Objective

Quantitative analysis in MRI is challenging due to variabilities in intensity distributions across patients, acquisitions and scanners and suffers from bias field inhomogeneity. Radiomic studies are impacted by these effects that affect radiomic feature values. This paper describes a dedicated pipeline to increase reproducibility in breast MRI radiomic studies.

Materials and methods

T1, T2, and T1-DCE MR images of two breast phantoms were acquired using two scanners and three dual breast coils. Images were retrospectively corrected for bias field inhomogeneity and further normalised using Z score or histogram matching. Extracted radiomic features were harmonised between coils by the ComBat method. The whole pipeline was assessed qualitatively and quantitatively using statistical comparisons on two series of radiomic feature values computed in the gel mimicking the normal breast tissue or in dense lesions.

Results

Intra and inter-acquisition variabilities were strongly reduced by the standardisation pipeline. Harmonisation by ComBat lowered the percentage of radiomic features significantly different between the three coils from 87% after bias field correction and MR normalisation to 3% in the gel, while preserving or improving performance of lesion classification in the phantoms.

Discussion

A dedicated standardisation pipeline was developed to reduce variabilities in breast MRI, which paves the way for robust multi-scanner radiomic studies but needs to be assessed on patient data.

中文翻译：

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专用于乳腺 MRI 的放射组学管道：对多扫描仪体模研究的验证

客观的

由于患者、采集和扫描仪的强度分布存在差异，并且存在偏置场不均匀性，因此 MRI 中的定量分析具有挑战性。放射组学研究受到这些影响放射组学特征值的影响。本文描述了一个专门的管道，以提高乳腺 MRI 放射组学研究的可重复性。

材料和方法

使用两个扫描仪和三个双乳房线圈获取两个乳房模型的 T1、T2 和 T1-DCE MR 图像。针对偏置场不均匀性对图像进行回顾性校正，并使用Z分数或直方图匹配进一步归一化。通过 ComBat 方法在线圈之间协调提取的放射组学特征。使用模拟正常乳腺组织或致密病变的凝胶中计算的两组放射组学特征值的统计比较，对整个管道进行了定性和定量评估。

结果

标准化管道极大地降低了采集内和采集间的可变性。ComBat 的协调将三个线圈之间显着不同的放射组学特征的百分比从偏置场校正和 MR 归一化后的 87% 降低到凝胶中的 3%，同时保留或提高了体模中病变分类的性能。

讨论

开发了专用的标准化管道以减少乳房 MRI 的变异性，这为稳健的多扫描仪放射组学研究铺平了道路，但需要根据患者数据进行评估。