目的 前瞻性评估乳腺良恶性病灶的增强形态、时间-信号强度曲线形态、早期增强率以及鉴别病变的价值。方法 40例乳腺病变行三维动态增强MRI检查，在工作站上绘制时间-信号强度曲线并计算早期增强率，分别根据病灶增强形态、时间-信号强度曲线分型和早期增强率大小诊断病变的良恶性。结果 40例41个病灶经病理证实,恶性病灶23个,良性病灶18个。良性病变边缘77.8%（14/18）为光滑或分叶,16.7%(3/18) 为不规则或毛刺,早期增强率为(55.5±28.3)%, 时间-信号强度曲线72%(13/18)为单相型;恶性病变边缘82.6%(19/23)为不规则或毛刺, 13%（3/23）为光滑或分叶,早期增强率为(90.5±38.6)%, 时间-信号强度曲线78.3%(18/23)为流出型。良恶性病变的形态分布、时间-信号强度曲线类型和早期增强率差异有显著性意义(χ2值分别为18.42、20.68、10.38, P值均<0.01)。病灶增强形态诊断的敏感性82.6%（19/23）,特异性77.8%（14/18）。时间-信号强度曲线诊断的敏感性95.7%（22/23），特异性72.2%（13/18）。早期增强率诊断的敏感性87%（20/23）,特异性61.1%（11/18）。结论 典型毛刺状形态和流出型时间-信号强度曲线均强烈提示恶性；单相型时间-信号强度曲线强烈提示良性；早期增强率诊断的特异性差。
Objective To prospectively evaluate the diagnostic ability of the lesions′ morphology, signal intensity time course, and early phase enhancement rate in dynamic MRI of the breast. Methods Forty cases with breast lesions were examined with a new Efgre 3D dynamic MR imaging series. Time signal intensity curves of the lesions were obtained and classified according to their shapes as monophasic, biphasic, or washout. Early phase enhancement rates of the lesions were calculated. The diagnostic indices were got by lesions′ morphology criterion, the time signal intensity curves criterion, and the enhancement rate criterion. Results There were 23 malignant and 18 benign lesions. The distribution of curve types for malignant lesions was monophasic (5%), biphasic (18%), and washout (77%). The distribution of curve types for benign lesions was monophasic (72%), biphasic (11%), and washout (17%). The distribution proved significantly difference (χ 2=20.68, P <0.001). The early phase enhancement rates of benign lesions (55.5±28.3)% and malignant lesions (90.5± 38.6)% were statistically different ( t =3.189 , P =0.003).The diagnostic indices for the lesions′ morphology had the sensitivity of 82.6%(19/23) and specificity of 77.8% (14/18). The diagnostic indices for time signal intensity curves had the sensitivity of 95.7% (22/23) and specificity of 72.2% (13/18). The diagnostic indices for the enhancement rate had the sensitivity of 87% (20/23) and specificity of 61.1% (11/18). Conclusions A spiculated border, or a washout time course is a strong indicator of malignancy. A monophasic time course is a strong indicator of benign lesions. The early phase enhancement rate has a poor specificity.
Chinese Journal of Radiology