使用CEST MRI对人良性和恶性肝脏肿瘤细胞外pH值进行无创检测

Noninvasive Detection of Extracellular pH in Human Benign and Malignant Liver Tumors Using CEST MRI.

作者信息

Tang Yanyan, Xiao Gang, Shen Zhiwei, Zhuang Caiyu, Xie Yudan, Zhang Xiaolei, Yang Zhongxian, Guan Jitian, Shen Yuanyu, Chen Yanzi, Lai Lihua, Chen Yuanfeng, Chen Shuo, Dai Zhuozhi, Wang Runrun, Wu Renhua

机构信息

Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China.

Department of Medical Imaging, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China.

出版信息

Front Oncol. 2020 Nov 2;10:578985. doi: 10.3389/fonc.2020.578985. eCollection 2020.

DOI:10.3389/fonc.2020.578985

PMID:33224880

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7667286/

Abstract

PURPOSE

In this study, we aimed to use 3T magnetic resonance imaging (MRI), which is clinically available, to determine the extracellular pH (pHe) of liver tumors and prospectively evaluate the ability of chemical exchange saturation transfer (CEST) MRI to distinguish between benign and malignant liver tumors.

METHODS

Different radiofrequency irradiation schemes were assessed for ioversol-based pH measurements at 3T. CEST effects were quantified using the asymmetric magnetization transfer ratio (MTRasym) at 4.3 ppm from the corrected Z spectrum. Generalized ratiometric analysis was conducted by rationing resolved ioversol CEST effects at 4.3 ppm at a flip angle of 60 and 350°. Fifteen patients recently diagnosed with hepatic carcinoma and five patients diagnosed with hepatic hemangioma [1 male; mean age, 48.6 (range, 37-59) years] were assessed.

RESULTS

By conducting dual-power CEST MRI, the pH of solutions was determined to be 6.0-7.2 at 3T . In vivo, ioversol signal intensities in the tumor region showed that the extracellular pH in hepatic carcinoma was acidic(mean ± standard deviation, 6.66 ± 0.19), whereas the extracellular pH was more physiologically neutral in hemangioma (mean ± standard deviation, 7.34 ± 0.09).The lesion size was similar between CEST pH MRI and T2-weighted imaging.

CONCLUSION

dual-power CEST MRI can detect extracellular pH in human liver tumors and can provide molecular-level diagnostic tools for differentiating benign and malignant liver tumors at 3T.

摘要

目的

在本研究中，我们旨在利用临床可用的3T磁共振成像（MRI）来测定肝肿瘤的细胞外pH值（pHe），并前瞻性评估化学交换饱和转移（CEST）MRI区分肝脏良恶性肿瘤的能力。

方法

评估了不同的射频照射方案用于在3T下基于碘海醇的pH测量。使用校正后的Z谱中4.3 ppm处的不对称磁化转移率（MTRasym）对CEST效应进行量化。通过在60°和350°翻转角下对4.3 ppm处分辨的碘海醇CEST效应进行定量分析，进行广义比率分析。对15例近期诊断为肝癌的患者和5例诊断为肝血管瘤的患者[1名男性；平均年龄48.6（范围37 - 59）岁]进行了评估。

结果

通过进行双功率CEST MRI，确定3T下溶液的pH值为6.0 - 7.2。在体内，肿瘤区域的碘海醇信号强度表明，肝癌中的细胞外pH呈酸性（平均值±标准差，6.66±0.19），而血管瘤中的细胞外pH更接近生理中性（平均值±标准差，7.34±0.09）。CEST pH MRI和T2加权成像之间的病变大小相似。