Prohlížení Diplomové práce - 14116 dle předmětu "For this purpose%2Cmeasurements in vitro were carried out using plastic flow phantom with the possibility to change the rate of constant flow. Spatial resolution was also altered. To simulate non-laminar flow%2Can artificial valve was inserted into the phantom tube. The error of eddy currents effect as well as its dependence on slice orientation was subsequently measured using a static gel phantom. Examination of two pacients%2Cone with a healthy aortal valve and the other with a valve stenosis%2Cwere performed. These data were used to assess the error resulting from an under- and oversized ROI and from a temporal resolution.It was found out that the noise error %280.05%25%29 of constant flow stroke volume is neglectable compared to flow fluctuations %280.25%25%29. The partial volume effect resulted in more severe error %28%2B0.45%25%29 in the in vivo measurement. The error of eddy currents effect was not evaluated with certainty%2Cwe estimate a value of 3 %25. An undersized ROI may result in fatal underestimation of stroke volume%2Cwhereas an oversized boundary leads to an error up to 6%25. The non-laminar flow stroke volume error was of %2B8%25 in our case.The over-all error of all investigated effects combined remains below 10%25 for laminar flow. It is important to note%2Chowever%2Cthat not all possible sources of errors were examined and also that some of the erros were assessed in vitro only. Additionally%2Csome of the measured data suggest a possibly not negligible stroke volume changes dependent on pacient%27s heart rate"
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