中文摘要：

目的 探讨扩散峰度成像（DKI）鉴别乳腺良、恶性病变的价值,以及DKI联合DWI和氢质子磁共振频谱（1H-MRS）对乳腺病变的诊断效能.方法 回顾性分析经穿刺活检或手术病理证实的53例乳腺病变,恶性肿瘤38例、良性肿瘤15例.患者均行常规T1WI和T2WI、DWI、DKI和1H-MRS扫描,观察病变形态和边缘,并测量ADC、平均扩散率（MD）及平均峰度值（MK值）,观察胆碱（Cho）峰是否出现.采用独立样本t检验（正态分布计量资料）或χ2检验（计数资料）比较良性组和恶性组间患者一般情况、病变形态及边缘和测量参数间的差异;以病理结果 为金标准,采用ROC评价DKI参数（MD、MK）及其结合ADC、Cho的诊断效能.结果 乳腺恶性病变组患病年龄高于良性组,绝经后女性多见,病灶边缘不清,与良性组差异均有统计学意义（P〈0.05）;良、恶性病变患者的体质量指数、纤维腺体类型及病灶大小形态的差异无统计学意义（P〉0.05）.良性组的ADC、MD和MK值分别为（1.464±0.348）×10^-3mm^2/s、（1.726±0.268）×10^-3mm^2/s和0.692±0.227,恶性组分别为（0.963±0.170）×10^-3mm^2/s、（1.158±0.262）×10^-3mm^2/s和1.311±0.218,差异均有统计学意义（P〈0.05）.ADC、MD及MK鉴别诊断乳腺良、恶性病变的ROC下面积分别为0.913、0.933、0.968.以1.110为最佳切点值,MK诊断的敏感度、特异度和准确度分别为89.5%（34/38）、93.3%（14/15）和90.6%（48/53）,优于Cho、ADC及MD.DKI参数和DWI、1H-MRS参数结合,诊断特异度提高,可达100.0%;但敏感度下降,最高仅81.6%,最低为71.1%.结论 DKI鉴别诊断乳腺良、恶性病变具有价值,MK的诊断效能较高.DKI联合DWI和1H-MRS诊断的特异度提高,但敏感度下降.

英文摘要：

Objective To evaluate the diagnostic performance of diffusion kurtosis imaging （DKI） and its combination with DWI and proton MR spectroscopy （1H-MRS） in differentiating malignancy from benign breast lesions. Methods Fifty-three patients with 38 histopathologically confirmed malignant and 15 benign breast lesions were retrospectively studied. The patients were examined by breast MRI at 3.0 T prior to operation, including conventional T1WI, fat-suppression imaging, DWI, DKI and 1H-MRS. The shape and margin of breast lesions, and their corresponding mean values for ADC, mean kurtosis （MK） and mean diffusivity （MD） were determined by two blinded radiologists in consensus. The presence or absence of choline （Cho） peak was identified using LCModel software. Independent-samples t test or χ2 test was performed for the comparison of clinical characteristics, shape and margin of lesions, and imaging parameters between malignancy and benign lesions. ROC analysis was performed to evaluate the diagnostic accuracy of DKI, DWI and 1H-MRS alone or in combination, in comparison with the histopathologic findings. Results The onset age of breast malignancy was higher than that of benign ones, and the difference has statistical significant （P〈0.05）. Malignant lesions were most often seen in postmenopausal women, with unclear margin. There was no significant differences for body mass index （BMI）, fiber type, the size and shape of lesions between benign lesions and malignancy （P〉0.05）. The mean ADC,MD and MK of benign lesions were（1.464 ± 0.348）×10^-3mm^2/s,（1.726 ± 0.268）×10^-3mm^2/s and（0.692 ± 0.227）, the mean ADC,MD and MK of malignancy were（0.963 ± 0.170）×10^-3mm^2/s,（1.158 ± 0.262）×10^-3mm^2/s and（1.311 ± 0.218）, respectively. Significant differences were obtained between benign and malignant lesions for all parameters （P〈0.05）.The area under the ROC curve （AUC） of ADC, MD and MK for differentiating malignancy from benign lesions was 0.913, 0.933 an