Kweon Jihoon, Yang Dong Hyun, Kim Guk Bae, Kim Namkug, Paek MunYoung, Stalder Aurelien F, Greiser Andreas, Kim Young-Hak
Department of Cardiology and Heart Institute, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Department of Radiology and Research Institute of Radiology, Cardiac Imaging Center, Asan Medical Center, University of Ulsan College of Medicine, Asanbyeongwon-gil 86, Seoul, 138-736, South Korea.
Eur Radiol. 2016 Oct;26(10):3588-97. doi: 10.1007/s00330-015-4181-6. Epub 2016 Jan 8.
To validate 4D flow MRI in a flow phantom using a flowmeter and computational fluid dynamics (CFD) as reference.
Validation of 4D flow MRI was performed using flow phantoms with 75 % and 90 % stenosis. The effect of spatial resolution on flow rate, peak velocity and flow patterns was investigated in coronal and axial scans. The accuracy of flow rate with 4D flow MRI was evaluated using a flowmeter as reference, and the peak velocity and flow patterns obtained were compared with CFD analysis results.
4D flow MRI accurately measured the flow rate in proximal and distal regions of the stenosis (percent error ≤3.6 % in axial scanning with 1.6-mm resolution). The peak velocity of 4D flow MRI was underestimated by more than 22.8 %, especially from the second half of the stenosis. With 1-mm isotropic resolution, the maximum thickness of the recirculating flow region was estimated within a 1-mm difference, but the turbulent velocity fluctuations mostly disappeared in the post-stenotic region.
4D flow MRI accurately measures the flow rates in the proximal and distal regions of a stenosis in axial scan but has limitations in its estimation of peak velocity and turbulent characteristics.
• 4D flow MRI accurately measures the flow rate in axial scan. • The peak velocity was underestimated by 4D flow MRI. •4D flow MRI demonstrates the principal pattern of post-stenotic flow.
使用流量计和计算流体动力学（CFD）作为参考，在流动模型中验证四维流动磁共振成像（4D流MRI）。
使用具有75%和90%狭窄程度的流动模型对4D流MRI进行验证。在冠状面和轴位扫描中研究空间分辨率对流速、峰值速度和流动模式的影响。以流量计为参考评估4D流MRI的流速准确性，并将获得的峰值速度和流动模式与CFD分析结果进行比较。
4D流MRI准确测量了狭窄近端和远端区域的流速（在1.6毫米分辨率的轴位扫描中，误差百分比≤3.6%）。4D流MRI的峰值速度被低估了超过22.8%，尤其是在狭窄后半段。在1毫米各向同性分辨率下，再循环流动区域的最大厚度估计相差在1毫米以内，但狭窄后区域的湍流速度波动大多消失。
4D流MRI在轴位扫描中能准确测量狭窄近端和远端区域的流速，但在峰值速度和湍流特征的估计方面存在局限性。
•4D流MRI在轴位扫描中能准确测量流速。•4D流MRI低估了峰值速度。•4D流MRI显示了狭窄后流动的主要模式。
