INTRODUCTION The aim of this study was to determine access recirculation in functioning catheters in the regular and reversed positions. MATERIALS AND METHODS Access recirculation was measured in 2 sequential hemodialysis sessions in patients with functioning internal jugular catheters inserted not earlier than 2 weeks before the study. The arterial and venous lines were in their regular posi...

In the framework of chaotic scattering we analyze passive tracer transport in finite systems. In particular, we study models with open streamlines and a finite number of recirculation zones. In the non trivial case with a small number of recirculation zones a description by mean of asymptotic quantities (such as the eddy diffusivity) is not appropriate. The non asymptotic properties of dispersi...

BACKGROUND AND PURPOSE Secondary-progressive MS is characterized by reduced acute inflammation and contrast enhancement but with increased axonal degeneration and cognitive/clinical disability that worsens with advanced disease. Relative recirculation, extracted from DSC is a surrogate measure of BBB integrity. We hypothesized that normal-appearing white matter relative recirculation is reduced...

Introduction By using the Dynamic Susceptibility Contrast (DSC) method for MR perfusion imaging, relative cerebral blood volume maps are obtained from integrating the first pass area of the local tissue concentration time curve CT(t). However, because of relatively high heart rate and fast circulation in small animal experiments, CT peak changes quickly and results in only few data points for q...

BACKGROUND Recirculation (R) and access blood flow (Qac) measurements are considered useful indicators of adequate delivery of haemodialysis. It was the purpose of this study to compare measurements of R and Qac obtained by two different techniques which are based on the same principle of indicator dilution, but which differ because of the characteristics of the injection and detection of the d...

BACKGROUND The presence of arterio-venous (A-V) fistula recirculation among hemodialysis (HD) patients markedly decrease adequacy of dialysis. OBJECTIVES The present article summarize some of observations about clinical significance, causes, the most common techniques for measurement, and main source of pitfall in calculation of access recirculation. MATERIALS AND METHODS A variety of liter...

Many practical applications exploit an external local magnetic field – magnetic obstacle – as an essential part of their construction. Recently, Votyakov et al. (2007) have demonstrated that the flow of an electrically conducting fluid influenced by an external field can show several kinds of recirculation. The present paper reports a 3D numerical study whose some results are compared with an e...