CAJ | 학술논문

目的探讨CT与SPECT图像配准不良对MPI CT衰减校正(CTAC)的影响.方法 99Tcm-MIBI MPI受检者19名,均为行健康体格检查者,其中男11名,女8名,年龄(65.3±9.6)岁.对MPI图像进行CTAC.利用仪器自带的软件对CT图像进行模拟位移:相对心脏位置进行上、下、左、右、前、后6个方向的移动,移动幅度分别为0.5、1.0、1.5、2.0、2.5、3.0、3.5、4.0和4.5 cm.重建不同位移状态的CTAC心肌断层图像,利用靶心图获得左心室各壁段的放射性计数百分比,比较位移前后左心室各壁段放射性计数的差异和图像差异.采用SPSS 13.0软件对数据进行配对t检验.结果当CT图像的移动距离为0.5 cm时,所有位移方向的CTAC图像均未见明显可识别的图像伪影.当CT图像的移动距离≥1.0 cm时,左心室各壁段出现不同程度的图像伪影以及放射性计数的改变;CT图像向上、下、左、右、前、后方向位移时,分别对心尖部,前壁和心尖部,间壁,前壁、心尖部和侧壁,侧壁和下后壁,前壁、心尖部和间壁放射性计数的影响最为显著.向下位移时左心室各壁段放射性计数的改变大于向上位移[(-9.68±8.06)％和(-2.04±1.83)％;t=6.573,P＜0.01],向右位移的改变大于向左位移[(-9.02±8.47)％和(-4.38±3.67)％;t=1.987,P＜0.05].在左心室各壁段中,前壁、心尖部和侧壁的伪影程度明显较下后壁和间壁显著.结论 CT与SPECT图像配准不良可使MPI CTAC图像出现不同程度的伪影,其伪影出现的部位和严重程度与配准不良的方向和幅度密切相关.
목적 탐토CT여SPECT도상배준불량대MPI CT쇠감교정(CTAC)적영향.방법 99Tcm-MIBI MPI수검자19명,균위행건강체격검사자,기중남11명,녀8명,년령(65.3±9.6)세.대MPI도상진행CTAC.이용의기자대적연건대CT도상진행모의위이:상대심장위치진행상、하、좌、우、전、후6개방향적이동,이동폭도분별위0.5、1.0、1.5、2.0、2.5、3.0、3.5、4.0화4.5 cm.중건불동위이상태적CTAC심기단층도상,이용파심도획득좌심실각벽단적방사성계수백분비,비교위이전후좌심실각벽단방사성계수적차이화도상차이.채용SPSS 13.0연건대수거진행배대t검험.결과 당CT도상적이동거리위0.5 cm시,소유위이방향적CTAC도상균미견명현가식별적도상위영.당CT도상적이동거리≥1.0 cm시,좌심실각벽단출현불동정도적도상위영이급방사성계수적개변;CT도상향상、하、좌、우、전、후방향위이시,분별대심첨부,전벽화심첨부,간벽,전벽、심첨부화측벽,측벽화하후벽,전벽、심첨부화간벽방사성계수적영향최위현저.향하위이시좌심실각벽단방사성계수적개변대우향상위이[(-9.68±8.06)％화(-2.04±1.83)％;t=6.573,P＜0.01],향우위이적개변대우향좌위이[(-9.02±8.47)％화(-4.38±3.67)％;t=1.987,P＜0.05].재좌심실각벽단중,전벽、심첨부화측벽적위영정도명현교하후벽화간벽현저.결론 CT여SPECT도상배준불량가사MPI CTAC도상출현불동정도적위영,기위영출현적부위화엄중정도여배준불량적방향화폭도밀절상관.
Objective To evaluate the effects of misregistration with different directions and magnitudes between SPECT and CT on image quality and semi-quantification of MPI.Methods The data of 19 healthy volunteers (11 males,8 females ; mean age:(65.3 ± 9.6) years) were retrospectively analyzed.They all had a low pretest likelihood of coronary artery disease according to exercise and rest 99Tcm-MIBI MPI.The CT attenuation correction (CTAC) was performed on a SPECT/CT system.The CT images were manually shifted by 0.5,1.0,1.5,2.0,2.5,3.0,3.5,4.0,4.5 cm distance along the up/down,left/ right,and anterior/posterior axes respectively by using the system built-in software.The counts of the left ventricle were measured using myocardial Bull's eye generated from the reconstructed CTAC images.The image quality and semi-quantification of the CTAC images reconstructed from the raw data with and without shifting were compared and analyzed.Paired t test was used to analyze the data.Results There was no visible artifact with 0.5 cm shifting.The image quality was deteriorated significantly and the counting difference was significant with shifting distance greater than or equal to 1.0 cm.The image artifact of apex wall was mainly due to the upward shift,anterior and apex wall due to the downward shift,septal wall due to the leftward shift,anterior,apex and lateral wall due to the rightward shift,lateral and infero-posterior wall due to the forward shift,anterior,apex and septal wall due to backward shift.The counting difference caused by the downward shift was significantly more severe than that caused by the upward shift ((-9.68±8.06) ％ and (-2.04±1.83)％,t=6.573,P＜0.01) ; and the rightward shift was more severe than the leftward shift ((-9.02± 8.47) ％ and (-4.38±3.67) ％ ; t =1.987,P＜0.05).The image artifacts in anterior,apex and lateral walls were more severe than those in the infero-posterior and septal walls.Conclusions CTAC image artifacts in myocardial perfusion SPECT/CT studies could be caused by misregistration ≥ 1.0 cm.Different directions and magnitudes of shift could result in different degrees of attenuation artifacts at different locations on the original images.