Features of nephrogenic systemic fibrosis on radiology examinations

Safety and Efficacy of A High Performance Graphene-Based Magnetic Resonance Imaging Contrast Agent for Renal Abnormalities

The etiology of renal insufficiency includes primary (e.g polycystic kidney disease) or secondary (e.g. contrast media, diabetes) causes. The regulatory restrictions placed on the use of contrast agents (CAs) for non-invasive imaging modalities such as X-ray computed tomography (CT) and magnetic resonance imaging (MRI) affects the clinical management of these patients. With the goal to develop a next-generation CA for unfettered use for renal MRI, here we report, in a rodent model of chronic kidney disease, the preclinical safety and efficacy of a novel nanoparticle CA comprising of manganese (Mn2+) ions intercalated graphene coated with dextran (hereafter called Mangradex). Nephrectomized rats received single or 5 times/week repeat (2 or 4 weeks) intravenous (IV) injections of Mangradex at two potential (low = 5 mg/kg, and high = 50 mg/kg) therapeutic doses. Histopathology results indicate that Mangradex does not elicit nephrogenic systemic fibrosis (NSF)-like indicators or questionable effects on vital organs of rodents. MRI at 7 Tesla magnetic field was performed on these rats immediately after IV injections of Mangradex at one potential therapeutic dose (25 mg/kg, [Mn2+] = 60 nmoles/kg) for 90 minutes. The results indicated significant (>100%) and sustained contrast enhancement in the kidney and renal artery at these low paramagnetic ion (Mn2+) concentration; 2 orders of magnitude lower than the paramagnetic ion concentration in a typical clinical dose of long circulating Gd3+-based MRI CA gadofosveset trisodium. The results open avenues for further development of Mangradex as a MRI CA to diagnose and monitor abnormalities in renal anatomy and vasculature.

Advantages and Limitations of Focal Liver Lesion Assessment with Ultrasound Contrast Agents: Comments on the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Guidelines

Contrast-enhanced ultrasound (CEUS) represents a significant breakthrough in sonography. Due to US contrast agents (UCAs) and contrast-specific techniques, sonography offers the potential to show enhancement of liver lesions in a similar way as contrast-enhanced cross-sectional imaging techniques. The real-time assessment of liver perfusion throughout the vascular phases, without any risk of nephrotoxicity, represents one of the major advantages that this technique offers. CEUS has led to a dramatic improvement in the diagnostic accuracy of US and subsequently has been included in current guidelines as an important step in the diagnostic workup of focal liver lesions (FLLs), resulting in a better patient management and cost-effective therapy. The purpose of this review was to provide a detailed description of contrast agents used in different cross-sectional imaging procedures for the study of FLLs, focusing on characteristics, indications and advantages of UCAs in clinical practice.

Crossed cerebellar hyperperfusion after MELAS attack followed up by whole brain continuous arterial spin labeling perfusion imaging

Crossed cerebellar hyperperfusion (CCH) is detected in patients with epilepsy by brain perfusion studies including single photon emission computed tomography and positron emission tomography. In addition, brain perfusion can be studied with arterial spin labeling (ASL), which is a non-invasive MRI perfusion method that quantitatively measures cerebral blood flow per unit tissue mass. We followed up a 47-year-old patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) by continuous arterial spin labeling technique, which showed crossed cerebellar hyperperfusion after acute stroke-like episode. This cerebellar hyperperfusion normalized in the follow-up.

Radiological considerations in von Hippel-Lindeau disease: imaging findings and the review of the literature

Background

Von Hippel Lindau disease is an autosomal dominant multisystem/multitumoral cancer disease diagnosed by clinical, radiologic and genetic findings. Its prevalence has been estimated to be of 1/36000 inhabitants. The tumours can be benign or malignant.

Case report

We represent MR findings of a family with ten children. Mother and five siblings had von Hippel-Lindau disease.

Conclusions

Radiologic imaging is very important for the early diagnosis and treatment of asymptomatic patients. Diagnosing it early is important because the tumours in von Hippel Lindau disease are treatable. Also, an early detection allows the patient’s survival and quality of life. A multidisciplinary team approach is important in screening.

Nephrogenic systemic fibrosis and its impact on abdominal imaging

The objective of this article is to review the current knowledge about nephrogenic systemic fibrosis (NSF) and how to prevent it. More than 300 cases of NSF in patients with severe chronic renal insufficiency or acute renal failure or in patients undergoing dialysis have been reported in the peer-reviewed literature, with an overwhelming majority occurring within weeks to months after injection of a gadolinium-based contrast agent (GBCA). Because administration of a high dose of a GBCA is a primary risk factor and because most high-dose magnetic resonance (MR) imaging applications involve abdominal imaging (eg, liver and abdominal MR angiography), NSF cases have been associated with abdominal MR imaging. Additional major risk factors for developing NSF include proinflammatory conditions, failure to perform dialysis promptly after GBCA administration, use of nonionic linear contrast agents, hyperphosphatemia, and younger age. Recent recommendations to use GBCAs with caution in patients with acute renal failure, patients receiving dialysis, or patients with an estimated glomerular filtration rate of less than 30 mL/min have resulted in virtually no new NSF cases being reported with onset in 2008 or 2009 in spite of a high level of awareness about this entity. In conclusion, NSF has been virtually eliminated by using caution in administering GBCAs to patients known to have severe or acute renal failure. In these patients, avoid high doses; and for patients undergoing dialysis, schedule MR imaging to occur just before a dialysis session to ensure rapid elimination of gadolinium.