CAJ | 학술논문

目的探讨本院使用不同扫描参数、电子密度体模和CT机对CT值-相对电子密度(CT-RED)转换曲线的影响因素.方法在不同扫描电压、层厚下测量TM164CT性能模体和CIRS062电子密度模体不同电子密度插件在东芝AQUILIONTM型、西门子SOMATOMTM SENSATIONTM 64型CT和西门子SOMATOMTMSENSATIONTM OPEN型CT机扫描的CT值,建立相应的CT-RED转换曲线并进行比较.结果 1、2、3 mm扫描层厚及不同扫描电流对CT值影响可忽略,低原子序数材料在不同型号CT、不同扫描电压下的CT值差异可忽略；不同扫描电压对高原子序数材料CT值有明显差异,同台CT机出现的最大差异约为400 HU;两种模体在软组织-致密骨范围内所提供的CT值有明显差异,最大可达约500 HU.结论不同电子密度模体、CT机及扫描电压对CT-RED转换曲线高原子序数材料部分有影响,因此在治疗计划系统使用前必须根据临床使用条件选用合适的电子密度模体对该曲线进行测量,以保证治疗计划剂量计算的精确度.
목적 탐토본원사용불동소묘삼수、전자밀도체모화CT궤대CT치-상대전자밀도(CT-RED)전환곡선적영향인소.방법 재불동소묘전압、층후하측량TM164CT성능모체화CIRS062전자밀도모체불동전자밀도삽건재동지AQUILIONTM형、서문자SOMATOMTM SENSATIONTM 64형CT화서문자SOMATOMTMSENSATIONTM OPEN형CT궤소묘적CT치,건립상응적CT-RED전환곡선병진행비교.결과 1、2、3 mm소묘층후급불동소묘전류대CT치영향가홀략,저원자서수재료재불동형호CT、불동소묘전압하적CT치차이가홀략；불동소묘전압대고원자서수재료CT치유명현차이,동태CT궤출현적최대차이약위400 HU;량충모체재연조직-치밀골범위내소제공적CT치유명현차이,최대가체약500 HU.결론 불동전자밀도모체、CT궤급소묘전압대CT-RED전환곡선고원자서수재료부분유영향,인차재치료계화계통사용전필수근거림상사용조건선용합괄적전자밀도모체대해곡선진행측량,이보증치료계화제량계산적정학도.
Objective To study the CT values of certain phantoms scanned by various CT scanners with dissimilar parameters.Methods The CT values of tissue equivalent inserts was measured in the TM164 and CIRS-062 phantom scanned by TOSHIBA AQUILIONTM,SIEMENS SOMATOMTMSENSATIONTM 64 and SIEMENS SOMATOMTM SENSATIONTM OPEN with different voltages,currents and slice thicknesses and then the corresponding CT-to-density curves was compared. Results There are no significant differences of CT values with various currents and slice thicknesses and also for low atom number materials scanned by different scanners with various tube voltages.The CT values of high atom number materials have obvious differences scanned with tube voltage,the maximum is about 400 HU.There are also significant differences between CT-density curves of two phantoms in the range from soft tissues to dense bone,the maximum is up to 500 HU.Conclusions CT-density curves were highly affected by materials of phantoms,scanners and tube voltages.It is necessary to measure the curve with a comfortable phantom and certain scanner to assure the accuracy for dose calculation for treatment planning system.