F-FDG符合线路显像图与CT图的三维容积融合及其应用

目的　探讨应用三维 (3D)融合软件进行非同机1 8F 脱氧葡萄糖 (FDG)符合线路显像图与CT图的 3D容积融合的可行性及其在病变定位中的价值。方法　选择 16例行全身1 8F FDG双探头符合线路显像时发现有阳性病变的患者 ,将其CT检查的数据用光盘存贮 ,然后输入SPECT仪中 ,用SPECT仪自带的 3D融合软件对CT采集的容积数据进行 3D重建。以最明显的解剖结构或病灶作为定位标志 ,重复比较1 8F FDG显像图与CT图的形态和位置 ,选择最适合的图像进行融合 ,并在融合图像上观察1 8F FDG浓聚灶在CT图像上的位置。结果　 3D融合软件能对CT数据和1 8F FDG显像数据自动归一化处理 ,并可进行任意厚度和角度的 3D重建。 16例患者1 8F FDG显像共发现阳性病灶 4 5处 ,包括1 8F FDG显像图上定位不明确的 14处病灶均在CT图上明确定位。结论　运用 3D融合软件可方便地进行非同机1 8F FDG符合线路显像图与CT图的融合 ,并可对1 8F FDG显像定位的病灶进行准确定位。     

18F-FDG符合线路显像与异机CT图像融合诊断非小细胞肺癌复发转移的价值

目的 评价18F-脱氧葡萄糖(FDG)符合线路显像与异机CT图像融合诊断非小细胞肺癌(NSCLC)术后放化疗后复发转移的价值.方法 对可疑复发转移的40例NSCLC患者行18F-FDG符合线路显像,并于显像前后1周内行CT扫描.用三维(3D)图像融合软件进行图像融合.结果 在18F-FDG符合线路显像与CT扫描相同的范围内,40例患者共检出病灶58处,其中恶性52处,良性6处.融合图像诊断NSCLC复发转移的灵敏度、特异性、准确性、阳性预测值、阴性预测值、阳性似然比及阴性似然比分别为94.23%(49/52),5/6,93.10%(54/58),98.00%(49/50),5/8,5.65及0.07.图像融合灵敏度、准确性明显高于CT.单纯18F-FDG符合线路显像诊断效能与图像融合无差别,但与CT图像融合可明显提高对病灶的定位诊断(提高44.83%).结论 18F-FDG符合线路与CT图像融合诊断NSCLC术后放化疗后复发转移灵敏度高,定位准确,值得推广应用.     

18F-FDG符合线路显像在乳腺癌诊断中的初步应用

目的研究18F-FDGSPECT/CT符合线路正电子显像在鉴别乳腺肿块性质和乳腺癌术前淋巴结转移分期中的应用价值。方法22例有乳腺肿块的女性患者行SPECT/CT符合线路18F-FDG显像,患者禁食6h以上,肘静脉注射18F-FDG185MBq～296MBq。静注60min后开始发射和X线CT透射扫描,然后进行符合线路PET连续采集30min。图像经X线衰减校正和有序子集最大期望值法(COSEM)叠代重建后,得到横断面、冠状面、矢状面三维断层图像及CT与FDGSPECT的融合图像。结果22例患者均通过手术切除治疗并获得病理结果。其中,乳腺癌16例,乳腺良性肿瘤6例。FDGSPECT诊断乳腺癌的敏感度、特异性和准确度分别是93.75%、100%和95.45%,明显高于乳腺X射线摄片。16例乳腺癌患者,15例FDGSPECT分期与临床手术分期一致。利用SPECT/CT仪所配备的定位CT,15例乳腺癌患者的病灶可准确定位。结论SPECT/CT符合线路18F-FDG显像在乳腺癌的诊断、转移灶定位以及临床分期方面具有重要的临床应用价值。     

18F-FDG符合线路SPECT显像联合CT、B超、MRI在结直肠癌术后复发及转移中的诊断价值

目的探讨18F-FDG 符合线路 SPECT 显像联合传统显像(CT、B 超、MRI)在结直肠癌术后复发及转移中的诊断价值.资料与方法107例结直肠癌术后患者行18F-FDG 符合线路 SPECT 显像,并联合 CT、B 超、MRI 诊断结直肠癌术后复发及转移.结果107例患者最终确定复发及转移共29例.18F-FDG 符合线路 SPECT 显像与传统显像诊断均为阳性的15例患者中,传统显像检出病灶20个,符合线路 SPECT 显像检出病灶26个.传统显像检出3个符合线路 SPECT 显像未发现的转移病灶,而符合线路 SPECT 显像检出9个传统显像未发现的病灶.18F-FDG 符合线路 SPECT 显像诊断结直肠癌术后复发及转移的灵敏度、特异性和准确率分别为79.3%、89.7%和86.9%;传统显像的诊断效能分别为62.1%、88.5%和81.3%;二者联合的诊断效能分别为89.7%、92.3%和91.6%.二者联合诊断结直肠癌术后复发及转移的灵敏度和准确率明显优于传统显像(P <0.05).结论18F-FDG 符合线路 SPECT 显像联合 CT、B 超、MRI 在监测结直肠癌术后复发及转移中具有重要临床价值.     

18F-FDGSPECT/CT显像在鼻咽癌治疗后EBV-DNA升高患者中的应用

目的:探讨18F-FDG SPECT/CT显像在检测鼻咽癌治疗后血清EBV-DNA升高患者,肿瘤复发和(或)转移病灶的价值.方法:鼻咽癌治疗后血清EBV-DNA升高患者45例,皆行全身18F-FDG SPECT/CT显像.所有图像经图像融合后,进行18F-FDG显像图像和CT图像帧对帧对比分析.肿瘤复发和(或)转移病灶根据病理检查结果、多种影像学诊断及临床随访而确诊.随访时间均＞6个月.采用SPSS 11.5软件进行统计学处理,进行x2检验.结果:45例患者中,明确诊断肿瘤复发和(或)转移者35例,单纯CT诊断肿瘤复发和(或)转移28例,其灵敏度为80.0％ (28/35);符合线路18F-FDG CT同机融合显像诊断肿瘤复发和(或)转移32例,灵敏度提高至91.4％ (32/35).结论:18F-FDG SPECT/CT在检测鼻咽癌治疗后EBV-DNA升高患者肿瘤复发和(或)转移病灶中有较好的应用价值.但角化型鼻咽癌可能出现假阴性.     

交互式胸部18F-FDG PET与CT三维容积图像融合技术的建立

目的建立可在PC机上运行的交互式胸部^18F-脱氧葡萄糖(FDG)PET与CT三维容积图像融合显示技术。方法对8例肺癌患者进行^18F-FDG PET全身显像和胸部螺旋CT检查。将PET发射和透射扫描三维容积数据和螺旋CT断层图像数据传入PC机。通过CT断层图像三维重建、像素转换、数据转换，采用胸部PET透射扫描显示解剖信息，结合^18F-FDG图像显示的病灶，以及心脏、肝脏、肾脏、脊柱骨髓等生理性显像图进行定位配准。采用交互式方式，对沿X、Y、Z轴的水平偏移量和旋转偏移角度进行调整，实现胸部PET-CT三维容积图像融合。结果8例肺癌患者，^18F-FDG PET显像共发现胸部阳性病灶25处，通过交互式PET-CT三维容积图像融合，所有病灶均在CT图像上明确定位。结论该图像融合技术对胸部^18F-FDG阳性病灶定位诊断有一定价值。     

不同能量放射性核素在PET/CT及SPECT采集中的相互影响

目的 利用模型探讨99TcmO4-与18F-氟脱氧葡萄糖(FDG)在图像采集中的相互影响,讨论同一患者是否可以同日分别采用PET/CT及SPECT两种仪器行高低两种能量放射性核素显像.材料与方法 利用统一规格、相同容积( 500ml)的5个塑料瓶(编号A、B、C、D、E),其内均注入500ml蒸馏水制作成模型.A瓶注入0.5mCi 18F-FDG行PET/CT显像;B瓶注入1mCi99TcmO4-行SPECT显像;C瓶内同时注入混合好的0.5mCi18F-FDG和1mCi99TcmO4-;D瓶内先注入1mCi99TcmO4-后再注入0.5mCi18F-FDG;E瓶先注入0.5mCi18F-FDG后再注入1mCi99TcmO4-.然后对C、D、E瓶分别行PET/CT显像和SPECT显像,并判断图像效果.结果 A瓶PET/CT显像和B瓶SPECT显像图像效果为1级;C、D瓶SPECT及PET/CT显像图像均为2级;E瓶SPECT显像图像为3级,PET/CT显像图像为1级.结论 同时加入18F-FDG和99TcmO4-对PET/CT和SPECT图像质量均有影响.先加入18F-FDG后加入99TcmO4-对PET/CT图像质量影响小,但SPECT图像不能分辨.先加入99TcmO4-后加入18F-FDG对PET/CT和SPECT图像质量均有影响.     

肺部病变18F-FDGSPECT符合线路显像

目的:探讨18F-FDG SPECT符合线路显像对肺部病变的定性诊断价值。材料和方法:用双探头SPECT符合线路对肺部病变患者进行18F-FDG肿瘤代谢显像,分析检查结果并与CT进行比较。结果:48例肺部病变患者18F-FDG显像诊断结果为真阳性37例,真阴性7例,假阳性3例和假阴性1例。其诊断的准确率、灵敏度和特异性分别为91.7％,97.4％和70％。诊断准确率显著高于CT检查。结论:18F-FDG SPECT符合线路显像对肺部病变具有较高的定性诊断价值。     

~(18)F-FDG符合线路SPECT/CT对肺孤立性病变的诊断价值

目的：应用^18F-脱氧葡萄糖（^18F-FDG）符合线路SPECT/CT显像半定量分析,探讨符合线路SPECT/CT对肺部孤立性病变的诊断价值。方法：回顾性分析经病理或随访证实的74例肺孤立性病变患者的^18F-FDG符合线路SPECT/CT图像,用半定量法（计算病灶组织与周围正常软组织的摄取比值,即T/NT）测量,所得数据进行统计学分析。结果：半定量分析显示恶性病变摄取^18F-FDG比值（9.57±6.13）明显高于良性病变（2.99±1.59）,差异有统计学意义（P〈0.05）。以T/NT≥3.5作为恶性病变的判定标准,74例肺孤立性病变中,真阳性49例,真阴性16例,假阳性7例,假阴性2例。敏感度、特异度、准确率、阳性预测值和阴性预测值分别为96.08%、69.57%、87.84%、87.50%和88.89%。结论：18F-FDG符合线路SPECT/CT显像对肺孤立性病变的诊断、鉴别诊断及预后评估具有重要的临床应用价值。     

18F-FDG PET/CT在黑色素瘤中的应用价值

目的 探讨18F-脱氧葡萄糖(FDG)PET/CT显像在黑色素瘤诊断、临床分期及监测治疗后肿瘤复发与转移灶中的应用价值.方法 黑色素瘤患者61例,均进行18F-FDG PET/CT全身显像.所有PET、CT及PET/CT融合图像均通过融合软件进行帧对帧对比分析.肿瘤病灶根据病理学检查、多种影像学检查及临床随访结果诊断.结果 18F-FDG PET/CT显像对黑色素瘤病灶检出的灵敏度、特异性和准确性分别为90.9%(40/44)、88.2%(15/17)和90.2%(55/61).其中12例治疗前患者中,18F-FDG PET/CT显像诊断的灵敏度为83.3%(10/12).在黑色素瘤病灶局部切除、尚未进行其他治疗的9例患者中,5例残余病灶18F-FDG PET/CT显像检出3例;4例远处转移灶患者全被检出,提高了临床分期,改变了治疗方案.首先发现转移性黑色素瘤病灶并且手术切除后,寻找原发灶的7例患者中,18F-FDG PET/CT检出原发灶2例,4例其他转移灶全被检出.黑色素瘤患者根治术后监测肿瘤复发或转移患者33例,18F-FDG PET/CT显像灵敏度、特异性和准确性分别为100.0%(19/19)、85.7%(12/14)和93.9%(31/33).与同期临床其他影像学检查比较,18F-FDG PET/CT显像发现更多,33例患者中,16例(48.5%)病灶提高临床分期;7例(21.2%)排除可疑病灶,降低临床分期;10例(30.3%)检出病灶与临床一致.结论 18F-FDG PET/CT显像对于黑色素瘤的诊断,残余病灶、复发病灶及转移灶的检出,临床分期的明确具有重要价值.     

Comparative study of hepatic venography using non-linear-blending images,monochromatic images and low-voltage images of dual-energy CT

Objective:

To investigate the use of non-linear-blending and monochromatic dual-energy CT (DECT) images to improve the image quality of hepatic venography.

Methods:

82 patients undergoing abdominal DECT in the portal venous phase were enrolled. For each patient, 31 data sets of monochromatic images and 7 data sets of non-linear-blending images were generated. The data sets of the non-linear-blending and monochromatic images with the best contrast-to-noise ratios (CNRs) for hepatic veins were selected and compared with the images obtained at 80 kVp and a simulated 120 kVp. The subjective image quality of the hepatic veins was evaluated using a four-point scale. The image quality of the hepatic veins was analysed using signal-to-noise ratio (SNR) and CNR values.

Results:

The optimal CNR between hepatic veins and the liver was obtained with the non-linear-blending images. Compared with the other three groups, there were significant differences in the maximum CNR, the SNR, the subjective ratings and the minimum background noise (p < 0.001). A comparison of the monochromatic and 80-kVp images revealed that the CNR and subjective ratings were both improved (p < 0.001). There was no significant difference in the CNR or subjective ratings between the simulated 120-kVp group and the control group (p = 0.090 and 0.053, respectively).

Conclusion:

The non-linear-blending technique for acquiring DECT provided the best image quality for hepatic venography.

Advances in knowledge:

DECT can enhance the contrast of hepatic veins and the liver, potentially allowing the wider use of low-dose contrast agents for CT examination of the liver.CT venography (CTV) is an important non-invasive examination to assess the hepatic veins and plays an important role in the pre-operative evaluation of liver transplants and the diagnosis of hepatic venous diseases.^1,2 Compared with CT hepatic artery angiography or multiphasic liver CT, CTV often requires a larger dose of the contrast agent to achieve sufficient contrast for filling in the hepatic veins.³ Increasing the contrast agent not only increases the economic burden of the patient but also raises the incidence of side effects and complications related to the contrast agent. One of the goals in the advancement of CT techniques is to continuously improve the image quality and clinical applications while reducing radiation exposure and promoting the reasonable use of contrast agents. Several studies suggest that low tube voltage CTV reduces radiation and improves vascular contrast^4–6 because iodinated contrast material is more conspicuous in low-kilovolt peak(kVp) images with an approximately 80% increase in CT attenuation at 80 kVp compared with that at 140 kVp.^6–8Dual-source CT (DSCT) was recently introduced into clinical practice. It can simultaneously acquire low- and high-energy image data using two X-ray tube and detector systems mounted in one gantry.⁹ Dual-energy CT (DECT) could improve the contrast and thereby the image quality of CTV images by virtual monochromatic imaging¹⁰ and non-linear-blending⁸ and linear-blending techniques.^7,11,12 Studies have shown that a DECT non-linear-blending technique could improve the conspicuity of myocardial delayed enhancement.⁸ The clinical application of DSCT undoubtedly greatly aides the choice of a suitable application from a variety of post-processing techniques that can significantly improve the contrast enhancement of hepatic veins. However, the ability to improve the conspicuity of hepatic veins via a dual-source DECT non-linear-blending technique and the performance of non-linear-blending and monochromatic imaging techniques have not been studied. Therefore, the purpose of our study was to improve the image quality of hepatic venography over single-energy CT by using DECT virtual monochromatic imaging and a non-linear-blending technique.     

Synthesized MR images: comparison with acquired images

Synthesized and directly acquired spin-echo images were compared in order to assess the validity of magnetic resonance (MR) image synthesis as a method enabling retrospective formation of images by interactive manipulation of scan parameters. Synthetic images subjectively compared favorably in both accuracy and precision with acquired images when formed for the same values of echo (TE) and repetition times (TR) and for interpolated and extrapolated values of both TE and TR. Plots of synthetic and acquired signals within the same pixel sectors quantitatively showed comparable values for several regions of interest in the brain. Percent error and noise-normalized differences between acquired and synthetic images were tested as a quantitative measure of accuracy. Percent error was consistently less than 5% for brain parenchyma, and synthetic signals were accurate to within four times the noise level at acquisition. The apparent signal-to-noise ratio of synthetic images was comparable, superior, or inferior to similar acquired images, depending on the values of TE and TR. Total acquisition time required for synthetic formation of images for arbitrary values of TE and TR was equivalent to that of a single direct acquisition with a TR of 2,500 msec.     

Registration of two-dimensional cardiac images to preprocedural three-dimensional images for interventional applications

PURPOSE: To evaluate the accuracy and efficiency of rigid-body registration of two-dimensional fast cine and real-time cardiac images to high-resolution and SNR three-dimensional preprocedural reference volumes for application during MRI-guided interventional procedures. MATERIALS AND METHODS: Mutual information (MI) and correlation ratio (CR) similarity measures were evaluated. The dependence of registration accuracy and efficiency on different resolution and SNR parameters, and also on cardiac-phase differences was evaluated in a porcine model. Two-dimensional images were initially misoriented at distances (d) of 2-10 mm, and rotations of +/-5 degrees about all axes. Registration error and computation time were evaluated, and performance was also assessed visually. RESULTS: The maximum registration error using MI (<2.7 mm and <3.6 degrees ) occurred for d = 10 mm, misrotation of +/-5 degrees , and relative SNR = 1. The computation time was 15 seconds for MI and 10 seconds for CR. CONCLUSION: Registration accuracy was not highly dependent on the relative timing, within the cycle, between the two-dimensional and three-dimensional images. Registration using CR was faster than that using MI, although accuracy was marginally higher with MI. J.