Daoudi Khalid, Hoogenboom Martijn, den Brok Martijn, Eikelenboom Dylan, Adema Gosse J, Fütterer Jürgen J, de Korte Chris L
Department of Radiology and Nuclear Medicine, Medical UltraSound Imaging Centre, Radboud University Nijmegen Medical Centre, Netherlands.
Department of Radiology and Nuclear Medicine, Radboud University Nijmegen Medical Centre, Netherlands.
Biomed Opt Express. 2017 Mar 20;8(4):2235-2244. doi: 10.1364/BOE.8.002235. eCollection 2017 Apr 1.
The thermal effect of high intensity focused ultrasound (HIFU) has been clinically exploited over a decade, while the mechanical HIFU is still largely confined to laboratory investigations. This is in part due to the lack of adequate imaging techniques to better understand the pathological and immunological effects caused by the mechanical treatment. In this work, we explore the use of high frequency ultrasound (US) and photoacoustics (PA) as a potential tool to evaluate the effect of mechanical ablation , e.g. boiling histotripsy. Two mice bearing a neuroblastoma tumor in the right leg were ablated using an MRI-HIFU system conceived for small animals and monitored using MRI thermometry. High frequency US and PA imaging were performed before and after the HIFU treatment. Afterwards, the tumor was resected for further assessment and evaluation of the ablated region using histopathology. High frequency US imaging revealed the presence of liquefied regions in the treated area together with fragmentized tissue which appeared with different reflecting proprieties compared to the surrounding tissue. Photoacoustic imaging on the other hand revealed the presence of deoxygenated blood within the tumor after the ablation due to the destruction of blood vessel network while color Doppler imaging confirmed the blood vessel network destruction within the tumor. The treated area and the presence of red blood cells detected by photoacoustics were further confirmed by the histopathology. This feasibility study demonstrates the potential of high frequency US and PA approach for assessing the effect of mechanical HIFU tumor ablation.
高强度聚焦超声（HIFU）的热效应已在临床上应用了十多年，而机械HIFU仍主要局限于实验室研究。部分原因是缺乏足够的成像技术来更好地理解机械治疗所引起的病理和免疫效应。在这项工作中，我们探索使用高频超声（US）和光声（PA）作为评估机械消融（例如沸腾组织粉碎术）效果的潜在工具。使用专为小动物设计的MRI-HIFU系统对两只右腿患有神经母细胞瘤肿瘤的小鼠进行消融，并使用MRI温度测量法进行监测。在HIFU治疗前后进行高频US和PA成像。之后，切除肿瘤以使用组织病理学进一步评估和评价消融区域。高频US成像显示治疗区域存在液化区域以及破碎组织，与周围组织相比，这些组织呈现出不同的反射特性。另一方面，光声成像显示消融后肿瘤内存在脱氧血液，这是由于血管网络被破坏所致，而彩色多普勒成像证实了肿瘤内血管网络的破坏。组织病理学进一步证实了光声检测到的治疗区域和红细胞的存在。这项可行性研究证明了高频US和PA方法在评估机械HIFU肿瘤消融效果方面的潜力。
