基于阈值分割法的原发性下肢淋巴水肿成分分析初步研究  

A Preliminary Study on the Component Analysis of Primary Lower Extremity Lymphedema Based on the Threshold Segmentation Method

作　　者：刘梦珂 田宇驰 李滨 李兴鹏 张怡梦 张晓杰 冯吉雪 王仁贵[1] LIU Mengke;TIAN Yuchi;LI Bin(Department of Radiology,Affiliated Beijing Shijitan Hospital,Capital Medical University,Beijing 100038,P.R.China)

机构地区：[1]首都医科大学附属北京世纪坛医院放射科,北京100038 [2]东软医疗系统股份有限公司,沈阳110167 [3]首都医科大学附属北京世纪坛医院MR室,北京100038

出　　处：《临床放射学杂志》2024年第7期1181-1186,共6页Journal of Clinical Radiology

基　　金：国家自然科学基金项目(编号:61876216);基于AI技术的肺炎影像学精准诊断系统构建及应用项目(编号:Z211100003521009)。

摘　　要：目的应用磁共振短时反转恢复(STIR)序列基础阈值分割法定量评价原发性下肢淋巴水肿(PLEL)的脂肪及液体等不同成分。方法回顾性分析2018年1月至2021年12月经北京世纪坛医院淋巴外科诊断为单侧PLEL的患者112例,通过医准人工智能科研平台采用半自动标注的方式标注小腿中段筋膜上及筋膜下区域,利用阈值分割法提取筋膜上脂肪、脂肪间隙水肿及积液成分并计算其体积(单位:像素个数)。采用Spearman相关分析不同成分的含量与淋巴水肿的标准测量结果[节段脂肪质量、体质量指数(BMI)、肢体节段细胞外水分比率及多频生物电阻抗]的相关性。按国际淋巴协会(ISL)临床分期标准将患者分为Ⅰ、Ⅱ、Ⅲ期,采用非参数检验比较不同临床分期之间脂肪、脂肪间隙水肿及积液成分体积。结果脂肪含量与细胞外水分比率呈中等程度负相关,与不同频率下电阻抗值呈中等程度正相关。脂肪水肿含量与BMI呈中等程度正相关(r=0.453,P<0.05),与细胞外水分比率(r=0.615,P<0.05)呈强正相关,与1 kHz、5 kHz、50 kHz、250 kHz、500 kHz及1000 kHz下电阻抗值均呈强高度负相关,其中与1 kHz下电阻抗值相关性最高,相关系数r=-0.730(P<0.05);积液含量与细胞外水分比率(r=0.661,P<0.05)呈强正相关,与不同kHz下电阻抗值均呈强负相关(r≥0.617)。不同临床分期之间脂肪水肿及积液含量均存在差异(P<0.05),三期之间两两比较,ISL-Ⅱ期和Ⅲ期的脂肪水肿及积液含量均大于Ⅰ期(P<0.05)。脂肪水肿及积液含量与临床分期均呈正相关,其中脂肪水肿含量与临床分期相关性最高(r=0.510,P<0.05)。结论基于阈值分割法的PLEL成分分析能够协助临床医师评估PLEL病变中水脂等成分的含量,并为临床分期提供一定的诊断依据。Objective Fluid and fat accumulation can be observed in MRI images of patients with primary lower extremity lymphedema;however,the distribution of components such as fat and fluid in the PLEL limb is currently unknown.The aim of this study was to apply the magnetic resonance STIR sequence-based threshold segmentation method to quantitatively evaluate the different components of PLEL such as fat and liquid.Methods A retrospective analysis of 112 patients diagnosed with unilateral primary lower limb lymphedema via the Department of Lymphatic Surgery at Beijing Shijitan Hospital between January 2018 and December 2021 was performed.The suprafascial and subfascial regions of the mid-calf were labeled using semi-automatic annotation via the Yizhun Artificial Intelligence Research Platform,and the suprafascial fat,fat-gap edema,and effusion components were extracted using the threshold segmentation method and their volumes were calculated(in number of pixels).Spearman's correlation was used to analyze the correlation between the content of the different components and standard measures of lymphedema(segmental fat mass,BMI,extracellular water ratio of limb segments,and multi-frequency bioelectrical impedance).Patients were categorized into stages Ⅰ,Ⅱ,and Ⅲ according to the International Society of Lymphology(ISL)clinical staging criteria,and non-parametric tests were used to compare the volumes of fat,fat-gap edema,and effusion components between the different clinical stages.Results Fat content was moderately negatively correlated with extracellular water ratio and moderately positively correlated with electrical impedance values at different frequencies.Adipoedema content showed a moderate positive correlation with BMI(r=0.453,P<0.05),a strong positive correlation with extracellular water ratio(r=0.615,P<0.05),and a strong and highly negative correlation with the electrical impedance values at 1 kHz,5 kHz,50 kHz,250 kHz,500 kHz,and 1000 kHz,with the highest correlation with electrical impedance at 1 kHz.The highe

关 键 词：淋巴水肿 下肢 成分 阈值分割 

分 类 号：R445.2[医药卫生—影像医学与核医学] R551.2[医药卫生—诊断学]