Evolving Characteristics of Gadolinium-Based Contrast Agents for MR Imaging: A Systematic Review of the Importance of Relaxivity.

Gadolinium-based contrast agents (GBCAs) are widely and routinely used to enhance the diagnostic performance of magnetic resonance imaging and magnetic resonance angiography examinations. T1 relaxivity (r) is the measure of their ability to increase signal intensity in tissues and blood on T1-weighted images at a given dose. Pharmaceutical companies have invested in the design and development of GBCAs with higher and higher T1 relaxivity values, and "high relaxivity" is a claim frequently used to promote GBCAs, with no clear definition of what "high relaxivity" means, or general concurrence about its clinical benefit.

Standardized Approaches to MR Safety Assessment of Patients with Implanted Devices.

Three dimensionally mapping the relative spatial distributions and magnitudes of the various energy sources used in the MR imaging process for a given MR scanner potentiates an understanding of the relative spatial distributions of the potential risks associated with each of these energies or fields. By systematically analyzing the data for each energy source relative to the location and type of implants, devices, and/or foreign bodies within a specific patient, one can prospectively assess and even begin to quantify the risks of exposing that patient to selected MR scanner hardware for a requested diagnostic study.

Dentate Nucleus Signal Intensity Increases Following Repeated Gadobenate Dimeglumine Administrations: A Retrospective Analysis.

Background Increased cerebral signal intensity (SI) has been reported in patients undergoing MRI with gadolinium-based contrast agents (GBCAs). Published data on gadobenate dimeglumine have been somewhat contradictory. Purpose To evaluate the relationship between dosage of gadobenate dimeglumine and SI change at MRI following multiple gadobenate dimeglumine administrations.

ACR guidance document on MR safe practices: Updates and critical information 2019.

The need for a guidance document on MR safe practices arose from a growing awareness of the MR environment's potential risks and adverse event reports involving patients, equipment, and personnel. Initially published in 2002, the American College of Radiology White Paper on MR Safety established de facto industry standards for safe and responsible practices in clinical and research MR environments. The most recent version addresses new sources of risk of adverse events, increases awareness of dynamic MR environments, and recommends that those responsible for MR medical director safety undergo annual MR safety training.

Safety Considerations of 7-T MRI in Clinical Practice.

Although 7-T MRI has recently received approval for use in clinical patient care, there are distinct safety issues associated with this relatively high magnetic field. Forces on metallic implants and radiofrequency power deposition and heating are safety considerations at 7 T. Patient bioeffects such as vertigo, dizziness, false feelings of motion, nausea, nystagmus, magnetophosphenes, and electrogustatory effects are more common and potentially more pronounced at 7 T than at lower field strengths.

Gadolinium Retention: A Research Roadmap from the 2018 NIH/ACR/RSNA Workshop on Gadolinium Chelates.

Gadolinium-based contrast agents (GBCAs) have revolutionized MRI, enabling physicians to obtain crucial life-saving medical information that often cannot be obtained with other imaging modalities. Since initial approval in 1988, over 450 million intravenous GBCA doses have been administered worldwide, with an extremely favorable pharmacologic safety profile; however, recent information has raised new concerns over the safety of GBCAs. Mounting evidence has shown there is long-term retention of gadolinium in human tissues.

The Impact of Gadolinium Deposition on Radiology Practice: An International Survey of Radiologists.

Rationale And Objectives: Brain deposition of gadolinium following the administration of gadolinium-based contrast agents (GBCAs) was initially reported in 2014. Gadolinium deposition is now recognized as a dose-dependent consequence of exposure. The potential clinical implications are not yet understood.

Frequency of acute longus colli tendinitis on CT examinations.

Purpose: We attempted to determine the frequency of acute longus colli tendinitis on diagnostic CT imaging performed at a large multicenter health care system. By correlating with the pre-imaging clinical information, we investigated which patient presentations should lead the radiologist to increased suspicion for this condition.

Methods: Images from a total of 8101 adult CT examinations of the neck and cervical spine performed over a 3-month period were evaluated by researchers independent of the original clinical report.

Gadolinium deposition in the brain: summary of evidence and recommendations.

Emerging evidence has linked MRI signal changes in deep nuclei of the brain with repeated administration of gadolinium-based contrast agents. Gadolinium deposits have been confirmed in brain tissue, most notably in the dentate nuclei and globus pallidus. Although some linear contrast agents appear to cause greater MRI signal changes than some macrocyclic agents, deposition of gadolinium has also been observed with macrocyclic agents.

Gadolinium based contrast agents (GBCA): Safety overview after 3 decades of clinical experience.

In the past three decades, we have learned much about the potential short-term and long-term safety issues associated with the intravenous administration of gadolinium based contrast agents (GBCAs). Yet, surprisingly, the past few years and even months have been accompanied by new discoveries in this field. This manuscript focuses predominantly on what we have learned - and are continuing to learn - about the long-term potential MR safety issues associated with the administration of the various GBCAs available today and will highlight areas in which they appear to differ from each other at least in a quantitative fashion, if not qualitatively.

Impact of magnetic resonance imaging on ventricular tachyarrhythmia sensing: Results of the Evera MRI Study.

Background: Studies have shown that magnetic resonance imaging (MRI) conditional pacemakers experience no significant effect from MRI on device function, sensing, or pacing. More recently, similar safety outcomes were demonstrated with MRI conditional defibrillators (implantable cardioverter-defibrillator [ICD]), but the impact on ventricular arrhythmias has not been assessed.

Objective: The purpose of this study was to assess the effect of MRI on ICD sensing and treatment of ventricular tachyarrhythmias.

Image Quality of Cardiac Magnetic Resonance Imaging in Patients With an Implantable Cardioverter Defibrillator System Designed for the Magnetic Resonance Imaging Environment.

Background: Recently, magnetic resonance (MR)-conditional implantable cardioverter defibrillator (ICD) systems have become available. However, associated cardiac MR image (MRI) quality is unknown. The goal was to evaluate the image quality performance of various cardiac MR sequences in a multicenter trial of patients implanted with an MR-conditional ICD system.

Full-Body MRI in Patients With an Implantable Cardioverter-Defibrillator: Primary Results of a Randomized Study.

Background: Magnetic resonance imaging (MRI) of patients with conventional implantable cardioverter-defibrillators (ICD) is contraindicated.

Objectives: This multicenter, randomized trial evaluated safety and efficacy of a novel ICD system specially designed for full-body MRI without restrictions on heart rate or pacing dependency. The primary safety objective was >90% freedom from MRI-related events composite endpoint within 30 days post-MRI.