No abstract

Objective-To examine the correlation between CT-based and radionuclide renogram-based measures of split renal function within a normal population of potential live kidney donors by use of 3D models generated from CT angiography.Materials and Methods-173 renal donor candidates were retrospectively evaluated with CT and radionuclide renogram between March 1, 2005 and February 28, 2006, of whom 152 met study inclusion criteria. A blinded investigator using 3-D models created semi-automatically from the precontrast, arterial and excretory phases made measurements of CT renal volumes and attenuations. Mean renal attenuation and volume were used to calculate the net accumulation of contrast, and split renal function for comparison with radionuclide renography. Split function from CT was calculated in the arterial and excretory phases as well as based on split renal volume and the Patlak method.Results-All four CT-based methods for the calculation of split renal function showed correlation with no significant difference from radionuclide renography (p>0.05, t test). Pearson correlations varied from 0.36 to 0.63 (p<0.001 for each). Difference scores revealed that the excretory and renal volume splits had the narrowest range, and demonstrate a linear, non-zero relationship to the renogram splits. Bland-Altman analysis confirms that the majority of difference scores between each CT method and the radionuclide renogram fall within the 95% CI of the differences.Conclusion-Split renal function based on 3D CT models can provide "one-stop" evaluation of both the anatomic and functional characteristics of the kidneys of potential live kidney donors. The excretory phase data and the split renal volume data show the best correlation and the smallest difference scores.

Managing the interference effects from multiple thin-layer structures allows for the control of optical transmittance and reflectance properties -often with very high precision. Widely used and technologically significant examples of such structures are antireflection coatings (ARCs) and distributed Bragg reflectors (DBRs), which rely on the careful control of destructive and constructive interference, respectively, between incident and reflected/transmitted radiation. While these structures have been known for over a century and have been extremely well investigated for many decades, the growing emergence of printable, large area electronics based on soluble materials brings a new emphasis. Namely the availability and use of materials in multilayer environments that are capable of transferring well-established ideas to a solution-based production.Here, we demonstrate the solution-fabrication of ARCs and all dielectric mirrors based on a DBR design utilizing alternating layers of recently developed organic/inorganic hybrid materials comprised of poly(vinyl alcohol) (PVAl), cross-linked with titanium oxide hydrates, and commercially available bulk commodity plastics. Our dip-coated ARCs exhibit an 88 % reduction in reflectance across the visible compared to uncoated glass, and fully solution-coated DBRs provide a reflection of >99 % across a 100 nm spectral band in the visible region. Detailed comparisons with transfer-matrix methods (TMM) highlight the excellent optical quality of the structures. The investigation also demonstrates the extremely low optical losses and impressive interface qualities the constituent layers exhibit. Furthermore, when exposed to elevated temperatures, the hybrid material can display a notable, reproducible and irreversible change in both the refractive index and film-thickness while maintaining excellent optical performance. In addition to allowing a degree of post-deposition tuning of the photonic structures, this may lend itself to thermo-responsive applications, including security features and product-storage environment monitoring.

No abstract

No abstract