目的与常规单次激发平面回波（Ss-EPI)弥散加权成像（DWI）比较，探讨读出方向分段采样平面回波（Rs-EPI）DWI序列在颅内占位性病变的临床应用价值。方法连续纳入临床诊断为颅内占位性病变的患者21例，采用SEIMENS Skyra 3.0T MRI及20通道的头颈联合线圈，行常规Ss-EPI DWI和Rs-EPI DWI序列扫描，由2名高年资影像诊断医师从对比噪声比（CNR）、信噪比（SNR）、伪影、图像整体质量及病变显示等方面进行评价分析。两种序列的图像质量比较采用非参数Wilcoxon符号秩和检验，2名阅片者之间一致性检测采用Kappa检验及组内相关系数（ICC）分析。结果21例患者均成功完成两组序列扫描。Ss-EPI DWI序列的SNR、CNR（130.46±49.10，33.22±18.86）高于Rs-EPI DWI序列（71.58±30.43，17.92±18.72）（P均<0.05）。鼻窦旁、乳突气房旁、额窦旁Rs-EPI DWI畸变伪影（3.67±0.48，3.57±0.50，3.90±0.30）小于Ss-EPI DWI（2.10±0.10，2.33±0.58，2.80±0.60）（P均<0.05）；Rs-EPI DWI病变显示优于Ss-EPI DWI（3.95±0.22 vs. 3.19±0.60，P<0.05）；Rs-EPI DWI图像整体质量优于Ss-EPI DWI（3.86±0.86 vs. 2.71±0.46，P<0.05）。Rs-EPI DWI图像变形小于Ss-EPI DWI（0.016±0.021 vs. 0.037±0.069，P=0.00）。2名阅片者对两种序列的主观及客观评价一致性好〔0.74≤Kappa值或ICC≤0.92〕。结论Rs-EPI DWI序列提高颅内占位性病变显示情况，降低了图像畸变伪影，可获得高分辨、高图像质量的弥散加权图像。
英文摘要:
Objective To explore the clinical value of readout-segmented echo planar imaging (Rs-EPI) sequence in the assessment of intracranial mass lesions compared to the standard single-shot EPI (Ss-EPI) sequence. Methods We included 21 patients with intracranial mass lesions who underwent both Ss-EPI diffusion weighted imaging（DWI）and Rs-EPI DWI at 3.0T MR scanner with a twenty-channel head-neck coil. The quality of images was assessed by two experienced radiologists independently. The differences in image quality between two sequences were analyzed using Wilcoxon signed-rank test. Inter-observer agreements were analyzed using interclass correlation coefficient （ICC） and Kappa test. Results All objectives were completed on 3.0T MR. The signal-to-noise ratio（SNR） and contrast-to-noise ratio （CNR） in Rs-EPI DWI were higher than those in Ss-EPI DWI (130.46±49.10 vs. 71.58±30.43，P=0.000; 33.22±18.86 vs. 17.92±18.72，P=0.003). The scores of overall image quality, ghost artifact where next to the paranasal sinuses，mastoid air cells and frontal sinus of Rs-EPI DWI were significantly higher than those of Ss-EPI DWI. Meanwhile, the geometric distortion of anatomical structures of Rs-EPI DWI were significantly lower compared to Ss-EPI DWI sequence (0.016±0.021 vs. 0.037±0.069，P=0.00). The inter-reader and intra-reader agreements for the assessment of qualitative parameters were good 〔0.74≤Kappa value or ICC≤0.92〕.Conclusion Rs-EPI DWI sequence is a potential technique to improve the imaging quality in the diagnosis of intracranial mass lesions.
