Flow Distributions in Hollow Fiber Hemodialyzers Using Magnetic Resonance Fourier Velocity Imaging

Zhang, Jieyi; Parker, Dennis L.; Leypoldt, John K.

doi:10.1097/00002480-199507000-00097

Cited by 46 publications

(24 citation statements)

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“…Unexpectedly, the spiral arterial port's velocity field was somewhat different from the designer's intention to uniformly distribute BF into the fiber bundle, which has complex vortices and flow directions [13] . The most striking point of this study was that we found that vortices in arterial ports negatively affect the BF in fiber bundles that could not be quantitatively described by previous studies [5][6][7] . Using hemodynamic parameters (BF, BV, and MTT), three-dimensional perfusion properties of hemodialyzers with different arterial port configurations were analyzed quantitatively.…”

Section: Discussioncontrasting

confidence: 70%

“…Agishi et al [4] collected local blood volume directly to show higher peripheral velocity, while Ronco et al [5] showed higher central BF distribution using computed tomography (CT). Other studies using magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) showed uniform BF profiles in fiber bundles [6,7] . To resolve this controversy, BF in arterial ports and hemodynamics in fiber bundles should be considered simultaneously.…”

Section: Introductionmentioning

confidence: 97%

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Effects of Arterial Port Design on Blood Flow Distribution in Hemodialyzers

Kim¹,

Kim

Sung

et al. 2009

Blood Purif

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Background/Aims: Blood flow profiles in fiber bundles depend on the design of the arterial port and affects the biocompatibility of the hemodialyzer. We analyzed the effects of arterial port design on blood flow distribution in fiber bundles using nonintrusive imaging techniques. Methods: The velocity fields in arterial ports and the hemodynamics in fiber bundles were analyzed for hemodialyzers with different configurations using particle image velocimetry and perfusion computed tomography. Results: In a hemodialyzer with standard arterial ports, high blood flow profiles in the central and peripheral regions and low blood profiles in the middle region were developed due to jet flow and vortices around the jet. In a hemodialyzer with spiral arterial ports, higher flow profiles were developed due to the central vortices that decrease perfusion into the fiber bundles. Conclusion: The arterial port design of hemodialyzers should be optimized such that jet flow and vortices do not impair dialysis efficiency and biocompatibility.

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Section: Discussioncontrasting

confidence: 70%

Section: Introductionmentioning

confidence: 97%

Effects of Arterial Port Design on Blood Flow Distribution in Hemodialyzers

Kim¹,

Kim

Sung

et al. 2009

Blood Purif

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“…T 1 and T 2 -weighted MRI has been used to determine cell distribution in coaxial hollow ®ber bioreactors (Custer, 1988;Macdonald et al, 1998), whereas Fourier velocity zeugmatographic imaging has been applied to observe Starling¯ow in conventional hollow ®ber bioreactors (Hammer et al, 1990;Donoghue et al, 1992;Zhang et al, 1995) and axial¯ow in spirally-wound bioreactors (Flendrig et al, 1997). However, this is the ®rst report of quantifying axial¯ow rates by phase±contrast velocity-encoded MRI in a radial-¯ow hollow ®ber bioreactor.…”

Section: Discussionmentioning

confidence: 99%

A novel multi‐coaxial hollow fiber bioreactor for adherent cell types. Part 1: Hydrodynamic studies

Wolfe

Hsu

Reíd

et al. 2001

Biotech & Bioengineering

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A novel multi-coaxial bioreactor for three-dimensional cultures of adherent cell types, such as liver, is described. It is composed of four tubes of increasing diameter placed one inside the other, creating four spatially isolated compartments. Liver acinar structure and physiological parameters are mimicked by sandwiching cells in the space between the two innermost semi-permeable tubes, or hollows fibers, and creating a radial flow of media from an outer compartment (ECC), through the cell mass compartment, and to an inner compartment (ICC). The outermost compartment is created by gas-permeable tubing, and the housing is used to oxygenate the perfusion media to periportal levels in the ECC. Experiments were performed using distilled water to correlate the radial flow rate (Q(r)) with (1) the pressure drop (DeltaP) between the media compartments that sandwich the cell compartment and (2) the pressure in the cell compartment (P(c)). These results were compared with the theoretical profile calculated based on the hydraulic permeability of the two innermost fibers. Phase-contrast velocity-encoded magnetic resonance imaging was used to visualize directly the axial velocities inside the bioreactor and confirm the assumptions of laminar flow and zero axial velocity at the boundaries of each compartment in the bioreactor. Axial flow rates were calculated from the magnetic resonance imaging results and were similar to the measured axial flow rates for the previously described experiments.

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“…Other authors used MRS/MRI techniques to test the performance of HFBs containing mammalian cells (Donoghue et al, 1992;Potter et al, 1998) and bioartificial livers (Macdonald et al, 1998). Others used these techniques to characterize the flow distribution in HFBs without cells (Hammer et al, 1990;Osuga et al, 1998;Zhang et al, 1995). However, to our knowledge, the only cell cultures which have been used to quantify the cellular transport of CAs by MRI are static cell cultures, such as cell pellets and cell monolayers (Aime et al, 2002;Schmalbrock et al, 2001).…”

Section: Mr-compatible Hfbmentioning

confidence: 99%

Hollow fiber bioreactor: New development for the study of contrast agent transport into hepatocytes by magnetic resonance imaging

Planchamp

Ivancevic

Pastor

et al. 2004

Biotech & Bioengineering

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The aim of our study was to develop a magnetic resonance (MR)-compatible in vitro model containing freshly isolated rat hepatocytes to study the transport of hepatobiliary contrast agents (CA) by MR imaging (MRI). We set up a perfusion system including a perfusion circuit, a heating device, an oxygenator, and a hollow fiber bioreactor (HFB). The role of the porosity and surface of the hollow fiber (HF) as well as the perfusate flow rate applied on the diffusion of CAs and O 2 was determined. Hepatocytes were isolated and injected in the extracapillary space of the HFB (4 Â 10 7 cells/mL). The hepatocyte HFB was perfused with an extracellular CA, gadopentetate dimeglumine (Gd-DTPA), and gadobenate dimeglumine (Gd-BOPTA), which also enters into hepatocytes. The HFB was imaged in the MR room using a dynamic T 1 -weighed sequence. No adsorption of CAs was detected in the perfusion system without hepatocytes. The use of a membrane with a high porosity (0.5 Am) and surface (420 cm 2 ), and a high flow rate perfusion (100 mL/min) resulted in a rapid filling of the HFB with CAs. The cellular viability of hepatocytes in the HFB was greater than 85% and the O 2 consumption was maintained over the experimental period. The kinetics of MR signal intensity (SI) clearly showed the different behavior of Gd-BOPTA that enters into hepatocytes and Gd-DTPA that remains extracellular. Thus, these results show that our newly developed in vitro model is an interesting tool to investigate the transport kinetics of hepatobiliary CAs by measuring the MR SI over time. B 2004 Wiley Periodicals, Inc.

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Flow Distributions in Hollow Fiber Hemodialyzers Using Magnetic Resonance Fourier Velocity Imaging

Cited by 46 publications

References 0 publications

Effects of Arterial Port Design on Blood Flow Distribution in Hemodialyzers

Effects of Arterial Port Design on Blood Flow Distribution in Hemodialyzers

A novel multi‐coaxial hollow fiber bioreactor for adherent cell types. Part 1: Hydrodynamic studies

Hollow fiber bioreactor: New development for the study of contrast agent transport into hepatocytes by magnetic resonance imaging

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