Clark Paul R, Chua-anusorn Wanida, St Pierre Timothy G
School of Physics, The University of Western Australia, Crawley, Perth, Western Australia 6009, Australia.
Magn Reson Imaging. 2003 Jun;21(5):519-30. doi: 10.1016/s0730-725x(03)00080-8.
A bi-exponential proton transverse relaxation rate (R(2)) image analysis technique has been developed that enables the discrimination of dual compartment transverse relaxation behavior in systems with rapid transverse relaxation enhancement. The technique is particularly well suited to single spin-echo imaging studies where a limited number of images are available for analysis. The bi-exponential R(2) image analysis is facilitated by estimation of the initial proton spin density signal within the region of interest weighted by the RF field intensities. The RF field intensity-weighted spin density map is computed by solving a boundary value problem presented by a high spin density, long T(2) material encompassing the region for analysis. The accuracy of the bi-exponential R(2) image analysis technique is demonstrated on a simulated dual compartment manganese chloride phantom system with relaxation rates and relative population densities between the two compartments similar to the bi-exponential transverse relaxation behavior expected of iron loaded liver. Results from analysis of the phantoms illustrate the potential of bi-exponential R(2) image analysis with RF field intensity-weighted spin density projection for quantifying transverse relaxation enhancement as it occurs in liver iron overload.
已经开发出一种双指数质子横向弛豫率（R(2)）图像分析技术，该技术能够区分具有快速横向弛豫增强的系统中的双室横向弛豫行为。该技术特别适用于单自旋回波成像研究，在这类研究中可用于分析的图像数量有限。通过估计由射频场强度加权的感兴趣区域内的初始质子自旋密度信号，有助于进行双指数R(2)图像分析。通过求解由围绕分析区域的高自旋密度、长T(2)材料呈现的边值问题，计算射频场强度加权自旋密度图。在模拟的双室氯化锰体模系统上证明了双指数R(2)图像分析技术的准确性，该系统中两个室之间的弛豫率和相对总体密度类似于铁过载肝脏预期的双指数横向弛豫行为。体模分析结果说明了利用射频场强度加权自旋密度投影进行双指数R(2)图像分析在量化肝脏铁过载中发生的横向弛豫增强方面的潜力。
