[Nephrogenic systemic fibrosis].
ABSTRACT 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.
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ABSTRACT: Als Schnittbildverfahren erlaubt die Magnetresonanztomographie (MRT) eine dreidimensionale Darstellung von Muskulatur, Bändern, Sehnen, Kapsel, Synovialis und Kochen in hochauflösender Qualität. Durch die Applikation von Kontrastmittel (Gadolinium-DTPA) ist ferner eine Aktivitätsbeurteilung möglich und dadurch die Differenzierung zwischen aktiven und chronisch entzündlichen Veränderungen. Der Nachweis des Knochenmarködems in der MRT bei Patienten mit rheumatoider Arthritis (RA) kann als Prognosefaktor für die Entwicklung von Erosionen gedeutet werden. Aufgrund dieser Vorteile wird die MRT immer mehr zur Frühdiagnostik von entzündlichen Gelenkerkrankungen eingesetzt. Semiquantitative Scores zur Auswertung und Befundgraduierung sind bereits entwickelt worden und im klinischen Einsatz. Da MRT-Untersuchungstechniken stabil reproduzierbar sind, können sie für die in der Rheumatologie so relevanten Verlaufsuntersuchungen praktikabel abgerufen werden. Therapieansprechen oder Progression können somit adäquat abgebildet werden. Dedizierte Niederfeld-MRT-Geräte mit einer Feldstärke von 0,2Tesla (T) sind seit Anfang der 90er Jahre bekannt und stellen inzwischen für die Rheumatologie eine neue Untersuchungsoption dar. Kleinere, offene Geräte mit niedrigeren Anschaffungs- und Unterhaltkosten, sowie ein – durch das Gerät selbst bedingt – deutlich besserer Komfort und damit höhere Akzeptanz durch den Patienten einerseits, als auch eine zunehmend bessere Datenlage der Niederfeld-MRT bei RA andererseits, unterstreichen den zunehmenden Stellenwert dieser bildgebenden Methode. Die Deutsche Gesellschaft für Rheumatologie (DGRh), vertreten durch die Kommission „Bildgebende Verfahren“, trägt dieser Entwicklung in der Verfassung von Empfehlungen und Standards für die Durchführung der Niederfeld-MRT und deren Beurteilung Rechnung und fasst die wichtigsten Informationen zur Technik, sowie zu den klinischen Indikationen zusammen. Magnetic resonance imaging (MRI) as a cross-sectional imaging procedure allows a three-dimensional representation of musculature, ligaments, tendons, capsules, synovial membranes, bones and cartilage with high resolution quality. An activity assessment is further possible by application of a contrast medium (gadolinium-DTPA) to differentiate between active and chronic inflammatory processes. Evidence of a bone marrow edema detected by MRI in patients with rheumatoid arthritis (RA) can be interpreted as a prognostic and predictive factor for the development of bone erosions. On the basis of these advantages MRI is being employed more and more in the early diagnosis of inflammatory joint diseases. Semi-quantitative scores for analysis and grading of findings have already been developed and are in clinical use. Because MRI technical performances are invariably reproducible they can be practically retrieved in the course of examination which is particularly relevant in rheumatology. Therapy response or progression can thus be adequately displayed. Open, dedicated low-field MRI with a low signal strength of 0.2 Tesla (T) has been known since the 90s and now represents new MRI examination options in rheumatology. Smaller devices with lower acquisition and maintenance expenses as well as considerably more convenience due to the device itself result in a higher subjective acceptability by the patients as well as objectively more data records of low-field MRI scans of RA, which underline the significance of this new technical method. The German Society for Rheumatology (DGRh), represented by the Committee for “Diagnostic Imaging”, meets this development with the release of recommendations and standards for the procedures of low-field MRI and their scoring and summarizes the most important technical data and information on clinical indications.Zeitschrift für Rheumatologie 69(1):79-86. · 0.45 Impact Factor
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ABSTRACT: Nephrogenic Systemic Fibrosis is a rare condition appearing only in patients with severe renal impairment or failure and presents with dermal lesions and involvement of internal organs. Although many cases are mild, an estimated 5% have a progressive debilitating course. To date, there is no known effective treatment thus stressing the necessity of ample prevention measures. An association with the use of Gadolinium based contrast agents (GBCA) makes Nephrogenic Systemic Fibrosis a potential side effect of contrast enhanced magnetic resonance imaging and offers the opportunity for prevention by limiting use of gadolinium based contrast agents in renal failure patients. In itself toxic, Gadolinium is embedded into chelates that allow its safe use as a contrast agent. One NSF theory is that Gadolinium chelates distribute into the extracellular fluid compartment and set Gadolinium ions free, depending on multiple factors among which the duration of chelates exposure is directly related to the renal function. Major medical societies both in Europe and in North America have developed guidelines for the usage of GBCA. Since the establishment of these guidelines and the increased general awareness of this condition, the occurrence of NSF has been nearly eliminated. Giving an overview over the current knowledge of NSF pathobiochemistry, pathogenesis and treatment options this review focuses on the guidelines of the European Medicines Agency, the European Society of Urogenital Radiology, the FDA and the American College of Radiology from 2008 up to 2011 and the transfer of this knowledge into every day practice.Journal of Cardiovascular Magnetic Resonance 05/2012; 14:31. · 4.44 Impact Factor
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ABSTRACT: OBJECTIVES: To assess the benefit of quantitative computed tomography (CT) perfusion for differentiating acute tubular necrosis (ATN) and acute rejection (AR) in kidney allografts. METHODS: Twenty-two patients with acute kidney allograft dysfunction caused by either AR (n = 6) or ATN (n = 16) were retrospectively included in the study. All patients initially underwent a multiphase CT angiography (CTA) protocol (12 phases, one phase every 3.5 s) covering the whole graft to exclude acute postoperative complications. Multiphase CT dataset and dedicated software were used to calculate renal blood flow. Renal biopsy or clinical course of disease served as the standard of reference. Mean effective radiation dose and mean amount of contrast media were calculated. RESULTS: Renal blood flow values were significantly lower (P = 0.001) in allografts undergoing AR (48.3 ± 21 ml/100 ml/min) compared with those with ATN (77.5 ± 21 ml/100 ml/min). No significant difference (P = 0.71) was observed regarding creatinine level with 5.65 ± 3.1 mg/dl in AR and 5.3 ± 1.9 mg/dl in ATN. The mean effective radiation dose of the CT perfusion protocol was 13.6 ± 5.2 mSv; the mean amount of contrast media applied was 34.5 ± 5.1 ml. All examinations were performed without complications. CONCLUSION: CT perfusion of kidney allografts may help to differentiate between ATN and rejection. KEY POINTS: • Quantitative CT perfusion of renal transplants is feasible. • CT perfusion could help to non-invasively differentiate AR from ATN. • CT perfusion might make some renal biopsies unnecessary.European Radiology 05/2013; · 4.34 Impact Factor