中文摘要：

目的通过比较原发性肝癌高强度聚焦超声（HIFU）治疗前后胆碱峰、脂质峰下积分面积及胆碱／脂质峰下积分面积比值的变化，探讨磁共振氢质波谱成像（^1HMRS）在HIFU治疗原发性肝癌疗效评估中的价值及可行性。方法24例原发性肝癌患者于HIFU治疗前及治疗后2周内行常规磁共振平扫及动态增强扫描。以呼吸触发的横轴位T2WI为定位像，在增强扫描前加扫单体素点分辨波谱序列。将波谱数据传输至个人电脑，采用Saker软件进行后处理。基线平稳、主要代谢物波峰可辨认且无重叠者视为技术成功，测量化学移位3．2ppm（磁共振频率的百万分之一）处胆碱峰及1．3ppm处脂质峰下积分面积，计算胆碱／脂质峰下积分面积比值。治疗前后峰下积分面积及积分面积比值差异的比较采用配对t检验，P〈0．05为差异有统计学意义。结果对24例患者的48次^1H—MRS检查中，成功率为87．50％（42／48），谱线图上可见4．7～4．8ppm处高而尖的水峰、3．2ppm处较水峰低的胆碱峰及1．3ppm处脂质峰。对20例获得满意谱线患者的20个感兴趣区，测量HIFU治疗前后的胆碱峰及脂质峰下积分面积，并计算胆碱／脂质峰下积分面积比值，结果发现HIFU治疗后，胆碱峰下积分面积明显减小（6372±2466比34597±6802，t=18．02，P〈0．01），脂质峰下积分面积增大（149069±16345比147948±16317，t=-15．11，P〈0．01），胆碱／脂质峰下积分面积比值明显降低（0．04±0．02比0．23±0．03，t=25．32，P〈0．01）。结论^1H—MRS评价原发性肝癌HIFU治疗后代谢产物变化可行，可作为其他磁共振波谱成像序列的补充。

英文摘要：

Objective To investigate the clinical value of ^1H magnetic resonance spectroscopy （^1H MRS） in the evaluation of high intensity focused ultrasound （HIFU） ablation for primary liver cancer. Methods Routine magnetic resonance sequences, contrast-enhanced magnetic resonance imaging and respiratory-triggered single voxel point resolved spectroscopy sequence （PRESS） were performed on 24 patients with primary liver cancer before and after HIFU ablation. A respiratory-triggered axial T2 weighted imaging （T2WI） was used as localizer for PRESS. Spectroscopy data was transmitted to a personal computer and was post-processed with a custom software （Saker, provided by Ning Jing, an engineer in GE Healthcare）. It would be considered ＂technical success＂ if the baselines of spectra were stable and main metabolites were without overlapping and could be identified. Integral areas of choline （Cho） peak at 3.2 parts per million （ppm） and lipid （Lip） peak at 1.3 ppm were measured, and the choline to lipid （Cho/Lip） ratios were calculated. The differences of areas of Cho, Lip peak and Cho/Lip ratios before and after HIFU ablation were compared by using paired samples t test, and a P value of less than 0.05 was considered statistically significant. Results The technical success rate of 1H-MRS was 87.50% （42/48）. Integral areas of Cho peak and Lip peak of 20 patients with satisfied spectra were measured, and the Cho/Lip ratios were calculated. The Integral area of Cho peak decreased from 34 597 ± 6 802 before HIFU ablation to 6 372 ± 2 466 after HIFU ablation （t = 18.02, P 〈 0.01）. The Integral area of Lip peak increased from 147 948 ± 16 317 before HIFU ablation to 149 069 ± 16 345 after HIFU ablation （t = -15.11, P 〈 0.01）. The Cho/Lip ratio decreased from 0.23 ±0.03 before HIFU ablation to 0.04 ± 0.02 after HIFU ablation （t = 25.32, P 〈 0.01）. Conclusion ^1H-MRS could provide information of metabolites changes of primary liver cancer after HIFU ablation and could b