螺旋CT平扫在输尿管结石中的诊断作用

目的 :评价螺旋CT平扫对输尿和结石诊断的价值。方法 :2 6例患者行腹盆部螺旋CT平扫。结果 :2 6例中见 30处输尿管结石 ,同时显示结石大小 ,形态、位置和CT值。结论 :螺旋CT平扫在诊断急诊输尿管结石具有重要的临床价值     

颅内血管周细胞瘤与血管瘤型脑膜瘤的磁共振成像征象对比分析

目的探讨颅内血管周细胞瘤(HPC)与血管瘤型脑膜瘤的MRI特征性表现的异同。材料与方法回顾性分析经手术和病理证实的16例HPC和24例血管瘤型脑膜瘤的术前MRI平扫及增强的影像学资料。采用χ~2检验和两独立样本t检验对二者的MRI表现进行统计分析,以P0.05为差异有统计学意义。结果 HPC与血管瘤型脑膜瘤比较,肿瘤的长径(t=2.066,P=0.046)、分叶征(χ~2=7.111,P=0.008)、T1WI信号(χ~2=17.220,P0.001)、T2WI信号(χ~2=22.247,P0.001)、DWI等低信号(χ~2=4.310,P=0.038)、囊变坏死(χ~2=7.111,P=0.008)、瘤周水肿程度(χ~2=9.864,P=0.014)、血管流空影(χ~2=8.087,P=0.004)、与硬脑膜窄基底相连(χ~2=15.973,P0.001)等因素差异有统计学意义(P0.05);脑膜尾征(χ~2=0.150,P=0.698)、瘤内出血(χ~2=2.338,P=0.126)、中线结构移位(t=-1.656,P=0.106)等因素差异无统计学意义(P0.05)。结论 HPC与血管瘤型脑膜瘤的MRI表现存在差异,对比分析二者的影像学征象有助于两者的诊断与鉴别诊断。     

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.     

磁敏感加权成像用于诊断非典型蛛网膜下腔出血的初步研究

目的分析非典型蛛网膜下腔出血(atypical subarachnoid hemorrhage,aSAH)在磁敏感加权成像(suscepti-bility-weighted imaging,SWI)上的影像表现,探讨SWI技术在aSAH的临床应用价值。方法分析22例接受CT和MRI(含SWI)检查并最终确诊为aSAH的患者。由两名工作10年以上具有高级职称的影像学医师分析患者CT和MRI(含SWI)数据,以判断蛛网膜下腔是否存在aSAH,并分析其影像表现。结果 SWI总共确定aSAH出血区域共47个,其中16个(34.04%)位于凸面或半球间,19个(40.43%)位于脑池,6个(12.77%)是小脑幕的蛛网膜下腔出血,6个(12.77%)位于脑室内。在脑沟或者脑池内,aSAH在SWI上表现为低信号(出血)周围环绕脑脊液信号,在较浅脑沟内可形成"三角"征;与静脉的平滑边界相比,蛛网膜下腔出血边界较粗糙,信号略显不均。aSAH在脑室内可呈现"液-液平面"。结论在SWI图上,aSAH可通过其信号和独特的形态得以确认,SWI能够提供较CT和常规MRI更多的信息显示出血少量的aSAH。     

CT与MRI在前列腺癌诊断中的应用

比较MRI及CT诊断前列腺癌的准确率。方法对48例经手术或穿刺病理证实的前列腺癌患者均行CT平扫及增强扫描,CT增强行双期动态扫描;MRI行常规扫描。将CT诊断结果与MRI诊断结果进行比较。结果 48例患者中,A期前列腺癌1例,B期前列腺癌14例,C期前列腺癌15例,D期前列腺癌18例。在15例A期或B期前列腺癌患者中,CT平扫和增强扫描直接确诊7例,诊断符合率为46.7%;MRI平扫直接确诊为13例,诊断符合率为86.7%,两者诊断符合率比较差异有统计学意义(P<0.05)。在33例C期或D期前列腺癌患者中,CT平扫和增强扫描直接确诊31例,诊断符合率为93.9%,MRI平扫直接确诊为32例,诊断符合率为96.97%,两者诊断符合率比较差异无统计学意义(P>0.05)。结论对于A或B期前列腺癌的诊断,MRI较CT有明显优势;对于C期或D期前列腺癌的诊断,CT和MRI无明显差异。     

CT仿真支气管内窥镜在中央型肺癌的应用

目的：探讨螺旋CT仿真支气管内窥镜的成像技术和成像效果，及其在中央型肺癌诊断和鉴诊断中的作用。方法：39例中央型肺癌病人，全部经螺旋CT薄层扫描，所获横断面图像传输到Prominence Scientific工作站，在“三维软件”进行气管三维图像重建，然后，在工作站“飞跃”软件包进行住址内窥镜成像，结果：运用仿真内窥镜观察，39例中央型肺癌病人均显示腔内肿块的形态及气受压狭窄或阻塞的情况，正演唱 管、支气管的形态及内表面亦得以显示，结论：仿真内窥镜可以成为纤维支气管内窥镜的补充手段，在显示支气管狭窄的范围和腔外发言为方面明显优于纤维支气管内窥镜。     

CT、MRI诊断原发性腹茧症一例

患者 男,32岁.因右下腹疼痛伴呕吐、食欲不振1个月余入院.发病以来,腹围渐渐增大,可触及肿块,体重无下降,既往体健,无手术及外伤史.体检:中下腹可触及一巨大肿块,质软、无压痛,下腹部叩诊为实音,移动性浊音不明显,胃肠蠕动波未见,肝、脾未触及,Murphy征阴性.血生化、三大常规正常.腹水常规:粉红色、李凡他试验( )、WBC 15×109/L,RBC( ),未见癌细胞、未找到结核杆菌,血沉15 mm/h,PPD试验阴性.     

弥散张量成像定位初级运动功能区的研究

目的 探讨弥散张量成像在定位初级运动功能区的价值.方法 20例脑深部肿瘤患者,分别进行常规MRI、fMRI及DTI检查,获取fMRI脑激活图、DTI图、3D解剖图.DTI通过三维重建皮质脊髓束定位初级运动功能区.fMRI采用手握拳激发模式,获取激活信号定位初级运动功能区.比较两种技术的吻合度,以评价DTI三维重建皮质脊髓束定位的初级运动功能区的准确性.结果 20例患者fMRI获得的激活信号主要位于对侧中央沟处,围绕着"Ω"形柄状结构分布,中央前回位于激活信号前方.所有患者均成功地完成DTI皮质脊髓束的三维重建,重建的皮质脊髓束也定位于激活信号前的脑回,两者均较好显示初级运动功能区且具有较好的一致性.结论 DTI可较好地定位初级运动功能区,这对于有肢体瘫痪患者及不能合作的儿童的初级运动功能区的定位有重要意义.     

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.     

多层螺旋CT三维重建在左肾静脉压迫综合征中的临床应用

目的探讨多层螺旋CT(MSCT)三维重建在左肾静脉压迫综合征中的诊断价值。方法应用16层螺旋CT对11例左肾静脉压迫综合征病例进行泌尿系增强多期扫描,并获得各种后处理图像。结果11例左肾静脉压迫综合征病例均可见肠系膜上动脉(SMA)压迫左肾静脉(LRV)的征象。CT多平面重建(MPR)直观地显示了腹主动脉(AO)与SMA之间的夹角(α),最大为21.88,°最小为12.86°,平均为17.95°。CT横断位图像显示扩张的左肾静脉直径为12~15.3 mm,平均为13.26 mm;LRV受SMA压迫狭窄处直径为3.0~4.0 mm,平均为3.26 mm。左侧卵巢静脉或睾丸静脉直径为2.1~2.6 mm,平均为2.2 mm。5例增强扫描肾实质期(后期)显示双肾实质密度相差20 HU以上。结论MSCT在胡桃夹综合征诊断中具有明显的优势。