1 School of Electronic and Information Engineering, Beijing Jiaotong University, No. 3 Shangyuancun, Haidan District, Beijing, China, 100084.
AJR Am J Roentgenol. 2014 Mar;202(3):W247-53. doi: 10.2214/AJR.13.10917.
The purpose of this article is to investigate the effect of b values on apparent diffusion coefficient (ADC) values estimated from 1.5-T diffusion-weighted MRI (DWI) of the prostate acquired with an endorectal coil in distinguishing prostate cancer from normal-tissue regions of interest (ROIs) and the correlation of ADC values with the tumor Gleason score.
Pretreatment DWI studies were analyzed retrospectively in 51 consecutive patients with prostate cancer with either two (b=0 and 1000 s/mm2; n=26 patients) or five (b=0, 50, 200, 1500, and 2000 s/mm2; n=25 patients) b values. In 45 normal peripheral-zone ROIs and 65 prostate cancer ROIs (14 in the central gland), ADC values were estimated by use of several combinations of two or five b values and a monoexponential model. We used the area under the receiver operating characteristic curve to characterize the effectiveness of ADC values in distinguishing prostate cancer from normal-tissue ROIs, and we calculated Spearman rank-order correlation between ADC values and the Gleason score.
ADC values were often significantly different (p<0.001) when estimated from different combinations of two or five b values. However, except when both b values were less than or equal to 200 mm2/s or greater than or equal to 1500 mm2/s, the AUC value for distinguishing prostate cancer from normal-tissue ROIs was similar (0.88-0.93). The correlation coefficients between ADC values and the Gleason score were between -0.30 and -0.68.
The choice of b values can significantly affect ADC estimates. ADC values can produce a similar discriminant performance in distinguishing prostate cancer from normal-tissue ROIs and in correlation with the Gleason score, but an appropriate ADC cutoff value needs to be selected specifically for each b-value combination.
本文旨在研究在使用直肠内线圈于 1.5-T 场强下进行前列腺弥散加权磁共振成像（DWI）时，b 值对表观弥散系数（ADC）值的影响，以区分前列腺癌与正常组织感兴趣区（ROI），并分析 ADC 值与肿瘤 Gleason 评分的相关性。
回顾性分析 51 例经直肠内线圈进行前列腺癌弥散加权成像（b 值分别为 0 和 1000 s/mm2，n=26 例；b 值分别为 0、50、200、1500 和 2000 s/mm2，n=25 例）的预处理 DWI 资料。在 45 例正常外周带 ROI 和 65 例前列腺癌 ROI（中央叶 14 例）中，使用双 b 值或五 b 值组合的单指数模型来估计 ADC 值。我们使用受试者工作特征曲线下面积来评价 ADC 值在区分前列腺癌与正常组织 ROI 中的有效性，并计算 ADC 值与 Gleason 评分之间的 Spearman 秩相关系数。
当使用不同的双 b 值或五 b 值组合来估计 ADC 值时，ADC 值往往有显著差异（p<0.001）。然而，当双 b 值均小于或等于 200 mm2/s 或大于或等于 1500 mm2/s 时，ADC 值鉴别前列腺癌与正常组织 ROI 的 AUC 值相似（0.88-0.93）。ADC 值与 Gleason 评分之间的相关系数在-0.30 到-0.68 之间。
b 值的选择会显著影响 ADC 值的估计。ADC 值在区分前列腺癌与正常组织 ROI 以及与 Gleason 评分相关方面有相似的判别性能，但需要针对每种 b 值组合选择合适的 ADC 截断值。
Zotero 插件