Enhanced computed tomography or magnetic resonance imaging: a choice between contrast medium-induced nephropathy and nephrogenic systemic fibrosis?

The history of magnetic resonance imaging and its reflections in Acta Radiologica

The first reports in Acta Radiologica on magnetic resonance imaging (MRI) were published in 1984, four years after the first commercial MR scanners became available. For the first two years, all MR papers originated from the USA. Nordic contributions started in 1986, and until 2020, authors from 44 different countries have published MR papers in Acta Radiologica. Papers on MRI have constituted, on average, 30%-40% of all published original articles in Acta Radiologica, with a high of 49% in 2019. The MR papers published since 1984 document tremendous progress in several areas such as magnet and coil design, motion compensation techniques, faster image acquisitions, new image contrast, contrast-enhanced MRI, functional MRI, and image analysis. In this historical review, all of these aspects of MRI are discussed and related to Acta Radiologica papers.

Non-contrast-enhanced magnetic resonance angiography of facial arteries for pre-operative evaluation of vascularized submental lymph node flaps

Background

The aim of this study was to compare non-contrast-enhanced 3D phase contrast magnetic resonance angiography (3D PC-MRA) and conventional intravenous administration of contrast media, i.e., contrast-enhanced MRA (CE-MRA), to evaluate the courses of facial arteries for the preparation of vascularized submental lymph node flap (VSLN flap) transfer.

Methods

The head and neck regions of 20 patients with limb lymphedema were imaged using a 3 T MRI scanner. To improve the evaluation of facial artery courses, MRA was fused with anatomical structures generated by high-resolution T1-weighted imaging. The diagnostic and image qualities of facial arteries for VSLN flap planning were independently rated by two radiologists. Interobserver agreement was evaluated using Cohen’s kappa. Differences between 3D PC-MRA and CE-MRA in terms of the diagnostic quality of facial arteries were evaluated using McNemar’s test.

Results

Cohen’s kappa indicated fair to good interobserver agreement for the diagnostic and image qualities of the bilateral facial arteries. No significant difference in terms of the diagnostic quality of the left and right facial arteries between 3D PC-MRA and CE-MRA, respectively, was identified.

Conclusions

Non-contrast 3D PC-MRA is a reliable method for the evaluation of facial artery courses prior to VSLN flap transfer and could serve as an alternative to CE-MRA for patients with renal insufficiency or severe adverse reactions to contrast media.

Toxicity Evaluation of a Novel Magnetic Resonance Imaging Marker, CoCl2-N-Acetylcysteine, in Rats

C4 (cobalt dichloride-N-acetylcysteine [1% CoCl₂:2% NAC]) is a novel magnetic resonance imaging contrast marker that facilitates visualization of implanted radioactive seeds in cancer brachytherapy. We evaluated the toxicity of C4. Rats were assigned to control (0% CoCl₂:NAC), low-dose (0.1% CoCl₂:2% NAC), reference-dose (C4), and high-dose (10% CoCl₂:2% NAC) groups. Agent was injected into the left quadriceps femoris muscle of the rats. Endpoints were organ and body weights, hematology, and serum chemistry and histopathologic changes of tissues at 48 hours and 28 and 63 days after dosing. Student's t tests were used. No abnormalities in clinical signs, terminal body and organ weights, or hematologic and serum chemistry were noted, and no gross or histopathologic lesions of systemic tissue toxicity were found in any treatment group at any time point studied. At the site of injection, concentration-dependent acute responses were observed in all treatment groups at 48 hours after dosing and were recovered by 28 days. No myofiber degeneration or necrosis was observed at 28 or 63 days in any group. In conclusion, a single intramuscular dose of C4 produced no acute or chronic systemic toxicity or inflammation in rats, suggesting that C4 may be toxicologically safe for clinical use in cancer brachytherapy.

Incidence of Nephrogenic Systemic Fibrosis Using Gadobenate Dimeglumine in 1423 Patients With Renal Insufficiency Compared With Gadodiamide

OBJECTIVE

The purpose of this study was to assess the incidence of nephrogenic systemic fibrosis (NSF) before and after educational interventions, implementation of a clinical screening process, and change to gadobenate dimeglumine in patients who had an estimated glomerular filtration rate (eGFR) of 30 mL/min per 1.72 m or less.

METHODS

This is a Health Insurance Portability and Accountability Act compliant, institutional review board exempt study. Two periods were studied-July 2005 to June 2006, during which gadodiamide was utilized as our magnetic resonance (MR) contrast agent, and November 2006 to August 2014, during which gadobenate dimeglumine was used as our MR contrast agent in patients who had an eGFR 30 mL/min per 1.72 m or less. In addition to a change in the MR contrast agent, education of our staff physician to the risks of NSF with MR contrast agents and the implementation of a clinical screening process occurred. The rate of NSF before and after the interventions was compared using the χ test.

RESULTS

There was a statistically significant difference in the incidence of NSF in patients with an eGFR 30 mL/min per 1.72 m or less between the 2 periods: July 2005 to June 2006, 6 of 246 patients were diagnosed with NSF (P < 0.001), versus November 2006 to August 2014, 0 of 1423 patients were diagnosed with NSF.

CONCLUSIONS

Our data demonstrates a marked decrease in the incidence of NSF after education of our referring physicians, implementation of clinical screening process, and change to gadobenate dimeglumine from gadodiamide in patients with renal insufficiency. This approach potentially provides an acceptable risk-benefit profile for patients with renal insufficiency that required MR imaging for clinical care.

Contribution of magnetic resonance imaging in lung cancer imaging

Lung cancer is the leading cause of cancer death worldwide. Prognosis and treatment outcomes are known to be related to the disease stage at the time of diagnosis. Therefore, an accurate assessment of the extent of disease is critical to determine the most appropriate therapy. Currently available imaging modalities for diagnosis and follow-up consist of morphological and functional imaging. Morphological investigations are mainly performed with CT-scan and in some cases with MRI. In this review, we describe the contribution of MRI in lung cancer staging focusing on solid pulmonary nodule characterization and TNM staging assessment using chest and whole-body MRI examinations, detailing in each chapter current recommendations and future developments.

Overview of left ventricular outpouchings on cardiac magnetic resonance imaging

Left ventricular outpouchings commonly include aneurysm, pseudoaneurysm, and diverticulum and are now being increasingly detected on imaging. Distinction between these entities is of prime importance to guide proper management as outcomes for these entities differ substantially. Chest radiograph is usually nonspecific in their diagnosis. Echocardiography, multi-detector computed tomography evaluation and angiography are helpful in the diagnosis with their inherit limitations. Cardiac magnetic resonance imaging (MRI) is emerging as a very useful tool that allows simultaneous anatomical and functional evaluation along with tissue characterization, which has diagnostic, theraputic and prognostic implications. This article gives an overview of left ventricular outpouchings with special emphasis on their differentiation using cardiac MRI.

Gadolinium-induced nephrogenic systemic fibrosis: the rise and fall of an iatrogenic disease

Background.

In 2006, nephrologists in Denmark unexpectedly identified chronic kidney disease (CKD) patients with a new syndrome, nephrogenic systemic fibrosis (NSF). Subsequently, 1603 NSF patients were reported to the Food and Drug Administration. Sixty hospitals in the USA account for 93% of these cases, and two hospitals in Denmark account for 4% of these reports. We review Denmark’s identification and subsequent rapid eradication of NSF.

Methods.

NSF reports from clinicians, the Danish Medicines Agency (DMA) and gadolinium-based contrast agents (GBCAs) manufacturers were reviewed (2002–11).

Results.

In 1994, the DMA approved a non-ionic linear GBCA, gadodiamide (0.1 mmol/kg), for magnetic resonance imagings (MRIs), with a renal insufficiency contraindication. In 1996, 0.3 mmol/kg dosing received DMA approval. In 1998, the DMA removed renal contraindications. In 1997 and 2002, radiologists at Skejby Hospital and Herlev Hospital, respectively, began performing gadodiamide-enhanced magnetic resonance angiography scans (0.3 mmol/kg) of CKD patients. In 2005, Herlev clinicians requested assistance in evaluating etiological causes of NSF occurring among 10 CKD patients who had developed NSF. This investigation, focusing on infectious agents, was inconclusive. In 2006, Herlev clinicians reported that of 108 CKD patients who had received gadodiamide-enhanced MRI, 20 had developed probable NSF. Herlev radiologists voluntarily discontinued administering gadodiamide to all patients and no new NSF cases at Herlev Hospital developed subsequently. After meeting with Herlev radiologists, Skejby radiologists also discontinued administering gadodiamide to all patients. In 2007, the European Medicines Agency and the DMA contraindicated gadodiamide administration to CKD patients. In 2008, in response to these advisories, radiologists at the other 36 Danish hospitals discontinued administering gadodiamide to all patients, following on practices adopted at Skejby and Herlev Hospitals. In 2009, clinicians at Skejby Hospital reported that a look-back survey identified 33 CKD patients with NSF developing after undergoing GBCA-enhanced MRIs between 1999 and 2007. In 2010, an independent review, commissioned by the Minister of Health, concluded that the DMA had erred in rescinding gadodiamide’s renal insufficiency contraindication in 1998 and that this error was a key factor in the development of NSF in Denmark. In 2011, three NSF cases associated with macrocyclic GBCA-associated NSF and three NSF patients with Stages 3 and 4 CKD disease from Skejby Hospital were reported.

Conclusion.

A confluence of factors led to the development and eradication of NSF in Denmark.

Nephrogenic systemic fibrosis: UK survey of the use of gadolinium-based contrast media

AIM

To identify the current practice of administration of gadolinium-based contrast media (Gd-CM) within the UK with respect to the European Society of Urogenital Radiology (ESUR) guidelines on nephrogenic systemic fibrosis (NSF).

MATERIALS AND METHODS

One hundred and fifty-two institutions were contacted to request details regarding the use of Gd-CM at their institution, their awareness of NSF, and of the ESUR guidelines, and their departmental policy on the administration of Gd-CM agents associated with NSF (high-risk agents) in patients with diminished renal function.

RESULTS

Of the 100 institutions that replied, 72% used a cyclic agent as a first-line Gd-CM. The majority of institutions used more than one Gd-CM, and 57% used a high-risk Gd-CM. Seventy percent were aware of the ESUR guidelines, and of the 57% that used a high-risk Gd-CM, 9% did not check renal function at all prior to administration. The course of action of the remaining 48% was varied in patients with diminished renal function with some changing to a low-risk Gd-CM and others electing not to use Gd-CM at all. Five percent continued to use a high-risk Gd-CM with an estimated glomerular filtration rate <30ml/min.

CONCLUSION

The present survey shows that the majority of institutions use a low-risk Gd-CM as a first-line agent; however, a number of institutions do use a high-risk Gd-CM and their course of action for patients with diminished renal function is varied. Given current evidence, it is advisable to use a low-risk Gd-CM, such as a cyclic agent, in patients with diminished renal function.

Toxicity of MRI and CT contrast agents

Anatomical and physiological imaging using CT and MRI are playing a critical role in patients' diagnosis, disease characterization and treatment planning. CT- and MRI-based protocols increasingly require an injection of iodinated CT and gadolinium (Gd)-based MRI contrast media. Although routinely used in clinical practice, iodinated and to a less extent Gd-based contrast media possess side effects: life-threatening contrast-induced nephropathy (CIN) is associated with CT and nephrogenic systemic fibrosis (NSF) with MRI contrast agents. CIN is defined as an acute decline in renal functions (serum creatinine increase > 0.5 mg/dl) after administration of iodinated contrast media. Patients with moderate-to-severe chronic kidney disease are considered the highest risk group for development of CIN. CIN is more common with ionic high-osmolar contrast CT media. NSF is a rare condition characterized by the formation of connective tissue in the skin and systemically in the lung, liver, heart and kidney. Patients with end stage kidney disease, acute kidney injury and stage 4-5 chronic kidney disease are at a high risk for NSF. The nonionic linear Gd-chelates are associated with the highest risk of NSF. This review summarizes the incidence, symptoms, safety profile of various CT and MRI contrast agents based on their physiochemical properties.

Blood oxygen level-dependent and perfusion magnetic resonance imaging: detecting differences in oxygen bioavailability and blood flow in transplanted kidneys

Functional magnetic resonance imaging (fMRI) is a powerful tool for examining kidney function, including organ blood flow and oxygen bioavailability. We have used contrast enhanced perfusion and blood oxygen level-dependent (BOLD) MRI to assess kidney transplants with normal function, acute tubular necrosis (ATN) and acute rejection. BOLD and MR-perfusion imaging were performed on 17 subjects with recently transplanted kidneys. There was a significant difference between medullary R2 values in the group with acute rejection (R2=16.2/s) compared to allografts with ATN (R2=19.8/s; P=.047) and normal-functioning allografts (R2=24.3/s;P=.0003). There was a significant difference between medullary perfusion measurements in the group with acute rejection (124.4+/-41.1 ml/100 g per minute) compared to those in patients with ATN (246.9+/-123.5 ml/100 g per minute; P=.02) and normal-functioning allografts (220.8+/-95.8 ml/100 g per minute; P=.02). This study highlights the utility of combining perfusion and BOLD MRI to assess renal function. We have demonstrated a decrease in medullary R2 (decrease deoxyhemoglobin) on BOLD MRI and a decrease in medullary blood flow by MR perfusion imaging in those allografts with acute rejection, which indicates an increase in medullary oxygen bioavailability in allografts with rejection, despite a decrease in blood flow.

Quantitative MR measures of intrarenal perfusion in the assessment of transplanted kidneys: initial experience

RATIONALE AND OBJECTIVES

The purpose of this study was to evaluate prospectively a gadolinium-based perfusion technique for intrarenal blood flow in transplanted kidneys and to determine if magnetic resonance imaging (MRI) measurements of intrarenal perfusion could be used to differentiate between normal-functioning kidney allografts and allografts with acute tubular necrosis (ATN) or acute rejection.

MATERIALS AND METHODS

Twenty-one subjects were enrolled within 4 months of receiving a kidney transplant. A biopsy was performed on subjects to diagnose each allograft as having either ATN or acute rejection. A group of subjects with normal functioning transplants was also enrolled in our study. MRI perfusion images were acquired on a 1.5 T MRI system within 48 hours after biopsy using an echo planar, T2*-weighted sequence, and an injection of gadodiamide contrast agent administered at a dose of 0.1 mmol/kg. Scan parameters were: repetition time/echo time/flip = 1000 ms/30 ms/60 degrees , field of view = 340 x 340 mm, matrix = 128 x 64, slice thickness = 10 mm, and temporal resolution = 1.0 seconds. Cortical and medullary blood flow values were calculated.

RESULTS

Medullary blood flow values were significantly (P = .02) lower in allografts undergoing acute rejection (121 +/- 41 mL/100 g/min) compared to normal-functioning allografts (221 +/- 96 mL/100 g/min) and those with ATN (247 +/- 124 mL/100 g/min). Cortical blood flow values were also significantly (P = .03) reduced in allografts with acute rejection (243 +/- 116 mL/100 g/min) compared to those with normal function (413 +/- 116 mL/100 g/min).

CONCLUSIONS

Preliminary results indicate that MRI perfusion techniques may provide a means of determining noninvasively the viability of renal allografts, potentially alleviating the need for biopsy in some patients.

Features of nephrogenic systemic fibrosis on radiology examinations

OBJECTIVE

The objective of this article is to illustrate the spectrum of imaging findings with photographic and histopathologic correlation in patients with biopsy-proven nephrogenic systemic fibrosis (NSF).

CONCLUSION

Features of NSF may be evident on the patient's skin as well as on routine imaging studies, although these imaging findings are nonspecific and are more likely to occur with other diseases.

Nephrogenic systemic fibrosis and management of high-risk patients

The purpose of this work is to provide current information on the rapidly evolving subject of nephrogenic systemic fibrosis (NSF), to establish the radiologic approach to the management of high-risk patients for NSF, and to assess the probabilistic risk of NSF compared to contrast induced nephropathy (CIN), as encountered with iodinated contrast media used in computed tomographic (CT) imaging. NSF is a disease process of considerable concern following gadolinium-containing contrast agents (GCCA) exposure in patients with diminished renal function. To minimize the possibility of NSF development in high-risk patients, GGCAs should not be used when they are not necessary, or the GCCAs, that have not at present been associated with NSF development, should be used at the lowest possible diagnostic dose, when they are necessary. Contrast-induced nephropathy is also a great risk in this patient population following the adminstration of iodinated contrast media (CM). In patients with diminished renal function who are not on regular dialysis, the risk of CIN following the administration of iodinated CM is higher than the risk of NSF following the administration of the most stable GCCAs. Risk benefit analysis should be performed prior to the administration of all CM, and the best combination of safety and diagnostic accuracy should be sought. Concern of NSF or CIN should not prevent the use of contrast agents in magnetic resonance imaging or computed tomography when they are deemed essential.

Assessment of adverse reaction rates to a newly approved MRI contrast agent: review of 23,553 administrations of gadobenate dimeglumine

OBJECTIVE

With the introduction of a newly approved MR contrast agent across a health care system encompassing 13 hospitals and associated imaging centers, the opportunity arose to compare the rates of adverse reactions in seven of these facilities with reactions reported in the literature. Data were collected to assess the relative risk of using gadobenate dimeglumine compared with published data for other approved agents and for this agent in preclinical testing.

SUBJECTS AND METHODS

As part of regular quality assurance procedures, technologists recorded contrast administrations and related adverse reactions, including the type of reaction and treatments rendered, on log sheets. All data were reviewed weekly by the institutional director of MR services and were evaluated globally and by site.

RESULTS

Over 13 months, 23,553 doses of gadobenate dimeglumine were administered. One hundred seventy-eight reactions were recorded (0.76% of contrast-enhanced examinations), of which 22 required treatment (13% of reactions) and eight (5% of reactions) qualified as serious.

CONCLUSION

With the introduction of the most recent MR contrast agent approved for use in the United States, our interest in its substantial potential clinical benefits that would result from its increased relaxivity was balanced by concern that the rate of adverse effects may increase. This concern has been ameliorated with the findings of rates of adverse reactions that are comparable to those published for other MR contrast agents.

Update on nephrogenic systemic fibrosis

Gadolinium-based contrast agents were for many years considered safe, but this is no longer the case. The least stable agents may trigger the development of nephrogenic systemic fibrosis (NSF), a generalized fibrotic disorder, in renal failure patients. The use of gadodiamide and gadopentetate dimeglumine is now contraindicated in Europe and Japan in patients who have a glomerular filtration rate less than 30 mL/min/1.73 m(2), including those on dialysis. The fear of NSF, however, should not lead to an enhanced MR imaging examination being denied when there is a good clinical indication to give a gadolinium-based contrast agent.

Nephrogenic systemic fibrosis: a report of 29 cases

OBJECTIVE

The purpose of this study was to determine the incidence of nephrogenic systemic fibrosis and its relation to renal failure and the administration of gadolinium-based contrast material at an academic medical center.

MATERIALS AND METHODS

A dermatopathology database was searched to identify patients in whom nephrogenic systemic fibrosis was diagnosed. The medical records of these patients were reviewed. Renal function concurrent with any administration of gadolinium-based contrast material was assessed, as was patient outcome. A database of patients undergoing long-term dialysis was reviewed separately to determine how many had received gadolinium and the frequency of nephrogenic systemic fibrosis among these patients.

RESULTS

Twenty-nine patients were found to have had nephrogenic systemic fibrosis between November 15, 1999, and December 31, 2006. It was known that gadolinium-based contrast material had been administered to 25 of these patients before diagnosis. All 29 patients had compromised renal function (27 had chronic renal failure, and two had acute renal failure). Determination of the temporal relation between gadolinium-based contrast administration and symptom onset often was difficult. Only eight patients had severe morbidity. Nephrogenic systemic fibrosis developed in 12 (2.9%) of 414 patients undergoing long-term dialysis who received gadolinium-based contrast material.

CONCLUSION

We confirm the strong association between nephrogenic systemic fibrosis and gadolinium-based contrast administration. Although the use of high doses of gadolinium and the occurrence of chronic renal failure have been implicated in other reports, several of our patients received standard doses of gadolinium, and two had transient acute renal failure before diagnosis. Most patients had mild or moderate symptoms. Nephrogenic systemic fibrosis developed in 2.9% of patients undergoing long-term dialysis who received gadolinium-based contrast material but in none of the long-term dialysis patients who did not receive gadolinium-based contrast material.

Extracellular gadolinium-based contrast media: an overview

Increasing use is made of extracellular MRI contrast agents that alter the image contrast following intravenous administration; they predominantly shorten the T1 relaxation time of tissues. The degree and location of these changes provide substantial diagnostic information. However gadolinium-based contrast agents (Gd-CA) are not inert drugs. They may cause acute non-renal adverse reactions (e.g. anaphylactoid reactions), acute renal adverse reactions (e.g. contrast induced nephropathy), delayed adverse reactions (nephrogenic systemic fibrosis) and problems at the site of injection (e.g. local necrosis). This review describes the current status of Gd-CA, their mechanism of action, chemical structure, pharmacokinetics, dosage, elimination, nephrotoxicity and adverse events.

Extracellular Gd-CA: differences in prevalence of NSF

Until recently it was believed that extracellular gadolinium-based contrast agents were safe for both the kidneys and all other organs within the dose range up to 0.3 mmol/kg body weight. However, in 2006, it was demonstrated that some gadolinium-based contrast agents may trig the development of nephrogenic systemic fibrosis, a generalized fibrotic disorder, in renal failure patients. As no prospective studies can be performed we must rely on retrospective data. From those data it is obvious that the prevalence of NSF is significantly higher after the unstable agent gadodiamide than after any other gadolinium-based agent (3-7% versus 0-1% per injection) in patients with reduced renal function. Prevalence after exposure to two gadodiamide injections is as high as 36% in patients with chronic kidney disease (CKD) stage 5. No report of NSF after the most stable agents has been reported in the peer-reviewed literature documenting that there is a difference between the various agents regarding triggering NSF.

MRI contrast media are used to improve visualization of abnormal structures or lesions in various parts of the body. Introduction

Until recently it was believed that extracellular gadolinium based contrast agents (Gd-CA) were safe for both the kidneys and all other organs within the dose range up to 0.3mmol/kg body weight. However, in 2006, it was demonstrated that some Gd-CA may trig the development of nephrogenic systemic fibrosis, a generalized fibrotic disorder, in renal failure patients. This sub-section of European Journal of Radiology covers the current knowledge about NSF from many aspects. The prevention of NSF must be given high priority, but it should not lead to a denial of a well-justified, enhanced MRI examination with a stable agent.

A serial dilution study of gadolinium-based MR imaging contrast agents

BACKGROUND AND PURPOSE

With the approval of gadobenate dimeglumine, higher relaxivity MR contrast agents were introduced into the clinical environment, and multiple in vivo studies compared the efficacy and safety with the previously approved agents. An in vitro study was conducted to demonstrate differences between the various agents to confirm published values and for imaging-sequence optimization.

MATERIALS AND METHODS

A contrast phantom was made with serial dilutions of commercially available formulations of 5 US Food and Drug Administration-approved gadolinium-based MR imaging contrast agents in human serum substitute. Dilution factors ranging from 1:8 to 1:4096 were included in the phantom. Spin-echo sequences were performed at 1.5T and 3T with varying TRs and TEs.

RESULTS

At physiologic concentrations and by using short TRs and TEs, gadobenate demonstrated the highest signal intensities, confirming greater R1 relaxivity. At higher concentrations and with longer TR and TE values, the greatest signal intensity loss was appreciated for gadobenate, confirming greater R2 relaxivity.

CONCLUSION

Using rigorous in vitro methodology and serial dilution techniques, this study confirms the reported higher R1 and R2 relaxivities of gadobenate relative to the other agents at 1.5T and 3T.

What nephrologists need to know about gadolinium

Gadolinium chelates are commonly used to improve tissue contrast in MRI. Until recently the use of gadolinium was thought to be risk-free compared with alternative contrast agents. Recent studies, however, have raised serious concerns regarding the safety of gadolinium chelates. Although safe in patients with normal kidney function, administration of these agents in people with renal dysfunction can result in up to three clinical problems that the nephrologist should be familiar with. The first is nephrogenic systemic fibrosis (NSF), which was initially observed in 1997. Although manifesting primarily in skin, NSF can also cause systemic fibrosis, leading to disabling contractures and even death. Gadodiamide is the agent that has been most frequently associated with NSF, but other chelates might also pose a risk. The second clinical problem is that gadolinium chelates cause acute kidney injury, especially at high doses required for angiography. The third problem is that several laboratory artifacts are associated with gadolinium administration, with pseudohypocalcemia being the most important. The risk of a patient experiencing all three of these complications increases as renal function declines. In light of these problems, nephrologists need to re-evaluate the risks and benefits of gadolinium administration in patients with chronic kidney disease stage 3 or greater, as well as in those with acute kidney injury.