Vessel-profile comparison.

<p>Top: SWI, NLM-SWI, IR-SWI and MIR-SWI axial brain slices (from left to right respectively) in a healthy volunteer. The red lines represent the domain used to plot the in-plane profiles of the voxel intensities perpendicular to a small right frontal vein. Bottom: the comparison of the corresponding in-plane profiles of the SWI (green line), NLM-SWI (yellow line), IR-SWI (cyan line) and MIR-SWI (dotted red line) voxel intensities shows that MIR-SWI, IR-SWI and NLM-SWI schemes enhance the SNR of the parenchyma (depicted by the line plateau) compared to the SWI vessel profile, but only the MIR-SWI does not introduce a detrimental blurring between the vessel and surrounding tissues.</p

Spectroscopic Characterization of the 3+ and 2+ Oxidation States of Europium in a Macrocyclic Tetraglycinate Complex

The 3+ and 2+ oxidation states of europium have drastically different magnetic and spectroscopic properties. Electrochemical measurements are often used to probe Eu^III/II oxidation state changes, but a full suite of spectroscopic characterization is necessary to demonstrate conversion between these two oxidation states in solution. Here, we report the facile conversion of an europium­(III) tetraglycinate complex into its Eu^II analogue. We present electrochemical, luminescence, electron paramagnetic resonance, UV–visible, and NMR spectroscopic data demonstrating complete reversibility from the reduction and oxidation of the 3+ and 2+ oxidation states, respectively. The Eu^II-containing analogue has kinetic stability within the range of clinically approved Gd^III-containing complexes using an acid-catalyzed dissociation experiment. Additionally, we demonstrate that the 3+ and 2+ oxidation states provide redox-responsive behavior through chemical-exchange saturation transfer or proton relaxation, respectively. These results will be applicable to a wide range of redox-responsive contrast agents and Eu-containing complexes

Results of different denoising pipelines on SWI image generation.

<p>Axial brain mIPs (corresponding to a volume of 20 mm) at the level of the lateral ventricles of SWI-100Hz (a), SWI (b), NLM-SWI (c), IR-SWI (d), MNLM-SWI (e), MNLM-HP-SWI (f), and MIR-SWI (g) images. The number of phase mask multiplications is set to 4. Enhanced visibility of venous structures without loss of tissue contrast is evident in (g) compared to (b-f).</p

Influence of different denoising pipelines on high-pass filtered phase images.

<p>Argument of the phase mask function (somehow equivalent to high-pass filtered phase) in the following pipelines: SWI-100Hz (a), SWI (b), IR-SWI (c), MNLM-SWI (d), MNLM-HP-SWI (e) and MIR-SWI (f). The tissues outside the brain were masked in order to focus on the denoising results. The image obtained with MIR-SWI scheme shows good noise suppression while preserving brain structures compared to both MNLM-SWI and MNLM-HP-SWI images.</p

The effect of the <i><b>n</b></i> values on SWI images in subject #1.

<p>mIPs of the same targeted volume of 20 mm at varying <i>n</i> values. In reference to the SWI-100Hz image, MIR-SWI shows both satisfactory noise removal and better vessel enhancement at increasing <i>n</i> values compared to the other SWI schemes.</p

Depiction of the smooth muscle FiberArea% algorithm.

<p>Smooth muscle micrographs (200× magnification, 1260×1400 resolution) of embryonic gizzard at incubation day 14 (<b>A</b>) and incubation day 17 (<b>B</b>). Four muscle bundles are randomly chosen in each micrograph and the results of the FiberArea% algorithm are shown in right corner.</p

Bar graph of VB-CNRs at different <i>n</i> values in subject #1.

<p>VB-CNR analysis performed on the same veins of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126835#pone.0126835.g004" target="_blank">Fig 4a</a> (AS: anterior septal vein, TS: thalamostriate vein, IC: internal cerebral vein, LA: lateral atrial vein, SC: sylvian cortical vein) as they appeared in the three rightmost columns of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126835#pone.0126835.g006" target="_blank">Fig 6</a>. From each vein, the triplets of bars with the same color correspond to the images with <i>n</i> value of 6, 7 and 8, from left to right, respectively. Among the denoising schemes under evaluation, only MIR-SWI (red bars) consistently showed increased VB-CNR in all selected veins.</p

VB-CNR analysis in subject #1.

<p>SWI-100HZ axial brain mIP (a) corresponding to a volume of 20 mm shows the five venous ROIs we used for the quantitative evaluation of the MIR-SWI denoising scheme. Green lines represent the veins used for VB-CNR analysis while cyan lines are the background counterparts positioned on neighbooring tissues (anterior septal vein, AS; thalamostriate vein, TS; internal celebral vein, IC; lateral atrial vein, LA; silvian cortical vein, SC). The VB-CNR bar graph of each vein (b) shows an overall higher contrast between veins and background of the MIR-SWI (red bars) compared to the other schemes.</p

Semiquantitative visual assessment.

<p>Frequency histogram of the semiquantitative scores for the display of the brain structures of the MNLM-SWI (gray), MNLM-HP-SWI (orange), SWI (green), NLM-SWI (yellow), IR-SWI (cyan) and MIR-SWI (red) images. Score values from 1 to 5 indicate increasing overall image quality (see text).</p

The 15 Directions of DTI.

<p>The 15 Directions of DTI.</p