9%, respectively). Intraobserver reproducibility for arterial stiffness and ventriculo-arterial coupling parameters was

the highest for the beta index (+/- 3.8%), and the lowest for the second systolic peak (+/- 22.4%). Interobserver reproducibility and repeatability varied between very good for the wave speed (+/- 5.5 and +/- 4.3%), and unsatisfactory for the negative area (+/- 31.8 and +/- 38.6%). FMD had good reproducibility (intraobserver +/- 11.6%, interobserver +/- 8%, repeatability +/- 7%), whereas augmentation index had only satisfactory results (+/- 17.8, +/- 8.4, +/- 23.8%, respectively). Only some parameters of vascular function have good reproducibility and repeatability, better or similar to other ultrasound methods and, therefore, these are ready to be used in routine clinical practice.”
“Four-dimensional computed ERK inhibitor tomography (4D-CT) plays an important role in lung cancer treatment because of its capability in providing a comprehensive characterization of respiratory motion for high-precision radiation therapy. However, due to the inherent high-dose exposure associated with CT, dense sampling along superior-inferior direction is often not practical, selleck chemicals llc thus resulting in an inter-slice

thickness that is much greater than in-plane voxel resolutions. As a consequence, artifacts such as lung vessel discontinuity and partial volume effects are often observed in 4D-CT images, which may mislead dose administration in radiation therapy. In this paper, we present Selleck MK 2206 a novel patch-based technique for resolution enhancement of 4D-CT images along the superior-inferior direction. Our working premise is that anatomical information that is missing in one particular phase can be recovered from other phases. Based on this assumption, we employ a hierarchical patch-based sparse representation mechanism to enhance the superior-inferior resolution of 4D-CT by reconstructing additional intermediate CT slices. Specifically, for each spatial location on an intermediate CT slice that we intend to reconstruct, we first agglomerate a dictionary of patches from images of

all other phases in the 4D-CT. We then employ a sparse combination of patches from this dictionary, with guidance from neighboring (upper and lower) slices, to reconstruct a series of patches, which we progressively refine in a hierarchical fashion to reconstruct the final intermediate slices with significantly enhanced anatomical details. Our method was extensively evaluated using a public dataset. In all experiments, our method outperforms the conventional linear and cubic-spline interpolation methods in preserving image details and also in suppressing misleading artifacts, indicating that our proposed method can potentially be applied to better image-guided radiation therapy of lung cancer in the future.”
“Objective.