Non-uniform polar tagging

Non-uniform polar tagging

Background CMR tagging in polar patterns is desirable because of its close compatibility to the annular geometry and motion of the left ventricle in short axis view. This circular symmetry does not exist in some pathological cases neither in the normal long axis view. An oval-shaped pattern is more suitable for assessment of the deformation in these conditions. Herein, we present the non-unifor...

Polar HARP for the polar CMR tagging

Background The polar coordinate system adapts best to the morphology of the heart. The recently developed sequences that allow the CMR Tagging in the circular and radial directions facilitate the calculation and presentation of the myocardium mechanics. Development of the corresponding processing methods is required to further enhance the utilization of these sequences. Here we suggest a proces...

Non-uniform PSC occurrence within the Arctic polar vortex

A multi-year dataset of lidar measurements of polar stratospheric clouds (PSCs) from two sites in the Arctic (Sodankylä, 67°N, 27°E, and Ny-Ålesund, 79°N, 12°E) has been analyzed with respect to the existence temperature of different PSC types. Due to the location of the measurement sites relative to the polar vortex, their observations are most of the time representative of vortex edge and vor...

Uniform Polar Quantization

Multiproduct Uniform Polar Quantizer

The aim of this paper is to reduce the complexity of the unrestricted uniform polar quantizer (UUPQ), keeping its high performances. To achieve this, in this paper we propose the multiproduct uniform polar quantizer (MUPQ), where several consecutive magnitude levels are joined in segments and within each segment the uniform product quantization is performed (i.e. all levels within one segments ...