Department of Radiology, NYU Langone Medical Center, New York, New York, USA.
J Magn Reson Imaging. 2013 Jan;37(1):164-71. doi: 10.1002/jmri.23794. Epub 2012 Nov 27.
To establish the utility of apparent diffusion coefficient (ADC) entropy in discrimination of benign and malignant adnexal lesions, using histopathology as the reference standard, via comparison of the diagnostic performance of ADC entropy with mean ADC and with visual assessments of adnexal lesions on conventional and diffusion-weighted sequences.
In all, 37 adult female patients with an ovarian mass that was resected between June 2006 and January 2011 were included. Volume-of-interest was drawn to incorporate all lesion voxels on every slice that included the mass on the ADC map, from which whole-lesion mean ADC and ADC entropy were calculated. Two independent radiologists also rated each lesion as benign or malignant based on visual assessment of all sequences. The Mann-Whitney test and logistic regression for correlated data were used to compare performance of mean ADC, ADC entropy, and the visual assessments.
No statistically significant difference was observed in mean ADC between benign and malignant adnexal lesions (P = 0.768). ADC entropy was significantly higher in malignant than in benign lesions (P = 0.009). Accuracy was significantly greater for ADC entropy than for mean ADC (0.018). ADC entropy and visual assessment by the less-experienced reader showed similar accuracy (P ≥ 0.204). The more experienced reader's accuracy was significantly greater than that of all other assessments (P ≤ 0.039).
ADC entropy showed significantly greater accuracy than the more traditional metric of mean ADC for distinguishing benign and malignant adnexal lesions. Although whole-lesion ADC entropy provides a straightforward and objective measurement, its potential benefit decreases with greater reader experience.
通过比较 ADC 熵与平均 ADC 及常规和弥散加权序列上附件病变的视觉评估对附件良恶性病变的诊断效能，确定表观弥散系数（ADC）熵在鉴别附件良恶性病变中的作用，以组织病理学为参考标准。
回顾性分析 2006 年 6 月至 2011 年 1 月期间行卵巢肿块切除术的 37 例成年女性患者资料，在 ADC 图上勾画包括肿块在内的所有病变的感兴趣区，计算全病变平均 ADC 和 ADC 熵。两名独立的放射科医生也根据所有序列的视觉评估将每个病变评为良性或恶性。采用 Mann-Whitney 检验和相关数据的 logistic 回归比较平均 ADC、ADC 熵和视觉评估的性能。
良性和恶性附件病变的平均 ADC 无统计学差异（P = 0.768）。恶性病变的 ADC 熵明显高于良性病变（P = 0.009）。ADC 熵的准确率明显高于平均 ADC（0.018）。经验较少的观察者的 ADC 熵和视觉评估具有相似的准确率（P≥0.204）。经验丰富的观察者的准确率明显高于其他所有评估（P≤0.039）。
ADC 熵在鉴别附件良恶性病变方面的准确率明显高于传统的平均 ADC 指标。虽然全病变 ADC 熵提供了一种简单、客观的测量方法，但随着观察者经验的增加，其潜在的益处会降低。
