Marie-France Bellin

Contrast induced nephropathy: updated ESUR Contrast Media Safety Committee guidelines

AbstractPurposeThe Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 1999 guidelines on contrast medium-induced nephropathy (CIN).Areas coveredTopics reviewed include the definition of CIN, the choice of contrast medium, the prophylactic measures used to reduce the incidence of CIN, and the management of patients receiving metformin.n Key Points• Definition, risk factors and prevention of contrast medium induced nephropathy are reviewed.• CIN risk is lower with intravenous than intra-arterial iodinated contrast medium.• eGFR of 45xa0ml/min/1.73xa0m2is CIN risk threshold for intravenous contrast medium.• Hydration with either saline or sodium bicarbonate reduces CIN incidence.• Patients with eGFR ≥60xa0ml/min/1.73xa0m2receiving contrast medium can continue metformin normally.

Nephrogenic systemic fibrosis and gadolinium-based contrast media: updated ESUR Contrast Medium Safety Committee guidelines

AbstractPurposeTo update the guidelines of the Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) on nephrogenic systemic fibrosis and gadolinium-based contrast media.Areas coveredTopics reviewed include the history, clinical features and prevalence of nephrogenic systemic fibrosis and the current understanding of its pathophysiology. The risk factors for NSF are discussed and prophylactic measures are recommended. The stability of the different gadolinium-based contrast media and the potential long-term effects of gadolinium in the body have also been reviewed.Key Points• Clinical features, risk factors and prevention of nephrogenic systemic fibrosis are reviewedn • Patients with GFR below 30xa0ml/min/1.73xa0m2have increased risk of developing NSFn • Low stability gadolinium contrast media show the strongest association with NSFn • Following guidelines regarding gadolinium contrast agents minimises the risk of NSFn • Potential long-term harm from gadolinium accumulation in the body is discussed

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.

Helical CT evaluation of the chemical composition of urinary tract calculi with a discriminant analysis of CT-attenuation values and density

The aim of this study was to evaluate the efficacy of helical CT using a combination of CT-attenuation values and visual assessment of stone density as well as discriminant linear analysis to predict the chemical composition of urinary calculi. One hundred human urinary calculi were obtained from a stone-analysis laboratory and placed in 20 excised pig kidneys. They were scanned at 80, 120 and 140xa0kV with 3-mm collimation. Average, highest and lowest CT-attenuation values and CT variability were recorded. The internal calculus structure was assessed using a wide window setting, and visual assessment of stone density was recorded. A stepwise discriminant linear analysis was performed. The following three variables were discriminant: highest CT-attenuation value, visual density, and highest CT-attenuation value/area ratio, all at 80xa0kV. The probability of correctly classifying stone composition with these three variables was 0.64, ranging from 0.54 for mixed calculi to 0.69 for pure calculi. The probabilities of correctly classifying calculus composition were: 0.91 for calcium oxalate monohydrate and brushite, 0.89 for cystine, 0.85 for uric acid, 0.11 for calcium oxalate dihydrate, 0.10 for hydroxyapatite, and 0.07 for struvite calculi. When the first two ranks of highest probability for the accurate classification of each calculus type were taken into account, 81% of the calculi were correctly classified. Assessment at 80xa0kV of the highest CT-attenuation value, visual density and the highest CT-attenuation value/area ratio accurately predicts the chemical composition of 64–81% of urinary calculi. When the first two ranks of highest probability for the accurate classification of each calculus type were taken into account, all cystine, calcium oxalate monohydrate and brushite calculi were correctly classified.

Contrast medium extravasation injury: guidelines for prevention and management.

Abstract. Extravasation of contrast material is a well-recognized complication of contrast-enhanced imaging studies. The management of this complication is contentious; therefore, the Contrast Media Safety Committee of The European Society of Urogenital Radiology decided to review the literature and issue guidelines. A comprehensive literature search was carried out. The resulting report was discussed at the 8th European Symposium on Urogenital Radiology in Genoa, Italy. Automated power injection may result in extravasation of large volumes and may or can lead to severe tissue damage. Infants, young children and unconscious and debilitated patients are particularly at risk of extravasation during contrast media injection. Fortunately, most extravasations result in minimal swelling or erythema, with no long-term sequelae; however, severe skin necrosis and ulceration may occur. Large volumes of high osmolar contrast media are known to induce significant tissue damage. Compartment syndrome may be seen associated with extravasation of large volumes. Conservative management is often adequate, but in serious cases the advice of a plastic surgeon is recommended. Based on the review simple guidelines for prophylaxis and management of contrast medium extravasation injuries are proposed.

Iron oxide-enhanced MR lymphography : initial experience

The detection of nodal metastases is of utmost importance in oncologic imaging. Ultrasmall superparamagnetic iron oxide particles (USPIO) are novel contrast agents specifically developed for MR lymphography. After intravenous administration, they are taken up by the macrophages of the lymph nodes, where they accumulate. They reduce the signal intensity (SI) of normally functioning nodes on postcontrast T2-and T2*-weighted images through the magnetic susceptibility effects on iron oxide. Metastatic nodes, in which macrophages are replaced by tumor cells, show no significant change in SI on postcontrast T2-and T2*-weighted images. Early clinical experience suggests that USPIO-enhanced MR lymphography improves the sensitivity and specificity for the detection of nodal metastases. It also suggests that micrometastases could be detected in normal-sized nodes. This article reviews the physiochemical properties of USPIO contrast agents, their enhancement patterns, and early clinical experience.

CT diagnosis of ureteral fibroepithelial polyps

We report a case of fibroepithelial polyp of the ureter with serial CT examinations. Progressive growth of the fibroepithelial polyp was documented by CT within a period of 62xa0months. Excretory phase contrast-enhanced CT images accurately contributed to the diagnosis of ureteral fibroepithelial polyp and allowed limited surgical resection. Accurate imaging assessment of ureteral fibroepithelial polyps is essential for a conservative surgical approach and/or observation alone.

Non-invasive detection of liver fibrosis: Is superparamagnetic iron oxide particle-enhanced MR imaging a contributive technique?

Abstract. The purpose of our study was to evaluate the ability of superparamagnetic iron oxide (SPIO)-enhanced MR imaging to detect liver fibrosis in patients with chronic liver disease and to compare the findings with histopathological data. Sixty-seven patients with chronic hepatitis (n=58) or focal nodular hyperplasia (FNH; n=9) were studied using a 1.5-T MR system. The protocol included proton density-weighted, T2-weighted spin-echo (SE) and fast SE (FSE) sequences before and after SPIO administration and T2*-weighted gradient-recalled-echo (GRE) sequences after SPIO. Pre- and post-contrast T2-weighted and T2*-weighted sequences were retrospectively evaluated by three independent observers for evidence of non-tumor hypersignal intensities. Three liver patterns were considered: thick reticulations; thin reticulations; and/or multiple areas of hypersignal intensities. Unenhanced or enhanced patterns were compared with histopathological specimens, which had been obtained by percutaneous biopsy of the right lobe within a maximum of 12xa0months of MR examination. Liver fibrosis was histologically graded using a five-level scale (F0–F4), according to the METAVIR classification. Histopathology demonstrated significant fibrosis (F2–F4) in 57 patients, non-significant fibrosis in 1 patient (F1), and normal liver surrounding FNH in 9 patients (F0). After SPIO administration, at least one pattern of non-tumor hypersignal intensities was seen in 43 (76%) of the 57 patients with F≥2 with good agreement (kappa=0.68) compared with 2 (20%) of the 10 F0/1 patients (p<0.01). Attenuated non-homogeneous liver-signal intensities with persistent thick reticulations, thin reticulations, or multiple areas of hypersignals were observed in, respectively, 30, 52, and 56% of patients with F≥2 with moderate agreement (kappa=0.51). Before SPIO, MR images were positive in 21 of 57 (37%) F≥2 and zero F0/1 patients. Post-contrast proton-density-weighted and T2*-weighted GRE were the most sensitive sequences for detecting non-tumor hypersignal intensities. In patients with chronic liver diseases, SPIO-enhanced MR imaging exhibits non-tumor hypersignal intensities indicative of liver fibrosis by decreasing the signal from the non-fibrotic areas where Kupffer cells are present.

Safety of MR liver specific contrast media

Over the past few years a number of magnetic resonance (MR) liver specific contrast agents have been introduced. In this report the safety issues of these agents are addressed. A literature search was carried out. Based on the available information, simple guidelines on the safety issue of liver specific contrast agents have been produced by the Contrast Media Safety Committee of the European Society of Urogenital Radiology. The report and guidelines were discussed at the 11th European Symposium on Urogenital Radiology in Santiago de Compostela. Liver specific contrast agents appear in general to be safe and well tolerated. However, the incidence of adverse reactions with iron oxides and the intravenous manganese based agent seems to be slightly higher than with gadolinium based agents. However, no safety information from comparative clinical trials has been published. Guidelines on the safety aspects are presented.

Comparison of 1.0 M gadobutrol and 0.5 M gadopentetate dimeglumine-enhanced magnetic resonance imaging in five hundred seventy-two patients with known or suspected liver lesions: results of a multicenter, double-blind, interindividual, randomized clinical phase-III trial

Objective:To evaluate the diagnostic efficacy (accuracy, sensitivity, specificity) of 1.0 M gadobutrol versus 0.5 M gadopentetate for the classification of lesions as either benign or malignant in patients with known or suspected liver lesions. Methods and Materials:A multicenter, phase-III, randomized, interindividually controlled comparison study with blinded reader evaluation was performed to investigate the diagnostic efficacy of a bolus injection of 1.0 M gadobutrol compared with 0.5 M gadopentetate at a dose of 0.1 mmol Gd/kg BW. The imaging protocol included a dynamic 3D-evaluation, static conventional, and fat saturated T1-weighted sequences. MR datasets were evaluated by 3 independent radiologists. The standard of reference was defined by an independent truth panel (radiologist or hepatologist). The safety evaluation included adverse events, vital signs, and physical examination. Results:A total of 497 of 572 patients were eligible for the final efficacy analysis. Noninferiority of gadobutrol-enhanced magnetic resonance imaging (MRI) for the classification of liver lesions was demonstrated on the basis of diagnostic accuracy determined by the on-site investigators (−0.098, 0.021) as well as for the average reader of the blinded evaluation (−0.096, 0.014) (95% confidence interval), compared with the predefined standard of reference. Very similar increases in sensitivity (ranging from ∼10% to ∼55%) and specificity (ranging from ∼1%–∼18%) compared with precontrast MRI were also observed for the 2 contrast agent groups, with maximum differences of 4%.Very similar, low rates of adverse events were recorded for each of the 2 groups. No clinically relevant changes in vital signs or the results of the physical examination were observed in any patient. Conclusion:This study documents evidence for the noninferiority of a single i.v. bolus injection of 1.0 M gadobutrol (0.1 mmol/kg body weight) to 0.5 M gadopentetate (0.1 mmol/kg body weight) in the diagnostic assessment of liver lesions with contrast-enhanced MRI. The known excellent safety profile of gadobutrol was confirmed in this clinical trial and is similar to that of gadopentetate.