Absence of potential gadolinium toxicity symptoms following 22,897 gadoteric acid (Dotarem®) examinations, including 3,209 performed on renally insufficient individuals

Gadolinium Enhances Dual-energy Computed Tomography Scan of Pulmonary Artery

OBJECTIVE

To evaluate the feasibility of using gadopentetate dimeglumine (Gd-DTPA) for dual-energy computed tomography pulmonary angiography (CTPA).

METHODS

Sixty-six patients were randomly divided into three groups and underwent CTPA. Group A had a turbo flash scan using an iohexol injection, Group B had a turbo flash scan using Gd-DTPA, and Group C had a dual-energy scan using Gd-DTPA. The original images of Group C were linearly blended with a blending factor of 0.5 or reconstructed at 40, 50, 60, 70, 80, 90, 100, and 110 keV, respectively. The groups were compared in terms of pulmonary artery CT value, image quality, and radiation dose.

RESULTS

The pulmonary artery CT values were significantly higher in Group C_40keV than in Groups B and C, but lower than in Group A. There was no significant difference in the image noise of Groups C_40keV, B, and C. Moreover, Group A had the largest beam hardening artifacts of the superior vena cava (SVC), followed by Groups B and C. Group C_40keV showed better vascular branching than the other three groups, among which Group B was superior to Group A. The subjective score of the image quality of Groups A, B, and C showed no significant difference, but the score was significantly higher in Group C_40keV than in Groups A and B. The radiation dose was significantly lower in Group B than in Groups A and C.

CONCLUSION

Gd-CTPA is recommended to patients who are unsuitable for receiving an iodine-based CTPA. Furthermore, a turbo flash scan could surpass a dual-energy scan without consideration for virtual monoenergetic imaging.

Nephrogenic Systemic Fibrosis in Patients with Chronic Kidney Disease after the Use of Gadolinium-Based Contrast Agents: A Review for the Cardiovascular Imager

Gadolinium-enhanced cardiac magnetic resonance has revolutionized cardiac imaging in the last two decades and has emerged as an essential and powerful tool for the characterization and treatment guidance of a wide range of cardiovascular diseases. However, due to the high prevalence of chronic renal dysfunction in patients with cardiovascular conditions, the risk of nephrogenic systemic fibrosis (NSF) after gadolinium exposure has been a permanent concern. Even though the newer macrocyclic agents have proven to be much safer in patients with chronic kidney disease and end-stage renal failure, clinicians must fully understand the clinical characteristics and risk factors of this devastating pathology and maintain a high degree of suspicion to prevent and recognize it. This review aimed to summarize the existing evidence regarding the physiopathology, clinical manifestations, diagnosis, and prevention of NSF related to the use of gadolinium-based contrast agents.

Systematic review: investigating the added diagnostic value of gadolinium contrast agents for osteomyelitis in the appendicular skeleton

OBJECTIVE

Osteomyelitis is an infection of the bone marrow. MRI with gadolinium-based contrast is frequently performed for cases of suspected osteomyelitis. The objective of this systematic review is to examine the diagnostic accuracy of contrast-enhanced vs non-contrast-enhanced MRI for osteomyelitis in the appendicular skeleton.

MATERIALS AND METHODS

We conducted a systematic review of MRI in the diagnosis of osteomyelitis by searching MEDLINE and EMBASE from January 2000 to March 2020. There were 21 studies that met the inclusion criteria for the systematic review for a total of 1095 patients. Analytic methods were based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Evidence was evaluated using the STARD criteria for evaluation of completeness and transparency of reporting.

RESULTS

For diagnosing osteomyelitis in the appendicular skeleton, MRI with gadolinium-based contrast has 89% sensitivity (95% CI, 86-92%), 79% specificity (95% CI, 75-83%), and 90% overall diagnostic accuracy ([SE] = 0.03). For diagnosing osteomyelitis in the appendicular skeleton, MRI without gadolinium-based contrast has a 92% sensitivity (95% CI, 87-96%), 89% specificity (95% CI, 84-93%), and 96% overall diagnostic accuracy ([SE] = 0.03). The median score of included studies was 85% utilizing the STARD criteria with excellent interobserver agreement of 83.4%. Limitations included small sample size of studies, with retrospective designs.

CONCLUSION

No evidence was found to suggest an added diagnostic value of gadolinium contrast for the diagnosis of osteomyelitis in the appendicular skeleton. For routine cases of suspected non-spinal osteomyelitis, non-contrast MRI of the area of interest is the next most appropriate study after radiographs.

The Use of Electronic Health Records to Study Drug-Induced Hypersensitivity Reactions from 2000 to 2021

Electronic health records (EHRs) have revolutionized the field of drug hypersensitivity reaction (DHR) research. In this systematic review, we assessed 140 articles from 2000-2021, classifying them under six themes: observational studies (n=61), clinical documentation (n=27), case management (n=22), clinical decision support (CDS) (n=18), case identification (n=9), and genetic studies (n=3). EHRs provide convenient access to millions of medical records, facilitating epidemiological studies of DHRs. Though the goal of CDS is to promote safe drug prescribing, allergy alerts must be designed and used in a way that supports this effort. Ultimately, accurate allergy documentation is essential for DHR prevention.

Atherosclerotic Renovascular Disease: A KDIGO (Kidney Disease: Improving Global Outcomes) Controversies Conference

The diagnosis and management of atherosclerotic renovascular disease (ARVD) is complex and controversial. Despite evidence from the ASTRAL (2009) and CORAL (2013) randomized controlled trials showing that percutaneous renal artery revascularization did not improve major outcomes compared with best medical therapy alone over 3-5 years, several areas of uncertainty remain. Medical therapy, including statin and antihypertensive medications, has evolved in recent years, and the use of renin-angiotensin-aldosterone system blockers is now considered the primary means to treat hypertension in the setting of ARVD. However, the criteria to identify kidneys with renal artery stenosis that have potentially salvageable function are evolving. There are also data suggesting that certain high-risk populations with specific clinical manifestations may benefit from revascularization. Here, we provide an overview of the epidemiology, diagnosis, and treatment of ARVD based on consensus recommendations from a panel of physician experts who attended the recent KDIGO (Kidney Disease: Improving Global Outcomes) Controversies Conference on central and peripheral arterial diseases in chronic kidney disease. Most focus is provided for contentious issues, and we also outline aspects of investigation and management of ARVD that require further research.

Pharmacokinetics, Dialysability, and Safety of Gadopiclenol, a New Gadolinium-Based Contrast Agent, in Patients With Impaired Renal Function

OBJECTIVES

The aims of this study were to evaluate the pharmacokinetics (PK) of gadopiclenol, a new macrocyclic gadolinium based-contrast agent, in subjects with impaired renal function, and to assess its dialysability in subjects with end-stage renal disease (ESRD).

METHODS AND MATERIALS

This 2-center, open-label, phase 1 study included 5 successive cohorts of 8 adult subjects: healthy subjects (cohort 1), subjects with mild (cohort 2), moderate (cohort 3), severe (cohort 4) renal impairment, or ESRD (cohort 5), who received a single intravenous injection of gadopiclenol (0.1 mmol/kg). Blood and urine samples were collected at different time points in cohorts 1 to 4, and blood and dialysate samples were collected at each hemodialysis session (4-hour session on day 1, day 3, and day 5) in cohort 5. Gadopiclenol elimination and safety were assessed for up to 6 months. Pharmacokinetics parameters were calculated using noncompartmental analysis.

RESULTS

A total of 40 subjects were included, with a mean age of 51.5 years (range, 18-71 years). No significant difference in the mean maximum concentration values and the distribution volume was observed among cohorts 1 to 4. Urinary excretion of unchanged gadopiclenol was delayed with the degree of renal impairment and ranged between 96% and 84% in subjects with mild to severe renal impairment. Compared with that of healthy subjects, the mean area under the plasma concentration curve was 54%, 148%, and 769% higher in subjects with mild, moderate, or severe renal impairment, respectively. The mean terminal half-life was prolonged with the degree of renal impairment (1.9, 3.3, 3.8, and 11.7 hours for cohorts 1-4). In ESRD subjects, gadopiclenol was effectively removed from the plasma (95% to 98%) after the first hemodialysis session. Gadopiclenol concentration in plasma was below the limit of quantification for all subjects after the second hemodialysis session. Gadopiclenol concentration was below limit of quantification in all plasma and urine samples collected at 1, 3, and 6 months. Five subjects (12.5%) experienced adverse events related to gadopiclenol, none serious and all resolved. Laboratory measurements, vital signs, and electrocardiography did not raise any safety concern.

CONCLUSIONS

Gadopiclenol elimination half-life was prolonged in subjects with mild to severe renal impairment, yet its renal clearance remains complete or nearly complete. In ESRD subjects, gadopiclenol was effectively removed from the plasma after 1 hemodialysis session, and up to 3 hemodialysis sessions were sufficient to completely clear it. No safety concern was raised. Therefore, no dose adjustment seems necessary in this patient population.

Layered terbium hydroxides for simultaneous drug delivery and imaging

Layered rare-earth hydroxides have begun to gather increasing attention as potential theranostic platforms owing to their extensive intercalation chemistry combined with magnetic and fluorescent properties. In this work, the potential of layered terbium hydroxide (LTbH) as a platform for simultaneous drug delivery and fluorescence imaging was evaluated. LTbH-Cl ([Tb2(OH)5]Cl·yH2O) was loaded with three nonsteroidal anti-inflammatory drugs (diclofenac, ibuprofen, and naproxen) via ion-exchange. Drug release studies in phosphate buffered saline (pH = 7.4) revealed all three formulations release their drug cargo rapidly over the course of approximately 5 hours. In addition, solid state fluorescence studies indicated that fluorescence intensity is strongly dependent on the identity of the guest anion. It was postulated that this feature may be used to track the extent of drug release from the formulation, which was subsequently successfully demonstrated for the ibuprofen loaded LTbH. Overall, LTbH exhibits good biocompatibility, high drug loading, and a strong, guest-dependent fluorescence signal, all of which are desirable qualities for theranostic applications.

Contrast-induced nephropathy in non-cardiac vascular procedures, a narrative review: Part 2

This is Part 2 of a narrative review summarizing the literature on CIN after non-cardiac vascular diagnostic or therapeutic procedures, focusing on peripheral artery disease (PAD) and renal artery stenosis (RAS). Part 1 discussed CIN in relation to aortic aneurysms and carotid stenosis. We comment on the incidence, biomarkers, risk factors, and consequences of CIN in patients with PAD or RAS, as well as on strategies to prevent CIN. Future perspectives in the field of CIN in relation to non-cardiac vascular procedures are also considered.

2021 Update on Safety of Magnetic Resonance Imaging: Joint Statement From Canadian Cardiovascular Society/Canadian Society for Cardiovascular Magnetic Resonance/Canadian Heart Rhythm Society

Magnetic resonance imaging (MRI) is often considered the gold-standard test for characterizing cardiac as well as noncardiac structure and function. However, many patients with cardiac implantable electronic devices (CIEDs) and/or severe renal dysfunction are unable to undergo this test because of safety concerns. In the past 10 years, newer-generation CIEDs and gadolinium-based contrast agents (GBCAs) as well as coordinated care between imaging and heart rhythm device teams have mitigated risk to patients and improved access to MRI at many hospitals. The purpose of this statement is to review published data on safety of MRI in patients with conditional and nonconditional CIEDs in addition to patient risks from older and newer GBCAs. This statement was developed through multidisciplinary collaboration of pan-Canadian experts after a relevant and independent literature search by the Canadian Agency for Drugs and Technologies in Health. All recommendations align with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Key recommendations include: (1) the development of standardized protocols for patients with a CIED undergoing MRI; (2) patients with MRI nonconditional pacemakers and pacemaker dependency should be programmed to asynchronous mode and those with MRI nonconditional transvenous defibrillators should have tachycardia therapies turned off during the scan; and (3) macrocyclic or newer linear GBCAs should be used in preference to older GBCAs because of their better safety profile in patients at higher risk of nephrogenic systemic fibrosis.

Assessment of Gadobutrol Safety in Combination with Ionizing Radiation Using a Preclinical MRI-Guided Radiotherapy Model

MR-linac technology enhances the precision of therapeutic radiation by clarifying the tumor-normal tissue interface and provides the potential for adaptive treatment planning. Accurate delineation of tumors on diagnostic magnetic resonance imaging (MRI) frequently requires gadolinium-based contrast agents (GBCAs). Despite generally being considered safe, previous literature suggests that GBCAs are capable of contrast-induced acute kidney injury (AKI). It is unclear if the risk for AKI is enhanced when GBCAs are administered concurrently with ionizing radiotherapy. During irradiation, gadolinium may be liberated from its chelator which may induce AKI. The goal of this work was to determine if radiation combined with GBCAs increased the incidence of AKI. Using a preclinical MRI-guided irradiation system, where MRI acquisitions and radiation delivery are performed in rapid succession, tumor-bearing mice with normal kidney function were injected with GBCA and treated with 2, 8 or 18 Gy irradiation. Renal function was assessed on days three and seven postirradiation to assess for AKI. No clinically relevant changes in blood urea nitrogen and creatinine were observed in any combination of GBCA and radiation dose. From these data, we conclude that GBCA in combination with radiation does not increase the risk for AKI in mice. Additional investigation of multiple doses of GBCA administered concurrently with irradiation is warranted to evaluate the risk of chronic kidney injury.

PVP-coated Gd-grafted nanodiamonds as a novel and potentially safer contrast agent for in vivo MRI

PURPOSE

Testing the potential use of saline suspension of polyvinylpyrrolidone (PVP)-coated gadolinium(Gd)-grafted detonation nanodiamonds (DND) as a novel contrast agent in MRI.

METHODS

Stable saline suspensions of highly purified de-agglomerated Gd-grafted DND particles coated by a PVP protective shell were prepared. T₁ and T₂ proton relaxivities of the suspensions with varying gadolinium concentration were measured at 8 Tesla. A series of ex vivo (phantom) and in vivo dynamic scans were obtained in 3 Tesla MRI using PVP-coated Gd-grafted DND and gadoterate meglumin in equal concentrations of gadolinium, and then T₁ -weighted hyperintensity was compared.

RESULTS

The proton relaxivities of PVP-coated Gd-grafted DND were found to be r₁ = 15.9 ± 0.8 s^-1 mM^-1 and r₂ = 262 ± 15 s^-1 mM^-1 , respectively, which are somewhat less than those for uncoated Gd-grafted DND but still high enough. Ex vivo MRI evaluation of PVP-coated Gd-grafted DND results with a dose-dependent T₁ -weighted hyperintensity with a significant advantage over the same for gadoterate meglumin. The same was found when the 2 contrast agents were tested in vivo.

CONCLUSION

The novel MRI contrast agent - saline suspensions of PVP-coated Gd-grafted DND - provides significantly higher signal intensities than the common tracer gadoterate meglumin, therefore increasing its potential for a safer use in clinics.

Risks and Options With Gadolinium-Based Contrast Agents in Patients With CKD: A Review

Gadolinium-based contrast agents (GBCAs) improve the diagnostic capabilities of magnetic resonance imaging. Although initially believed to be without major adverse effects, GBCA use in patients with severe chronic kidney disease (CKD) was demonstrated to cause nephrogenic systemic fibrosis (NSF). Restrictive policies of GBCA use in CKD and selective use of GBCAs that bind free gadolinium more strongly have resulted in the virtual elimination of NSF cases. Contemporary studies of the use of GBCAs with high binding affinity for free gadolinium in severe CKD demonstrate an absence of NSF. Despite these observations and the limitations of contemporary studies, physicians remain concerned about GBCA use in severe CKD. Concerns of GBCA use in severe CKD are magnified by recent observations demonstrating gadolinium deposition in brain and a possible systemic syndrome attributed to GBCAs. Radiologic advances have resulted in several new imaging modalities that can be used in the severe CKD population and that do not require GBCA administration. In this article, we critically review GBCA use in patients with severe CKD and provide recommendations regarding GBCA use in this population.

Risk for Nephrogenic Systemic Fibrosis After Exposure to Newer Gadolinium Agents: A Systematic Review

BACKGROUND

The risk for nephrogenic systemic fibrosis (NSF) after exposure to newer versus older gadolinium-based contrast agents (GBCAs) remains unclear.

PURPOSE

To synthesize evidence about NSF risk with newer versus older GBCAs across the spectrum of kidney function.

DATA SOURCES

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science for English-language references from inception to 5 March 2020.

STUDY SELECTION

Randomized controlled trials, cohort studies, and case-control studies that assessed NSF occurrence after GBCA exposure.

DATA EXTRACTION

Data were abstracted by 1 investigator and verified by a second. Investigator pairs assessed risk of bias by using validated tools.

DATA SYNTHESIS

Of 32 included studies, 20 allowed for assessment of NSF risk after exposure to newer GBCAs and 12 (11 cohort studies and 1 case-control study) allowed for comparison of NSF risk between newer and older GBCAs. Among 83 291 patients exposed to newer GBCAs, no NSF cases developed (exact 95% CI, 0.0001 to 0.0258 case). Among the 12 studies (n = 118 844) that allowed risk comparison between newer and older GBCAs, 37 NSF cases developed after exposure to older GBCAs (exact CI, 0.0001 to 0.0523 case) and 4 occurred (3 confounded) after exposure to newer GBCAs (exact CI, 0.0018 to 0.0204 case). Data were scant for patients with acute kidney injury or those at risk for chronic kidney disease.

LIMITATIONS

Study heterogeneity prevented meta-analysis. Risk of bias was high in most studies because of inadequate exposure and outcome ascertainment.

CONCLUSION

Although NSF occurrence after exposure to newer GBCAs is very rare, the relatively scarce data among patients with acute kidney injury and those with risk factors for chronic kidney disease limit conclusions about safety in these populations.

PRIMARY FUNDING SOURCE

U.S. Department of Veterans Affairs. (PROSPERO: CRD42019135783).

Baseline characteristics, diagnostic efficacy, and peri-examinational safety of IV gadoteric acid MRI in 148,489 patients

BACKGROUND

Magnetic resonance imaging (MRI) examinations with intravenous (IV) contrast are performed worldwide in routine daily practice. In order to detect and enumerate even rare adverse events (AE) and serious adverse events (SAE), and to relate them with patients' baseline characteristics and diagnostic effectiveness, high quantity sample size is necessary.

PURPOSE

To assess safety, diagnostic effectiveness, and baseline characteristics of patients undergoing IV gadoteric acid (Dotarem®) MRI in routine practice.

MATERIAL AND METHODS

Data from two observational post-marketing surveillance (PMS) databases compiled by 139 and 52 German centers in 2004-2011 and 2011-2013, respectively, were pooled, yielding data on a total of 148,489 patients examined over a 10-year period. Radiologists used a standardized questionnaire to report data including patient demographics, characteristics of MR examinations, and results in terms of diagnosis and patient safety.

RESULTS

Overall, 712 AEs were reported in 467 (0.3%) patients, mainly nausea (n = 224, 0.2%), vomiting (n = 29, <0.1%), urticaria (n = 20, <0.1%), and feeling hot (n = 13, <0.1%). AEs were considered related to gadoteric acid in 362 (0.2%) patients. Higher frequencies of AEs were observed among patients with a previous reaction to a contrast agent (2.0%), liver dysfunction (0.7%), bronchial asthma (0.7%), and a history of allergies (0.6%). There were 49 SAEs in 18 (<0.1%) patients, including two children. No fatal SAE was reported. Examinations were diagnostic in 99.8% of all patients, and image quality was excellent or good in 97.7% of the patients.

CONCLUSION

Gadoteric acid is a safe peri-examinational and effective contrast agent for MRI in routine practice.

Risk of Nephrogenic Systemic Fibrosis in Patients With Stage 4 or 5 Chronic Kidney Disease Receiving a Group II Gadolinium-Based Contrast Agent: A Systematic Review and Meta-analysis

IMPORTANCE

Risk of nephrogenic systemic fibrosis (NSF) to individual patients with stage 4 or 5 chronic kidney disease (CKD; defined as estimated glomerular filtration rate of <30 mL/min/1.73 m2) who receive a group II gadolinium-based contrast agent (GBCA) is not well understood or summarized in the literature.

OBJECTIVE

To assess the pooled risk of NSF in patients with stage 4 or 5 CKD receiving a group II GBCA.

DATA SOURCES

A health sciences informationist searched the Ovid (MEDLINE and MEDLINE Epub Ahead of Print, In-Process & Other Non-Indexed Citation, and Daily and Versions), Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Open Grey databases from inception to January 29, 2019, yielding 2700 citations.

STUDY SELECTION

Citations were screened for inclusion in a multistep process. Agreement for final cohort inclusion was determined by 2 blinded screeners using Cohen κ. Inclusion criteria consisted of stage 4 or 5 CKD with or without dialysis, administration of an unconfounded American College of Radiology classification group II GBCA (gadobenate dimeglumine, gadobutrol, gadoterate meglumine, or gadoteridol), and incident NSF as an outcome. Conference abstracts, retracted manuscripts, narrative reviews, editorials, case reports, and manuscripts not reporting total group II GBCA administrations were excluded.

DATA EXTRACTION AND SYNTHESIS

Data extraction was performed for all studies by a single investigator, including publication details, study design and time frame, patient characteristics, group II GBCA(s) administered, total exposures for patients with stage 4 or stage 5 CKD, total cases of unconfounded NSF, reason for GBCA administration, follow-up duration, loss to follow-up, basis for NSF screening, and diagnosis.

MAIN OUTCOMES AND MEASURES

Pooled incidence of NSF and the associated upper bound of a 2-sided 95% CI (risk estimate) for the pooled data and each of the 4 group II GBCAs.

RESULTS

Sixteen unique studies with 4931 patients were included (κ = 0.68) in this systematic review and meta-analysis. The pooled incidence of NSF was 0 of 4931 (0%; upper bound of 95% CI, 0.07%). The upper bound varied owing to different sample sizes for gadobenate dimeglumine (0 of 3167; upper bound of 95% CI, 0.12%), gadoterate meglumine (0 of 1204; upper bound of 95% CI, 0.31%), gadobutrol (0 of 330; upper bound of 95% CI, 1.11%), and gadoteridol (0 of 230; upper bound of 95% CI, 1.59%).

CONCLUSIONS AND RELEVANCE

This study's findings suggest that the risk of NSF from group II GBCA administration in stage 4 or 5 CKD is likely less than 0.07%. The potential diagnostic harms of withholding group II GBCA for indicated examinations may outweigh the risk of NSF in this population.

TRIAL REGISTRATION

PROSPERO identifier: CRD42019123284.

Peroxidase Sensitive Amplifiable Probe for Molecular Magnetic Resonance Imaging of Pulmonary Inflammation

An amplifiable magnetic resonance imaging (MRI) probe that combines the stability of the macrocyclic Gd-DOTAGA core with a peroxidase-reactive 5-hydroxytryptamide (5-HT) moiety is reported. The incubation of the complex under enzymatic oxidative conditions led to a 1.7-fold increase in r₁ at 1.4 T that was attributed to an oligomerization of the probe upon oxidation. This probe, Gd-5-HT-DOTAGA, provided specific detection of lung inflammation by MRI in bleomycin-injured mice.

[Contrast media - Guidelines for practical use]

Contrast agents have become an indispensable part of everyday life in diagnostic radiology. In multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI), they provide essential diagnostic information, especially for vascular, inflammatory or oncologic diseases, which otherwise could not be answered. The two most important groups are iodine- and gadolinium-containing contrast agents. Rare side effects include PC-AKI (post-contrast acute kidney injury); more common are allergic and chemotoxic reactions. Since the introduction of guidelines, nephrogenic fibrosis has not been reported anymore, whereas gadolinium deposition in the central nervous system (CNS) has become a new topic. Concerning contrast media use in patients with reduced renal function, at a eGFR threshold of <45 ml/min or <30 ml/min, hydration and a review of indication for enhanced MDCT, depending on the application, is recommended. Low kV and DE-scan protocols with MDCT can help to reduce the amount of iodinated contrast agents. In MRI examinations, only macrocyclic contrast agents should be used for enhanced MRI exams. There has to be a careful risk-benefit analysis with enhanced studies in pregnancy, during lactation and in the pediatric population. Patient information and legal aspects with nonapproved indications are indispensable parts of daily clinical routine. The continuous updating and broadening of knowledge regarding the appropriate use of the various contrast agents has to be an integral part of clinical diagnostic radiology.