Gadolinium Enhances Dual-energy Computed Tomography Scan of Pulmonary Artery

Objective To evaluate the feasibility of using gadopentetate dimeglumine(Gd-DTPA)for dual-energy computed tomography pulmonary angiography(CTPA).Methods Sixty-six patients were randomly divided into three groups and underwent CTPA.Group A had a turbo flash scan using an iohexol injection,Group B had a turbo flash scan using Gd-DTPA,and Group C had a dual-energy scan using Gd-DTPA.The original images of Group C were linearly blended with a blending factor of 0.5 or reconstructed at 40,50,60,70,80,90,100,and 110 keV,respectively.The groups were compared in terms of pulmonary artery CT value,image quality,and radiation dose.Results The pulmonary artery CT values were significantly higher in Group C40keV than in Groups B and C,but lower than in Group A.There was no significant difference in the image noise of Groups C40keV,B,and C.Moreover,Group A had the largest beam hardening artifacts of the superior vena cava(SVC),followed by Groups B and C.Group C40keV showed better vascular branching than the other three groups,among which Group B was superior to Group A.The subjective score of the image quality of Groups A,B,and C showed no significant difference,but the score was significantly higher in Group C40keV than in Groups A and B.The radiation dose was significantly lower in Group B than in Groups A and C.Conclusion Gd-CTPA is recommended to patients who are unsuitable for receiving an iodine-based CTPA.Furthermore,a turbo flash scan could surpass a dual-energy scan without consideration for virtual monoenergetic imaging.

Special kinetics features of scandium antimonide thin films conducive to swiftly embedded phase-change memory applications

Embedded phase-change random-access memory(ePCRAM)applications demand superior data retention in amorphous phase-change materials(PCMs).Traditional PCM design strategies have focused on enhancing the thermal stability of the amorphous phase,often at the expense of the crystallization speed.While this approach supports reliable microchip operations,it compromises the ability to achieve rapid responses.To address this limitation,we modified ultrafast-crystallizing Sb thin films by incorporating Sc dopants,achieving the highest 10-year retention temperature(~175℃)among binary antimonide PCMs while maintaining a sub-10-ns SET operation speed.This reconciliation of two seemingly contradictory properties arises from the unique kinetic features of the 5-nm-thick Sc12Sb88 films,which exhibit an enlarged fragile-to-strong crossover in viscosity at medium supercooled temperature zones and an incompatible sublattice ordering behavior between the Sc and Sb atoms.By tailoring the crystallization kinetics of PCMs through strategic doping and nanoscale confinement,we provide new opportunities for developing robust yet swift ePCRAMs.