate disodium increased compared with gadobutrol, due to intolerable respiratory suspension after the third arterial phase.

Off-label intrathecal use of gadobutrol: safety study and comparison of administration protocols

Purpose

Magnetic resonance imaging (MRI) contrast agents have been used off-label for diagnosis of cerebrospinal fluid (CSF) leaks and lately also for assessment of the glymphatic system and meningeal lymphatic drainage. The purpose of this study was to further evaluate the short- and long-term safety profile of intrathecal MRI contrast agents.

Methods

In this prospective study, we compared the safety profile of different administration protocols of intrathecal gadobutrol (Gadovist^TM; 1.0 mmol/ml). Gadobutrol was administered intrathecal in a dose of 0.5 mmol, with or without iodixanol (Visipaque^TM 270 mg I/ml; 3 ml). In addition, a subgroup was given intrathecal gadobutrol in a dose of 0.25 mmol. Adverse events were assessed at 1 to 3 days, 4 weeks, and after 12 months.

Results

Among the 149 patients, no serious adverse events were seen in patients without history of prior adverse events. The combination of gadobutrol with iodixanol did not increase the occurrence of non-serious adverse events after days 1–3. Intrathecal gadobutrol in a dose of 0.25 mmol caused less severity of nausea, as compared with the dose of 0.5 mmol. The clinical diagnosis was the major determinant for occurrence of non-serious adverse events after intrathecal gadobutrol.

Conclusion

This prospective study showed that intrathecal administration of gadobutrol in a dose of 0.5 mmol is safe. Non-serious adverse events were to a lesser degree affected by the administration protocols, though preliminary data are given that side effects of intrathecal gadobutrol are dose-dependent.

Intrathecal use of gadobutrol for gadolinium-enhanced MR cisternography in the evaluation of patients with otorhinorrhea

PURPOSE

Intrathecal gadolinium-enhanced MR cisternography (IGE-MRC) has a high sensitivity to detect accurate localization of cerebrospinal fluid (CSF) leakage in otorhinorrhea patients. Our purpose in this study was to describe our experience in analyzing clinically suspected CSF leakage by IGE-MRC by using gadobutrol with emphasis on its safety and diagnostic performance.

METHODS

We retrospectively reviewed our imaging and clinical database for the evaluation of patients admitted to our clinic with complaints of otorhinorrhea between 2017 and 2019. Two radiologists evaluated the imaging studies independently. Consensus data was used in the analysis. Medical record review and phone call were used for the follow-up.

RESULTS

Of the 85 patients included in the retrospective analysis, 82 (96.5%) had rhinorrhea and 3 (3.5%) had otorrhea. Overall, 29 patients (34.1% of all patients) underwent operation for repair of the CSF leakage site. Beta-transferrin test was available and positive in 33 patients (38.8%). Five (5.9%) patients complained headaches after the procedure and complaints were resolved with increased water intake. Postprocedurally, 3 patients (3.5%) had vertigo and 1 patient (1.2%) complained nausea but spontaneous regression were observed in a few hours. None of the patients experienced a significant complication or adverse reaction during follow-up period. Sixty-seven patients (78.8%) had medical record and telephone follow-up. Mean follow-up duration with call was 14.2 months.

CONCLUSION

IGE-MRC is a minimally invasive and highly sensitive imaging technique. The current results during our follow-up demonstrate the relative safety and feasibility of IGE-MRC by using gadobutrol to evaluate CSF leakage.

Image quality of late gadolinium enhancement in cardiac magnetic resonance with different doses of contrast material in patients with chronic myocardial infarction

Background

Contrast-enhanced cardiac magnetic resonance (CMR) is pivotal for evaluating chronic myocardial infarction (CMI). Concerns about safety of gadolinium-based contrast agents favour dose reduction. We assessed image quality of scar tissue in CMRs performed with different doses of gadobutrol in CMI patients.

Methods

Informed consent was waived for this Ethics Committee-approved single-centre retrospective study. Consecutive contrast-enhanced CMRs from CMI patients were retrospectively analysed according to the administered gadobutrol dose (group A, 0.10 mmol/kg; group B, 0.15 mmol/kg; group C, 0.20 mmol/kg). We calculated the signal-to-noise ratio for scar tissue (SNR_scar) and contrast-to-noise ratio between scar and either remote myocardium (CNR_scar-rem) or blood (CNR_scar-blood).

Results

Of 79 CMRs from 79 patients, 22 belonged to group A, 26 to group B, and 31 to group C. The groups were homogeneous for age, sex, left ventricular morpho-functional parameters, and percentage of scar tissue over whole myocardium (p ≥ 0.300). SNR_scar was lower in group A (46.4; 40.3–65.1) than in group B (70.1; 52.2–111.5) (p = 0.013) and group C (72.1; 59.4–100.0) (p = 0.002), CNR_scar-rem was lower in group A (62.9; 52.2–87.4) than in group B (96.5; 73.1–152.8) (p = 0.008) and in group C (103.9; 83.9–132.0) (p = 0.001). No other significant differences were found (p ≥ 0.335).

Conclusions

Gadobutrol at 0.10 mmol/kg provides inferior scar image quality of CMI than 0.15 and 0.20 mmol/kg; the last two dosages seem to provide similar LGE. Thus, for CMR of CMI, 0.15 mmol/kg of gadobutrol can be suggested instead of 0.20 mmol/kg, with no hindrance to scar visualisation. Dose reduction would not impact on diagnostic utility of CMR examinations.

Late-onset acute respiratory distress syndrome induced by a gadolinium-based contrast agent

Rapid decline of pulmonary function in acute respiratory distress syndrome (ARDS) can make ARDS a dangerous and potentially life-threatening condition. Gadolinium-based contrast agents are considered safe alternatives to iodine-based contrast agents, with comparatively fewer adverse effects and a lower incidence of serious adverse events, such as dyspnea or hypotension. There are five reported cases of gadolinium-induced ARDS. A 59-year-old woman with respiratory failure 30 min after gadolinium administration was diagnosed with ARDS; she was admitted to the intensive care unit. Her condition improved by artificial respiration management and adrenaline and steroids administration. She was discharged on day 13. Considering ARDS occurred 30 min after gadolinium administration and findings suggesting anaphylaxis, such as wheezing and failure in organs other than the lungs, were absent, the involvement of any immediate-onset reaction was excluded; thus, a diagnosis of gadolinium-induced ARDS was made.

Visible T1-hyperintensity of the dentate nucleus after multiple administrations of macrocyclic gadolinium-based contrast agents: yes or no?

OBJECTIVES

To investigate the appearance of visible dentate nucleus (DN) T1-hyperintensity and quantify changes in DN/pons (DN/P) signal intensity (SI) ratio in MS patients after the exclusive administration of macrocyclic GBCAs.

MATERIALS AND METHODS

One hundred forty-nine patients with confirmed MS were evaluated. Patients received at least two administrations of gadobutrol (n = 63), gadoterate (n = 57), or both (n = 29). Two experienced neuroradiologists in consensus evaluated unenhanced T1-weighted MR images from all examinations in each patient for evidence of visible DN hyperintensity. Thereafter, SI measurements were made in the left and right DN and pons on unenhanced T1-weighted images from the first and last scans. A two-sample t test compared the DN/P SI ratios for patients with and without visible T1-hyperintensity.

RESULTS

Visible T1-hyperintensity was observed in 42/149 (28.2%) patients (19 after gadobutrol only, 15 after gadoterate only, 8 after both), typically at the 4th or 5th follow-up exam at 3-4 years after the initial examination. Significant increases in DN/P SI ratio from first to last examination were determined for patients with visible T1-hyperintensity (0.998 ± 0.002 to 1.153 ± 0.016, p < 0.0001 for gadobutrol; 1.003 ± 0.004 to 1.110 ± 0.014, p < 0.0001 for gadoterate; 1.004 ± 0.011 to 1.163 ± 0.032, p = 0.0004 for both) but not for patients without visible T1-hyperintensity (p > 0.05; all groups).

CONCLUSION

Multiple injections of gadobutrol and/or gadoterate can lead to visible and quantifiable increases in DN/P SI ratio in some patients with MS.

Dynamic contrast-enhanced MR imaging of the prostate: intraindividual comparison of gadoterate meglumine and gadobutrol

OBJECTIVES

To intraindividually compare the signal-enhancing effect of 0.5 M gadoterate meglumine and 1.0 M gadobutrol in dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging of the prostate.

METHODS

Fifty patients who underwent two 3-T MR examinations of the prostate were included in this IRB-approved retrospective uncontrolled, unrandomized study. All received two scans (mean time interval, 20.5 months) including T1-weighted DCE-MR imaging, one with 0.5 M gadoterate meglumine and one with 1.0 M gadobutrol. Equimolar doses of gadolinium (0.1 mmol/kg body weight) were administered with identical injection speed (2 mL/s), resulting in differing gadolinium delivery rate. An identical region of interest (ROI_tz) within a BPH-node was identified on both scans. The area under the time-enhancement curve of each ROI_tz from 0 to 180 s post contrast arrival and pharmacokinetic parameters were calculated. Relative enhancement and signal-to-noise (SNR) and contrast-to-noise (CNR) ratios in the delayed phase at about 180 s were compared between both agents.

RESULTS

There was a significantly larger area under the time-enhancement curve (5.53 vs 4.97 p = 0.0007) and higher relative enhancement of BPH nodules (2.23 vs 1.96 p < 0.0001) with gadobutrol compared with gadoterate meglumine. There were no significant differences in SNR (44.55 vs 37.63 p = 0.12), CNR (31.22 vs 26.39 p = 0.18), and pharmacokinetic parameters Ktrans (0.31 vs 0.32 p = 0.86), Ve (1.36 vs 0.98 p = 0.13), and Kep (0.34 vs 0.36 p = 0.12).

CONCLUSIONS

At equimolar doses, increased gadolinium delivery over time using gadobutrol provides higher relative enhancement parameters in BPH nodules compared with gadoterate meglumine, but does not translate into improved SNR or CNR.

KEY POINTS

• At equal injection rate and equimolar total dose, gadobutrol compared with gadoterate meglumine provides a significantly greater relative enhancement in DCE-MR imaging of BPH over the first 180 s. • There are no significant differences in SNRs, CNRs, and pharmacokinetic parameters between the two GBCAs.

Safety of gadobutrol: results of a non-interventional study of 3710 patients, including 404 children

Background

The safety of gadolinium-based contrast agents is a hot topic in radiology.

Purpose

To evaluate the safety profile of gadobutrol during routine use.

Material and Methods

Prospective, non-interventional study in 80 centers in Germany. The primary outcome was the number of adverse drug reactions (ADR) following gadobutrol administration.

Results

A total of 3710 patients were included in the analysis, including 404 children (10.9%). A total of 6026 magnetic resonance imaging examinations of organs/organ systems and 872 magnetic resonance angiography examinations were performed. A total of 22 (0.59%) patients experienced at least one ADR. Nausea and vomiting were the most frequent ADRs, experienced by nine (0.24%) and three (0.08%) patients, respectively. One serious ADR was recorded (anaphylactoid reaction). No deaths were reported.

Conclusion

This non-interventional study in 3710 patients confirmed gadobutrol as a safe and reliable contrast agent in adults and children.

Preliminary study: Breast cancers can be well seen on 3T breast MRI with a half-dose of gadobutrol

BACKGROUND

Dynamic contrast enhanced (DCE) breast MRI is highly sensitive for breast cancer and requires gadolinium-based contrast agents (GBCA)s, which have potential safety concerns.

PURPOSE

Test whether breast cancers imaged by 3T DCE breast MRI with 0.05 mmol/kg of gadobutrol are detectable.

METHODS

Analysis of 3T DCE breast MRIs with half dose of gadobutrol from patients included in an IRB-approved and HIPPA-compliant prospective study of breast PET/MRI. Between 11/7/2014 and 3/2/2018, 41 consecutive women with biopsy-proven breast cancer that was at least 2 cm, multi-focal or multi-centric, had axillary metastasis, or had skin involvement who gave informed consent were included. Two breast radiologists independently recorded lesion conspicuity on a 4-point scale (0 = not seen, 1 = questionably seen, 2 = adequately seen, 3 = certainly seen), and measured the lesion. Size was compared between radiologists and with size on available mammogram, ultrasound, MRI, and surgical pathology. Inter-reader agreement was assessed by kappa coefficient for conspicuity. Lesion size comparisons were assessed using the Spearman rank correlation.

RESULTS

In 40 patients (ages 28.4-80.5, 51.9 years), there were 49 cancers. 10.1% of lesions were 1 cm or less and 26.5% of lesions were 2 cm or less. Each reader detected 49/49 cancers. Conspicuity scores ranged from 2 to 3, mean 2.9/3 for both readers (p = 0.47). Size on half-dose 3T DCE-MRI correlated with size on surgical pathology (r = 0.6, p = 0.03) while size on mammogram and ultrasound did not (r = 0.25, p = 0.46; r = 0.25, p = 0.42).

CONCLUSION

All breast cancers in this cohort, as small as 0.4 cm, were seen on 3T DCE breast MRI with 0.05 mmol/kg dose of gadobutrol.

Post-marketing surveillance of gadobutrol for contrast-enhanced magnetic resonance imaging in Japan

PURPOSE

To evaluate the safety of gadobutrol for magnetic resonance imaging in a prospective, non-interventional, post-marketing surveillance in Japan.

MATERIALS AND METHODS

Gadobutrol was administered in accordance with Japanese prescribing information over a 2-year enrollment period, using a standardized questionnaire to collect information. The primary outcome was the incidence of adverse reactions (ARs) following gadobutrol injection.

RESULTS

Questionnaire data were analyzed for 3337 patients (age, 58.1 ± 17.4 years [mean±SD]). Gadobutrol was administered at a dose of 0.10 ± 0.02 mL/kg body weight. Thirty-three patients were observed to have 42 ARs suspected to be due to gadobutrol, an incidence proportion of 0.99%; 29 ARs were acute (<1 h post-injection)-including one case of severe acute AR (0.03%). Patient subpopulations (with hepatic, renal, cardiovascular diseases) did not differ markedly in AR proportions categorized by age, sex, presence of comorbidity, or imaging indication. No cases of nephrogenic systemic fibrosis were reported. Investigators rated images as improved or profoundly improved following gadobutrol injection in 91.1% of examinations.

CONCLUSION

Gadobutrol was well tolerated with a good safety profile in this post-marketing surveillance of a large patient population in Japan.

The effects of flip angle optimization on the precision and reproducibility of feature tracking derived strain assessment in contrast enhanced bSSFP cine images

OBJECTIVES

The aim of this study was to investigate whether a flip angle adaptation, which is known to improve SNR and CNR in post contrast SSFP imaging, improves the precision and reproducibility of Feature Tracking (FT) derived strain assessments in post contrast bSSFP imaging.

METHODS AND RESULTS

At 1.5T balanced SSFP midventricular short axis cine images were acquired with various flip angles (FA) before (FA = 50°) and 5 min after (FAs = 50°, 80°, 90°, 100°) injection of double dose Gadobutrol. FT derived systolic circumferential strain was then calculated for all pre- and post-contrast images, the intra- and inter-observer variability of strain measurements was assessed. FT derived midventricular peak systolic circumferential strain (PSCS) derived from unadapted (FA: 50°) contrast enhanced bSSFP images was significantly lower than strain derived from unenhanced bSSFP images (-16.45 ± 5.1% vs -20.57 ± 6.2%; p < 0.001) and showed low agreement (mean difference of -4.13 ± 2.4, 95% CI:-5.3 to -3) in all 20 subjects. After adaption of the flip angle (FA: 100°), agreement between strain derived from unenhanced and adapted contrast enhanced bSSFP images (-20.57 ± 6%) was strong (0.01 ± 0.9, CI:-0.43 to 0.41). In comparison to intra- and interobserver variability of strain derived from unenhanced images (intra 2.9%; inter: 3.9%), strain measurements derived from adapted contrast enhanced images (FA: 100°) showed a slightly lower variability (intra: 2.5%; inter: 2.3%).

CONCLUSION

If flip angle adaptation is performed, FT based strain analysis may be performed on contrast enhanced bSSFP cine images without loss of precision and accuracy.

[Comparison of Time-intensity Curve with Gadobenatedimeglumine and Gadobutrol on Multiphase Contrast-enhanced Breast MRI]

The purpose of this study was to compare the time-intensity curve (TIC) on multiphase contrast-enhanced breast magnetic resonance imaging (MRI) between Gadobenatedimeglumine (Gd-DTPA) and Gadobutrol. We assessed the images of 53 cases obtained from MRI that had malignant findings by pathology from October 2015 to October 2016 in our institute. Gd-DTPA and Gadobutrol were administrated in 16 and 37 cases, respectively. The TIC of the lesion was classified according to the Kuhl's method (type I: persistent pattern, type II: plateau pattern and type III: washout pattern). Type III was the most common TIC pattern in both the groups (Gd-DTPA, 12 cases; Gadobutrol, 18 cases). Type II was the second common TIC pattern in Gadobutrol group (12 cases). As a result, there was no significant difference in TIC analysis between Gd-DTPA and gadobutrol. In conclusion, the contrast between Gd-DTPA and Gadobutrol contrast media did not differ in TIC pattern of multiphasic contrast-enhanced breast MRI.

High-throughput gadobutrol-enhanced CMR: a time and dose optimization study

BACKGROUND

Reducing time and contrast agent doses are important goals to provide cost-efficient cardiovascular magnetic resonance (CMR) imaging. Limited information is available regarding the feasibility of evaluating left ventricular (LV) function after gadobutrol injection as well as defining the lowest dose for high quality scar imaging. We sought to evaluate both aspects separately and systematically to provide an optimized protocol for contrast-enhanced CMR (CE-CMR) using gadobutrol.

METHODS

This is a prospective, randomized, single-blind cross-over study performed in two different populations. The first population consisted of 30 patients with general indications for a rest CE-CMR who underwent cine-imaging before and immediately after intravenous administration of 0.1 mmol/kg body-weight of gadobutrol. Quantitative assessment of LV volumes and function was performed by the same reader in a randomized and blinded fashion. The second population was composed of 30 patients with indication to late gadolinium enhancement (LGE) imaging, which was performed twice at different gadobutrol doses (0.1 mmol/kg vs. 0.2 mmol/kg) and at different time delays (5 and 10 min vs. 5, 10, 15 and 20 min), within a maximal interval of 21 days. LGE images were analysed qualitatively (contrast-to-noise ratio) and quantitatively (LGE%-of-mass).

RESULTS

Excellent correlation between pre- and post-contrast cine-imaging was found, with no difference of LV stroke volume and ejection fraction (p = 0.538 and p = 0.095, respectively). End-diastolic-volume and end-systolic-volume were measured significantly larger after contrast injection (p = 0.008 and p = 0.001, respectively), with a mean difference of 3.7 ml and 2.9 ml, respectively. LGE imaging resulted in optimal contrast-to-noise ratios 10 min post-injection for a gadobutrol dose of 0.1 mmol/kg body-weight and 20 min for a dose of 0.2 mmol/kg body-weight. At these time points LGE quantification did not significantly differ (0.1 mmol/kg: 11% (16.4); 0.2 mmol/kg: 12% (14.5); p = 0.059), showing excellent correlation (ICC = 0.957; p < 0.001).

CONCLUSION

A standardized CE-CMR rest protocol giving a dose of 0.1 mmol/kg of gadobutrol before cine-imaging and performing LGE 10 min after injection represents a fast low-dose protocol without significant loss of information in comparison to a longer protocol with cine-imaging before contrast injection and a higher dose of gadobutrol. This approach allows to reduce examination time and costs as well as minimize contrast-agent exposure.

Fatal anaphylactic reaction to intravenous gadobutrol, a gadolinium-based MRI contrast agent

We present the rare case of a fatal anaphylactic reaction to gadobutrol, a magnetic resonance imaging contrast agent, in a 42-year-old man. The patient underwent elective magnetic resonance imaging for diagnostic clarification of a suspicious finding in the abdomen. The patient had undergone contrast-enhanced computed tomography previously without the occurrence of any adverse effects. Adverse drug reactions in gadobutrol have a very low prevalence of 0.32%-3.5%, with serious adverse drug reactions in <0.1%. There are only a few cases of fatal anaphylactoid reactions to gadolinium-based contrast agents in general. However, if an anaphylactoid reaction occurs, it can present itself with a fulminant course within minutes.

A clinical combined gadobutrol bolus and slow infusion protocol enabling angiography, inversion recovery whole heart, and late gadolinium enhancement imaging in a single study

BACKGROUND

The use of gadolinium contrast agents in cardiovascular magnetic resonance is well-established and serves to improve both vascular imaging as well as enable late gadolinium enhancement (LGE) imaging for tissue characterization. Currently, gadofosveset trisodium, an intravascular contrast agent, combined with a three-dimensional inversion recovery balanced steady state free precession (3D IR bSSFP) sequence, is commonly used in pediatric cardiac imaging and yields excellent vascular imaging, but cannot be used for late gadolinium enhancement. Gadofosveset use remains limited in clinical practice, and manufacture was recently halted, thus an alternative is needed to allow 3D IR bSSFP and LGE in the same study.

METHODS

Here we propose a protocol to give a bolus of 0.1 mL/kg = 0.1 mmol/kg gadobutrol (GADAVIST/GADOVIST) for time-resolved magnetic resonance angiography (MRA). Subsequently, 0.1 mmol/kg is diluted up to 5 or 7.5 mL with saline and then loaded into intravenous tubing connected to the patient. A 0.5 mL short bolus is infused, then a slow infusion is given at 0.02 or 0.03 mL/s. Image navigated (iNAV) 3D IR bSSFP imaging is initiated 45-60 s after the initiation of the infusion, with a total image acquisition time of ~5 min. If necessary, LGE imaging using phase sensitive inversion recovery reconstruction (PSIR) is performed at 10 min after the infusion is initiated.

RESULTS

We have successfully performed the above protocol with good image quality on 10 patients with both time-resolved MRA and 3D IR bSSFP iNAV imaging. Our initial attempts to use pencil beam respiratory navigation failed due to signal labeling in the liver by the navigator. We have also performed 2D PSIR LGE successfully, with both LGE positive and LGE negative results.

CONCLUSION

A bolus of gadobutrol, followed later by a slow infusion, allows time-resolved MRA, 3D IR bSSFP using the iNAV navigation technique, and LGE imaging, all in a single study with a single contrast agent.

Gadobutrol-enhanced magnetic resonance imaging of meningeal carcinomatosis: case report with emphasis on early diagnosis

Background

Timely diagnosis of meningeal carcinomatosis is often difficult even with the assistant of magnetic resonance imaging examination, cerebrospinal fluid analysis, or both. To the best of our knowledge, gadobutrol-enhanced MRI has not been reported in the diagnosis of meningeal carcinomatosis. Here we present two cases where meningeal carcinomatosis was identified on gadobutrol-enhanced magnetic resonance imaging.

Case presentation

We identified two cases of meningeal carcinomatosis who had been diagnosed with malignant tumors several years ago. Both patients presented with progressive headache and seizures. Gadopentetate dimeglumine-enhanced magnetic resonance imaging of the brain was performed and did not detect any abnormality of meninges. Lumbar puncture was performed repeatedly, but cerebrospinal fluid cytology showed no evidence of malignant cells. Finally the gadobutrol-enhanced magnetic resonance imaging detected the meningeal metastasis, and supported the diagnosis of meningeal carcinomatosis.

Conclusion

Gadobutrol provides higher lesion conspicuity and enhances lesion detection in meningeal metastasis compared with gadopentetate dimeglumine. Our observation is a cue to analyze the accuracy in the diagnosis of meningeal carcinomatosis, and presents a choice that may facilitate early diagnosis.

Intravenous injection of gadobutrol in an epidemiological study group did not lead to a difference in relative signal intensities of certain brain structures after 5 years

PURPOSE

To investigate if application of macrocyclic gadolinium-based contrast agents in volunteers is associated with neuronal deposition detected by magnetic resonance imaging in a 5-year longitudinal survey.

MATERIALS AND METHODS

Three hundred eighty-seven volunteers who participated in a population-based study were enrolled. Subjects underwent plain T1-weighted brain MRI at baseline and 5 years later with identical sequence parameters. At baseline, 271 participants additionally received intravenous injection of the macrocyclic contrast agent gadobutrol (0.15 mmol/kg). A control group including 116 subjects received no contrast agent. Relative signal intensities of thalamus, pallidum, pons and dentate nucleus were compared at baseline and follow-up.

RESULTS

No difference in relative signal intensities was observed between contrast group (thalamus, p = 0.865; pallidum, p = 0.263; pons, p = 0.533; dentate nucleus, p = 0.396) and control group (thalamus, p = 0.683; pallidum; p = 0.970; pons, p = 0.773; dentate nucleus, p = 0.232) at both times. Comparison between both groups revealed no significant differences in relative signal intensities (thalamus, p = 0.413; pallidum, p = 0.653; pons, p = 0.460; dentate nucleus, p = 0.751). The study showed no significant change in globus pallidus-to-thalamus or dentate nucleus-to-pons ratios.

CONCLUSIONS

Five years after administration of a 1.5-fold dose gadobutrol to normal subjects, signal intensity of thalamus, pallidum, pons and dentate nucleus did not differ from participants who had not received gadobutrol.

KEY POINTS

• Gadobutrol does not lead to neuronal signal alterations after 5 years. • Neuronal deposition of macrocyclic contrast agent could not be confirmed. • Macrocyclic contrast agents in a proven dosage are safe.

The effects of extracellular contrast agent (Gadobutrol) on the precision and reproducibility of cardiovascular magnetic resonance feature tracking

BACKGROUND

Today feature tracking (FT) is considered to be a robust assessment tool in cardiovascular magnetic resonance (CMR) for strain assessment. The FT algorithm is dependent on a high contrast between blood pool and myocardium. Extracellular contrast agents decrease blood-myocardial contrast in SSFP images and thus might affect FT results. However, in a routine CMR scan, SSFP-cine images including short axis views are partly acquired after contrast agent injection. The aim of this study was to investigate the effect of extracellular contrast agent (Gadobutrol) (CA) on the precision and reproducibility of the feature tracking algorithm.

METHODS

A total of 40 patient volunteers (mean age 51.2 ± 19 years; mean LVEF 61 ± 9 %) were scanned in supine position on a clinical 1.5 T MR scanner (Philips Ingenia). SSFP-cine images in midventricular short axis view (SA) as well as horizontal long axis view (HLA) were acquired before and 10-15 min after injection of a double dose Gadobutrol. FT derived systolic circumferential and longitudinal strain parameters were then calculated for pre- and post-contrast images.

RESULTS

FT derived midventricular peak systolic circumferential strain (PSCS) (-24.8 ± 6.4 % vs. -20.4 ± 6.3 %), apical PSCS (-28.67 ± 6.5 % vs. -24.06 ± 8.5 %), basal PSCS (-24.42 % ± 6.5 vs. -20.68 ± 7.1 %), peak systolic longitudinal strain (-19.57 ± 3.3 % vs. -17.24 ± 4.1 %), midventricular epicardial PSCS (-9.84 ± 3.4 % vs. -8.13 ± 3.4 %) , midventricular PSCS-rate (-1.52 ± 0.4 vs. -1.28 ± 0.5) and peak diastolic circumferential strain rate (1.4 ± 0.5 vs. 1.05 ± 0.5) were significantly reduced after CA application. Post CA strain assessment showed higher intra- and interobserver variability. Pre-CA: intraobserver: mean 0.21, Limits of agreement (LoA) -2.8 and 3.2; interobserver: mean 0.64, LoA -2.8 and 4.1. Post-CA: intraobserver: mean -0.11, LoA -5.1 to 4.9; interobserver: mean 4.93 LoA 2.4 to 12.2.

CONCLUSION

The FT algorithm is dependent on a high contrast between blood and myocardium. Post CA strain results are significantly lower and less reproducible than pre-CA strain results.

In vivo effects of bupivacaine and gadobutrol on the intervertebral disc following discoblock and discography: a histological analysis

OBJECTIVES

The aim of the present study was to histologically compare chondrotoxicity in surgically harvested intervertebral discs (IVDs) of patients following discoblock, discography, or no preoperative intervention.

METHODS

Thirty patients (IVD degeneration Modic ≥ 2°, Pfirrmann 3° or 4°) at L4/5 or L5/S1 who were planned for anterior lumbar interbody fusion were randomly assigned to three groups (open MRI: group DG - discography with gadobutrol; group DB - discoblock with bupivacaine at 4 weeks prior to surgery; group C - no intervention). The intervertebral discs were histologically evaluated and compared using ANOVA and Bonferroni tests for cell count, apoptosis, and proliferation.

RESULTS

A reduced cell count (groups DG vs. DB vs. C: 14.9 ± 7.1, 9.2 ± 3.8, and 16.6 ± 5.2 cells/mm², respectively; p _ANOVA = 0.016), increased apoptosis (groups DG vs. DB vs. C: 34.9 ± 10.2, 47.4 ± 16.3, 32.6 ± 12.2 %, respectively; p _ANOVA = 0.039) and increased cell proliferation (post hoc pDB vs. DG or C p < 0.001; for 3-7 cell monoclonal cell nests: groups DG vs. DB vs. C: 2.4 ± 1, 3.9 ± 1, 2.2 ± 1.1, respectively; p _{interventionx nest size} = 0.006) were found in the IVDs of patients in group DB.

CONCLUSIONS

This in vivo study suggests that chondrotoxic effects occur in IVD cells after the intradiscal injection of bupivacaine but not after gadobutrol administration.

KEY POINTS

• Local bupivacaine administration to intervertebral discs leads to cell toxicity and proliferation. • Gadobutrol demonstrated no significant effect on cell count, apoptosis, or cell proliferation. • In vivo cytotoxicity was demonstrated histologically in humans for the first time. • Addition/administration of bupivacaine during discographies must be judged critically.

Safety of gadobutrol in over 23,000 patients: the GARDIAN study, a global multicentre, prospective, non-interventional study

OBJECTIVES

To investigate the safety and tolerability of gadobutrol at the recommended dose in patients requiring contrast-enhanced magnetic resonance imaging/angiography (MRI/MRA) in the routine setting.

METHODS

GARDIAN prospectively enrolled 23,708 patients undergoing routine gadobutrol-enhanced MRI/MRA for approved indications at 272 study centres in Europe, Asia, North America, and Africa and monitored for adverse events.

RESULTS

Median gadobutrol dose was 0.11 mmol/kg body weight. The overall incidence of adverse drug reactions (ADRs) was 0.7 % (n = 170 patients), with similar incidences in patients with renal impairment or cardiac disease, from different geographic regions and in different gadobutrol dose groups. Patients at risk for contrast media reaction had an ADR incidence of 2.5 %. Five patients (0.02 %) experienced serious adverse events, four were drug-related. One patient experienced a fatal anaphylactoid shock, assessed to be related to injection of gadobutrol. The contrast quality of gadobutrol-enhanced images was rated by treating physicians as good or excellent in 97 % cases, with similar ratings in all patient subgroups and indications.

CONCLUSIONS

The GARDIAN study shows that gadobutrol at the recommended dose is well tolerated across a large, diverse patient population.

KEY POINTS

• Gadobutrol at recommended dose shows low rates of adverse drug reactions • Gadobutrol demonstrates a uniform safety profile across diverse patient groups • Gadobutrol provides excellent contrast quality in routine practice.

Safety of gadobutrol in more than 1,000 pediatric patients: subanalysis of the GARDIAN study, a global multicenter prospective non-interventional study

BACKGROUND

Gadobutrol is a gadolinium-based contrast agent, uniquely formulated at 1.0 mmol/ml. Although there is extensive safety evidence on the use of gadobutrol in adults, few studies have addressed the safety and tolerability of gadobutrol in pediatric patients.

OBJECTIVE

This subanalysis of data from the GARDIAN study evaluated the safety and use of gadobutrol in pediatric patients (age <18 years).

MATERIALS AND METHODS

The GARDIAN study was a large phase IV non-interventional prospective multicenter post-authorization safety study performed in Europe, Asia, North America and Africa. A total of 23,708 patients were included who were scheduled to undergo cranial or spinal MRI, liver or kidney MRI, or MR angiography with gadobutrol enhancement. The primary study endpoint was the overall incidence of adverse drug reactions (ADRs) and serious adverse events (SAEs) following gadobutrol administration.

RESULTS

The GARDIAN study included 1,142 children (age <18 years) who received gadobutrol at a mean dose of 0.13 (range 0.04-0.50) mmol/kg body weight. Gadobutrol was well tolerated in these children, with low rates of ADRs (0.5%) and no SAEs, consistent with results in adults enrolled in the GARDIAN study. Rates of adverse events and ADRs were unrelated to pediatric age or gadobutrol weight-adjusted dose. There were no symptoms suggestive of nephrogenic systemic fibrosis. Investigators rated the contrast quality of gadobutrol-enhanced images as good or excellent in 97.8% of pediatric patients, similar to the main study population.

CONCLUSION

Gadobutrol is very well tolerated and provides excellent contrast quality at the recommended weight-adjusted dose in children (age <18 years), similar to the profile in adults.

What Evidence Is There That Gadobutrol Causes Increasing Signal Intensity within the Dentate Nucleus and Globus Pallidus on Unenhanced T1W MRI in Patients with RRMS?

KEY POINTS : The study by Stojanov et al does not convincingly support the conclusion that gadobutrol causes higher T1 enhancement in brain on unenhanced MRI. The study by Stojanov et al does not rule out confounding factors . The study by Stojanov et al has limitations in study design.

Prostate diffusion-weighted imaging at 3T: effect of intravenous gadobutrol administration

OBJECTIVE

To investigate whether gadolinium-based contrast agent (GBCA) administration significantly affects diffusion-weighted imaging (DWI) at 3 T in the evaluation of prostate cancer and benign tissue.

METHOD

Thirty-four consecutive patients with surgically proven prostate cancer underwent preoperative DWI at 3 T before and after GBCA administration. Exponential apparent diffusion coefficient (EADC) and ADC maps were developed from DWI data. The ADC and EADC values pre- and post-contrast were measured in the cancer and benign tissue, respectively. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were evaluated on pre- and post-contrast DWI.

RESULTS

The ADC and EADC values of the cancer and benign transition zone were not significantly different between pre- and post-contrast, respectively (P > 0.05), while those in the benign peripheral zone were significantly different (P = 0.030 and 0.037, respectively). In all tissues, the SNRs and CNRs of the DWI, ADC map and EADC map were not significantly different between pre- and post-contrast (P > 0.05). Between pre- and post-contrast, ADC and EADC values showed excellent agreement (intraclass correlation coefficient ≥ 0.894) and variability of ≤3.2 %.

CONCLUSION

Prostate 3 T-DWI after GBCA administration may be used without a significant difference in SNR or CNR, with minimal variability of the cancer ADC and EADC values.

KEY POINTS

• ADCs and EADCs have excellent agreement before and after gadobutrol administration. • SNRs of prostate DWI are similar before and after gadobutrol administration. • CNRs of cancers are similar between pre- and post-contrast DWI.

Respiratory motion artefacts in dynamic liver MRI: a comparison using gadoxetate disodium and gadobutrol

OBJECTIVES

Our aim was to retrospectively evaluate the occurrence of respiratory motion artefacts in patients undergoing dynamic liver magnetic resonance (MR) either with gadoxetate disodium or gadobutrol.

METHODS

Two hundred and thirty liver MR studies (115 with gadobutrol, 115 with gadoxetate disodium) were analysed. Respiratory motion artefacts on dynamic 3D T1-weighted MR images (pre-contrast, arterial, venous, and late-dynamic phase) were assessed using a five-point rating scale. Severe motion was defined as a score ≥ 4. Mean motion scores were compared with the Mann-Whitney-U-test. The chi-squared-test was used for dichotomous comparisons.

RESULTS

Mean motion scores for gadoxetate disodium and gadobutrol showed no relevant differences for each phase of the dynamic contrast series (pre-contrast: 1.85 ± 0.70 vs. 1.88 ± 0.57, arterial: 1.85 ± 0.81 vs. 1.87 ± 0.74, venous: 1.82 ± 0.67 vs. 1.74 ± 0.64, late-dynamic: 1.75 ± 0.62 vs. 1.79 ± 0.63; p = 0.469, 0.557, 0.382 and 0.843, respectively). Severe motion artefacts had a similar incidence using gadoxetate disodium and gadobutrol (11/460 [2.4%] vs. 7/460 [1.5%]; p = 0.341).

CONCLUSIONS

Gadoxetate disodium is associated with equivalent motion scores compared to gadobutrol in dynamic liver MRI. In addition, both contrast agents demonstrated a comparable and acceptable rate of severe respiratory motion artefacts.

KEY POINTS

• Gadobutrol and gadoxetate disodium showed comparable motion scores in dynamic phase imaging. • The incidence of severe motion artefacts was pronounced in arterial phase imaging. • Adverse respiratory side effects were not recorded in 115 examinations with gadoxetate disodium.

Intraindividual comparison of T1 relaxation times after gadobutrol and Gd-DTPA administration for cardiac late enhancement imaging

PURPOSE

To evaluate T1-relaxation times of chronic myocardial infarction (CMI) using gadobutrol and gadopentetate dimeglumine (Gd-DTPA) over time and to determine the optimal imaging window for late enhancement imaging with both contrast agents.

MATERIAL AND METHODS

Twelve patients with CMI were prospectively included and examined on a 1.5 T magnetic resonance (MR) system using relaxivity-adjusted doses of gadobutrol (0.15 mmol/kg) and Gd-DTPA (0.2 mmol/kg) in random order. T1-relaxation times of remote myocardium (RM), infarcted myocardium (IM), and left ventricular cavity (LVC) were assessed from short-axis TI scout imaging using the Look-Locker approach and compared intraindividually using a Wilcoxon paired signed-rank test (α<0.05).

RESULTS

Within 3 min of contrast agent administration (CA), IM showed significantly lower T1-relaxation times than RM with both contrast agents, indicating beginning cardiac late enhancement. Differences between gadobutrol and Gd-DTPA in T1-relaxation times of IM and RM were statistically not significant through all time points. However, gadobutrol led to significantly higher T1-relaxation times of LVC than Gd-DTPA from 6 to 9 min (220 ± 15 ms vs. 195 ± 30 ms p<0.01) onwards, resulting in a significantly greater ΔT1 of IM to LVC at 9-12 min (-20 ± 35 ms vs. 0 ± 35 ms, p<0.05) and 12-15 min (-25 ± 45 ms vs. -10 ± 60 ms, p<0.05). Using Gd-DTPA, comparable ΔT1 values were reached only after 25-35 min.

CONCLUSION

This study indicates good delineation of IM to RM with both contrast agents as early as 3 min after administration. However, we found significant differences in T1 relaxation times with greater ΔT1 IM-LVC using 0.15 mmol/kg gadobutrol compared to 0.20 mmol/kg Gd-DTPA after 9-15 min post-CA suggesting earlier differentiability of IM and LVC using gadobutrol.

Interference of gadolinium-based contrast agents on colorimetric calcium assays

OBJECTIVE

The aim of this study was to evaluate the potential interference of five gadolinium-based contrast agents (GBCAs), gadodiamide (Omniscan®), gadobenate dimeglumine (Multihance®), gadoxetate disodium (Primovist®), gadobutrol (Gadovist®), and gadoteridol (Prohance®), on three clinical laboratory widely used colorimetric calcium assays including the newly developed 5-nitro-5'methyl-l,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (NM-BAPTA) method.

METHODS

Plasma was collected from healthy volunteers aged 23-52, and spiked with varying concentrations of the five GBCAs. Calcium determinations were performed in duplicates using the o-cresolphthalein complexone (OCP), arsenazo-III dye, and NM-BAPTA methods on the Roche Integra 400, Abbott Architect 16000, and Roche Modular P automated analyzers respectively.

RESULTS

Gadobenate dimeglumine, gadobutrol, and gadoteridol did not interfere with any of the assays. There was a small positive bias (8%, p<0.01) at a very high concentration (25mmol/L) of gadoxetate disodium when calcium was assayed using the arsenazo-III method. Gadodiamide at a very high concentration (50mmol/L) induced a significant positive bias (16%, p<0.01) on calcium when measured using the NM-BAPTA method; however a much larger bias (90%, p≪0.01) was observed when calcium was measured using the arsenazo-III method. Significant interferences in calcium measurements using the OCP method began at gadodiamide concentrations as low as 0.5mmol/L (-9%, p<0.01). This negative bias was more pronounced at higher gadodiamide concentrations.

CONCLUSIONS

Of all 5 GBCAs tested, only gadodiamide showed significant interference on the OCP calcium assay at clinically relevant concentrations. The NM-BAPTA assay showed minimum interference with the five GBCAs and demonstrated equal or better performance than the OCP and the arsenazo-III methods in terms of interference with GBCAs.