Department of Oncologic Imaging, Institut Bergonié, Comprehensive Cancer Center of Nouvelle-Aquitaine, Bordeaux, France.
Bordeaux University, Bordeaux, France.
J Magn Reson Imaging. 2021 Aug;54(2):537-548. doi: 10.1002/jmri.27558. Epub 2021 Feb 16.
Magnetic resonance imaging (MRI)-based radiomics features (RFs) quantify tumors radiological phenotypes but are sensitive to postprocessing parameters, including the intensity harmonization technique (IHT), while mappings enable objective quantitative assessment.
To investigate whether T2 mapping could improve repeatability, reproducibility, and performances of radiomics compared to conventional T2-weighted imaging (T2WI).
Prospective.
Twenty-six healthy adults.
FIELD STRENGTH/SEQUENCE: Respiratory-trigged radial turbo spin echo (TSE) multiecho T2 mapping (prototype) and conventional TSE T2WI of the abdomen were acquired twice at 1.5 T.
T2 maps were reconstructed using a two-parameter exponential fitting model. Volumes-of-interest (VOIs) were manually drawn in six tissues: liver, kidney, pancreas, muscle, bone, and spleen. After co-registration, conventional T2WIs were processed with two IHTs (standardization [std] and histogram-matching [HM]) resulting in four paired input image types: initial T2WI, T2WI , T2WI , and T2-map. VOIs were propagated to extract 45 RFs from MRI-1 and MRI-2 of each image type (LIFEx, v5.10).
Influence of the input data type on RF values was evaluated with analysis of variance. RFs test-retest repeatability and reproducibility over multiple segmentations were evaluated with intra-class correlation coefficient (ICC). Correlations between k-means clusters and the six tissues depending on the RFs dataset were investigated with adjusted-Rand-index (ARI).
About 41 of 45 (91.1%) RFs were significantly influenced by the input image type (P values < 0.05), which was the most influential factor on repeatability of RFs (P-value < 0.05). Repeatability ICCs from T2-map displayed intermediate values between the initial T2WI (range: 0.407-0.736) and the T2WI (range: 0.724-0.817). The number of RFs with interobserver and intraobserver reproducibility ICCs ≥ 0.90 was 37/45 (82.2%) for T2WI , 33/45 (73.3%) for T2WI , 31/45 (68.9%) for T2 map, and 25/45 (55.6%) for the initial T2WI. T2 map provided the best tissue discrimination (ARI = 0.414 vs. 0.157 with T2WI ).
T2 mapping provided RFs with moderate to substantial repeatability and reproducibility ICCs, along with the most preserved discriminative information.
1 TECHNICAL EFFICACY: 1.
磁共振成像（MRI）基于放射组学特征（RFs）定量肿瘤的影像学表型，但对后处理参数（包括强度匀化技术（IHT））敏感，而图谱则可实现客观的定量评估。
研究与常规 T2 加权成像（T2WI）相比，T2 映射是否能提高放射组学的可重复性、可再现性和性能。
前瞻性。
26 名健康成年人。
磁场强度/序列：在 1.5T 下采集腹部呼吸触发的放射状涡轮自旋回波（TSE）多回波 T2 图谱（原型）和常规 TSE T2WI 两次。
T2 图谱使用双参数指数拟合模型重建。在六个组织（肝、肾、胰腺、肌肉、骨和脾）中手动绘制感兴趣区（VOI）。配准后，对常规 T2WI 进行两种 IHT（标准化[std]和直方图匹配[HM]）处理，产生四种配对的输入图像类型：初始 T2WI、T2WI、T2WI和 T2 图。将 VOI 传播到每个图像类型的 MRI-1 和 MRI-2 中提取 45 个 RF（LIFEx，v5.10）。
采用方差分析评估输入数据类型对 RF 值的影响。采用组内相关系数（ICC）评估多个分割的 RF 测试-再测试重复性和再现性。根据 RF 数据集，用调整后的 Rand 指数（ARI）研究 k-均值聚类与六个组织之间的相关性。
约 41/45（91.1%）的 RF 受输入图像类型的显著影响（P 值<0.05），这是对 RF 重复性影响最大的因素（P 值<0.05）。T2 图的重复性 ICC 值介于初始 T2WI（范围：0.407-0.736）和 T2WI（范围：0.724-0.817）之间。T2WI、T2WI、T2 图和初始 T2WI 的观察者间和观察者内可重复性 ICC 值≥0.90 的 RF 数量分别为 37/45（82.2%）、33/45（73.3%）、31/45（68.9%）和 25/45（55.6%）。T2 图提供了最佳的组织区分度（ARI=0.414 比 T2WI=0.157）。
T2 映射提供了具有中等至较大重复性和可再现性 ICC 的 RFs，同时保留了最具鉴别性的信息。
1 技术功效：1。
