Department of Radiology, Paramedical School, University of Tabriz Medical Sciences, Tabriz, Iran.
Br J Radiol. 2011 Apr;84(1000):342-9. doi: 10.1259/bjr/18588668. Epub 2010 Oct 19.
Previous studies have shown that the organ blood flows (OBFs) calculated using the T(1) weighted MRI technique were lower than the expected values. The aim of this study was a flow measurement comparison between the theoretical and experimental flows based on the technique before and after corrections (coil non-uniformity and inflow) using a flow phantom at two different concentrations (0.8 and 1.2 mmol l(-1)).
A flow phantom was designed to produce three different flow rates at the same time. Theoretical flow was calculated by measuring the volumes of the phantom and dividing them by the time taken to fill these volumes. T(1) weighted turbo fast low-angle shot images were used to measure signal intensity (SI) change during the first bolus passage of the contrast medium through the phantom using linear phase-encoding acquisition.
The corrected experimental flow based on the technique shows a good agreement with the theoretical flow, where the flow rate is low at the two concentrations.
The T(1) weighted MRI technique after the two correction factors can be used to measure the absolute flow where the flow rate is low, such as in the capillaries. For measuring high flow rate (e.g. artery), additional correction factors should be considered.
先前的研究表明，使用 T1 加权 MRI 技术计算出的器官血流（OBF）低于预期值。本研究旨在使用流量体模在两种不同浓度（0.8 和 1.2mmol/L）下，比较基于该技术的理论和实验流量在（线圈不均匀性和流入）校正前后的流量测量结果。
设计了一个流量体模，可同时产生三种不同的流速。理论流量通过测量体模的体积并将其除以填充这些体积所需的时间来计算。使用线性相位编码采集，在对比剂通过体模的第一次团注通过期间，T1 加权涡轮快速低角度 shot 图像用于测量信号强度（SI）的变化。
该技术校正后的实验流量与理论流量具有良好的一致性，在两种浓度下，流速较低。
经过两个校正因子的 T1 加权 MRI 技术可用于测量流速较低的绝对流量，例如毛细血管中的流量。对于测量高流速（例如动脉），应考虑其他校正因子。
