Department of Radiological Sciences, University of California, Irvine, CA 92697, USA.
Med Phys. 2011 Nov;38(11):5961-8. doi: 10.1118/1.3646756.
To investigate the difference of MR percent breast density measured from fat-suppressed versus nonfat-suppressed imaging sequences.
Breast magnetic resonance imaging (MRI) with and without fat suppression was acquired from 38 subjects. Breasts were divided into subgroups of different morphological patterns ("central" and "intermingled" types). Breast volume, fibroglandular tissue volume, and percent density were measured. The results were compared using nonparametric statistical tests and regarded as significant at p < 0.05.
Breast volume, fibroglandular volume, and percent density between fat-suppressed and nonfat-suppressed sequences were highly correlated. Breast volumes measured on these two sequences were almost identical. Fibroglandular tissue volume and percent density, however, had small (<5%) yet significant differences between the two sequences-they were both higher on the fat-suppressed sequence. Intraobserver variability was within 4% for both sequences and different morphological types. The fibroglandular tissue volume measured on downsampled images showed a small (<5%) yet significant difference.
The measurement of breast density made on MRI acquired using fat-suppressed and nonfat-suppressed T1W images was about 5% difference, only slightly higher than the intraobserver variability of 3%-4%. When the density data from multiple centers were to be combined, evaluating the degree of difference is needed to take this difference into account.
探究在脂肪抑制和非脂肪抑制成像序列中测量的乳腺磁共振（MR）百分密度之间的差异。
对 38 例患者进行了具有和不具有脂肪抑制的乳腺磁共振成像（MRI）检查。将乳房分为不同形态模式（“中央”和“混杂”型）的亚组。测量乳房体积、纤维腺体组织体积和百分密度。使用非参数统计检验比较结果，并认为 p<0.05 具有统计学意义。
脂肪抑制和非脂肪抑制序列之间的乳房体积、纤维腺体体积和百分密度高度相关。这两种序列测量的乳房体积几乎相同。然而，纤维腺体组织体积和百分密度之间存在微小（<5%）但具有统计学意义的差异——脂肪抑制序列上的数值更高。两种序列和不同形态类型的观察者内变异性均在 4%以内。在降采样图像上测量的纤维腺体组织体积显示出微小（<5%）但具有统计学意义的差异。
使用脂肪抑制和非脂肪抑制 T1W 图像获得的 MRI 测量的乳腺密度差异约为 5%，仅略高于 3%-4%的观察者内变异性。当需要合并来自多个中心的密度数据时，需要评估这种差异的程度，并考虑到这种差异。
