Abhilash Rakkunedeth H, Chauhan Sunita, Che Ma Voon, Ooi Chin-Chin, Bakar Rafidah Abu, Lo Richard H G
Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Alberta, Canada.
Biomechatronics Devices and Systems, BiDS Group, Department of MAE, Monash University, Clayton, Victoria, Australia.
Ultrasound Med Biol. 2016 Jul;42(7):1681-8. doi: 10.1016/j.ultrasmedbio.2016.01.015. Epub 2016 Apr 25.
Respiration-induced movement of abdominal organs hampers the targeting accuracy of non-invasive surgical techniques such as focused ultrasound surgery and radiosurgery. Unaccounted organ movement can result in either under dosage or damage to intervening healthy tissues. The respiration-induced movement is known to be significantly large in kidneys; however, the impact of abnormalities such as tumors and cysts on kidney movement is poorly understood. In this study, we quantified the movement patterns of kidneys in 48 normal and 62 affected kidneys (43 calcified cysts, 11 angiomyolipomas, 4 renal cell carcinomas and 4 polycystic kidneys) using ultrasound and simultaneously tracked the respiratory movement patterns using a stereo camera system. The kidneys were localized from 2-D ultrasound sequences using a template matching technique. The average movements of the right and left kidneys were, respectively, 24.54 ± 6.4 and 17.06 ± 3.66 mm in the superior-inferior and 13.62 ± 3.71 and 9.80 ± 3.32 mm in the transverse directions. Average movement in the superior-inferior direction of normal kidneys was greater than that of affected kidneys for both right (26.9 ± 5.1 vs. 22.6 ± 3.3, p < 0.001) and left (17.8 ± 2.5 vs. 16.1 ± 4.2, p = 0.01) kidneys. On the basis of spatial extent of abnormality, affected kidneys were categorized as category A (<10 mm in 26 patients), category B (10-20 mm in 22 patients) and category C (>20 mm in 14 patients). Compared with normal patients, the extent of movement was significantly reduced in abnormal categories B (p < 0.001) and C (p < 0.001), but the change was not significant in category A (p = 0.04). Hysteresis plots of the kidneys revealed a maximum change of 12.3 mm. The movement patterns of the kidneys also closely correlated with the respiratory movement pattern (Pearson correlation = 0.89 [right] and 0.87 [left]). We expect that the movement pattern analyses and quantification carried out in this study would aid in developing movement adaptive surgical protocols for non-invasive treatment of kidney tumors/cancers.
呼吸引起的腹部器官运动妨碍了聚焦超声手术和放射外科等非侵入性手术技术的靶向准确性。未考虑到的器官运动可能导致剂量不足或对中间健康组织造成损伤。已知呼吸引起的肾脏运动幅度很大;然而,肿瘤和囊肿等异常情况对肾脏运动的影响却知之甚少。在本研究中,我们使用超声对48个正常肾脏和62个病变肾脏(43个钙化囊肿、11个血管平滑肌脂肪瘤、4个肾细胞癌和4个多囊肾)的运动模式进行了量化,并使用立体相机系统同时跟踪呼吸运动模式。利用模板匹配技术从二维超声序列中定位肾脏。右肾和左肾在上下方向的平均运动分别为24.54±6.4和17.06±3.66毫米,在横向方向分别为13.62±3.71和9.80±3.32毫米。正常肾脏在上下方向的平均运动在右肾(26.9±5.1对22.6±3.3,p<0.001)和左肾(17.8±2.5对16.1±4.2,p=0.01)方面均大于病变肾脏。根据异常的空间范围,将病变肾脏分为A类(26例患者<10毫米)、B类(22例患者10-20毫米)和C类(14例患者>20毫米)。与正常患者相比,B类(p<0.001)和C类(p<0.001)异常患者的运动幅度明显减小,但A类患者的变化不显著(p=0.04)。肾脏的滞后图显示最大变化为12.3毫米。肾脏的运动模式也与呼吸运动模式密切相关(皮尔逊相关系数=右肾0.89,左肾0.87)。我们期望本研究中进行的运动模式分析和量化将有助于制定针对肾肿瘤/癌症非侵入性治疗的运动自适应手术方案。