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The Effect of Spatial and Temporal Resolution of Cine Phase Contrast MRI on Wall Shear Stress and Oscillatory Shear Index Assessment

View Article: PubMed Central - PubMed

ABSTRACT

Introduction: Wall shear stress (WSS) and oscillatory shear index (OSI) are associated with atherosclerotic disease. Both parameters are derived from blood velocities, which can be measured with phase-contrast MRI (PC-MRI). Limitations in spatiotemporal resolution of PC-MRI are known to affect these measurements. Our aim was to investigate the effect of spatiotemporal resolution using a carotid artery phantom.

Methods: A carotid artery phantom was connected to a flow set-up supplying pulsatile flow. MRI measurement planes were placed at the common carotid artery (CCA) and internal carotid artery (ICA). Two-dimensional PC-MRI measurements were performed with thirty different spatiotemporal resolution settings. The MRI flow measurement was validated with ultrasound probe measurements. Mean flow, peak flow, flow waveform, WSS and OSI were compared for these spatiotemporal resolutions using regression analysis. The slopes of the regression lines were reported in %/mm and %/100ms. The distribution of low and high WSS and OSI was compared between different spatiotemporal resolutions.

Results: The mean PC-MRI CCA flow (2.5±0.2mL/s) agreed with the ultrasound probe measurements (2.7±0.02mL/s). Mean flow (mL/s) depended only on spatial resolution (CCA:-13%/mm, ICA:-49%/mm). Peak flow (mL/s) depended on both spatial (CCA:-13%/mm, ICA:-17%/mm) and temporal resolution (CCA:-19%/100ms, ICA:-24%/100ms). Mean WSS (Pa) was in inverse relationship only with spatial resolution (CCA:-19%/mm, ICA:-33%/mm). OSI was dependent on spatial resolution for CCA (-26%/mm) and temporal resolution for ICA (-16%/100ms). The regions of low and high WSS and OSI matched for most of the spatiotemporal resolutions (CCA:30/30, ICA:28/30 cases for WSS; CCA:23/30, ICA:29/30 cases for OSI).

Conclusion: We show that both mean flow and mean WSS are independent of temporal resolution. Peak flow and OSI are dependent on both spatial and temporal resolution. However, the magnitude of mean and peak flow, WSS and OSI, and the spatial distribution of OSI and WSS did not exhibit a strong dependency on spatiotemporal resolution.

No MeSH data available.


Related in: MedlinePlus

The mean WSS [Pa] of each quarter by CFD and by PC-MRI measurements at different spatial and temporal resolutions in the CCA and ICA.* shows the highest WSS quarter and + shows the lowest WSS quarter.
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pone.0163316.g005: The mean WSS [Pa] of each quarter by CFD and by PC-MRI measurements at different spatial and temporal resolutions in the CCA and ICA.* shows the highest WSS quarter and + shows the lowest WSS quarter.

Mentions: The mean WSS of each quarter for four measurements in the CCA and the ICA is shown in Fig 5. For the CCA, the highest WSS quarter was the bottom right quarter (0.14 ± 0.01 Pa) and the lowest WSS quarter was the top left quarter (0.07 ± 0.02 Pa). These highest and the lowest WSS regions of the CCA were found in all measurements regardless of spatial and temporal resolution. Based on CFD calculations, the bottom right quarter was also found as the highest WSS quarter (0.19 Pa) and the top left quarter was the lowest WSS quarter (0.11 Pa) for the CCA. For the ICA, the highest WSS quarter was the bottom right quarter which was found in all measurements (0.13 ± 0.02 Pa) and also in CFD calculation (0.30 Pa). The lowest WSS quarter for the ICA was the top left quarter (0.04 ± 0.02 Pa) in 28/30 measurements (93%). The lowest WSS quarter in the ICA was the bottom left quarter (0.08 Pa) based on CFD calculations and the WSS at the top left quarter was 0.12 Pa.


The Effect of Spatial and Temporal Resolution of Cine Phase Contrast MRI on Wall Shear Stress and Oscillatory Shear Index Assessment
The mean WSS [Pa] of each quarter by CFD and by PC-MRI measurements at different spatial and temporal resolutions in the CCA and ICA.* shows the highest WSS quarter and + shows the lowest WSS quarter.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5036833&req=5

pone.0163316.g005: The mean WSS [Pa] of each quarter by CFD and by PC-MRI measurements at different spatial and temporal resolutions in the CCA and ICA.* shows the highest WSS quarter and + shows the lowest WSS quarter.
Mentions: The mean WSS of each quarter for four measurements in the CCA and the ICA is shown in Fig 5. For the CCA, the highest WSS quarter was the bottom right quarter (0.14 ± 0.01 Pa) and the lowest WSS quarter was the top left quarter (0.07 ± 0.02 Pa). These highest and the lowest WSS regions of the CCA were found in all measurements regardless of spatial and temporal resolution. Based on CFD calculations, the bottom right quarter was also found as the highest WSS quarter (0.19 Pa) and the top left quarter was the lowest WSS quarter (0.11 Pa) for the CCA. For the ICA, the highest WSS quarter was the bottom right quarter which was found in all measurements (0.13 ± 0.02 Pa) and also in CFD calculation (0.30 Pa). The lowest WSS quarter for the ICA was the top left quarter (0.04 ± 0.02 Pa) in 28/30 measurements (93%). The lowest WSS quarter in the ICA was the bottom left quarter (0.08 Pa) based on CFD calculations and the WSS at the top left quarter was 0.12 Pa.

View Article: PubMed Central - PubMed

ABSTRACT

Introduction: Wall shear stress (WSS) and oscillatory shear index (OSI) are associated with atherosclerotic disease. Both parameters are derived from blood velocities, which can be measured with phase-contrast MRI (PC-MRI). Limitations in spatiotemporal resolution of PC-MRI are known to affect these measurements. Our aim was to investigate the effect of spatiotemporal resolution using a carotid artery phantom.

Methods: A carotid artery phantom was connected to a flow set-up supplying pulsatile flow. MRI measurement planes were placed at the common carotid artery (CCA) and internal carotid artery (ICA). Two-dimensional PC-MRI measurements were performed with thirty different spatiotemporal resolution settings. The MRI flow measurement was validated with ultrasound probe measurements. Mean flow, peak flow, flow waveform, WSS and OSI were compared for these spatiotemporal resolutions using regression analysis. The slopes of the regression lines were reported in %/mm and %/100ms. The distribution of low and high WSS and OSI was compared between different spatiotemporal resolutions.

Results: The mean PC-MRI CCA flow (2.5±0.2mL/s) agreed with the ultrasound probe measurements (2.7±0.02mL/s). Mean flow (mL/s) depended only on spatial resolution (CCA:-13%/mm, ICA:-49%/mm). Peak flow (mL/s) depended on both spatial (CCA:-13%/mm, ICA:-17%/mm) and temporal resolution (CCA:-19%/100ms, ICA:-24%/100ms). Mean WSS (Pa) was in inverse relationship only with spatial resolution (CCA:-19%/mm, ICA:-33%/mm). OSI was dependent on spatial resolution for CCA (-26%/mm) and temporal resolution for ICA (-16%/100ms). The regions of low and high WSS and OSI matched for most of the spatiotemporal resolutions (CCA:30/30, ICA:28/30 cases for WSS; CCA:23/30, ICA:29/30 cases for OSI).

Conclusion: We show that both mean flow and mean WSS are independent of temporal resolution. Peak flow and OSI are dependent on both spatial and temporal resolution. However, the magnitude of mean and peak flow, WSS and OSI, and the spatial distribution of OSI and WSS did not exhibit a strong dependency on spatiotemporal resolution.

No MeSH data available.


Related in: MedlinePlus