双指数扩散及扩散峰度成像鉴别诊断乳腺良恶性病变

目的 评价双指数体素内相位不相干运动成像（IVIM）及扩散峰度成像（DKI）在乳腺良恶性病变鉴别诊断中的价值。方法 回顾性分析经穿刺或手术病理证实的44例乳腺病变患者，术前均接受常规DWI、IVIM扩散成像及DKI，获得ADC、扩散系数（D）、灌注相关扩散系数（D^*）、灌注分数（f）、平均峰度（MK）、轴向扩散峰度（AK）及径向扩散峰度（RK）值。比较乳腺良恶性病变间IVIM及DKI参数的统计学差异，并利用ROC曲线评价其鉴别诊断效能。结果 44例病例共52个病灶，其中恶性30个，良性22个。良恶性病灶间ADC值差异无统计学意义（P=0.080）。IVIM参数中，恶性病变D值显著下降（P<0.001），而D^*值和f值差异无统计学意义（P均>0.05）。DKI参数中，恶性病变MK值和AK值显著升高（P均<0.001），而RK值差异无统计学意义（P=0.060）。D值、MK值及AK值诊断乳腺良恶性病变的ROC曲线的AUC分别为0.942，0.957和0.975，其敏感度、特异度分别为88.89%、81.82%，90.90%、88.89%和95.50%、88.78%。结论 IVIM和DKI参数中的D、MK及AK值有助于鉴别乳腺良恶性病变。

Bi-exponential diffusion and diffusion kurtosis imaging in differential diagnosis of benign and malignant breast lesions

Objective To explore the application value of bi-exponential intravoxel voxel incoherent imaging (IVIM) and diffusion kurtosis imaging (DKI) in differential diagnosis of benign and malignant breast lesions. Methods Totally 44 patients with breast lesions confirmed by biopsy or surgical pathology were retrospectively analyzed. All patients underwent conventional DWI, IVIM diffusion imaging and DKI imaging before operation. ADC, diffusion coefficient (D), perfusion-related diffusion coefficient (D^*), perfusion fraction (f), mean kurtosis (MK), axial kurtosis (AK) and radial kurtosis (RK) values of benign and malignant breast lesions were measured and compared. ROC curve was used to evaluate the differential diagnostic efficacy. Results There were 52 lesions in 44 patients, including 30 malignant lesions and 22 benign lesions. The ADC value showed no significant difference between malignant and benign lesions (P=0.080). In IVIM parameters, D value of malignant lesions significantly decreased (P<0.001), while there was no significant difference of D^* value and f value between benign and malignant breast lesions (both P>0.05). For DKI parameters, the values of MK and AK in malignant lesions significantly increased (both P<0.001), while the values of RK were not significantly different between benign and malignant breast lesions (P=0.060). The AUC of D, MK and AK value was 0.942, 0.957 and 0.975, respectively. The sensitivity and specificity of D were 88.89% and 81.82%, of MK were 90.90% and 88.89%, of AK were 95.50% and 88.78%, respectively. Conclusion D, MK and AK derived from IVIM and DKI can help to differentiate benign and malignant breast lesions.