Scimitar Syndrome in an Asymptomatic Adult: Fortuitous Diagnosis by Imaging Technique

Congenital cardiopathies in adults are a rare clinical entity in the cardiology consultations. Advances in imaging techniques allow the fortuitous diagnosis of mild forms of these congenital abnormalities. We describe a case of an asymptomatic 41-year-old man, with a medical history of recurrent pneumonia during childhood and an established diagnosis of scimitar syndrome by computed tomography.

Whole-genome sequences of influenza A(H3N2) viruses isolated from Brazilian patients with mild illness during the 2014 season

The influenza A(H3N2) virus has circulated worldwide for almost five decades and is the dominant subtype in most seasonal influenza epidemics, as occurred in the 2014 season in South America. In this study we evaluate five whole genome sequences of influenza A(H3N2) viruses detected in patients with mild illness collected from January-March 2014. To sequence the genomes, a new generation sequencing (NGS) protocol was performed using the Ion Torrent PGM platform. In addition to analysing the common genes, haemagglutinin, neuraminidase and matrix, our work also comprised internal genes. This was the first report of a whole genome analysis with Brazilian influenza A(H3N2) samples. Considerable amino acid variability was encountered in all gene segments, demonstrating the importance of studying the internal genes. NGS of whole genomes in this study will facilitate deeper virus characterisation, contributing to the improvement of influenza strain surveillance in Brazil.

Full-genome sequences of hepatitis B virus subgenotype D3 isolates from the Brazilian Amazon Region

The Brazilian Amazon Region is a highly endemic area for hepatitis B virus (HBV). However, little is known regarding the genetic variability of the strains circulating in this geographical region. Here, we describe the first full-length genomes of HBV isolated in the Brazilian Amazon Region; these genomes are also the first complete HBV subgenotype D3 genomes reported for Brazil. The genomes of the five Brazilian isolates were all 3,182 base pairs in length and the isolates were classified as belonging to subgenotype D3, subtypes ayw2 (n = 3) and ayw3 (n = 2). Phylogenetic analysis suggested that the Brazilian sequences are not likely to be closely related to European D3 sequences. Such results will contribute to further epidemiological and evolutionary studies of HBV.

SLAM using an Imaging Sonar for Partially Structured Underwater Environments

In this paper we describe a system for underwater navigation with AUVs in partially structured environments, such as dams, ports or marine platforms. An imaging sonar is used to obtain information about the location of planar structures present in such environments. This information is incorporated into a feature-based SLAM algorithm in a two step process: (I) the full 360deg sonar scan is undistorted (to compensate for vehicle motion), thresholded and segmented to determine which measurements correspond to planar environment features and which should be ignored; and (2) SLAM proceeds once the data association is obtained: both the vehicle motion and the measurements whose correct association has been previously determined are incorporated in the SLAM algorithm. This two step delayed SLAM process allows to robustly determine the feature and vehicle locations in the presence of large amounts of spurious or unrelated measurements that might correspond to boats, rocks, etc. Preliminary experiments show the viability of the proposed approach

Draft genome sequences of three NDM-1-producing Enterobacteriaceae species isolated from Brazil

The emergence of multidrug-resistant Enterobacteriaceae strains producing carbapenemases, such as NDM-1, has become a major public health issue due to a high dissemination capacity and limited treatment options. Here we describe the draft genome of three NDM-1-producing isolates: Providencia rettgeri(CCBH11880), Enterobacter hormaecheisubsp. oharae(CCBH10892) and Klebsiella pneumoniae(CCBH13327), isolated in Brazil. BesidesblaNDM-1, resistance genes to aminoglycosides [aadA1, aadA2,aac(6’)-Ib-cr] and quinolones (qnrA1,qnrB4) were observed which contributed to the multidrug resistance profile. The element ISAba125 was found associated to theblaNDM-1 gene in all strains.

Effect of length and location of heterologous sequences on RecA-mediated strand exchange.

We systematically investigated the effect of heterology on RecA-mediated strand exchange between double-stranded linear and single-stranded circular DNA. Strand exchange took place through heterologies of up to 150-200 base pairs when the insertion was at the proximal (initiating) end of the duplex DNA but was completely blocked by an insert of only 22 base pairs placed at the distal end of the duplex. In the case of medial heterology created by insertion either in the duplex or the single-stranded DNA, the ability of RecA to exchange strands decreased as the heterology was shifted toward the distal end of the duplex. These results suggest that two different strand exchange mechanisms operate in the proximal and distal portions of the duplex substrate.

Free-breathing renal magnetic resonance angiography with steady-state free-precession and slab-selective spin inversion combined with radial k-space sampling and water-selective excitation.

The impact of radial k-space sampling and water-selective excitation on a novel navigator-gated cardiac-triggered slab-selective inversion prepared 3D steady-state free-precession (SSFP) renal MR angiography (MRA) sequence was investigated. Renal MRA was performed on a 1.5-T MR system using three inversion prepared SSFP approaches: Cartesian (TR/TE: 5.7/2.8 ms, FA: 85 degrees), radial (TR/TE: 5.5/2.7 ms, FA: 85 degrees) SSFP, and radial SSFP combined with water-selective excitation (TR/TE: 9.9/4.9 ms, FA: 85 degrees). Radial data acquisition lead to significantly reduced motion artifacts (P < 0.05). SNR and CNR were best using Cartesian SSFP (P < 0.05). Vessel sharpness and vessel length were comparable in all sequences. The addition of a water-selective excitation could not improve image quality. In conclusion, radial k-space sampling reduces motion artifacts significantly in slab-selective inversion prepared renal MRA, while SNR and CNR are decreased. The addition of water-selective excitation could not improve the lower CNR in radial scanning.

Coronary MR imaging using free-breathing 3D steady-state free precession with radial k-space sampling.

PURPOSE: To investigate the potential of free-breathing 3D steady-state free precession (SSFP) imaging with radial k-space sampling for coronary MR-angiography (MRA), coronary projection MR-angiography and coronary vessel wall imaging. MATERIALS AND METHODS: A navigator-gated free-breathing T2-prepared 3D SSFP sequence (TR = 6.1 ms, TE = 3.0 ms, flip angle = 120 degrees, field-of-view = 360 mm(2)) with radial k-space sampling (384 radials) was implemented for coronary MRA. For projection coronary MRA, this sequence was combined with a 2D selective aortic spin tagging pulse. Coronary vessel wall imaging was performed using a high-resolution inversion-recovery black-blood 3D radial SSFP sequence (384 radials, TR = 5.3 ms, TE = 2.7 ms, flip angle = 55 degrees, reconstructed resolution 0.35 x 0.35 x 1.2 mm(3)) and a local re-inversion pulse. Six healthy volunteers (two for each sequence) were investigated. Motion artifact level was assessed by two radiologists. Results: In coronary MRA, the coronary lumen was displayed with a high signal and high contrast to the surrounding lumen. Projection coronary MRA demonstrated selective visualization of the coronary lumen while surrounding tissue was almost completely suppressed. In coronary vessel wall imaging, the vessel wall was displayed with a high signal when compared to the blood pool and the surrounding tissue. No visible motion artifacts were seen. Conclusion: 3D radial SSFP imaging enables coronary MRA, coronary projection MRA and coronary vessel wall imaging with a low motion artifact level.

Diffusion spectrum magnetic resonance imaging (DSI) tractography of crossing fibers.

MRI tractography is the mapping of neural fiber pathways based on diffusion MRI of tissue diffusion anisotropy. Tractography based on diffusion tensor imaging (DTI) cannot directly image multiple fiber orientations within a single voxel. To address this limitation, diffusion spectrum MRI (DSI) and related methods were developed to image complex distributions of intravoxel fiber orientation. Here we demonstrate that tractography based on DSI has the capacity to image crossing fibers in neural tissue. DSI was performed in formalin-fixed brains of adult macaque and in the brains of healthy human subjects. Fiber tract solutions were constructed by a streamline procedure, following directions of maximum diffusion at every point, and analyzed in an interactive visualization environment (TrackVis). We report that DSI tractography accurately shows the known anatomic fiber crossings in optic chiasm, centrum semiovale, and brainstem; fiber intersections in gray matter, including cerebellar folia and the caudate nucleus; and radial fiber architecture in cerebral cortex. In contrast, none of these examples of fiber crossing and complex structure was identified by DTI analysis of the same data sets. These findings indicate that DSI tractography is able to image crossing fibers in neural tissue, an essential step toward non-invasive imaging of connectional neuroanatomy.

Assessment of melanocytic skin lesions with a high-definition laser Doppler imaging system.

BACKGROUND: Early detection is a major goal in the management of malignant melanoma. Besides clinical assessment many noninvasive technologies such as dermoscopy, digital dermoscopy and in vivo laser scanner microscopy are used as additional methods. Herein we tested a system to assess lesional perfusion as a tool for early melanoma detection.¦METHODS: Laser Doppler flow (FluxExplorer) and mole analyser (MA) score (FotoFinder) were applied to histologically verified melanocytic nevi (33) and malignant melanomas (12).¦RESULTS: Mean perfusion and MA scores were significantly increased in melanoma compared to nevi. However, applying an empirically determined threshold of 16% perfusion increase only 42% of the melanomas fulfilled the criterion of malignancy, whereas with the mole analyzer score 82% of the melanomas fulfilled the criterion of malignancy.¦CONCLUSION: Laser Doppler imaging is a highly sensitive technology to assess skin and skin tumor perfusion in vivo. Although mean perfusion is higher in melanomas compared to nevi the high numbers of false negative results hamper the use of this technology for early melanoma detection.

Imagerie cardiaque non invasive: apport spécifique en clinique des nouvelles modalités (I). Evaluation morphologique [Cardiac imaging: specific clinical role of newly developed non invasive techniques. Part 1: Morphological evaluation].

Echocardiography is the preferred initial test to assess cardiac morphology and ventricular function. Cardiac MRI enables an optimal visualisation of heart muscle without contrast injection, and precise measurement of the ventricular volumes and systolic function. It is therefore an ideal test for patients with poor echocardiographic windows or for the specific evaluation of right heart chambers. Heart CT also remarkably images heart muscle and precisely measures ventricular systolic function after intravenous injection of iodinated contrast. Coronary CT may also, in selected cases, avoid the need for diagnostic coronary angiography. Although very accurate, these imaging modalities are expensive and may be contra-indicated for a particular patient. Their use in clinical practice has to follow the accepted guidelines.

A Monte Carlo method for accelerating the computation of animated radiosity sequences

Realistic rendering animation is known to be an expensive processing task when physically-based global illumination methods are used in order to improve illumination details. This paper presents an acceleration technique to compute animations in radiosity environments. The technique is based on an interpolated approach that exploits temporal coherence in radiosity. A fast global Monte Carlo pre-processing step is introduced to the whole computation of the animated sequence to select important frames. These are fully computed and used as a base for the interpolation of all the sequence. The approach is completely view-independent. Once the illumination is computed, it can be visualized by any animated camera. Results present significant high speed-ups showing that the technique could be an interesting alternative to deterministic methods for computing non-interactive radiosity animations for moderately complex scenarios

Detailed 3D seismic imaging of a fault zone beneath Lake Geneva, Switzerland

An efficient high-resolution (HR) three-dimensional (3D) seismic reflection system for small-scale targets in lacustrine settings was developed. In Lake Geneva, near the city of Lausanne, Switzerland, the offshore extension of a complex fault zone well mapped on land was chosen for testing our system. A preliminary two-dimensional seismic survey indicated structures that include a thin (<40 m) layer of subhorizontal Quaternary sediments that unconformably overlie south-east-dipping Tertiary Molasse beds and a major fault zone (Paudeze Fault Zone) that separates Plateau and Subalpine Molasse (SM) units. A 3D survey was conducted over this test site using a newly developed three-streamer system. It provided high-quality data with a penetration to depths of 300 m below the water bottom of non-aliased signal for dips up to 30degrees and with a maximum vertical resolution of 1.1 m. The data were subjected to a conventional 3D processing sequence that included post-stack time migration. Tests with 3D pre-stack depth migration showed that such techniques can be applied to HR seismic surveys. Delineation of several horizons and fault surfaces reveals the potential for small-scale geologic and tectonic interpretation in three dimensions. Five major seismic facies and their detailed 3D geometries can be distinguished. Three fault surfaces and the top of a molasse surface were mapped in 3D. Analysis of the geometry of these surfaces and their relative orientation suggests that pre-existing structures within the Plateau Molasse (PM) unit influenced later faulting between the Plateau and SM. In particular, a change in strike of the PM bed dip may indicate a fold formed by a regional stress regime, the orientation of which was different from the one responsible for the creation of the Paudeze Fault Zone. This structure might have later influenced the local stress regime and caused the curved shape of the Paudeze Fault in our surveyed area.

A New Imaging Software To Evaluate The Centration Of Capsulorhexis And Intraocular Lens (IOL) After Cataract Surgery

Purpose: IOL centration and stability after cataract surgery is of high interest for cataract surgeons and IOL-producing companies. We present a new imaging software to evaluate the centration of the rhexis and the centration of the IOL after cataract surgery.Methods: We developed, in collaboration with the Biomedical Imaging Group (BIG), EPFL, Lausanne, a new working tool in order to assess precisely outcomes after IOL-implantation, such as ideal capsulorhexis and IOL-centration. The software is a plug-in of ImageJ, a general-purpose image processing and image-analysis package. The specifications of this software are: evaluation of the rhexis-centration and evaluation the position of the IOL in the posterior chamber. The end points are to analyze the quality of the centration of a rhexis after cataract surgery, the deformation of the rhexis with capsular bag retraction and the centration of the IOL after implantation.Results: This software delivers tools to interactively measure the distances between limbus, IOL and capsulorhexis and its changes over time. The user is invited to adjust nodes of three radial curves for the limbus, rhexis and the optic of the IOL. The radial distances of the curves are computed to evaluate the IOL implantation. The user is also able to define patterns for ideal capsulorhexis and optimal IOL-centration. We are going to present examples of calculations after cataract surgery.Conclusions: Evaluation of the centration of the rhexis and of the IOL after cataract surgery is an important end point for optimal IOL implantation after cataract surgery. Especially multifocal or accommodative lenses need a precise position in the bag with a good stability over time. This software is able to evaluate these parameters just after the surgery but also its changes over time. The results of these evaluations can lead to an optimizing of surgical procedures and materials.

131I/123I-metaiodobenzylguanidine (mIBG) scintigraphy: procedure guidelines for tumour imaging.

The aim of this document is to provide general information about mIBG scintigraphy in cancer patients. The guidelines describe the mIBG scintigraphy protocol currently used in clinical routine, but do not include all existing procedures for neuroendocrine tumours. The guidelines should therefore not be taken as exclusive of other nuclear medicine modalities that can be used to obtain comparable results. It is important to remember that the resources and facilities available for patient care may vary from one country to another and from one medical institution to another. The present guidelines have been prepared for nuclear medicine physicians and intend to offer assistance in optimizing the diagnostic information that can currently be obtained from mIBG scintigraphy. The corresponding guidelines of the Society of Nuclear Medicine (SNM) and the Dosimetry, Therapy and Paediatric Committee of the EANM have been taken into consideration, and partially integrated into this text. The same has been done with the most relevant literature on this topic, and the final result has been discussed within a group of distinguished experts.