Nephrogenic Systemic Fibrosis Research Articles

Editor’s Pick: Correlation of Cutaneous Manifestations with the Severity of Disease in Patients with Chronic Kidney Disease and Effect of Hemodialysis: An Observational Study

Aim: Chronic kidney disease is a non-communicable disease, and is the sixth fastest growing contributor of morbidity and mortality. Hemodialysis is one of the important therapeutic modalities that can improve survival in these patients, and can increase their life expectancy, but the cutaneous disorder can precede or follow the initiation of hemodialysis. Methods: This is a retrospective, observational study with a sample size of 250 patients, with a glomerular filtration rate <60 mL/min/1.73 m2 for a minimum duration of 3 months or more, undergoing hemodialysis. Patients post-renal transplant, HIV-positive cases, and pregnant patients were excluded from the study. Studied cases were recruited equally into two groups: the dialytic group (Group A) and non-dialytic group (Group B). Results: In the authors’ study, the prevalence of dermatological manifestations was 79% in the dialytic group and 75% in the non-dialytic group. The most common finding overall was xerosis (58%), which was more common in the dialytic (66%) group, both in number of patients and severity. The second most common finding was pallor (55%), which was seen more in the dialytic group (60%). Other major findings were pruritus (49%) and hyperpigmentation (37%). The intensity of pruritus was higher in non-dialytic patients. Specific cutaneous manifestations, such as Kyrle’s disease, were seen only in eight patients. Skin infections were seen in 17% of patients overall, and there was no major difference seen in both groups. The prevalence of nail findings, mucosal changes, and hair changes was also high in the dialytic group. Other specific cutaneous manifestations, like calciphylaxis, uremic frost, and nephrogenic fibrosing dermopathy, were not seen in the authors’ study. Hemodialysis has increased the life expectancy of patients with end-stage renal disease and has also brought about a rise in the number of manifestations, by giving time for these changes to occur. The severity of symptoms was also higher in patients on dialysis. This could be because of the higher mean duration of disease in the dialytic group compared to the non-dialytic group. Conclusion: Dermatological manifestations of chronic kidney disease were significantly associated with the mean duration of disease, which was higher in patients on dialysis. There was a higher prevalence of non-specific dermatological findings, such as xerosis, hyperpigmentation, nail findings, hair, and mucosal changes in the dialytic group, except pruritus. Any such cutaneous marker in the absence of a primary dermatological problem warrants a thorough search, including blood, urine, and radiological investigations, to rule out kidney disease.

Turbo spin-echo-based enhanced acceleration-selective arterial spin labeling without electrocardiography or peripheral pulse unit triggering and contrast enhancement for lower extremity MRA

PurposeLower extremity magnetic resonance angiography (MRA) without electrocardiography (ECG) or peripheral pulse unit (PPU) triggering and contrast enhancement is beneficial for diagnosing peripheral arterial disease (PAD) while avoiding synchronization failure and nephrogenic systemic fibrosis. This study aimed to compare the diagnostic performance of turbo spin-echo-based enhanced acceleration-selective arterial spin labeling (eAccASL) (TSE-Acc) of the lower extremities with that of turbo field-echo-based eAccASL (TFE-Acc) and triggered angiography non-contrast enhanced (TRANCE). MethodsNine healthy volunteers and a patient with PAD were examined on a 3.0 Tesla magnetic resonance imaging (MRI) system. The artery-to-muscle signal intensity ratio (SIR) and contrast-to-noise ratio (CNR) were calculated. The arterial visibility (1: poor, 4: excellent) and artifact contamination (1: severe, 4: no) were independently assessed by two radiologists. Phase-contrast MRI and digital subtraction angiography were referenced in a patient with PAD. Friedman's test and a post-hoc test according to the Bonferroni-adjusted Wilcoxon signed-rank test were used for the SIR, CNR, and visual assessment. p < 0.05 was considered statistically significant. ResultsNo significant differences in nearly all the SIRs were observed among the three MRA methods. Higher CNRs were observed with TSE-Acc than those with TFE-Acc (anterior tibial artery, p = 0.014; peroneal artery, p = 0.029; and posterior tibial artery, p = 0.014) in distal arterial segments; however, no significant differences were observed upon comparison with TRANCE (all p > 0.05). The arterial visibility scores exhibited similar trends as the CNRs. The artifact contamination scores with TSE-Acc were significantly lower (but within an acceptable level) compared to those with TFE-Acc. In the patient with PAD, the sluggish peripheral arteries were better visualized using TSE-Acc than those using TFE-Acc, and the collateral and stenosis arteries were better visualized using TSE-Acc than those using TRANCE. ConclusionPeripheral arterial visualization was better with TSE-Acc than that with TFE-Acc in lower extremity MRA without ECG or PPU triggering and contrast enhancement, which was comparable with TRANCE as the reference standard. Furthermore, TSE-Acc may propose satisfactory diagnostic performance for diagnosing PAD in patients with arrhythmia and chronic kidney disease.

Clinical Safety of Gadobutrol: Review of Over 25 Years of Use Exceeding 100 Million Administrations.

The macrocyclic gadolinium-based contrast agent gadobutrol was introduced to the market in February 1998. Over the last 25 years, gadobutrol has been administered more than 100 million times worldwide providing a wealth of data related to safety. The aim of this study was to perform a thorough review and status update on gadobutrol's safety. Safety data from the clinical phase II-IV program and postmarketing surveillance were descriptively analyzed from February 1998 until December 31, 2022. Literature on special at-risk populations and specific safety aspects was critically summarized. Forty-five clinical phase II-IV studies recruited 7856 patients receiving gadobutrol. Drug-related adverse events (AEs) were reported in 3.4% and serious AEs in <0.1% of patients. Nausea (0.7%) and dysgeusia (0.4%) were the most reported AEs. All other drug-related AEs occurred ≤0.3%. After more than 100 million gadobutrol administrations, overall adverse drug reactions (ADRs) from postmarketing surveillance (including clinical trials) were rare with an overall reporting rate of 0.0356%, hypersensitivity reactions (0.0147%), nausea (0.0032%), vomiting (0.0025%), and dyspnea (0.0010%). All other ADRs were <0.001%. No trend for higher rates of AEs was found in patients with reduced renal or liver function. Seven clinical studies reported safety findings in 7292 children ≤18 years, thereof 112 newborns/toddlers younger than 2 years. Overall, 61 ADRs (0.84%) were reported, including 3 serious ones. Adverse events in patients ≥65 years of age ("elderly") were significantly less frequent than in younger patients. A total of 4 reports diagnostic of or consistent with nephrogenic systemic fibrosis have been received. No causal relationship has been established between clinical signs and symptoms and the presence of small amounts of gadolinium in the body in patients with normal renal function after use of gadobutrol. More than 100 million administrations worldwide have shown gadobutrol's well-established benefit-risk profile in any approved indication and populations.

A Bis(Aquated) Mn(II)-Based MRI Contrast Agent with a Rigid Hydroquinazoline Unit: Synthesis, Characterization, and in Vivo MR Imaging Study.

Since the finding of nephrogenic systemic fibrosis (NFS) in patients with renal impairment and the long-term accumulation of Gd(III) ions in the central nervous system, the search for nongadolinium ion-based MRI contrast agents made of nutrient metal ions has drawn paramount attention. In this context, the development of Mn(II)-based MRI contrast agents has been a subject of interest for the last few decades. Herein, we report a pentadentate ligand (Li2[BenzPic2]) composed of two picolinate moieties and a rigid 1,2,3,4-tetrahydroquinazoline unit and the corresponding bis(aquated) Mn(II) complex (Complex 1). The complex exhibited high thermodynamic stability (log Kcond = 11.62) and kinetic inertness similar to that of the clinically approved Gd(III)-based contrast agent Magnevist. Complex 1 exerted longitudinal relaxivity (r1) of 5.32 mM-1 s-1 at 1.41 T, 37 °C, pH 7.4, and it increased by 3.6-fold in the presence of serum albumin protein, confirming a substantial rigidifying interaction (albumin association constant KA = 1.66 × 103 M-1) between the protein and the amphiphilic (log P = -0.45) contrast agent. An intravenous dose of 0.08 mmol/kg in a healthy mouse, excellent MRI signal intensity enhancement in the vasculature of the mouse liver, and brightened images of the gallbladder, kidney, and liver were realized.

Synthesis of gadolinium-enhanced glioma images on multisequence magnetic resonance images using contrastive learning.

Gadolinium-based contrast agents are commonly used in brain magnetic resonance imaging (MRI), however, they cannot be used by patients with allergic reactions or poor renal function. For long-term follow-up patients, gadolinium deposition in the body can cause nephrogenic systemic fibrosis and other potentialrisks. Developing a new method of enhanced image synthesis based on the advantages of multisequence MRI has important clinical value for these patients. In this paper, an end-to-end synthesis model structure similarity index measure (SSIM)-based Dual Constrastive Learning with Attention (SDACL) based on contrastive learning is proposed to synthesize contrast-enhanced T1 (T1ce) using three unenhanced MRI images of T1, T2, and Flair in patients withglioma. The model uses the attention-dilation generator to enlarge the receptive field by expanding the residual blocks and to strengthen the feature representation and context learning of multisequence MRI. To enhance the detail and texture performance of the imaged tumor area, a comprehensive loss function combining patch-level contrast loss and structural similarity loss is created, which can effectively suppress noise and ensure the consistency of synthesized images and real images. The normalized root-mean-square error (NRMSE), peak signal-to-noise ratio (PSNR), and SSIM of the model on the independent test set are 0.307 0.12, 23.337 3.21, and 0.881 0.05,respectively. Results show this method can be used for the multisequence synthesis of T1ce images, which can provide valuable information for clinical diagnosis.

Noninvasive Diagnosis of Kidney Dysfunction Using a Small-Molecule Manganese-Based Magnetic Resonance Imaging Probe.

Contrast-enhanced magnetic resonance imaging (CE-MRI) is a promising approach for the diagnosis of kidney diseases. However, safety concerns, including nephrogenic systemic fibrosis, limit the administration of gadolinium (Gd)-based contrast agents (GBCAs) in patients who suffer from renal impairment. Meanwhile, nanomaterials meet biosafety concerns because of their long-term retention in the body. Herein, we propose a small-molecule manganese-based imaging probe Mn-PhDTA as an alternative to GBCAs to assess renal insufficiency for the first time. Mn-PhDTA was synthesized via a simple three-step reaction with a total yield of up to 33.6%, and a gram-scale synthesis can be realized. Mn-PhDTA has an r1 relaxivity of 2.72 mM-1 s-1 at 3.0 T and superior kinetic inertness over Gd-DTPA and Mn-EDTA with a dissociation time of 60 min in the presence of excess Zn2+. In vivo and in vitro experiments demonstrate their good stability and biocompatibility. In the unilateral ureteral obstruction rats, Mn-PhDTA provided significant MR signal enhancement, enabled distinguishing structure changes between the normal and damaged kidneys, and evaluated the renal function at different injured stages. Mn-PhDTA could act as a potential MRI contrast agent candidate for the replacement of GBCAs in the early detection of kidney dysfunction and analysis of kidney disease progression.

MRI Gadolinium-Based Contrast Media: Meeting Radiological, Clinical, and Environmental Needs.

Gadolinium-based contrast agents (GBCAs) are routinely used in magnetic resonance imaging (MRI). They are essential for choosing the most appropriate medical or surgical strategy for patients with serious pathologies, particularly in oncologic, inflammatory, and cardiovascular diseases. However, GBCAs have been associated with an increased risk of nephrogenic systemic fibrosis in patients with renal failure, as well as the possibility of deposition in the brain, bones, and other organs, even in patients with normal renal function. Research is underway to reduce the quantity of gadolinium injected, without compromising image quality and diagnosis. The next generation of GBCAs will enable a reduction in the gadolinium dose administered. Gadopiclenol is the first of this new generation of GBCAs, with high relaxivity, thus having the potential to reduce the gadolinium dose while maintaining good in vivo stability due to its macrocyclic structure. High-stability and high-relaxivity GBCAs will be one of the solutions for reducing the dose of gadolinium to be administered in clinical practice, while the development of new technologies, including optimization of MRI acquisitions, new contrast mechanisms, and artificial intelligence may help reduce the need for GBCAs. Future solutions may involve a combination of next-generation GBCAs and image-processing techniques to optimize diagnosis and treatment planning while minimizing exposure to gadolinium. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 3.

NSF evaluation of gadolinium biodistribution in renally impaired rats: Using novel metabolic Gd2O3 nanoparticles coated with β-cyclodextrin (Gd2O3@PCD) in MR molecular imaging

The use of conventional gadolinium(Gd)-based contrast agents in magnetic resonance imaging (MRI) poses a significant risk of Nephrogenic Systemic Fibrosis (NSF) syndrome in patients with impaired renal function (grades 4 and 5). To address this issue, a new study has introduced a novel metabolic Gadolinium oxide nanoparticle (Gd2O3 NPs) coated with β-cyclodextrin (βCD). The study aims to investigate NSF syndrome by quantifying tissue Gd deposition biodistribution in renal impairment rats using MR molecular imaging. This is the first study of its kind to use this approach.A group of 20 rats were divided into four groups, each containing five rats that underwent 5/6 nephrectomy. The rats received 12 intravenous injections of a novel homemade synthesized gadolinium oxide polycyclodextrin (Gd2O3@PCD) at a dose of 0.1 mmol/kg, conventional contrast agents (CAs) drugs of Omniscan (Gd-DTPA-BMA) and Dotarem (Gd-DOTA), at a dose of 2.5 mmol/kg, and 250 μl saline for two injections per week during six weeks. T1-weighted MR imaging was performed before the injections and once a week for six weeks to quantify Gd deposition in four different organs (skin, liver, heart, and lung) in rats using inductively coupled plasma mass spectrometry (ICP-MS). The relationship between Signal-to-Noise Ratio (SNR) and biodistribution of Gd deposition due to NSF-induced syndrome was also calculated.The results of the study showed that the Gd concentrations in tissues were significantly higher in the Gd2O3@PCD group compared to the other groups, without any significant histopathological changes (P < 0.05). In the Gd2O3@PCD group, Gd was mainly deposited in the skin, followed by the liver, lung, and heart, without any symptoms of thickening or hardening of the skin. The Gd concentrations in the skin, liver, lung, and heart were significantly lower in the Dotarem group than in the Omniscan group (P < 0.05). In the histopathological examinations, the Omniscan group showed increased cellularity in the dermis. A significant hyperintensity was observed in the Gd2O3@PCD-treated rats compared to the Dotarem and Omniscan groups in the liver, heart, and lung.Compared to conventional Gd-based CAs, the novel metabolically Gd2O3@PCD with increased SNR, biosafety, and a considerably lower probability of developing NSF, has potential applicability for diagnosing patients with renal diseases in clinical MR Molecular Imaging (MRMI).

Therapeutic Apheresis, Immunosuppression and Human Monoclonal Antibodies in Nephrology

Most of the immunologic or non-immunologic renal diseases have a bad prognosis without treatment, and the treatment is complicated in these diseases. With the introduction of therapeutic apheresis, since more than 45 years, has led in combination with immunosuppressive therapies and/or human monoclonal antibodies to a steady increase in survival rates over the last years. Therapeutic apheresis is accepted as supportive therapy in all severe renal diseases such as acute kidney injury, nephrogenic systemic fibrosis, rapid progressive glomerulonephritis, hemolytic uremic hemolytic syndrome, and in renal transplant rejection. Other modern therapy concepts are different human monoclonal antibodies with or without therapeutic apheresis. For these renal disorders, besides the pathological aspect, the first-line and second-line therapies are shown. Therapeutic apheresis has been shown to effectively remove antibody, toxic substances and others from blood and lead to rapid improvement. The guidelines of the Apheresis Applications Committee of the American Society for Apheresis are cited.

Structurally Optimized Fluorinated Small‐Sized Graphene Oxide for Enhanced Magnetic Resonance Imaging during Pregnancy

AbstractGadolinium‐based complex contrast agents (GBCAs), frequently applied in magnetic resonance imaging (MRI), are associated with severe acute anaphylactic shock and incurable nephrogenic systemic fibrosis. Besides, the repeated use of GBCAs may result in the accumulation in various tissues. Given these potential adverse effects, GBCAs have not been well used during pregnancy. Herein, a novel metal‐free T2‐weighted MRI nanoprobe, designated fluorinated small‐sized graphene oxide with optimized fluorine content (LF‐sGO), is developed via graphene oxide materials. By introducing specific polar C─F bonds onto the small‐sized graphene oxide (sGO) skeleton, the prepared nanoprobe exhibits excellent water solubility, as well as superior MRI capabilities, thereby furnishing high‐resolution MRI anatomical information. Furthermore, the free radicals on LF‐sGO stabilized by C─F bonds confer LF‐sGO enrichment in the tumor region, enabling comprehensive imaging capability. The cytotoxicity study in vitro indicates that LF‐sGO has the potential to serve as a biocompatible imaging probe. Moreover, detailed in vivo studies on pregnant mice and zebrafish adequately demonstrate that microinjection of LF‐sGO does not induce dysontogensis and teratogenesis. This study successfully showcases a metal‐free nanoprobe that exhibits exceptional MRI capabilities for the purpose of tumor diagnosis. Notably, this nanoprobe holds promise for safe and effective tumor diagnosis during pregnancy.

Safety and incremental prognostic value of stress CMR in patients with known chronic kidney disease

Abstract Background Cardiovascular disease (CVD) is the main cause of mortality in patients with chronic kidney disease (CKD). Although several studies have demonstrated the consistently high prognostic value of stress cardiovascular magnetic resonance (CMR), its prognostic value in patients with CKD is not well established. We aimed to assess the safety and the incremental prognostic value of vasodilator stress perfusion CMR in consecutive symptomatic patients with known CKD. Methods Between 2008 and 2021, we conducted a bi-center longitudinal study with all consecutive symptomatic patients with known CKD, defined by estimated glomerular filtration rate (eGFR) between 30 and 60 ml/min/1.73 m2, referred for vasodilator stress CMR. All patients with eGFR &amp;lt;30 ml/min/1.73 m² (n=62) were excluded due the risk of nephrogenic systemic fibrosis. All patients were followed for the occurrence of major adverse cardiovascular events (MACE) defined as cardiac death or recurrent nonfatal myocardial infarction (MI). Cox regressions were used to determine the prognostic value of stress CMR parameters. Results Of 825 patients with known CKD (71.4±8.8 years, 70% men), 769 (93%) completed the CMR protocol, and among those 702 (91%) completed the follow-up (median follow-up 6.4 (4.0–8.2) years). Stress CMR was well tolerated without occurrence of death or severe adverse event related to the injection of gadolinium or nephrogenic systemic fibrosis case. The presence of inducible ischemia was associated with the occurrence of MACE (hazard ratio [HR] 12.50; 95% confidence interval [CI]: 7.50–20.8; p&amp;lt;0.001). In multivariable analysis, ischemia and late gadolinium enhancement were independent predictors of MACE (HR 15.5; 95% CI: 7.72 to 30.9; and HR:4.67 [95%CI: 2.83-7.68]; respectively, both p&amp;lt;0.001). After adjustment, stress CMR findings showed the best improvement in model discrimination and reclassification above traditional risk factors (C-statistic improvement: 0.13; NRI=0.477; IDI=0.049). Conclusions In patients with known CKD, stress CMR is safe and its findings have an incremental prognostic value to predict MACE over traditional risk factors.Cumulative rates of MACECompeting risk analysis

Reducing Gadolinium Contrast With Artificial Intelligence.

Gadolinium contrast is an important agent in magnetic resonance imaging (MRI), particularly in neuroimaging where it can help identify blood-brain barrier breakdown from an inflammatory, infectious, or neoplastic process. However, gadolinium contrast has several drawbacks, including nephrogenic systemic fibrosis, gadolinium deposition in the brain and bones, and allergic-like reactions. As computer hardware and technology continues to evolve, machine learning has become a possible solution for eliminating or reducing the dose of gadolinium contrast. This review summarizes the clinical uses of gadolinium contrast, the risks of gadolinium contrast, and state-of-the-art machine learning methods that have been applied to reduce or eliminate gadolinium contrast administration, as well as their current limitations, with a focus on neuroimaging applications. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 1.

Update on Gadolinium Based Contrast Agent Safety, From the AJR Special Series on Contrast Media.

Since its introduction 35 years ago, gadolinium-enhanced MRI has fundamentally changed medical practice. While extraordinarily safe, gadolinium-based contrast agents (GBCAs) may have side effects. Four distinct safety considerations include: acute allergic-like reactions, nephrogenic systemic fibrosis (NSF), gadolinium deposition, and symptoms associated with gadolinium exposure. Acute reactions after GBCA administration are uncommon-far less than with iodinated contrast agents-and, while rare, serious reactions can occur. NSF is a rare, but serious, scleroderma-like condition occurring in patients with kidney failure after exposure to American College of Radiology (ACR) Group 1 GBCAs. Group 2 and 3 GBCAs are considered lower risk, and, through their use, NSF has largely been eliminated. Unrelated to NSF, retention of trace amounts of gadolinium in the brain and other organs has been recognized for over a decade. Deposition occurs with all agents, although linear agents appear to deposit more than macrocyclic agents. Importantly, to date, no data demonstrate any adverse biologic or clinical effects from gadolinium deposition, even with normal kidney function. This article summarizes the latest safety evidence of commercially available GBCAs with a focus on new agents, discusses updates to the ACR NSF GBCA safety classification, and describes approaches for strengthening the evidence needed for regulatory decisions.

P16 The wood for the trees

P16 The wood for the trees

OA15 Missing the wood(-y induration) for the trees

OA15 Missing the wood(-y induration) for the trees

Where does the gadolinium go? A review into the excretion and retention of intravenous gadolinium.

Gadolinium-based contrast agents (GBCAs) are commonly used in medical imaging. Most intravenously (IV) administered gadolinium is excreted via the kidneys, and pathological retention in renal failure leading to nephrogenic systemic fibrosis (NSF) is well described. More recently, retention of gadolinium in the body in the absence of renal disease has been identified, with unknown clinical consequences. Many patients are aware of this, either through the media or via comprehensive consent documentation. Some internet sites, without hard evidence, have suggested a constellation of possible symptoms associated with GBCA retention. Recent experience with patients ascribing symptoms to a contrast-enhanced MRI examination prompted this review of the fate of injected GBCA after MRI study, and of information available to patients online regarding gadolinium retention.

Safety and incremental prognostic value of stress CMR in patients with known chronic kidney disease

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiovascular disease (CVD) is the main cause of mortality in patients with chronic kidney disease (CKD). Although several studies have demonstrated the consistently high prognostic value of stress cardiovascular magnetic resonance (CMR), its prognostic value in patients with CKD is not well established. We aimed to assess the safety and the incremental prognostic value of vasodilator stress perfusion CMR in consecutive symptomatic patients with known CKD. Methods Between 2008 and 2021, we conducted a bi-center longitudinal study with all consecutive symptomatic patients with known CKD, defined by estimated glomerular filtration rate (eGFR) between 30 and 60 ml/min/1.73 m2, referred for vasodilator stress CMR. All patients with eGFR &amp;lt;30 ml/min/1.73 m² (n=62) were excluded due the risk of nephrogenic systemic fibrosis. All patients were followed for the occurrence of major adverse cardiovascular events (MACE) defined as cardiac death or recurrent nonfatal myocardial infarction (MI). Cox regressions were used to determine the prognostic value of stress CMR parameters. Results Of 825 patients with known CKD (71.4±8.8 years, 70% men), 769 (93%) completed the CMR protocol, and among those 702 (91%) completed the follow-up (median follow-up 6.4 (4.0–8.2) years). Stress CMR was well tolerated without occurrence of death or severe adverse event related to the injection of gadolinium or nephrogenic systemic fibrosis case. The presence of inducible ischemia was associated with the occurrence of MACE (hazard ratio [HR] 12.50; 95% confidence interval [CI]: 7.50–20.8; p&amp;lt;0.001). In multivariable analysis, ischemia and late gadolinium enhancement were independent predictors of MACE (HR 15.5; 95% CI: 7.72 to 30.9; and HR:4.67 [95%CI: 2.83–7.68]; respectively, both p&amp;lt;0.001). After adjustment, stress CMR findings showed the best improvement in model discrimination and reclassification above traditional risk factors (C-statistic improvement: 0.13; NRI=0.477; IDI=0.049). Conclusions In patients with known CKD, stress CMR is safe and its findings have an incremental prognostic value to predict MACE over traditional risk factors.

What you need to know about: imaging in patients with renal failure.

Contrast-enhanced medical imaging is commonly requested in clinical practice. Contrast media provide better differentiation of tissue enhancement, improves the soft tissue contrast resolution, and enhances the ability to study the physiology and function of the organs and/or systems. However, contrast media may cause complications, especially in patients with renal failure. This article discusses the use of contrast media in common imaging modalities and the relationship between contrast media and renal function. Administration of iodinated contrast media in computed tomography may cause contrast-associated acute kidney injury; the risk factors and preventive strategies for this are elaborated in this article. Administration of gadolinium-based contrast media in magnetic resonance imaging may lead to nephrogenic systemic fibrosis. Therefore, precautions should be taken when planning for medical imaging for patients with pre-existing acute kidney injury or end-stage chronic kidney disease, for whom contrast media administration in computed tomography or magnetic resonance imaging may be relatively contraindicated. Alternatively, ultrasound contrast agents can be safely used in patients with acute kidney injury or chronic kidney disease. Clinical teams should discuss these patients with radiologists, taking into account the risk-benefits of contrast media, to determine the optimal imaging protocol or modality to answer the clinical query.

Capability of constructive interference in steady state sequence versus postcontrast T1-weighted imaging in cerebellopontine angle and internal auditory canal masses

Background: The tumor size is one of the main factors in the treatment of cerebellopontine angle (CPA) tumors, and magnetic resonance imaging (MRI) with gadolinium-based contrast agent (GBCA) provides the best evaluation. However, administration of the gadolinium is time consuming and increasing in cost. There is a risk of nephrogenic systemic fibrosis in patients with renal failure and liver or renal transplantation. Objective: The purpose of this study was to assess the capability of constructive interference in steady state (CISS) sequence in measuring the tumor size of the CPA and internal auditory canal (IAC) masses compared to postcontrast T1-weighted images (T1-WI). Materials and Methods: The 118 MR studies with both CISS sequence and postcontrast T1-WI of 45 patients with CPA and IAC masses were retrospectively reviewed. Results: There was no significant difference between CISS and postcontrast T1-WI in measuring size in transverse diameter of the masses (p = 0.051-0.06). The longitudinal diameter measurement revealed a significant difference (p &lt; 0.001) and the measured size on postcontrast T1-WI was slightly larger than the CISS image. The difference in median measurement between two sequences was less than 0.9 mm. and Bland-Altman plots revealed that differences between the two sequences in longitudinal and transverse diameters of the masses were within the limits of agreement. Interobserver agreement showed excellent correlation (r = 0.994-0.999, p &lt; 0.001 by Pearson's product-moment correlation). Conclusions: The CISS sequence may be sufficient for assessing the size of CPA and IAC masses, which can be used interchangeably with postcontrast T1-weighted image as a contrast-free option, especially in follow-up studies and vulnerable settings of gadolinium administration.

Ferumoxytol-Enhanced MRI in Children and Young Adults: State of the Art.

Ferumoxytol is an ultrasmall iron oxide nanoparticle that was originally approved by the FDA in 2009 for IV treatment of iron deficiency in adults with chronic kidney disease. Subsequently, its off-label use as an MRI contrast agent increased in clinical practice, particularly in pediatric patients in North America. Unlike conventional MRI contrast agents that are based on the rare earth metal gadolinium (gadolinium-based contrast agents), ferumoxytol is biodegradable and carries no potential risk of nephrogenic systemic fibrosis. At FDA-approved doses, ferumoxytol shows no long-term tissue retention in patients with intact iron metabolism. Ferumoxytol provides unique MRI properties, including long-lasting vascular retention (facilitating high-quality vascular imaging) and retention in reticuloendothelial system tissues, thereby supporting a variety of applications beyond those possible with gadolinium-based contrast agents (GBCAs). This Clinical Perspective describes clinical and early translational applications of ferumoxytol-enhanced MRI in children and young adults through off-label use in a variety of settings, including vascular, cardiac, and cancer imaging, drawing on the institutional experience of the authors. In addition, we describe current advances in pre-clinical and clinical research using ferumoxytol in cellular and molecular imaging as well as the use of ferumoxytol as a novel potential cancer therapeutic agent.