腹盆腔充盈度对膈肌位置的影响

Position of the diaphragm influenced by the filling degree of the abdominal and pelvic cavity

目的研究腹盆腔充盈度对膈肌位置的影响。方法回顾性查阅2018年3月至2020年9月,苏州大学附属第一医院影像存储和传输系统(PACS)存储具有4~7次CT图像患者,共搜集25例、137次CT影像。勾画自膈顶至耻骨联合上缘每横断面腹盆腔轮廓,分别计算腹、盆腔及整体充盈体积。同一患者多次影像,两两排列组合共379组进行比较,计算腹盆腔体积变化率(△VR)、膈顶高度差值(△H);腹盆腔整体充盈度增大且膈顶升高为一致组,而膈顶降低为不一致组。统计一致组在所有样本占比,不一致组中过度深吸气占总样本比例;一致组和不一致组的△VR、△H行组间比较,一致组中腹、盆腔的△VR进行比较,均采用Mann-Whitney检验;一致组中腹、盆腔△VR与膈顶升高高度的相关性采用Spearman相关性分析;模拟计算腹盆腔充盈增加500 ml,所有样本、一致组的膈顶平均升高高度。结果一致组占比为67.28%;不一致组中深吸气在总样本占比为26.39%;一致组较不一致组,腹盆腔整体△VR、△H差异具有统计学意义(Z=-4.95、-5.49,P<0.05);一致组中,腹腔与盆腔△VR比较,差异有统计学意义(Z=-7.53,P<0.05);膈顶升高高度与腹腔△VR相关(r_(s)=0.43,P<0.05);模拟计算腹盆腔平均充盈增加500 ml可导致所有样本、一致组膈顶平均分别升高4.54、8.43 mm。结论腹盆腔充盈度可能是影响膈肌位置及相关器官放疗精准性的主要因素之一,其中腹腔充盈度对其影响较大,建议尽可能在放疗疗程中重复CT定位扫描时充盈程度。

ObjectiveTo explore the affects of the filling degree of the abdominal and pelvic cavity to the position of the diaphragm.MethodsThe computed tomography(CT)images of 25 patients from 137 CT scans stored in the Picture Archiving and Communication System of the First Affiliated Hospital of Soochow University from March 2018 to September 2020 were reviewed and analyzed retrospectively.Every patient was scanned 4-7 times.The outline of the abdominal and pelvic cavity from the diaphragmatic dome to the superior margin of pubic symphysis was drawn at every cross section,and then the filling volumes of the abdominal and pelvic cavities and the overall filling volume were calculated.For the same patient within 4-7 CT scans,per pair of different images was compared randomly and 379 comparison pairs were obtained.The volume change rate(△VR)of the abdominal and pelvic cavity and the height difference(△H)of the diaphragmatic dome were calculated.The images with"larger overall filling volume of the abdominal and pelvic cavity and higher diaphragmatic dome"were defined as consistent group,and those with"larger overall filling volume and lower diaphragmatic dome"were defined as inconsistent group.The percentage of images in the consistent group in all samples and the percentage of images showing deep inspiration in the inconsistent group in all samples were calculated.△VR and△H were compared between the consistent and inconsistent groups.△VR of the abdomen and pelvic cavities in the consistent group was compared using the Mann-Whitney test.The correlations between△VR of the abdomen and pelvic cavities and the elevation of the diaphragmatic dome in the consistent group were analyzed using Spearman correlation analysis.The average elevation of the diaphragmatic dome in all samples and the consistent group was simulated if the filling volume of the abdomen and pelvic cavity was increased by 500 ml.ResultsThe percentage of images in the consistent group in all samples was 67.28%.The percentage of images showing deep inspiration in the inconsistent group in all samples was 26.39%.There were significant differences in△VR and△H of the abdomen and pelvic cavity between the consistent and inconsistent groups(Z=-4.95,-5.49,P<0.05).In the consistent group,there were significant differences in△VR between the abdominal cavity and pelvic cavity(Z=-7.53,P<0.05),and the elevation of the diaphragmatic dome was correlated with the△VR of the abdominal cavity(r_(s)=0.43,P<0.05).The simulated calculation showed that an average increase of 500 ml in the filling volume of the abdominal and pelvic cavity result ed in an average elevation of 4.54 and 8.43 mm in the diaphragmatic dome in all samples and the consistent group,respectively.ConclusionsThe filling degree of the abdominal and pelvic cavity may be one of the main factors affecting the position of the diaphragm and the precision of radiotherapy for relevant organs near the diaphragm,especially the filling degree of the abdominal cavity.It is recommended to repeat the filling degree of the abdominal and pelvic cavity by CT localization scanning as much as possible during radiotherapy.