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Gadolinium-based contrast agents (GBCAs) have transformed magnetic resonance imaging (MRI) by facilitating the use of contrast-enhanced MRI to allow vital clinical diagnosis in a plethora of disease that would otherwise remain undetected. Although over 500 million doses have been administered worldwide, scientific research has documented the retention of gadolinium in tissues, long after exposure, and the discovery of a GBCA-associated disease termed nephrogenic systemic fibrosis, found in patients with impaired renal function. An understanding of the pharmacokinetics in humans and animals alike are pivotal to the understanding of the distribution and excretion of gadolinium and GBCAs, and ultimately their potential retention. This has been well studied in humans and more so in animals, and recently there has been a particular focus on potential toxicities associated with multiple GBCA administration. The purpose of this review is to highlight what is currently known in the literature regarding the pharmacokinetics of gadolinium in humans and animals, and any toxicity associated with GBCA use.

Microbubbles (MBs) combined with ultrasound sonothrombolysis (STL) appears to be an alternative therapeutic strategy for acute ischemic stroke (IS), but clinical results remain controversial. The aim of this systematic review is to identify the parameters tested; to assess evidence on the safety and efficacy on preclinical data on STL; and to assess the validity and publication bias. Pubmed® and Web of ScienceTM databases were systematically searched from January 1995 to April 2017 in French and English. We included studies evaluating STL on animal stroke model. This systematic review was conducted in accordance with the PRISMA guidelines. Data were extracted following a pre-defined schedule by two of the authors. The CAMARADES criteria were used for quality assessment. A narrative synthesis was conducted. Sixteen studies met the inclusion criteria. The result showed that ultrasound parameters and types of MBs were heterogeneous among studies. Numerous positive outcomes on efficacy were found, but only four studies demonstrated superiority of STL versus recombinant tissue-type plasminogen activator on clinical criteria. Data available on safety are limited. Quality assessment of the studies reviewed revealed a number of biases. Further in vivo studies are needed to demonstrate a better efficacy and safety of STL compared to currently approved therapeutic options. http://syrf.org.uk/protocols/.

Salmonella infection is an increasingly important public health problem owing to the emergence of multidrug resistance and the lack of broadly efficient vaccines. Novel strategies of vaccination are required to induce protective immune responses at mucosal surfaces and in the circulation, to limit bacteria entry and dissemination. To this aim, intranasal anti-Salmonella vaccination with an innovative formulation composed of gas-filled microbubbles and the pathogen-derived protective protein serodominant secreted effector protein B (SseB-MB) was evaluated in a mouse infection model. Intranasal application of SseB-MB induced gut and systemic immunoglobulin A, T-helper type 17 cell (Th17), and Th1 responses, all of which are associated with natural immunity against Salmonella. In vaccinated mice, a significant reduction in bacterial load was observed in intestinal tissues and the spleen after an otherwise lethal oral infection. Therefore, MB serve as an efficient carrier for nasal delivery of a Salmonella antigen that results in protection upon activation of the common mucosal immune system.

Objective To evaluate the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) in the early detection of residual tumour after radiofrequency ablation (RFA) of renal tumours. Methods Patients referred to our institution for RFA of renal tumours prospectively underwent CEUS and computed tomography (CT) or magnetic resonance imaging (MRI) before, within 1 day and 6 weeks after treatment. Identification of residual tumour was assessed by three blinded radiologists. Reference standard was CT/MRI performed at least 1 year after RFA. Results A total of 66 renal tumours in 43 patients (median age 62 years; range 44–71.5) were studied. Inter-reader agreement ( κ value) was 0.84 for CEUS. Prevalence of residual disease was 19%. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), respectively, were as follows: 64% [confidence interval (CI) 39–84], 98% [CI 91–100], 82% [CI 52–95] and 92% [CI 83–97] on 24-h CEUS; 79% [CI 52–92], 100% [CI 94–100], 100% [CI 74–100] and 95% [CI 87–100] on 6-week CEUS; 79% [CI 52–92], 95% [CI 86–98], 79% [CI 52–92] and 95% [CI 86–98] on 24-h CT/MRI; and 100% [CI 72–100], 98% [CI 90–100], 91% [CI 62–98] and 100% [CI 93–100] on 6-week CT/MRI. Conclusion CEUS has high specificity for the early diagnosis of residual tumour after renal RFA.

New ultrasound parameters, potentially predictive of tumor response to chemotherapy, were sought after analyzing details of vascular architecture of mammary tumors during chemotherapy. Tumor-bearing rats were separated into untreated or docetaxel-treated group (6 mg/kg/week). Power Doppler Index and vascular contrast-enhanced ultrasound (CEUS) reference endpoints (Peak, area under the curve (AUC), blood flow) were evaluated at the beginning ( W 0 ), and after 2 and 6 weeks of docetaxel treatment ( W +2 and W +6 ). An improved CEUS image analysis, taking advantage of individual pixel intensity, was developed to quantify large, medium, and small vessels of tumors. Standard immunohistochemistry validated this new methodology analyzing tumor vascular architecture. In rats, there was an enrichment of vascularization with large vessels during tumor growth indicative of a vascular adjustment to tumor size. Docetaxel stopped tumor growth, and showed a sequential effect on vascular parameters. After an initial enrichment in larger vessels (by threefold) at W +2 , docetaxel led to a diminution of vascular parameters at W +6 (−46 % for peak, −55 % for AUC −31 % compared to W 0 ) and a vascular remodeling in favor of small vessels. One of the CEUS parameters measured before chemotherapy, the so-called global contrast-enhanced pixels density, was predictive of rat tumor response to treatment ( r  = 0.80; p  < 0.01). The method was then applied in a clinical setting to detect changes of vascular architecture during chemotherapy of human breast carcinoma. The docetaxel chemotherapy of breast carcinomas induced a similar sequential effect, with vessel enlargement after two cycles of docetaxel treatment and an antiangiogenic effect after six cycles. Such vascular remodeling was not noticed when patients were treated with 5-fluorouracil–epirubicin–cyclophosphamide. Taken together, the sharpened analysis of CEUS pixel intensity presented here strengthened the monitoring of breast tumor vasculature with the potential to improve the prediction of docetaxel efficacy.

Myocardial infarction is frequently developed in canine and porcine models but exceptionally in non-human primates. The aim of this study was to develop a minimally invasive myocardial ischemic/reperfusion model in the monkey intended to be combined with imaging techniques, in particular myocardial contrast echocardiography (MCE). A balloon-tipped catheter was advanced via the femoral artery into the left anterior descending artery (LAD) under fluoroscopic guidance in ten anaesthetized male rhesus monkeys ( Macaca mulatta ). The balloon was inflated to completely occlude the vessel. Coronary angiography (CA) was performed to control the reality of the LAD occlusion/reperfusion. The ischemia period was followed by 3–6 h of reperfusion. Myocardial perfusion was evaluated during ischemia and at reperfusion by MCE using a novel ultrasound contrast agent (BR38). Occlusion was successfully induced during 18–50 min in nine out of the ten evaluated monkeys. ST segment elevation indicated myocardial ischemia. MCE showed complete transmural arrest of myocardial blood flow during the ischemia period and no persistent microvascular perfusion defects during reperfusion. A minimally invasive closed-chest model was successfully developed for creating myocardial ischemia in the rhesus monkey ( Macaca mulatta ). This technique could have an important role in mimicking acute coronary syndrome under physiologically and ethically-acceptable conditions. MCE provides non-invasively information on myocardial perfusion status, information not available from CA.

The aim of our study is to propose an approach for transfer function placental development using ultrasound images. This approach is based to the selection of tissues, feature extraction by discrete cosine transform DCT, discrete wavelet transform DWT and classification of different grades of placenta by artificial neural network and especially the multi layer perceptron MLP. The proposed approach is tested for ultrasound images of placenta, resulting in 75% success rate of classification using DCT and 92% using DWT. The method based on multi resolution decomposition analysis and on supervised neural network technique MLP, seems a good method to study the transfer function of placental development in ultrasound.

Significant advances have been recently introduced into various fields of technology, taking advantage of the use of new piezoelectric materials and the large diffusion of broadband transducers. Various types of modulation may be applied to the pulse characteristics, using single pulse, multipulse or multiline techniques, and resulting in improved spatial resolution and better penetration. Non-linear imaging uses the harmonics component, which is generated by tissues or by contrast agents. Different modalities can be used to separate harmonics from fundamental bands from the received signal. New Doppler modes have been developed, whereas grey-scale flow imaging allows the simultaneous imaging of blood flow and tissues. Compounding techniques improve the contrast resolution of tissues and reduce artefacts. If 3D techniques are now currently available, real-time 4D imaging has been recently introduced. Elastographic imaging is still under evaluation, but promising clinical results have been shown. Recent release of the DICOM specification has made the full integration of ultrasound to the PACS systems easier. All these advances indicate that the contribution and potential of ultrasound in patient management is still growing.