Objective: To investigate the diagnostic value of PET/MRI for malignant pleural effusion (MPE), and compare its diagnostic difference with PET/CT. Methods: The data of 57 patients with suspected MPE admitted into Union Hospital of Tongji Medical College of Huazhong University of Science and Technology from October 2017 to January 2020 was analyzed. A total of 53 patients were included in the prospective study, and the whole body PET/CT and thoracic PET/MRI were performed on them respectively. Two physicians used a blind method to evaluate the morphological features of PET/CT and PET/MRI images, delineate the region of interest (ROI), obtain the maximum standard uptake value (SUVmax) of the ROI in the PET/CT and PET/MRI images. The target-to-background ratio (TBR) of the lesion was calculated. The diffusion-weighted imaging (DWI) characteristics of the pleura in PET/MRI images were analyzed. Taking pathological diagnosis as the gold standard, the diagnostic effect of PET/CT and PET/MRI on MPE were evaluated. Results: The 53 patients who were finally included were (62.8±1.7) years old, consisting of 31 males. Pathological results showed that 41 cases were MPE and 12 cases were benign pleural effusion (BPE). There were no statistical differences in age, gender and smoking history between the two groups (P>0.05). Bland-Altman analysis showed that the SUVmax of pleural lesions by PET/MRI was higher than that by PET/CT (6.4±0.6 vs 5.3±0.5, P<0.001). The TBR of PET/MRI was higher than that of PET/CT (2.2±0.2 vs 1.8±0.2, P<0.001). The sensitivity, specificity, and accuracy of PET/MRI in the diagnosis of MPE by combining imaging features such as SUVmax and DWI of pleural lesions were 75.6%, 100%, and 81.1%, respectively. The sensitivity, specificity, and accuracy of PET/CT combined with SUVmax and imaging features of pleural lesions in the diagnosis of MPE were 85.4%, 83.3%, and 77.4%, respectively. There was no statistically significant difference between PET/MRI and PET/CT in the area under the curve (AUC) for diagnosing MPE (0.934 vs 0.873, P>0.05). Conclusions: PET/MRI and PET/CT have the equivalent diagnostic efficiency for MPE. However, PET/MRI shows higher SUVmax and TBR for pleural lesions, and has specific pleural DWI imaging characteristics, which is worthy of further clinical research.
目的： 探讨PET/MRI对恶性胸腔积液（MPE）的诊断价值，并比较其与PET/CT的诊断差异。 方法： 前瞻性收集2017年10月至2020年1月在华中科技大学同济医学院附属协和医院就诊的57例疑似MPE的患者资料，最终纳入53例患者，分别对其进行全身PET/CT和胸腔PET/MRI检查。评估PET/CT和PET/MRI图像的形态学特征，勾画感兴趣区（ROI），获取PET/CT和PET/MRI图像中ROI的最大标准摄取值（SUVmax），计算出病灶的靶本比（TBR）。分析PET/MRI图像中胸膜的弥散加权成像（DWI）特征。以病理诊断为金标准，评价PET/CT和PET/MRI对MPE的诊断效果。 结果： 53例患者年龄（62.8±1.7）岁，男31例。病理结果显示41例为MPE，12例为良性胸腔积液（BPE）。两组之间年龄、性别和吸烟史差异均无统计学意义（P>0.05）。PET/MRI显示胸膜病灶的SUVmax高于PET/CT（6.4±0.6比5.3±0.5，P<0.001）。PET/MRI的TBR高于PET/CT（2.2±0.2比1.8±0.2，P<0.001）。PET/MRI通过联合胸膜病变部位SUVmax和DWI等影像学特征对MPE诊断的灵敏度、特异度、准确度分别为75.6%、100%、81.1%。而PET/CT联合胸膜病变部位SUVmax和影像学特征对MPE诊断的灵敏度、特异度、准确度分别为85.4%、83.3%、77.4%。PET/MRI和PET/CT对于诊断MPE的曲线下面积（AUC）差异无统计学意义（0.934比0.873，P>0.05）。 结论： PET/MRI与 PET/CT在MPE中的诊断效率相当。但PET/MRI对胸膜病灶显示更高的SUVmax和更高的TBR，并具有特异的胸膜DWI影像学特征，值得临床进一步研究。.