Gadolinium-based Contrast Media and the Development of Nephrogenic Systemic Fibrosis in Patients with Renal Insufficiency

Benefits and problems of transarterial therapy in patients with hepatocellular carcinoma and chronic kidney disease

PURPOSE

To evaluate the feasibility of transarterial therapy (transcatheter arterial chemoembolization and transcatheter arterial infusion) for patients with hepatocellular carcinoma and chronic kidney disease (CKD).

MATERIALS AND METHODS

The study enrolled 35 patients who received transarterial therapy. The patients were classified into a CKD group (n = 10 nondialysis chronic kidney disease [NDCKD] and n = 9 end-stage renal disease [ESRD]) or a non-CKD group (n = 16). The survival rates between the two groups were compared using two different starting points: (a) from initial diagnosis of hepatocellular carcinoma and (b) from enrollment in the study. The tolerance of transarterial therapy in patients with CKD was evaluated by comparing the incidence of major adverse events.

RESULTS

The 2-year and 5-year survival rates from initial diagnosis were 83.9% and 53.8% in the CKD group and 70.1% and 40.4% in the non-CKD group (P = .478). The corresponding 3-year survival rate from enrollment in the two groups was 25.6% and 41.2%, respectively (P = .995). The 2-year and 5-year survival rates from initial diagnosis were 70.1% and 40.4% in the non-CKD group, 90.0% and 39.4% in NDCKD patients, and 76.2% and 76.2% in ESRD patients (P = .380). The corresponding 2-year survival rates from enrollment in these groups were 54.9%, 48.0%, and 48.6% (P = .943). Severe contrast-induced nephropathy (n = 3) and late-onset death caused by cholesterol crystal embolism (n = 1) were observed in the NDCKD group.

CONCLUSIONS

Transcatheter arterial chemoembolization is feasible in patients with CKD by instituting periprocedural hemodialysis with similar 2-year and 5-year survival compared with patients without CKD.

Application of fullerenes in nanomedicine: an update

Fullerenes are carbon spheres presently being pursued globally for a wide range of applications in nanomedicine. These molecules have unique electronic properties that make them attractive candidates for diagnostic, therapeutic and theranostic applications. Herein, the latest research is discussed on developing fullerene-based therapeutics as antioxidants for inflammatory diseases, their potential as antiviral/bacterial agents, utility as a drug delivery device and the promise of endohedral fullerenes as new MRI contrast agents. The recent discovery that certain fullerene derivatives can stabilize immune effector cells to prevent or inhibit the release of proinflammatory mediators makes them potential candidates for several diseases such as asthma, arthritis and multiple sclerosis. Gadolinium-containing endohedral fullerenes are being pursued as diagnostic MRI contrast agents for several diseases. Finally, a new class of fullerene-based theranostics has been developed, which combine therapeutic and diagnostic capabilities to specifically detect and kill cancer cells.

Heterogeneous staining in the liver parenchyma after the injection of perflubutane microbubble contrast agent

This study aimed to characterize the features of heterogeneous staining in the liver after injection of perflubutane microbubble agent (Sonazoid(TM), 0.0075 mL/kg). Digitized hepatic contrast sonograms from 906 subjects were reviewed to assess time-related changes in heterogeneous staining and the possible association between this effect and the clinical backgrounds was analyzed. Heterogeneous staining was found in seven subjects (0.77%) on 15-min phase sonograms. The staining initially appeared as hyper-enhanced circular spots in the liver 10 min or later after the agent injection. The number of spots increased gradually with unequally-spaced distribution. Although the staining pattern did not improve during the examination, there were no abnormal findings in vital signs or symptoms on the day and blood test results or sonograms on the following day. Heterogeneous staining is a side effect that impedes ultrasound examination. However, at present, the precise causes and underlying mechanisms of this event are unknown.

Current problems and future opportunities of abdominal magnetic resonance imaging at higher field strengths

Introduction of high-field-strength whole-body MR scanners to clinical routine made abdominal magnetic resonance (MR) imaging widely available. Higher field strength provides improved signal yield, but other issues such as shorter wavelength and increased power deposition of radiofrequency in tissue must also be taken into account. This review describes current problems and future opportunities of abdominal MR imaging at 3.0 T under special consideration of relevant physical properties and technical challenges: impact of higher field strength on signal-to-noise ratio, Larmor frequency, and chemical shift effects are elucidated in detail. Furthermore, changes in longitudinal and transverse relaxation times as well as increased susceptibility effects at 3.0 T are reported. General safety issues and limitations in radiofrequency power deposition are discussed. Subsequently, implications of the previously mentioned changed MR properties at 3.0 T on clinical abdominal examinations applying different sequence types are described.

ECG-gated nonenhanced 3D steady-state free precession MR angiography in assessment of transplant renal arteries: comparison with DSA

PURPOSE

To evaluate noncontrast material-enhanced steady-state free precession (SSFP) magnetic resonance (MR) angiography in the assessment of transplant renal arteries (RAs) by using digital subtraction angiography (DSA) as the reference standard.

MATERIALS AND METHODS

This prospective study was approved by the institutional review board; written informed consent was obtained from all participants. In 20 renal allograft recipients scheduled for DSA, the transplant RAs were assessed with electrocardiographically gated nonenhanced SSFP MR angiography performed at 1.5 T; the degree of stenosis was compared with that of DSA. Subjective image quality for SSFP MR angiography was assessed independently by two radiologists on a four-point scale (from 1, nondiagnostic to 4, excellent) in four predefined segments (I, the iliac artery; II, the main transplant artery; III, segmental branches; and IV, parenchymal branches). Sensitivity, specificity, and accuracy of SSFP MR angiography for the detection of relevant (> or =50%) transplant RA stenosis (TRAS) were calculated on a per-artery basis.

RESULTS

One patient was excluded because SSFP MR angiography failed to adequately visualize the allograft vasculature owing to low cardiac output. The mean image quality assessed by both readers was 3.98 +/- 0.16 (standard deviation), 3.5 +/- 0.68, 2.71 +/- 1.12 and 2.03 +/- 1.09 for segments I, II, III, and IV, respectively (kappa = 0.80). DSA helped identify eight relevant (> or =50%) stenoses in six transplant RAs. Kinking of the transplant artery without relevant stenosis was found in seven patients. The degree of stenosis was overestimated in three patients by using SSFP MR angiography. As compared with DSA, the sensitivity, specificity, and accuracy of SSFP MR angiography to help detect relevant TRAS were 100% (six of six), 88% (14 of 16), and 91% (20 of 22), respectively.

CONCLUSION

Nonenhanced SSFP MR angiography is a reliable alternative imaging technique for the assessment of transplant RAs in patients for whom contrast-enhanced MR angiography is contraindicated.

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.

The value of contrast administration in the MRI evaluation of scoliosis in the pediatric population

The aim of this study was to analyze the added utility of contrast administration for spine MRI in children with scoliosis. A retrospective review of 663 consecutive contrast-enhanced spine MRI performed in 319 patients as part of the work up of scoliosis in children 2-18 years with clinically suspected or known scoliosis over a seven year period. Those patients with known tumors (13 patients) being evaluated for scoliosis were excluded from the study. In 306 patients with scoliosis and no history of tumor pathologic contrast enhancement was seen in seven (2%) patients. Lack of enhancement helped to characterize benign lesions in 31 (10%) of the patients. Although MRI is often recommended to exclude intraspinal pathology in pediatric patients with scoliosis, the need for contrast enhanced imaging is very limited and contrast medium should not be administered unless questionable pathology is detected on noncontrast MR spine imaging.

Prevalence of nephrogenic systemic fibrosis in renal insufficiency patients: results of the FINEST study

PURPOSE

Nephrogenic systemic fibrosis (NSF) is characterized by widespread tissue fibrosis, mainly affecting the skin. Gadolinium chelates have been implicated in the onset of NSF in patients with renal impairment (RI). The FINEST study (FIbrose Néphrogénique SysTémique) was designed to determine the prevalence of NSF after magnetic resonance imaging (MRI) in French RI patients.

MATERIALS AND METHODS

We studied all patients with RI who had at least one MRI examination during a one-year period, with or without gadolinium chelate administration. Data were collected retrospectively from 9 Nephrology Departments in France, and included sex, age, renal function, type of gadolinium administered, and subsequent cutaneous disorders. If a patient presented a cutaneous disorder, a skin biopsy was performed to confirm the diagnostic.

RESULTS

The 308 eligible patients had a mean age of 59.9 years, 59% were men, and 54% had stage 5 RI. 75% of those 308 patients received a Gadolinium chelate. Among those patients who received a gadolinium chelate, 76% received gadoterate, 20% gadopentetate, 3% gadodiamide and 1% gadobenate. No cutaneous disorders were recorded after MRI.

CONCLUSION

These results confirm that NSF is a rare disease. Based on a reported frequency, approximately 3.5% in patients with glomerular filtration rate <30ml/min/1.73m(2)), some cases should have been observed in our study which included 308 patients. Most patients received gadoterate, a macrocyclic gadolinium chelate for which no case of NSF has been observed worldwide. This suggests that more stable macrocyclic agents may be less likely to induce NSF.

Gadolinium-based contrast agents and nephrogenic systemic fibrosis: a systematic review and meta-analysis

BACKGROUND

In the past decade, more than 200 cases of nephrogenic systemic fibrosis (NSF) have been identified, primarily among patients with advanced kidney disease. Multiple studies have suggested an association between gadolinium-based contrast agents (GBCAs) and NSF. We performed a systematic review and meta-analysis to examine this potential association.

METHODS

A systematic review of studies examining the association between any GBCA and NSF was performed. A search for controlled studies was conducted in MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials. If controlled data for a GBCA was not available, we searched for case reports and series. Relevant data were extracted and meta-analyses were performed.

RESULTS

Seven of 144 identified studies met inclusion criteria; gadodiamide was the sole or predominant GBCA in four of these; one study exclusively examined gadopentetate. Other GBCAs were not specifically examined in controlled or uncontrolled studies. Meta-analysis of controlled trials demonstrated a significant association between GBCA exposure and NSF [odds ratio (OR) 26.7; 95% confidence interval (CI) 10.3-69.4] and gadodiamide and NSF (OR 20.0; 95% CI 3.7-107.8). Examination of the evidence using established criteria suggested that this association was causal.

CONCLUSIONS

The current state of evidence suggests an association and potentially causal link between the use of GBCAs and the development of NSF among patients with advanced kidney disease. Additional study is warranted to clarify the potential association of GBCAs other than gadodiamide with NSF.

Incidence of nephrogenic systemic fibrosis at two large medical centers

PURPOSE

To determine the incidence and associated risk factors of nephrogenic systemic fibrosis (NSF) in patients who undergo gadolinium-based contrast agent (GBCA)-enhanced magnetic resonance (MR) imaging.

MATERIALS AND METHODS

Institutional review board approval was obtained for retrospective review of the medical records from two hospitals to identify all cases of biopsy-confirmed NSF and all patients administered a GBCA from January 1, 1997, to June 30, 2007. Informed patient consent was not required. The incidence of NSF was calculated for patients who received a standard dose of GBCA, patients who received a high dose, and subgroups of patients with renal impairment.

RESULTS

Fifteen patients developed NSF after gadolinium-enhanced MR imaging. All of them had an estimated glomerular filtration rate (eGFR) lower than 30 mL/min, and 11 had acute renal failure or acute deterioration of chronic renal failure. The incidence of NSF after gadolinium-enhanced MR imaging without screening for renal function was zero of 74,124 patients with the standard dose of GBCA and 15 (0.17%) of 8997 patients with the high dose (P < .001). The NSF incidence associated with a high dose of GBCA increased to 0.4% in patients in a chronic hemodialysis program and to 8.8% in those who had an eGFR lower than 15 mL/min but were not undergoing hemodialysis (P < .001). The NSF incidence in the patients with acute renal failure who received a high dose when their creatinine level was increasing was 19% (11 of 58 patients) when hemodialysis was delayed for longer than 2 days. More patients with NSF had proinflammatory events, and compared with patients without NSF, these patients had lower pH, younger age, lower eGFR, elevated serum phosphorus levels, and a longer delay between GBCA injection and hemodialysis.

CONCLUSION

For patients with an eGFR lower than 15 mL/min, hemodialysis helped to prevent NSF. For patients with an eGFR lower than 30 mL/min who received a high dose of GBCA, acute renal failure, delayed hemodialysis after contrast agent injection, proinflammatory events, and hyperphosphatemia were associated with increased risk of NSF.

Safety and utility of uterine artery embolization with CO2 and a gadolinium-based contrast medium

The authors evaluated the safety and clinical outcomes of uterine artery embolization (UAE) without the use of conventional iodinated contrast media for symptomatic uterine leiomyomata. Patients underwent UAE with use of CO(2) gas and a gadolinium-based contrast medium. The safety and feasibility of the technique were assessed. Patients were followed up at 24 hours, 1 month, and 6 months after UAE and yearly thereafter. UAE without iodinated contrast medium was attempted in eight patients (mean age, 42.7 years +/- 4.1), and bilateral UAE was successful in all patients. The mean fluoroscopy time was 14.9 minutes. The mean amount of gadolinium-based contrast medium used was 30.6 mL or 0.181 mmol/kg. No major complications were noted. The mean improvement in the symptom severity score was 53.8. The mean reduction in leiomyoma volume was 42%. To date, no repeat interventions have been performed. UAE with CO(2) and a gadolinium-based contrast medium is a viable treatment option for patients with a severe allergy to iodinated contrast media or renal insufficiency.

[Nephrogenic systemic fibrosis]

A scleromyxedema-like disease was recognized in 1997. In 2000 this disorder was first published and termed nephrogenic fibrosing dermopathy because all patients had advanced renal failure. In 2006 it was discovered that the patients had a history of a preceding contrast-enhanced magnetic resonance imaging (MRI). All patients had acute or chronic severe renal insufficiency with a glomerular filtration rate (GFR) <30 ml/min per 1.73 m(2). So far a total of about 215 patients with this new skin disorder have been reported to international registries. The skin thickening has a typical histology and begins in the peripheral extremities and progresses proximally, including also the abdominal wall and the head in some patients. NSF involves not only the skin, but also the muscles and other organs (e.g., lungs, heart, eyes) in some patients. Therefore the term nephrogenic systemic fibrosis (NSF) was introduced. Skin fibrosis and sclerosis are usually progressive with disabling contractures of involved joints (knees, hands, feet). NSF may be lethal in up to 28% of patients. Spontaneous remissions are rare. No generally accepted treatment is available. So far, the pathogenesis is not well understood. One hypothesis supposes a role of gadolinium liberated from the contrast agents. As patients with acute or chronic advanced renal failure (GFR <30 ml/min per 1.73 m(2)) including those with hepatorenal dysfunctions are at high risk to develop NSF after exposure to gadolinium-based contrast agents, contrast-enhanced MRI should be avoided in this group and alternative diagnostic procedures should be used whenever possible.

Advances in vascular imaging

Advances in vascular surgery have mirrored advances in diagnostic imaging. Indeed, the endovascular revolution has been made possible largely by advances in computed tomography, magnetic resonance imaging, and vascular ultrasound. As technology allows better noninvasive vascular diagnosis, conventional angiography, once the gold standard for the diagnosis of vascular disease, is now reserved largely for intervention. This article discusses the current state of vascular imaging. Specific emphasis is placed on the comparative clinical utility of different imaging modalities in the detection and management of vascular disease.

Aneurysm Sac pressure measurement with minimally invasive implantable pressure sensors: an alternative to current surveillance regimes after EVAR?

Current protocols for surveillance after endovascular repair (EVAR) of abdominal aortic aneurysms are mostly based on costly and time-consuming imaging procedures and aim to detect adverse events such as graft migration, endoleaks or aneurysm sac enlargement. These imaging procedures are either associated with radiation exposure to the patients or may be harmful to the patient due to the use of iodine- or gadolinium-containing contrast agents. Furthermore the advantages of EVAR in the short term might be negated by the necessity for endograft surveillance over years. Thus, alternative modalities for follow-up are being investigated. One of these technologies provides pressure information directly from the aneurysm sac. This noninvasive, telemetric pressure sensing was tested in vitro as well as in first clinical trials and was able to identify successful aneurysm exclusion after EVAR. The telemetric pressure sensors showed a promising efficacy and accuracy in detecting type I and type III endoleaks and will help to clarify the clinical relevance of type II endoleaks. This article provides an overview of the in vitro sensors investigated as well as the first clinical trials and the sensors' potential to change the current endograft surveillance regimes.

MR angiography at 3 T for assessment of the external carotid artery system

OBJECTIVE

A number of clinical situations exist in which high-resolution depiction of the external carotid artery system is required, a task not previously addressed by MR angiography. The purpose of this study was to evaluate the extent to which high-spatial-resolution MR angiography at 3 T can be used to map the normal external carotid artery system.

SUBJECTS AND METHODS

Twenty-three consenting adult patients were prospectively evaluated. Images acquired were evaluated by two independent observers, and each branch vessel was scored with regard to image quality, presence and grade of stenoses, and artifacts. Interobserver agreement regarding image quality and the presence and degree of stenosis was tested using the kappa coefficient. Differences in quality ratings between the two observers were assessed using the paired Student's t test.

RESULTS

Of 828 vessels analyzed, 92.63% were designated of diagnostic quality with no significant difference between the observers' image quality scores (p = 0.63). Good agreement was determined regarding image quality achieved (kappa = 0.716). All examinations were free of artifact sufficient to interfere with confident interpretation. Excellent correlation was seen with regard to stenosis detection and grading (kappa = 0.857). Of the external carotid artery systems assessed, 82.6% showed conventional anatomic vascular branching.

CONCLUSION

High-spatial-resolution, 3D contrast-enhanced MR angiography at 3 T using sagittal source data acquisition and an advanced acceleration factor of 6 allows high-quality (92.63% of arterial segments) visualization of the external carotid artery system, with complete head and neck vascular coverage.

Nephrogene systemische Fibrose

Nephrogenic systemic fibrosis is a new disease entity which was first described in 2000. It is characterized by dermal and visceral fibrosis in patients with impaired renal function. Recently, the etiology of this disease has been unveiled. The application of gadolinium-containing contrast media in patients with decreased renal function can lead to gadolinium deposition in various tissues which induces the fibrotic process. Numerous publications within the last few months have supported this hypothesis and have led to recommendations by the health authorities to carefully weigh the benefits and risks of using gadolinium in patients with impaired renal function.

Accuracy and utility of three-dimensional contrast-enhanced magnetic resonance angiography in planning carotid stenting

BACKGROUND

Contrast-enhanced magnetic resonance angiography (CE-MRA) is a proven diagnostic tool for the evaluation of carotid stenosis; however, its utility in planning carotid artery stenting (CAS) has not been addressed. This study assessed the accuracy of three-dimensional CE-MRA as a noninvasive screening tool, compared with digital subtraction angiography (DSA), for evaluating carotid and arch morphology before CAS.

METHODS

In a series of 96 CAS procedures during a 2-year period, CE-MRAs and DSAs with complete visualization from the aortic arch to the intracranial circulation were obtained before CAS in 60 patients. Four additional patients, initially considered potential candidates for CAS, were also evaluated with CE-MRA and DSA. The two-by-two table method, receiver operating characteristic curve, and Bland-Altman analyses were used to characterize the ability of CE-MRA to discriminate carotid and arch anatomy, suitability for CAS, and degree of carotid stenosis.

RESULTS

The sensitivity and specificity of CE-MRA were, respectively, 100% and 100% to determine CAS suitability, 87% and 100% to define aortic arch type, 93% and 100% to determine severe carotid tortuosity, and 75% and 98% to detect ulcerated plaques. CE-MRA had 87% sensitivity and 100% specificity for the detection of carotid stenosis >/=80%. The accuracy of CE MRA to determine optimal imaging angles and stent and embolic protection device sizes was >90%. The operative technique for CAS was altered because of the findings of preoperative CE-MRA in 22 procedures (38%). The most frequent change in the operative plan was the use of the telescoping technique in 11 cases (18%). CAS was aborted in four patients (5%) due to unfavorable anatomy identified on CE-MRA, including prohibitive internal carotid artery tortuosity (n = 1), long string sign of the internal carotid artery (n = 2), and concomitant intracranial disease (n = 1). Among patients considered suitable for CAS by CE-MRA, technical success was 100%, and the 30-day stroke/death rate was 1.6%.

CONCLUSIONS

Contrast-enhanced magnetic resonance angiography of the arch and carotid arteries is accurate in determining suitability for CAS and may alter the operative technique. Certain anatomic contraindications for CAS may be detected without DSA. Although CE-MRA is less accurate to estimate the degree of stenosis, it can accurately predict imaging angles, and stent and embolic protection device size, which may facilitate safe and expeditious CAS.

[Nephrogenic systemic fibrosis and gadolinium-based contrast media]

Nephrogenic systemic fibrosis (NSF) is a recently characterized systemic fibrosing disorder occurring in patients with underlying renal disease. This condition principally leads to skin thickening and hardening and may induce joint immobility and inability to walk. In 2006, clusters of NSF were associated to an exposure to gadolinium containing contrast agents during magnetic resonance imaging. Gadolinium has been detected in skin tissue of patients with NSF. Gadodiamide, a linear gadolinium chelate appears to be particularly at risk. During renal failure, gadodiamide accumulation may explain the development of NSF. Regulatory decisions have been taken to contraindicate gadodiamide in patients with severe renal impairment.