对比自旋回波与平面回波弥散张量成像显示颞叶放射性脑病

Turbo spin echo and echo planar imaging diffusion tensor imaging for displaying temporal lobe radiation encephalopathy

目的对比自旋回波(TSE)弥散张量成像(DTI)与平面回波(EPI)DTI显示颞叶放射性脑病(REP)图像质量。方法前瞻性纳入30例疑REP进展的放射治疗后鼻咽癌患者,以5分制对TSE-DTI和EPI-DTI图像清晰度、磁化率伪影及变形程度进行主观评分,并对其平均弥散系数(MD)、各向异性分数(FA)、信噪比(SNR)、对比度噪声比(CNR)及失真率(DR)差异进行客观评价。结果TSE-DTI磁化率伪影及变形评分均高于EPI-DTI(P均<0.001)。REP边缘及正常脑组织FA均低于、SNR和CNR均高于EPI-DTI(P均<0.001),而REP病灶及双侧颞叶DR均低于EPI-DTI(P均<0.001)。结论相比EPI-DTI,TSE-DTI可通过减少图像磁化率伪影和变形而显著提高图像显示REP质量。

Objective To compare image quality of turbo spin echo(TSE)diffusion tensor imaging(DTI)and echo planar imaging(EPI)DTI for displaying temporal lobe radiation encephalopathy(REP).Methods Thirty nasopharyngeal carcinoma patients with suspected REP disease progression were prospectively enrolled.Subjective evaluation of image sharpness,susceptibility artifacts and deformation of TSE-DTI and EPI-DTI was performed using a 5-point scale,while objective evaluation aimed on the mean diffusion coefficient(MD),fractional anisotropic(FA),signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR)and distortion ratio(DR)were carried on.Results The susceptibility artifacts and deformation scores of TSE-DTI were higher than that of EPI-DTI(P<0.001).FA of REP edge and normal brain tissue were lower than those of EPI-DTI,with SNR and CNR higher than those of EPI-DTI(both P<0.001).DR of REP lesions and bilateral temporal lobes were lower than those of EPI-DTI(all P<0.001).Conclusion Compared with EPI-DTI,TSE-DTI could significantly improve image quality for displaying REP by reducing susceptibility artifacts and deformation of images.