Effects of reconstruction technique on the quality of abdominal CT angiography: A comparison between forward projected model-based iterative reconstruction solution (FIRST) and conventional reconstruction methods.

PURPOSE: This study aimed to compare the quality of abdominal CT angiography (CTA) images obtained using conventional reconstruction algorithms with those obtained using a novel iterative algorithm (forward projected model-based iterative reconstruction solution, FIRST) for evaluating arteries in the abdomen. MATERIALS AND METHODS: Abdominal CTA images from 60 patients (M:F = 27:33; mean age, 62.4 ± 16.7 years) were reconstructed using three algorithms - filtered back projection (FBP), adaptive iterative dose reduction 3D (AIDR 3D), and FIRST. Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) in the abdominal aorta, celiac trunk, superior mesenteric, renal, and right hepatic arteries were objectively evaluated via region-of-interest analysis and compared using the one-way analysis of variance test. Two radiologists independently scored and selected the best (score 3), second best (score 2), and the worst (score 1) images based on the visual image quality of peripheral arteries. Wilcoxon signed rank test was used for comparing image quality scores. RESULTS: FIRST and AIDR 3D significantly reduced image noise compared with FBP (P < 0.001). SNR and CNR were significantly higher with AIDR 3D and FIRST than with FBP reconstruction (P < 0.001), with FIRST displaying the highest CNR (14.31 ± 4.17) for the right hepatic artery than the other two methods (P < 0.05). Both radiologists scored FIRST images as having the best image quality among the three methods for peripheral abdominal artery evaluation (3.0 ± 0.0, P < 0.001). CONCLUSION: FIRST reconstruction yielded superior abdominal CTA images as compared with FBP or AIDR 3D reconstruction.

Thieno[3,4-c]phosphole-4,6-dione: A Versatile Building Block for Phosphorus-Containing Functional π-Conjugated Systems.

A versatile phosphorus-containing π-conjugated building block, thieno[3,4-c]phosphole-4,6-dione (TPHODO), has been developed. The utility of this simple but hitherto unknown building block has been demonstrated by preparing novel functional organophosphorus compounds and bandgap-tunable conjugated polymers.

Revisiting phosphorus analogues of phthalimides and naphthalimides: syntheses and comparative studies.

A series of phosphorus analogues of aromatic-fused monoimides (phthalimides and naphthalimides) bearing a mesityl group on the P center have been synthesized. In a comparison of their photophysical, electrochemical, and thermal properties with those of the corresponding imides, the impact of P incorporation was revealed. Furthermore, theoretical studies using DFT methods were conducted to understand their properties.

2,6-Diphospha-s-indacene-1,3,5,7(2 H,6 H)-tetraone: a phosphorus analogue of aromatic diimides with the minimal core exhibiting high electron-accepting ability.

Phosphorus analogues of pyrromellitic diimides (PyDIs), which represent a family of privileged electron-accepting organic compounds, have been successfully synthesized as novel electron-accepting π-conjugated molecules. Investigation into their physicochemical properties uncovered their prominent electron-accepting abilities over the corresponding PyDI. Furthermore, theoretical studies revealed the significant contribution of σ*-π* hyperconjugation in stabilizing the LUMO+1.

Structure and dynamics of a bisurea-based supramolecular polymer in n-dodecane.

The structure and dynamics of a supramolecular polymer formed by a bisurea-type compound, 2,4-bis(2-ethylhexylureido)toluene (EHUT), in an apolar solvent, n-dodecane (C12), were examined in detail. The EHUT/C12 organo-gel system forms long, dynamic chain-like supramolecular polymers, which lead to an entangled network showing remarkable viscoelastic behavior with two major relaxation modes. A slow relaxation mode with an approximately constant relaxation time, tauS, was observed in a flow region and the other, fast, relaxation mode with a time tauF1 (