64排螺旋CT重建层厚及时相间隔对左心室容积测量的影响  

Effect of different thickness of reconstruction slice and phase interval on measurement of left ventricular volume by 64-MDCT

作　　者：梁亚光[1] 张宇[1] 隋岩[1] 赵维敬[1] 何悦明[1] 

机构地区：[1]首都医科大学附属复兴医院放射科,北京100038

出　　处：《北京医学》2012年第2期108-111,共4页Beijing Medical Journal

摘　　要：目的比较不同重建时相间隔及重建层厚对左心室舒张末期容积(EDV)、收缩末期容积(ESV)及射血分数(EF)的影响,优化重建方案。方法回顾性分析20例冠状动脉CTA检查的患者资料,将患者原始CT数据分别重建为层厚0.625、1.25、2.5mm的横断面图像,并以心动周期的10%和5%为间隔拆分为10和20个时相。利用图像工作站中基于CT值的容积分割算法计算舒张末期及收缩末期左心室容积以及左心室射血分数(LVEF),比较不同重建时相间隔和不同重建层厚左心室容积测量值的差异。结果 2.5mm获得的左心室容积测量值为,EDV(142.4±24.8)ml,ESV(48.9±16.9)ml;小于0.625mm[EDV(152.5±26.6)ml,ESV(56.9±19.5)ml]及1.25mm的值[EDV(152.3±26.3)ml,ESV(56.6±21.3)ml,P<0.001]。LVEF2.5mm的测量值大于0.625及1.25mm的值[(66.4±6.5)%vs.(63.3±7.5)%,(63.7±8.7)%,P<0.001]。不同重建时相间隔获得的左心室收缩末期容积存在差异,以间隔5%的心动周期时相获得的结果小于间隔10%重建的结果(P<0.01)。左心室舒张末期容积两者之间无显著性差异。两种重建方法获得的LVEF存在差异,间隔5%重建获得的LVEF值大于间隔10%重建的结果(P<0.01)。结论 64排螺旋CT能够以不同重建时相间隔和图像层厚获得左心室容积数据。较大的重建层厚和较少重建时相间隔可减少后处理图像数量,但导致低估或高估左心室容积。Objective To obtain left ventricular volume data using 64-multidetector row Computed Tomography （64-MDCT） retrospective ECG-gated scan and investigate the effect of different reconstruction interval in cardiac phase and slice thickness on measurement of left ventricular （LV） end diastolic volume （EDV）, end systolic volume （ESV） and ejection fraction （EF）. Methods The data of 20 patients who underwent coronary CT angiography for routine examinations were collected and analyzed retrospectively. For each patient＇s CT raw data, the axial images of three different slice thickness were reconstructed at 0.625 mm, 1.25 mm and 2.5 mm in 10% intervals of cardiac cycle. Twenty and ten phases of axial images at 1.25 mm thickness were reconstructed at every 5% and 10% interval of cardiac cycle. The left ventricular volumes were obtained on dedicated workstation using a Hounsfield unit-based volume segmentation algorithm. The results were compared among different slice thickness and between different phase intervals. Results The left ventricular volumes obtained from 2.5 mm slice thickness were lower than those obtained at 1.25 mm and 0.625 mm slice thickness （P 〈 0.001） but with higher LVEF values （P 〈 0.001）. The values of ESV obtained from 5% intervals were lower than 10% intervals but with higher LVEF values （P 〈 0.01）. There were no significant differences of volumetric values between 1.25 mm and 0.625 mm datasets. Conclusions Using 64-MDCT can measure LV volumetric parameters at different slice thickness levels and different phase intervals. The greater slice thickness and fewer reconstruction intervals result in fewer reconstruction images but can overestimate or underestimate the LV volume.

关 键 词：左心室容积 CT 测量 

分 类 号：R816.2[医药卫生—放射医学]