Wengert Georg J, Pinker Katja, Helbich Thomas H, Vogl Wolf-Dieter, Spijker Sylvia M, Bickel Hubert, Polanec Stephan H, Baltzer Pascal A
Medical University of Vienna, Department of Biomedical Imaging and Image-Guided Therapy, Division of Molecular and Gender Imaging, Vienna, Austria.
Memorial Sloan-Kettering Cancer Center, Dept. of Radiology, New York, USA.
NMR Biomed. 2017 Jun;30(6). doi: 10.1002/nbm.3705. Epub 2017 Mar 10.
To demonstrate the accuracy of fully automated, quantitative, volumetric measurement of the amount of fibroglandular breast tissue (FGT), using MRI, and to investigate the impact of different MRI sequences using anthropomorphic breast phantoms as the ground truth. In this study, 10 anthropomorphic breast phantoms that consisted of different known fractions of adipose and protein tissue, which closely resembled normal breast parenchyma, were developed. Anthropomorphic breast phantoms were imaged with a 1.5 T unit (Siemens, Avantofit) using an 18-channel breast coil. The sequence protocol consisted of an isotropic Dixon sequence (Di), an anisotropic Dixon sequence (Da), and T 3D FLASH sequences with and without fat saturation (T1). Fully automated, quantitative, volumetric measurement of FGT for all anthropomorphic phantoms and sequences was performed and correlated with the amounts of fatty and protein components in the phantoms as the ground truth. Fully automated, quantitative, volumetric measurements of FGT with MRI for all sequences ranged from 5.86 to 61.05% (mean 33.36%). The isotropic Dixon sequence yielded the highest accuracy (median 0.51%-0.78%) and precision (median range 0.19%) compared with anisotropic Dixon (median 1.92%-2.09%; median range 0.55%) and T -weighted sequences (median 2.54%-2.46%; median range 0.82%). All sequences yielded good correlation with the FGT content of the anthropomorphic phantoms. The best correlation of FGT measurements was identified for Dixon sequences (Di, R = 0.999; Da, R = 0.998) compared with conventional T -weighted sequences (R = 0.971). MRI yields accurate, fully automated, quantitative, volumetric measurements of FGT, an increasingly important and sensitive imaging biomarker for breast cancer risk. Compared with conventional T sequences, Dixon-type sequences show the highest correlation and reproducibility for automated, quantitative, volumetric FGT measurements using anthropomorphic breast phantoms as the ground truth.
为了验证使用磁共振成像（MRI）对乳腺纤维腺组织（FGT）量进行全自动、定量、容积测量的准确性，并以仿真人体乳房模型作为参照标准，研究不同MRI序列的影响。在本研究中，制作了10个仿真人体乳房模型，其由不同比例已知的脂肪和蛋白质组织构成，与正常乳腺实质极为相似。使用18通道乳腺线圈，通过1.5T设备（西门子，Avantofit）对仿真人体乳房模型进行成像。序列方案包括各向同性狄克逊序列（Di）、各向异性狄克逊序列（Da）以及有和没有脂肪饱和的T 3D FLASH序列（T1）。对所有仿真人体模型和序列进行FGT的全自动、定量、容积测量，并将其与模型中脂肪和蛋白质成分的量作为参照标准进行关联。所有序列通过MRI进行FGT的全自动、定量、容积测量范围为5.86%至61.05%（平均33.36%）。与各向异性狄克逊序列（中位数1.92% - 2.09%；中位数范围0.55%）和T加权序列（中位数2.54% - 2.46%；中位数范围0.82%）相比，各向同性狄克逊序列具有最高的准确性（中位数0.51% - 0.78%）和精密度（中位数范围0.19%）。所有序列与仿真人体模型的FGT含量均具有良好的相关性。与传统T加权序列（R = 0.971）相比，狄克逊序列（Di，R = 0.999；Da，R = 0.998）的FGT测量相关性最佳。MRI能够对FGT进行准确、全自动、定量、容积测量，FGT是评估乳腺癌风险中一项日益重要且敏感的成像生物标志物。与传统T序列相比，狄克逊型序列在以仿真人体乳房模型作为参照标准进行FGT的自动化、定量、容积测量时，显示出最高的相关性和可重复性。
