12 research outputs found
Stoichiometric Self-Assembly of Isomeric, Shape-Persistent, Supramacromolecular Bowtie and Butterfly Structures
Two novel macromolecular constitutional isomers have
been self-assembled
from previously unreported terpyridine ligands in a three-component
system. The terpyridine ligands were synthesized in high yields via
a key Suzuki coupling. Restrictions of the possible outcomes for self-assembly
ultimately provided optimum conditions for isolation of either a molecular
bowtie or its isomeric butterfly motif. These isomers have been characterized
by ESI-MS, TWIM-MS, <sup>1</sup>H NMR, and <sup>13</sup>C NMR. Notably,
these structural isomers have remarkably different drift times in
ion mobility separation, corresponding to different sizes and shapes
at high charge states
Left Ventricular Function Evaluation on a 3T MR Scanner with Parallel RF Transmission Technique: Prospective Comparison of Cine Sequences Acquired before and after Gadolinium Injection
<div><p>Objectives</p><p>To compare cine MR b-TFE sequences acquired before and after gadolinium injection, on a 3T scanner with a parallel RF transmission technique in order to potentially improve scanning time efficiency when evaluating LV function.</p><p>Methods</p><p>25 consecutive patients scheduled for a cardiac MRI were prospectively included and had their b-TFE cine sequences acquired before and right after gadobutrol injection. Images were assessed qualitatively (overall image quality, LV edge sharpness, artifacts and LV wall motion) and quantitatively with measurement of LVEF, LV mass, and telediastolic volume and contrast-to-noise ratio (CNR) between the myocardium and the cardiac chamber. Statistical analysis was conducted using a Bayesian paradigm.</p><p>Results</p><p>No difference was found before or after injection for the LVEF, LV mass and telediastolic volume evaluations. Overall image quality and CNR were significantly lower after injection (estimated coefficient cine after > cine before gadolinium: -1.75 CI = [-3.78;-0.0305], prob(coef>0) = 0% and -0.23 CI = [-0.49;0.04], prob(coef>0) = 4%) respectively), but this decrease did not affect the visual assessment of LV wall motion (cine after > cine before gadolinium: -1.46 CI = [-4.72;1.13], prob(coef>0) = 15%).</p><p>Conclusions</p><p>In 3T cardiac MRI acquired with parallel RF transmission technique, qualitative and quantitative assessment of LV function can reliably be performed with cine sequences acquired after gadolinium injection, despite a significant decrease in the CNR and the overall image quality.</p></div
LV short axis cine b-TFE slice in the telediastolic phase before (left) and after (right) gadolinium contrast injection.
<p>LV short axis cine b-TFE slice in the telediastolic phase before (left) and after (right) gadolinium contrast injection.</p
Cohen’s Kappa with quadratic ponderation.
<p>Cohen’s Kappa with quadratic ponderation.</p
Placement of the ROIs in the left ventricular short axis before and after gadolinium injection.
<p>Placement of the ROIs in the left ventricular short axis before and after gadolinium injection.</p
Acquisition parameters of the b-TFE cine sequences in the LV short axis plane.
<p>Acquisition parameters of the b-TFE cine sequences in the LV short axis plane.</p
Results of the descriptive analysis for qualitative evaluation.
<p>Results of the descriptive analysis for qualitative evaluation.</p
Results of inferential bayesian analysis for quantitative evaluation.
<p>Results of inferential bayesian analysis for quantitative evaluation.</p