新发传染病电子杂志2025，Vol.10Issue(2)：54-62,9.DOI:10.19871/j.cnki.xfcrbzz.2025.02.010
以多相T2弛豫时间模型解释表观弥散系数对T2弛豫时间的高度依赖性
High dependence of ADC on T2 relaxation time explained by the multiple T2 elements model
摘要
Abstract
For in vivo diffusion weighted imaging,apparent diffusion coefficient(ADC)has been considered to reflect tissue diffusion.The ADC is widely used in clinical practice,including in the imaging of infectious lesions.It is generally assumed that the diffusion of tumors is restricted,while the diffusion of tissues with more water will be freer.However,the ADC values obtained in actual clinical work often deviate from the expected tissue diffusion.For example,although the abscess contains liquid components,the ADC measured for the abscess fluid is generally very low;while the ADC of some hard tissues such as cartilage and intervertebral discs is very high.Although the abscess fluid may have certain viscosity,myxomas often have high ADC.HCC ADC has been noted to have restricted diffusion relative to the liver.However,as HCCs are mostly associated with increased blood supply and increased proportion of arterial blood supply and higher water content,it is unlikely that HCC has a true lower diffusion.In fact,with the slow diffusion coefficient(SDC)method recently proposed by us,we measured faster diffusion for HCC than for the adjacent liver parenchyma.We proposed that in vivo ADC measure is strongly associated with T2 relaxation time(T2).T2 can be divided into short T2 band(＜60ms),intermediate T2 band(60-80ms),and long T2 band(＞80 ms,all 3T values).For the short T2 time band,there is a negative correlation between T2 and ADC.For the long T2 time band,there is a positive correlation between T2 and ADC.A tissue likely measures a low ADC if its T2 is close to 70 ms.In this article,we attempt to explain the T2 dependency of ADC with the concept of the intravoxel incoherent motion model.We suggest that we do not routinely use the term of"diffusion restriction"when interpreting clinical high b-value DW images and ADC maps.关键词
表观弥散系数/慢速弥散系数/体素内不相干运动模型/弥散受限Key words
Apparent diffusion coefficient/Slow diffusion coefficient/Intravoxel incoherent motion model/Diffusion restriction分类
医药卫生引用本文复制引用
王毅翔..以多相T2弛豫时间模型解释表观弥散系数对T2弛豫时间的高度依赖性[J].新发传染病电子杂志,2025,10(2):54-62,9.基金项目
香港基础研究基金项目(14112521) （14112521）
