扩散加权成像及表观扩散系数在评估克罗恩病活动度中的诊断价值：1.5T或3T

OBJECTIVE

The objective of this study is to evaluate the role of diffusion-weighted imaging (DWI) in assessment of the activity of Crohn disease (CD) and to explore differences between DWI in 3 T and 1.5 T.

METHODS

Postcontrast magnetic resonance enterography with DWI of 72 patients with pathological proof of CD was retrospectively evaluated for restricted diffusion qualitatively and quantitavely in 3 T (n = 40) and 1.5 T (n = 32). Magnetic resonance activity score of 7 or higher was used as reference of activity.

RESULTS

Fifty-five patients had active lesions. Diffusion-weighted imaging hyperintensity showed sensitivity (100%, 100%) and specificity (88.89%, 100%) in 1.5/3 T for activity assessment. Mean ± SD apparent diffusion coefficient for active lesions was 1.21 ± 0.42 and 1.28 ± 0.59 × 10 mm/s in 1.5 and 3 T, respectively. The proposed cutoff values of 1.35 and 1.38 × 10 mm/s in 1.5 and 3 T, respectively, had sensitivity (80%, 93%), specificity (100%, 90%), accuracy (88%, 93%), and no significant difference in accuracy between 1.5/3 T (P = 0.48).

CONCLUSIONS

Diffusion-weighted imaging hypersensitivity and apparent diffusion coefficient values accurately assessed the activity of CD. No significant statistical difference in diagnostic accuracy was detected between 1.5 and 3 T.

目的

本研究旨在评估扩散加权成像（DWI）在评估克罗恩病（CD）活动度中的作用，并探讨3T和1.5T条件下DWI的差异。

方法

回顾性评估72例经病理证实为CD患者的增强磁共振肠造影及DWI图像，分别在3T（n = 40）和1.5T（n = 32）条件下对扩散受限进行定性和定量分析。以磁共振活动评分7分及以上作为活动度参考标准。

结果

55例患者有活动性病变。DWI高信号在1.5T/3T条件下评估活动度的敏感度为（100%，100%），特异度为（88.89%，100%）。1.5T和3T条件下活动性病变的平均表观扩散系数（Mean ± SD）分别为1.21 ± 0.42和1.28 ± 0.59×10⁻³mm²/s。1.5T和3T条件下分别设定的表观扩散系数截断值1.35×10⁻³mm²/s和1.38×10⁻³mm²/s，敏感度分别为（80%，93%），特异度分别为（100%，90%），准确度分别为（88%，93%），1.5T/3T之间准确度无显著差异（P = 0.48）。