ESTIMATING OXYGEN-SATURATION OF BLOOD INVIVO WITH MR IMAGING AT 1.5T
ESTIMATING OXYGEN-SATURATION OF BLOOD INVIVO WITH MR IMAGING AT 1.5T
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DOI：
10.1002/jmri.1880010303
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发表时间：
1991-05-01
期刊：
影响因子：
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通讯作者：
MACOVSKI, A
中科院分区：
文献类型：
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作者：
WRIGHT, GA;HU, BS;MACOVSKI, A
研究了磁共振 (MR) 成像的用途，通过早期 MR 波谱测量研究中确定的弛豫特性，无创地估计体内人体血液的氧饱和度 (%HbO2)。为此，提出了一个序列，用于确定身体和血液本身的运动提出重大挑战的区域中血管血液的 T2。通过在商用 1.5-T 全身成像仪上使用该序列，可以根据体内预期条件在体外校准血液的 T2 和 %HbO2 之间的关系。随着 %HbO2 从 30% 变化到 96%，T2 可预测从约 30 到 250 毫秒变化。对几名健康受试者纵隔血管血进行原位测量的 T2 值定性地反映了体外观察到的行为。通过体外校准获得的这些血管的 % HbO2 估计值似乎是合理的，特别是对于静脉血，尽管在选择适当的校准因子时会出现困难。这些令人鼓舞的初步结果支持对潜在误差源进行更系统的研究，并通过与血管中 % HbO2 的直接测量进行比较来检查体内测量的准确性。
The use of magnetic resonance (MR) imaging is investigated for noninvasively estimating the oxygen saturation of human blood (%HbO2) in vivo by means of relaxation characteristics identified in earlier MR spectrometry studies. To this end, a sequence is presented for determining the T2 of vascular blood in regions in which motions of the body and of the blood itself present a major challenge. With use of this sequence on a commercial 1.5-T whole-body imager, the relationship between the T2 and %HbO2 of blood is calibrated in vitro for the conditions expected in vivo. T2 varies predictably from about 30 to 250 msec as %HbO2 varies from 30% to 96%. T2 values measured in situ for vascular blood in the mediastinum of several healthy subjects qualitatively reflected the behavior observed in vitro. Estimates of % HbO2 for these vessels obtained with the in vitro calibration appear reasonable, particularly for venous blood, although difficulties arise in selecting the appropriate calibration factors. These encouraging initial results support a more systematic study of potential sources of error and an examination of the accuracy of in vivo measurements by comparison with direct measurements of % HbO2 in vessels.