摘要
目的∶应用运动模体研究呼吸运动对四维CT(fou-dmensional computed tomgraphy,4D-CT)和四维锥形束CT(fou-dmensional cone beam compated tomgmpy,4D-CBCT)成像结果的影响。方法∶利用QUASAR运动模体模拟16种呼吸模式,其中振幅设定为5mm、10 mm,20mm和30mm四种;频率设定为10次/min、12次/min、15次/mi和20次/min四档。运用4D-CT和4D-CBCT对16种呼吸模式下的QUASAR模体进行扫描。将获取的图像通过D-COM网络传输至MIM工作站,分别在各时相CT图像中勾画出QUASAR模体中包含的特定模块(直径分别为1cm、2 cm的球体以及边长为3cm的正方体,密度为1.41 gcm^2),统计并比较各时相CT图像中不同模块的体积。结果∶16种呼吸模式下,4D-CT扫描得到的图像结果显示,QUASAR模体中直径为1cm,2cm的球体以及边长为3cm的正方体体积变化率平均值分别为62.42%±47.64%、35.95%±32.①%和32.71%±20.31%,而4D-CBCT扫描得到的结果分别为48.59%±26.7%,8.80%±1.43%和I8.19%±9.05%;4D-CT扫描结果显示16种扫描模式下如%~70%时相三个插件体积变化相对其他时相平稳,且体积变化率平均值分别下降至3.02%±14.12%、17.29%±7.58%和23.43%±11.11%。与4D-CT相比,4D-CBCT得到的扫描结果各时相体积变化相对稳定。结论∶呼吸运动会影响4D-CT和4D-CBCT成像的结果,针对运动模体,4D-CT和4D-CBCT扫描的图像结果体积均偏大,4D-CT中40%~70%的呼吸时相体积与真实体积更接近,建议在肿瘤体积勾画与呼吸门控治疗时使用40%~70%时相。
Objective:To study the effect of respiratory motion on four-dimensional computed tomography(4D-CT)and four-dimensional cone beam computed tomography(4D-CBCT)imaging using QUASAR motion phantom.Methods:Breathing pattens with diferent peak-peak anplitudes(5,10,20 and 30 mm)and frequencies(10,12,15 and 20 rpm)were simulated using a progammable motion phantom(Modus QA).The phantom was scanned by 4D-CT and 4D-CBCT under 16 breathing modes registered.The image dutasets were tnnsmited to the MIM Software through Digital Imaging and Communications in Medicine(DICOM).The inserts[2 spheres with diameter of 1 cm and2 cm(S1 and S2)and a cube with edge length of3 em(C3),density 1.41 g/cm^3]of the QUASAR phantom were delineated in diferent phases of CT images.Volumes of inserts in the diferent phases of CT scans were recorded and analyzed.Results:Volume change rates of S1,S2 and C3 inserts in 10 phases of 4D-CT scan were 62.42%±47.64%,35.95%±32.02%and 32.71%±20.31%,respectively,and those of 4D-CBCT scan were 48.59%±26.76%,8.80%±11.43%and 18.19%±9.05%,respectively.Volumes ofS1,S2 and C3 inserts in 40%~70%phases of 4D-CT scan decreased to 37.02%±14.12%,17.29%±7.58%and 23.43%±11.11%,respectively,which is more stable compared to olher phases.Compare with 4D-CT,the 4D-CBCT results showed a lower inerease of the contoured volumes,and were lower in volume variability along the whole interval of phases.Conclusion:Respiratory motion will afet the results of 4D-CT and 4D-CBCT imaging.Volumes of the QUASAR phantom scanned by 4D-CT and 4D-CBCT are rlatively larger than real volumes.Volumres in 40%~70%pha-ses of 4D-CT scan are comparetively closer to real volumes.It is recommended to u8e 40%-70%phases for contouring target volumes and Lreatment in respiration-gated radiotherapy.
作者
刘首鹏
廖雄飞
黎杰
王首龙
郎锦义
Liu Shoupeng;Liao Xiongfei;Li Jie;Wang Shoulong;Lang Jinyi(School of Medicine,University of Electronic Science and Technology of China,Chengdu 610054,Sichuan,China;Radiotherapy Center,Sichuan Cancer Hospital&Institute,Sichuan Cancer Center,School of Medicine,University of Electronic Science and Technology of China,Chengdu 610041,Sichuan,China)
出处
《肿瘤预防与治疗》
2021年第1期53-58,共6页
Journal of Cancer Control And Treatment
基金
国家重点研发计划(编号:2017YFC0U3100)
成都市重点研发支撑计划(编号:2019-YF09-00095-SN)。
关键词
QUASAR
模体
4D-CT
呼吸运动
4D-CBCT
QUASAR phantom
Four dimensional computed tomography
Respirntory molion
Four-dimensional cone beum computed tomogmaphy
