Department of System Control Engineering, Graduate School of Engineering, Tokushima Bunri University, 1314-1 Shido, Sanuki-city, Kagawa 769-2193, Japan; Department of Radiological Technology, Faculty of Health and Welfare, Tokushima Bunri University, 1314-1 Shido, Sanuki-city, Kagawa 769-2193, Japan; Division of Health Sciences, Graduate School of Medical Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa 920-0942, Japan.
Department of Radiology, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
Magn Reson Imaging. 2021 Jun;79:85-96. doi: 10.1016/j.mri.2021.03.006. Epub 2021 Mar 13.
This study aims to investigate the influence of time-intensity curves (TICs) on the shapes using a dynamic contrast-enhanced magnetic resonance imaging (MRI) study depending on the Cartesian and radial orders for benign and cancerous breast tumors.
Based on kinetic curve parameters, the signal intensities of six concentration gradients comprising two benign and four cancer models were used. The study aimed to construct a dynamic simulated image by creating a digital phantom image according to the following steps: (1) creating a simple numerical phantom, (2) setting the signal intensity in the contrast area, (3) creating the k-space in each time phase, (4) extracting data from k-space in each time phase, (5) filling in the k-space and adding data to the k-space assembly, and (6) creating a magnitude image. The TICs of Cartesian (centric and sequential) and radial (full-length [RFL] and half-length [RHL]) orders were created and sigmoid curve fitting was performed to compare these curves. Maximum slope (MS, s), width of the response (WOR, s), and primary signal response (PSR) were then calculated. Phase encode steps were set for 512 and 256.
MS was significantly decreased by radial order in the cancer model. No change was observed in WOR in Cartesian order, whereas RFL and RHL orders increased in the cancer models. PSR increased remarkably in the radial orders of cancer models. The difference in the fill slope in radial orders was remarkable when the TIC was steeper compared with when it was gentle, especially RHL. In WOR, both radial RFL and RHL were well matched except for the one benign model, and the shape of radial TIC was similar to sequential order as compared to centric order in 256 steps.
The effects of Cartesian and radial orders on the patterns of TICs in a dynamic contrast-enhanced MRI study of benign and cancerous breast tumors were revealed. Interestingly, the TIC gradient of radial orders became gentler, particularly in the breast cancer MRI.
本研究旨在探讨基于笛卡尔和径向序的时间-强度曲线（TICs）对良恶性乳腺肿瘤的形状的影响。
基于动力学曲线参数，使用 6 种浓度梯度的信号强度，这些梯度由 2 个良性和 4 个恶性模型组成。该研究旨在根据以下步骤创建一个动态模拟图像：（1）创建一个简单的数值体模；（2）设置对比区域的信号强度；（3）在每个时间相位创建 k 空间；（4）从每个时间相位的 k 空间中提取数据；（5）填充 k 空间并将数据添加到 k 空间组装中；（6）创建一个幅度图像。创建了笛卡尔（中心和顺序）和径向（全长[RFL]和半长[RHL]）顺序的 TIC，并进行了 S 型曲线拟合以比较这些曲线。然后计算最大斜率（MS，s）、响应宽度（WOR，s）和主要信号响应（PSR）。相位编码步长设置为 512 和 256。
在恶性模型中，MS 随着径向顺序的增加而显著降低。在笛卡尔顺序中，WOR 没有变化，而 RFL 和 RHL 顺序的 WOR 则增加。在恶性模型的径向顺序中，PSR 显著增加。在 TIC 较陡的情况下，径向顺序的填充斜率差异显著，尤其是 RHL。在 WOR 中，除了一个良性模型外，径向 RFL 和 RHL 都很好地匹配，与 256 步的顺序相比，径向 TIC 的形状与顺序相似。
本研究揭示了时间-强度曲线（TICs）在良性和恶性乳腺肿瘤的动态对比增强磁共振成像研究中，笛卡尔和径向顺序对 TICs 模式的影响。有趣的是，特别是在乳腺癌 MRI 中，径向顺序的 TIC 梯度变得更加平缓。
