低剂量多层面CT在肺内结节检出中的研究

目的　探讨低剂量多层面螺旋CT(LDCT)在肺内结节检出中的价值。方法　对 3 1例常规剂量多层面CT(SD CT)发现肺内结节的病人行LDCT检查 ,两者管电流分别为 15 0mAs和 2 5mAs。LDCT采用两种参数重建 ,LDCT 10mm :重建层厚和重建间隔均为 10mm ,LDCT 5mm :重建层厚和重建间隔均为 5mm ,并把三者对肺内结节检出的结果进行比较。结果　三者检出肺内结节总数无显著性差异 (H =0 .0 3 7,P >0 .0 5 ) ;三者检出肺内结节的诊断置信度总体无显著性差异 (H=4.0 7,P >0 .0 5 ) ;<3mm结节 ,LDCT 5mm的诊断置信度低于SDCT(t =2 .74,P <0 .0 5 ) ,而LDCT 10mm与SDCT无显著性差异。三者检出有伪影图像数分别为 0、75、2 75幅 ,有显著性差异 (χ2 =165 .71,P <0 .0 5 ) ;其中影响诊断图像数分别为 0、4、61幅 ,SDCT与LDCT 10mm无显著性差异 (P =0 .12 45 >0 .0 12 5 ,Fisher确切概率法 ) ,SDCT与LDCT 5mm、LDCT10mm与LDCT 5mm间均有显著性差异 (χ2 =3 1.3 5 ,2 2 .2 5 ,P <0 .0 12 5 )。以SDCT结果为金标准 ,LDCT 10mm对肺内结节检出的敏感性和阳性预测值分别为 64 %和 72 % ,LDCT 5mm分别为 67%和 69%。结论　LDCT ,尤其是LDCT 10mm完全可以替代SDCT进行肺内结节的检出 ,具有重要临床价值。     

术中内镜诊断小肠出血的临床应用

在消化道出血中 ,小肠出血占 9% ,诊断较为困难[1] 。小肠镜检、放射性核素扫描、选择血管造影等方法 ,在许多基层医院应用也受限制。小肠出血大多需手术治疗 ,术中内镜检查仍是一种操作较简便 ,检出率高的方法。几年来 ,我们对17例小肠出血患者 ,应用术中内镜 ,检出出血原因和部位 ,报道如下。一、对象和方法1.对象 :17例因消化道出血住院患者 ,内科止血治疗 3ｄ以上无效 ,经胃镜、结肠镜检查 ,排除了胃、十二指肠和结肠病变 ,经Ｂ超和腹部ＣＴ检查排除胆道和胰腺出血。男 11例 ,女 6例 ,年龄 2 5～ 74岁 ,平均年龄 (39± 5 )岁。2 .方法 :…     

食管曲张静脉结扎前后的监护和处理

食管曲张静脉结扎前后的监护和处理陈周谋薛挥段仲璧黎庶熙刘大巍张素红我们从１９９２年１０月开展食管曲张静脉结扎术（ＥＶＬ）以来，共治疗４１例，结扎８９次，结扎静脉２８９条，临床效果较好，没有出现严重的副作用，其中一个重要的因素是我们重视术前的准备和术后...     

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.     

HSV-1 UL15 exon-Ⅱ的原核表达及抗体制备

目的 构建pQE-HSV-1 UL15 exon Ⅱ原核表达载体,在大肠埃希菌中高效表达并免疫家兔制备抗体.方法 以HSV-1感染后的Vero细胞总RNA为模板,通过RT-PCR扩增HSV-1 UL15 exon-Ⅱ基因,克隆入原核表达载体pQE-31;重组质粒经酶切、测序鉴定无误后转化大肠埃希菌JM109,IPTG诱导表达;SDS-PAGE检测蛋白表达情况;表达蛋白用Ni-NTA亲和层析纯化及透析复性处理后免疫家兔制备特异性抗体,抗体的免疫原性用Western blotting进行检测.结果 通过RT-PCR扩增获得了HSV-1 UL15 exon-Ⅱ全长基因;构建的pOE-HSV-1 UL15 exon Ⅱ重组质粒经酶切及测序鉴定无误;阳性转化菌株经WIG诱导后SDS-PAGE电泳显示表达蛋白的相对分子质量约为43 000,与理论值一致,蛋白表达率约为35%～40%;表达蛋白经纯化及透析复性后免疫家兔获得的抗血清经Western blotting鉴定具有较好的特异性和敏感性.结论 成功构建了pQE-HSV-1 UL15 exon Ⅱ原核表达载体,诱导蛋白表达并进一步用表达的蛋白制备了特异性抗体,为HSV-1末端酶全长基因表达情况的鉴定及最终构建抗病毒组装药物的分子筛选模型奠定了前期实验基础.     

肾上腺疾病的CT诊断

由于CT机器性能的不断改进和诊断经验的积累,目前对于直径1cm以上肾上腺肿瘤的诊断,不仅能作出正确的定位,而且有些可以作到定性以及良恶性的鉴别。本文将我院经手术病理证实的50例,结合我们的诊断经验和文献报告作一阐述。     

乳腺癌相关临床检查对评价肿瘤大小准确性的研究

目的：评价物理检查、超声、钼靶和MRI测量乳腺癌肿瘤大小的准确性。方法：2008年10月～2009年12月，49例浸润性乳腺癌，术前采用相关检查测出肿瘤最大径。限期手术，以手术切除新鲜标本测量肿瘤最大径为标准，比较各种方法测量肿物大小的准确性。结果：49例乳腺癌病理的最大径为1.0～4.0cm，平均直径（1.92±0.57）cm。MRI、超声、物理检查、钼靶测得的回归系数分别为0.253、0.228、0.170、0.019。MRI标准误最小（0.085）。结论：本研究显示，MRI对乳腺癌原发肿瘤大小测量的准确度明显好于超声、物理检查和钼靶。MRI可为测量乳腺癌肿瘤大小提供准确的依据。     

局部点压数字摄影在乳腺疾病X线检查中的应用

乳腺癌的早期诊断，现今首选的检查方法仍为乳腺钼靶X线摄影。常规摄影时，由于部分占位病变可因腺体重叠显示不清。而局部点压数字摄影改善腺体重叠所造成的影响，使病变区域组织得到充分压迫，图像达到最优化，提高局部乳腺组织结构的清晰度。本研究旨在探讨局部点压数字摄影在显示乳腺疾病中的价值。     

动态增强CT扫描对孤立性肺结节鉴别诊断的应用价值

目的：评价动态增强CT扫描对孤立性肺结节鉴别诊断的应用价值。材料与方法：收集发现孤立性肺结节（SPN）并行动态增强CT扫描的临床病例42例，将病灶的强化形态分成无强化、环状强化、均匀强化和不均匀强化4种类型，测量增强前后各扫描时点病灶的CT值，并根据增强后CT增加值绘制动态曲线。结果：增强后肺癌组18例表现为均匀一致的强化，其中2例病灶内部见点状血管性强化，7例表现为不均匀强化；10例炎性结节8例表现为均匀强化，2例环状强化；7例结核瘤增强后5例无强化，2例表现为边缘壳样环状强化。增强后强化峰值在肺癌与结核瘤、炎性结节与结核瘤间均有显著性差异（P<0.001；P<0.01）。肺癌组曲线呈先缓慢后迅速上升－缓慢下降型，到达强化峰值的时间为39s；炎性结节呈迅速上升－缓慢下降－再上升型，到达强化峰值的时间为36s；结核瘤表现为平稳型曲线。结论：动态增强CT图像上SPN的强化方式、强化程度及动态曲线可以补充更多的鉴别诊断信息，对提高定性诊断的准确率具有重要价值。