64层螺旋CT冠状动脉成像在心肌桥和壁冠状动脉诊断中的价值

目的探讨64层螺旋CT冠状动脉成像对心肌桥(MB)的诊断及其临床价值。资料与方法1422例患者均行64层CT扫描,所有数据传至工作站进行重组和后处理,观察有无MB,测量MB的长度、厚度、壁冠状动脉狭窄程度等。所有MB病例均行冠状动脉造影(CAG)检查并与CT结果对比。结果共发现104例119段MB,平均长度及厚度分别为(5.0±2.7)mm、(2.0±1.6)mm,壁冠状动脉狭窄程度为(31±17)%。104例MB患者CAG发现42例44段MB,其长度、厚度与CT结果存在明显差异。结论64层CT对MB和壁冠状动脉清晰显示,有特殊的临床价值。     

心率对64排螺旋CT冠状动脉成像质量的影响及对策

目的:探讨心率对64排CT冠状动脉成像质量的影响,以及运用多时相重建、多点重建、心电图(ECG)编辑等技术的价值。方法:353例患者行64排螺旋CT冠状动脉成像,对75%R-R间期重建图像上存在伪影的202例,进行多时相重建和/或多点重建和/或ECG编辑再重建。根据心率及心率变化分组,评价不同心率、不同心率波动时和采用3种重建方法时的图像质量。结果:本组中心率≤65bpm组图像合格率为98.3%,66~70bpm组为94.2%,>70bpm组为69.2%。心率>70bpm组和/或心率变化大于10%时图像质量均显著下降(P<0.01)。59.3%(35/59)不可评价图像经多时相重建和/或多点重建和/或ECG编辑再重建后成为可评价图像。结论:64排螺旋CT冠状动脉成像时,心率低于70bpm且波动小于10%能获得较好的图像质量;心率>70bpm和/或波动>10%者,应用多时相重建、多点重建和ECG编辑再重建能明显提高图像质量。     

64层螺旋CT胸部低剂量扫描方案优选的多中心研究

目的 比较自动曝光控制技术(AEC)与管电流恒定技术(CCC)2种不同低剂量MSCT扫描方案对胸部CT图像质量的影响,探讨更加合理的肺低剂量扫描参数方案.方法 采用前瞻性多中心研究方法,研究对象为7所医院就诊的280例行胸部低剂量MSCT检查的受检者,设定管电流(mA)为研究变量,方法一为AEC技术,下设噪声标准差值(SD)为25(A1)及30(A2)各1组,并设定管电流上限为80 mA,下限为10 mA;方法二为CCC技术,下设40 mA(C1)及50 mA(C2)各1组;共4组,采用同一机型64层MSCT行胸部低剂量扪描.2名放射科医师应用双肓法阅片,比较2种不同扫描技术的曝光剂量、SD值,横断面、MPR的图像质量以及体质量指数(BMI)对图像质量的影响.曝光剂量及SD比较行方差分析及t检验;图像质量比较行Mann-Whitney检验;医师对图像诊断一致性检验行Kappa分析.结果 剂量长度乘积(DLP)AEC组较CCC组明显降低[(82.62±40.31)和(110.81±18.21)mGy·cm,F=56.88,P＜0.01].AEC技术中A2组DLP较A1组低[(72.77±36.68)和(92.46±41.61)mGy·cm],差异无统计学意义(t=0.82,P＞0.05).前者SD值在肺窗[(41.50±9.58)和(40.86±7.03)HU]及纵隔窗[(41.19±7.83)和(40.92±9.89)HU]均略高于后者,差异无统计学意义(F肺窗=0.835、1.910,P值均＞0.05).横断面图像质量AEC组肺窗得分除右下肺静脉水平[(4.92±0.25)和(4.93±0.17)分]、[左膈顶上缘水平(4.91±0.27)和(4.93±0.22)分]较CCC组略低外,AEC组得分均较CCC组略高[头臂静脉上缘(4.49±0.56)和(4.38±0.64)分;主动脉弓上缘(4.86±0.23)和(4.81±0.32)分;右肺上叶支气管开口(4.87±0.27)和(4.84±0.22)分;右肺中叶支气管开口(4.90±0.25)和(4.88±0.21)分],差异无统计学意义(F=0.076～1.748,P值均＞0.05);纵隔窗得分除头臂静脉上缘水平AEC组较CCC组高[(2.57±0.77)和(2.46±0.59)分],且差异有统计学意义(F=8.459,P=0.047)外,余各层面AEC组得分均较CCC组略低[(主动脉弓上缘(3.36±0.63)和(3.45±0.60)分;右肺上叶支气管开口(3.94±0.56)和(3.95±0.51)分;右肺中叶支气管开口(3.80±0.58)和(3.87±0.50)分;右下肺静脉(3.72±0.56)和(3.78±0.53)分;左膈顶上方(3.58±0.63)和(3.68 ±0.56)分],但差异均无统计学意义(F=0.083～3.380,P值均＞0.05).MPR图像质量肺窗及纵隔窗观察均略好于CCC组(Z肺窗=-2.358,Z纵隔窗=-1.330,P值均＞0.05).偏瘦、正常或偏重人群组,A1组肺窗及纵隔窗图像质量均优于A2组,差异无统计学意义(偏瘦:Z肺窗=0.000、Z纵隔窗=0.000;正常:Z肺窗=-0.062、Z纵隔窗=-0.746;偏重:Z肺窗=-1.177、Z纵隔窗=-1.715;P值均＞0.05),但在偏重人群纵隔窗图像质量A1组更好于A2组(Z=-1.715,P=0.144).结论 AEC组总曝光剂量明显低于CCC组,而AEC组的图像质量及SD值无论在肺窗或纵隔窗均与CCC组无明显差异,故建议在胸部低剂量筛查方案选择中应用AEC技术,对偏胖者宜采用SD=25方案,对正常及偏瘦者宜采用SD=30方案.

Abstract：

Objective To compare the image quality of chest low dose CT (LDCT) using automatic exposure control (AEC) and constant current control (CCC) and explore a more reasonable scanning protocol. Methods Two hundred and eighty participants were examined with 64 CT scanner at 7 centers in China. All were divided into 4 groups. Two groups underwent LDCT using AEC with standard deviation set at 25 (A1) and 30 (A2) respectively and the tube current ranged from 10 mA to 80 mA. The other two groups underwent LDCT using CCC with tube current set at 40 mA (C1) and 50 mA (C2) respectively. The axial and MPR images were evaluated by two radiologists who were blinded to the scanning protocols.The radiation dose, noise and the image quality of the 4 groups were compared and analyzed statistically.Differences of radiation dose and noise among groups were determined with variance analysis and t test,image quality with Mann-Whitney test and the consistency of diagnosis with Kappa test. Results There was a significant lower DLP in AEC group than in CCC group [(82.62±40.31)vs ( 110.81±18.21) mGy·cm (F =56. 88 ,P ＜ 0. 01 )], whereas no significant difference was observed between group A2 and group A1 0. 05]. The noisy of AEC group was higher than that of CCC group both on lung window(41.50±9.58 vs 40.86±7.03) and mediastinum window (41.19±7.83 vs 40.92±9.89), but there was no significant difference( Flung =0.835, P=0.476, Fmediastinum =1.910, P=0.128).The quality score of axial image in AEC group was higher than that in CCC group (superior margin of the brachiocephalic vein level: 4.49±0.56 vs4.38±0.64,superior margin of the aortic arch: 4.86±0.23 vs 4.81±0.32,the right superior lobar bronchus Level:4.87±0.27 vs 4. 84 ± 0. 22, the right middle lobar bronchus Level: 4.90±0.25 vs 4.88±0.21) except on the right inferior pulmonary vein level(4. 92 ±0. 25 vs 4. 93 ±0. 17) and superior margin of the left diaphragmatic dome level (4. 91±0.27 vs 4.93±0.22) on lung window, but no significant differences (F=0.076-1.748, P＞0.05) were observed. A significant higher score in AEC group was observed on mediastinum window compared with CCC group on superior margin of brachiocephalic vein level (2.57±0.77 vs 2. 46 ± 0. 59, F = 8. 459, P ＜ 0. 05 ), however, the score of AEC group was lower than that of CCC group on other levels without significant differences (superior margin of the aortic arch:3.36 ±0. 63 vs 3.45 ±0. 60,the right superior lobar bronchus level: 3.94 ±0. 56 vs 3. 95 ±0. 51 ,the right middle lobar bronchus Level: 3.80 ±0. 58 vs 3. 87 ±0. 50,the right inferior pulmonary vein level: 3.72 ±0. 56 vs 3.78 ±0. 53, superior margin of the left diaphragmatic dome level: 3.58 ± 0.63 vs 3.68±0.56,F=0.083-3.380,P ＞ 0.05 ). The MPR image quality of AEC group was better than that of CCC group both on lung window and mediastinum window (Zlung =-2.258, Zmedlastinum=-1.330, P＞0.05). For all participants including the underweighted group, the normal group and the overweighted group, the image quality of A1 group was better than that of A2 group without significant differences (the underweighted group: Zlung=0.000, P=1.000, Zmedastinum= 0.000, P=1.000;the normal group: Zlung =-0.062, P=0.950, Zmediastinum =-0.746, P = 0.456; the overweighted group: Zlung = - 1.177, P = 0.239,Zmediastinum =-1.715, P=0.144) both on lung and mediastinum windows, and for the higher BMI participants, a better image quality was obtained in A1 group than in A2 group on the mediastinum window (Z = -1. 715, P = 0. 144). Conclusions The total radiation exposure dose of AEC group is significantly lower than that of CCC group, but no statistical significant differences are observed between both groups in image quality and noise level. The AEC technique is highly recommended in thoracic LDCT scan for screening program, and the SD25 ( SD value = 25) scan protocol is suggested for higher BMI population while the SD30 (SD value = 30) scan protocol for lower BMI population.     

64层螺旋CT血管造影在人工血管移植术后随访中的价值

目的 探讨64层螺旋CT血管造影检查在人工血管移植术后随访复查中的应用价值.方法 对23例人工血管移植术后的患者定期进行64层螺旋CT血管造影检查,利用容积再现(VR)、多平面重组(MPR)、曲面重建(CPR)、血管探针等技术方法分析移植血管的通畅情况.结果 23例患者中,5例上腔静脉综合征、4例主动脉瘤及1例布加综合征患者的移植血管在观察期内均通畅;13例下肢动脉粥样硬化患者的移植血管在观察期内3例通畅,5例轻度狭窄,2例中重度狭窄,3例闭塞.结论 64层螺旋CT血管造影检查对于人工血管移植术后的随访复查具有重要价值.     

64层螺旋CT血管造影对癌性上腔静脉综合征的诊断

目的 探讨多层螺旋CT血管造影对上腔静脉综合征(SVCS)的诊断价值.方法 回顾性分析18例病理确诊为癌性SVCS的64层螺旋CT血管造影表现.结果 (1)原发病变:肺癌位于右上肺叶8例,右上纵隔型7例,淋巴瘤2例,侵袭性胸腺瘤1例.(2)上腔静脉梗阻征:单侧压迫(5例)、半环状包埋(8例)、环状包埋(4例)、夹心状包埋(1例).(3)继发侧枝循环:侧枝循环开放10例.结论 多层螺旋CT血管造影能全面、准确地诊断SVCS,为临床诊断与治疗提供更丰富的影像学信息.     

64排螺旋CT对冠状动脉瘘的诊断价值

目的:探讨64排螺旋CT对冠状动脉瘘的诊断价值。方法:回顾性分析经造影或手术证实的6例冠状动脉瘘患者的64排螺旋CT表现,由两名放射科医师独立评价64排螺旋CT图像的质量和诊断准确性。结果:6例冠状动脉CTA图像可供评价,与术中所见和选择性动脉造影吻合。6例冠状动脉瘘中,2例冠状动脉-肺动脉瘘,3例冠状动脉-右室瘘,1例冠状动脉-左房瘘,6例均作出正确诊断。3例冠状动脉-右室瘘合并右冠状动脉扩张,射血分数(EF)为50%～72%,其余3例EF为65%～71%。结论:64排螺旋CT能比较全面显示冠状动脉异常血管、瘘口以及评估心功能,是诊断冠状动脉瘘的可靠方法。     

急性阑尾炎低剂量CT扫描联合多平面重组技术的诊断价值

急性阑尾炎是外科常见的急腹症之一,依据典型的临床表现和实验室检查一般可以作出诊断[1].但约有1/3在发病时没有典型的临床表现,往往需要与其他疾病鉴别,特别是女性,患急性妇科疾病可有相似的临床表现而诊断更难.     

急性阑尾炎低剂量CT扫描联合多平面重组技术的诊断价值

急性阑尾炎是外科常见的急腹症之一,依据典型的临床表现和实验室检查一般可以作出诊断[1].但约有1/3在发病时没有典型的临床表现,往往需要与其他疾病鉴别,特别是女性,患急性妇科疾病可有相似的临床表现而诊断更难.     

椎动脉双点智能追踪法头颅CTA的应用价值

【摘要】目的：探讨采用椎动脉双点智能追踪法行单Volume头颅CT血管成像（CTA）的临床应用价值。方法：随机选取行头颅CTA检查的80例患者,其中40例采用椎动脉双点智能监测法进行扫描（实验组）,40例采用手动触发法进行扫描（对照组）。选取椎动脉、基底动脉、大脑前动脉、大脑中动脉、大脑后动脉及眼动脉为目标动脉血管,上矢状窦、直窦及乙状窦为目标静脉血管,测量目标动脉、目标静脉的CT值,同时记录两组的剂量长度乘积（DLP）,对两组图像质量进行主观评分,并进行统计学分析。结果：实验组与对照组椎动脉、基底动脉、大脑前动脉、大脑中动脉、大脑后动脉、眼动脉的CT值分别为（448.83±81.43） vs （480.07±112.50）HU、（403.40±92.11） vs （433.55±109.88）HU、（357.96±82.83） vs （375.57±104.10）HU、（452.56±91.50） vs （471.65±118.60）HU、（343.84±85.76） vs （374.31±114.66）HU、（205.47±60.69） vs （206.61±70.41）HU,实验组的目标动脉血管CT值小于对照组,但差异均无统计学意义（t值分别为1.423、1.330、0.837、0.806、1.346、0.078,P值均>0.05）。实验组与对照组上矢状窦、直窦、乙状窦的CT值分别为（117.18±56.60） vs （151.31±61.20）HU、〖JP2〗（145.41±63.08） vs （177.06±65.10）HU、（96.40±46.38） vs （136.18±49.78）HU,实验组目标静脉血管的CT值明显小于对照组,且差异均有统计学意义（t值分别为2.589、2.208、3.698,P值均<0.05）。实验组与对照组的辐射剂量分别为〖JP2〗（363.8±8.99）mGy·cm和（366.5±8.68）mGy·cm,差异无统计学意义（t=1.424,P>0.05）。实验组的图像质量主观评分(4.63±0.59)高于对照组(4.25±0.78),差异有统计学意义（t=2.44,P<0.05）。结论：采用椎动脉双点智能追踪法行单Volume头颅CTA可显著降低颅内静脉污染,更准确地突显目标动脉,提高图像质量。