From the Molecular Imaging Branch, Division of Convergence Technology, National Cancer Center, Research Building, Ilsanro-323, Ilsandong-gu, Goyang 10408, Korea.
Radiology. 2018 May;287(2):476-484. doi: 10.1148/radiol.2017171603. Epub 2018 Jan 24.
Purpose To investigate whether high-intensity focused ultrasound (HIFU)-induced macrophage infiltration could be longitudinally monitored with fluorine 19 (F) magnetic resonance (MR) imaging in a quantitative manner. Materials and Methods BALB/c mice were subcutaneously inoculated with 4T1 cells and were separated into three groups: untreated mice (control, n = 9), HIFU-treated mice (HIFU, n = 9), and HIFU- and clodronate-treated mice (HIFU+Clod, n = 9). Immediately after HIFU treatment, all mice were intravenously given perfluorocarbon (PFC) emulsion. MR imaging examinations were performed 2, 4, 7, 10, and 14 days after HIFU treatment. Two-way repeated measures analysis of variance was used to analyze the changes in F signal over time and differences between groups. Histologic examinations were performed to confirm in vivo data. Results Fluorine 19 signals were detected at the rims of tumors and the peripheries of ablated lesions. Mean F signal in tumors was significantly higher in HIFU-treated mice than in control mice up to day 4 (0.82 ± 0.26 vs 0.42 ± 0.17, P < .001). Fluorine 19 signals were higher in the HIFU+Clod group than in the control group from day 4 (0.82 ± 0.23, P < .001) to day 14 (0.55 ± 0.16 vs 0.28 ± 0.06, P < .05). Histologic examination revealed macrophage infiltration around ablated lesions. Immunofluorescence staining confirmed PFC labeling of macrophages. Conclusion Fluorine 19 MR imaging can longitudinally capture and quantify HIFU-induced macrophage infiltration in preclinical tumor models. RSNA, 2018 Online supplemental material is available for this article.
目的 探讨氟 19（F）磁共振（MR）成像是否可定量监测高强度聚焦超声（HIFU）诱导的巨噬细胞浸润。
材料与方法 BALB/c 小鼠皮下接种 4T1 细胞，分为 3 组：未处理组（对照组，n = 9）、HIFU 处理组（HIFU 组，n = 9）和 HIFU 联合氯膦酸二钠（Clod）处理组（HIFU+Clod 组，n = 9）。HIFU 治疗后立即，所有小鼠均经静脉给予全氟碳（PFC）乳剂。HIFU 治疗后 2、4、7、10 和 14 天进行 MR 成像检查。采用双因素重复测量方差分析比较不同时间点 F 信号的变化和组间差异。行组织学检查以确认体内数据。
结果 F 信号在肿瘤边缘和消融病灶周边被检测到。与对照组相比，HIFU 治疗组的肿瘤 F 信号在 4 天内均显著升高（0.82 ± 0.26 比 0.42 ± 0.17，P <.001）。HIFU+Clod 组在第 4 天（0.82 ± 0.23，P <.001）至第 14 天（0.55 ± 0.16 比 0.28 ± 0.06，P <.05）的 F 信号均高于对照组。组织学检查显示消融病灶周围有巨噬细胞浸润。免疫荧光染色证实了 PFC 标记的巨噬细胞。
结论 F 磁共振成像可在临床前肿瘤模型中对 HIFU 诱导的巨噬细胞浸润进行纵向捕获和定量。
放射学学会，2018 年 在线补充材料可从本文网址获取。
