磁共振STIR-EPI序列在肺良恶性结节鉴别诊断中的应用

The value of MR diffusion weighted imaging with STIR-EPI sequence for differentiating benign from malignant pulmonary nodules

目的探讨磁共振STIR-EPI序列在良恶性肺结节鉴别诊断中的临床应用价值。方法对CT平扫发现肺结节且未进行放、化疗的97例患者进行MR常规扫描及STIR-EPI序列弥散加权成像。观察肺结节的MRI形态学表现,并对肺结节的信号强度进行评分,测量其表观弥散系数(ADC)值与信噪比(SNR)值。结果 MR对肺结节形态学的细微结构的显示并不优于CT(P>0.05),但对肺结节宽基底与胸膜相连征的显示优于CT,对鉴别诊断有意义(χ2=7.762,P=0.005);恶性肺结节的信号强度评分(3.93±1.26)明显高于良性结节(2.26±1.37),其差异具有统计学意义(t=-3.629,P=0.001);恶性肺结节的ADC值(1.392±0.237)×10 mm-3/s)明显低于良性结节(1.948±0.416)×10 mm-3/s,两者差异具有统计学意义(t=2.874,P=0.006);恶性肺结节的SNR值(275.01±77.33)明显高于良性结节(195.63±58.27),两者差异具有统计学意义(t=0.629,P=0.033)。结论磁共振STIR-EPI序列弥散加权成像非常有助于良、恶性肺结节的鉴别诊断,可成为肺结节定性诊断的重要手段。

Objectve To assess the value of MR diffusion weighted imaging（DWI） with short time inversion recovery echo planar imaging（STIR-EPI） sequence for differentiating benign from malignant pulmonary nodules（PNs）.Methods Ninety-seven patients with PNs confirmed by plain CT scans but without radiotherapy and chemotherapy were examined by routine MRI and MR DWI-EPI sequence.The observation of PN shape and the measurement of the signal intensity score of DWI,apparent diffusion coefficient（ADC） value and signal-noise ratio（SNR） value of PNs were performed in all patients.Results No statistical difference was found in subtle morphological manifestation of PNs on MRI and CT images（P 0.05）,except widened base attached to pleura sign（χ2 =7.762,P = 0.005）.The signal intensity score of malignant PNs（3.93±1.26） was significantly higher than that（2.26±1.37） of benig PNs（P = 0.001）.The ADC value（×10 mm-3/s） of malignant PNs（1.392±0.237） was significantly lower than that（1.948±0.416） of benign PNs（P = 0.006）.The SNR value of matignant PNs（275.01±77.33） was significantly higher than that（195.63±58.27） of benign PNs（P = 0.033）.Conclusion MR DWI with STIR-EPI sequence is very helpful to differentiate benign from malignant PNs and it can be taken as an important modality in the definite diagnosis of PNs.