Analysis of Factors Influencing Accuracy of Volume Flow Measurement in Dialysis Access Fistulas Based on Duplex Ultrasound Simulation
| Autor: | Mark D. Anderson, Florence H. Sheehan, Alberto Aliseda, R. Eugene Zierler, Daniel F. Leotta, Kurt Sansom |
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| Rok vydání: | 2019 |
| Předmět: |
medicine.medical_specialty
Fistula Transducers Duplex (telecommunications) Manikins Upper Extremity Dialysis access Arteriovenous Shunt Surgical Predictive Value of Tests Renal Dialysis medicine Humans Computer Simulation Ultrasonography Doppler Color Observer Variation business.industry Medical simulation Ultrasound Models Cardiovascular Reproducibility of Results General Medicine medicine.disease Volumetric flow rate Regional Blood Flow Hydrodynamics Surgery Cardiology and Cardiovascular Medicine business Blood Flow Velocity Biomedical engineering |
| Zdroj: | Vascular and endovascular surgery. 53(7) |
| ISSN: | 1938-9116 |
| Popis: | Objective:We developed a duplex ultrasound simulator and used it to assess accuracy of volume flow measurements in dialysis access fistula (DAF) models.Methods:The simulator consists of a mannequin, computer, and mock transducer. Each case is built from a patient’s B-mode images that are used to create a 3-dimensional surface model of the DAF. Computational fluid dynamics is used to determine blood flow velocities based on model vessel geometry. The simulator displays real-time B-mode and color-flow images, and Doppler spectral waveforms are generated according to user-defined settings. Accuracy was assessed by scanning each case and measuring volume flow in the inflow artery and outflow vein for comparison with true volume flow values.Results:Four examiners made 96 volume flow measurements on four DAF models. Measured volume flow deviated from the true value by 35 ± 36%. Mean absolute deviation from true volume flow was lower for arteries than veins (22 ± 19%, N = 48 vs. 58 ± 33%, N = 48, p < 0.0001). This finding is attributed to eccentricity of outflow veins which resulted in underestimating true cross-sectional area. Regression analysis indicated that error in measuring cross-sectional area was a predictor of error in volume flow measurement (β = 0.948, p < 0.001). Volume flow error was reduced from 35 ± 36% to 9 ± 8% ( p < 0.000001) by calculating vessel area as an ellipse.Conclusions:Duplex volume flow measurements are based on a circular vessel shape. DAF inflow arteries are circular, but outflow veins can be elliptical. Simulation-based analysis showed that error in measuring volume flow is mainly due to assumption of a circular vessel. |
| Databáze: | OpenAIRE |
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