Lipiński Kamil, Bogorodzki Piotr
Institute of Radioelectronics and Multimedia Technology, Faculty of Electronics and Information Technology, Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warsaw, Poland.
Diagnostics (Basel). 2024 Mar 20;14(6):653. doi: 10.3390/diagnostics14060653.
Intravoxel Incoherent Motion (IVIM) imaging provides non-invasive perfusion measurements, eliminating the need for contrast agents. This work explores the feasibility of IVIM imaging in whole brain perfusion studies, where an isotropic 1 mm voxel is widely accepted as a standard. This study follows the validity of a time-limited, precise, segmentation-ready whole-brain IVIM protocol suitable for clinical reality. To assess the influence of on the estimation of , , , and IVIM parameters, a series of measurements and simulations were performed in MATLAB for the following three estimation techniques: segmented grid search, segmented curve fitting, and one-step curve fitting, utilizing known "ground truth" and noised data. Scanner-specific was estimated based on a healthy subject IVIM MRI study in a 3T scanner. Measurements were conducted for 25.6 × 25.6 × 14.4 cm FOV with a 256 × 256 in-plane resolution and 72 slices, resulting in 1 × 1 × 2 mm voxel size. Simulations were performed for 36 levels around the measured value. For a single voxel grid, the search algorithm mean relative error , f^, D^*, and D^ of at the expected level were 5.00%, 81.91%, 76.31%, and 18.34%, respectively. Analysis has shown that high-resolution IVIM imaging is possible, although there is significant variation in both accuracy and precision, depending on and the chosen estimation method.
体素内不相干运动(IVIM)成像可提供无创灌注测量,无需使用造影剂。本研究探讨了IVIM成像在全脑灌注研究中的可行性,其中各向同性1毫米体素被广泛视为标准。本研究遵循了一种适用于临床实际的、限时、精确且可用于分割的全脑IVIM方案的有效性。为了评估噪声对IVIM参数D、D*、f和D的估计的影响,在MATLAB中针对以下三种估计技术进行了一系列测量和模拟:分段网格搜索、分段曲线拟合和一步曲线拟合,使用已知的“真实值”和带噪声的数据。基于在3T扫描仪中对一名健康受试者进行的IVIM MRI研究估计了特定扫描仪的噪声。测量在25.6×25.6×14.4厘米的视野内进行,平面分辨率为256×256,有72层,体素大小为1×1×2毫米。围绕测量的噪声值对36个噪声水平进行了模拟。对于单个体素网格,在预期噪声水平下,搜索算法的D、f^、D*和D^的平均相对误差分别为5.00%、81.91%、76.31%和18.34%。分析表明,高分辨率IVIM成像是可行的,尽管根据噪声和所选估计方法,准确性和精密度都存在显著差异。