使用 1.5、3 和 7 T 的 T1 和 T2 映射检测关节中的低血浓度：一项体外研究。
Detecting low blood concentrations in joints using T1 and T2 mapping at 1.5, 3, and 7 T: an in vitro study.
机构信息
Department of Radiology, Division of Imaging and Oncology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
Image Sciences Institute, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
出版信息
Eur Radiol Exp. 2021 Dec 2;5(1):51. doi: 10.1186/s41747-021-00251-z.
BACKGROUND
Intra-articular blood causes irreversible joint damage, whilst clinical differentiation between haemorrhagic joint effusion and other effusions can be challenging. An accurate non-invasive method for the detection of joint bleeds is lacking. The aims of this phantom study were to investigate whether magnetic resonance imaging (MRI) T1 and T2 mapping allows for differentiation between simple and haemorrhagic joint effusion and to determine the lowest blood concentration that can be detected.
METHODS
Solutions of synovial fluid with blood concentrations ranging from 0 to 100% were scanned at 1.5, 3, and 7 T. T1 maps were generated with an inversion recovery technique and T2 maps from multi spin-echo sequences. In both cases, the scan acquisition times were below 5 min. Regions of interest were manually drawn by two observers in the obtained T1 and T2 maps for each sample. The lowest detectable blood concentration was determined for all field strengths.
RESULTS
At all field strengths, T1 and T2 relaxation times decreased with higher blood concentrations. The lowest detectable blood concentrations using T1 mapping were 10% at 1.5 T, 25% at 3 T, and 50% at 7 T. For T2 mapping, the detection limits were 50%, 5%, and 25%, respectively.
CONCLUSIONS
T1 and T2 mapping can detect different blood concentrations in synovial fluid in vitro at clinical field strengths. Especially, T2 measurements at 3 T showed to be highly sensitive. Short acquisition times would make these methods suitable for clinical use and therefore might be promising tools for accurate discrimination between simple and haemorrhagic joint effusion in vivo.
背景
关节内出血会导致不可逆转的关节损伤，而临床上区分出血性关节积液和其他积液具有挑战性。目前缺乏一种准确的、非侵入性的关节出血检测方法。本研究旨在探讨磁共振成像（MRI）T1 和 T2 mapping 是否可用于区分单纯性和出血性关节积液，并确定可检测到的最低血液浓度。
方法
在 1.5、3 和 7T 下对滑膜液与血液浓度为 0 至 100%的混合溶液进行扫描。T1 图谱采用反转恢复技术生成，T2 图谱采用多回波自旋序列生成。在这两种情况下，扫描采集时间均在 5 分钟以内。由两位观察者手动在每个样本的获得的 T1 和 T2 图谱上绘制感兴趣区域。确定所有场强下的最低可检测血液浓度。
结果
在所有场强下，T1 和 T2 弛豫时间随血液浓度的增加而降低。使用 T1 映射的最低可检测血液浓度在 1.5T 时为 10%，在 3T 时为 25%，在 7T 时为 50%。对于 T2 映射，检测限分别为 50%、5%和 25%。
结论
T1 和 T2 映射可在临床场强下体外检测滑膜液中的不同血液浓度。特别是在 3T 时的 T2 测量显示出高度的敏感性。较短的采集时间使这些方法适用于临床应用，因此可能是准确区分体内单纯性和出血性关节积液的有前途的工具。
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