SPECT与CT3D图像异机融合的实验研究

目的:初步探讨SPECT与CT图像异机融合.方法:利用核医学质控PET-CT模型,分别使用SPECT、64排CT、SPECT/CT分别进行采集,然后利用MIPAV软件对SPECT、64排CT图像进行异机融合.以SPECT/CT PET-CT模型同机融合图像为金标准,视觉评价异机融合图像质量.结果:利用M1PAV软件可将SPECT和64排CT所采集PET-CT模型图像较为理想地进行异机融合.由影像科医师对异机融合图像与同机融合图像进行比较,图像质量无显著差异.结论:对于SPECT和CT所采集图像,利用MIPAV软件进行3D图像异机融合具有临床可行性.     

320层容积CT心肌灌注成像对心肌灌注缺损的诊断价值

目的 探讨320层容积CT心肌灌注成像(CT-MPI)的可行性及其对心肌灌注缺损的诊断价值.方法 对14例经SPECT心肌灌注成像(SPECT-MPI)阳性的已知或可疑冠心病患者行静息和腺苷负荷320层容积CT-MPI检查,使用专用心肌灌注软件对CT-MPI进行分析.以心肌16节段标准分段方法(心尖除外)分别分析核素和容积CT-MPI的固定或可逆性灌注缺损.以SPECT-MPI为参考标准评价CT-MPI对心肌灌注缺损诊断的敏感度、特异度.结果 所有患者均成功完成320层容积CT-MPI.SPECT-MPI显示14例患者中共有39段心肌出现固定或可逆性灌注缺损,CT-MPI正确显示了其中12例患者的34段心肌灌注缺损.320层容积CT-MPI诊断心肌灌注缺损的敏感度、特异度分别为87.2％( 34/39)和91.4％(169/185).结论 320层容积CT-MPI对诊断心肌灌注缺损有较高的敏感度和特异度.     

冠心病无创性检查的研究进展

无创性检查方式是评价冠心病和亚l临床冠心病的有效手段,包括CT、核心脏病学、MRI以及图像融合.此综述重点阐述了各种无创性检查方式用于评价冠心病和亚临床冠心病的优缺点.利用CT可行钙化积分,对冠状动脉钙化程度进行定量分析,亦可行无创性冠状动脉造影.目前核心脏病学是评价心肌血流灌注应用最广泛的无创性检查方式,包括SPECT和PET,分别可对心肌血流和冠脉血流行半定量和定量分析.现研究多致力于无创性冠脉造影和MRI心肌血流灌注显像.如今图像融合设备亦迅猛发展,可同时包含解剖和功能信息,对诊断冠心病具有很大的价值.     

腺苷负荷心肌灌注显像评价心肌血流供应异常的临床研究

目的 回顾性分析腺苷负荷/静息心肌灌注显像用于评价冠心病心肌血流供应异常的准确性和临床价值.方法 1858例临床确诊或可疑冠心病患者行常规标准程序两日法腺苷负荷/静息99Tcm-甲氧基异丁基异腈心肌灌注断层显像,由2位以上核医学科医师共同阅片定性分析图像.所有患者在显像前后1个月内行冠状动脉（简称冠脉）造影检查.方法间的一致性分析用Kappa检验,Kappa＞0.45为一致性较好.结果 1858例患者中,冠脉造影有1支及1支以上冠脉狭窄≥50%的患者957例,其中单支病变506例,双支病变256例,三支病变195例;共累及冠脉1603支,其中左前降支（LAD）765支、左回旋支（LCX）399支、右冠脉（RCA）439支.腺苷负荷/静息心肌灌注显像示心肌缺血或心肌梗死者1126例,与冠脉造影对照,其诊断冠心病的灵敏度为91.54%（876/957）,特异性为72.25%（651/901）,阳性预测值为77.80%（876/1126）,阴性预测值为88.93%（651/732）,2种方法一致性好（Kappa=0.641）.对LAD、LCX和RCA病变诊断的灵敏度分别为81.31%（622/765）,56.64%（226/399）和70.62%（310/439）;对单支、双支和三支冠脉病变的灵敏度分别为87.55%（443/506）,94.92%（243/256）和97.44%（190/195）.腺苷不良反应的发生率为84.12%（1563/1858）,无严重心脏事件发生.结论 腺苷负荷心肌灌注断层显像诊断冠心病有较高的灵敏度、特异性和准确性,对评价心肌血流供应异常有重要的临床价值.     

SPECT／CT显像评价“功能相关冠状动脉病变”的价值

目的探讨SPECT／CT显像评价“功能相关冠状动脉（简称冠脉）病变”的可行性及临床价值。方法40例可疑或确诊冠心病患者同机完成^99Tcm-甲氧基异丁基异腈（MIBI）负荷／静息心肌灌注断层显像和冠脉CT造影（CTCA）。负荷／静息心肌灌注显像采用标准二日法,首日行腺苷负荷心肌灌注显像,次日行静息心肌灌注显像及CTCA。腺苷按患者体质量以0．84mg·kg^-1·min^-1经静脉泵匀速给药,CTCA使用标准自动对比剂跟踪扫描程序完成。通过专用融合软件将心肌血流灌注与冠脉三维成像图融合,评价心肌缺血与冠脉病变的相关关系,确定“功能相关冠脉病变”。结果40例患者,CTCA正常20例,异常20例;120支冠脉中共检出33支病变血管,累及左前降支15支,左回旋支9支,右冠脉9支。心肌灌注显像正常22例,心肌缺血和（或）心肌梗死18例。SPECT心肌灌注和CTCA融合图像显示供血区心肌血流灌注正常且无狭窄冠脉占总的无狭窄冠脉的92．47％（86／93）,狭窄〈75％的冠脉中,其供血区心肌缺血或梗死的阳性率占42．86％（6／14,例）,狭窄〉75％或闭塞冠脉中,其供血区心肌缺血的阳性率占92．31％（12／13,例）。120支冠状动脉中20．83％（25／120,支）的病变冠脉为“功能相关冠脉病变”,检测出27例患者中25．93％（7／27,例）有无狭窄病变的冠脉导致心肌缺血;使15．38％（2／13,例）冠脉病变患者免除有创性诊断检查;指导对42．86％（6／14,例）的狭窄〈75％冠脉行药物治疗或冠脉血管重建术治疗;为1支狭窄〉75％的冠脉无需行血管重建术提供依据。结论SPECT／CT心肌灌注和CTCA融合显像可确定“功能相关冠脉病变”,可提供综合信息诊断冠心病和指导治疗。     

SPECT肺灌注与CT异机融合图像评价非小细胞肺癌肺功能的价值

目的 探讨SPECT肺灌注与CT异机融合图像评价Ⅲ期非小细胞肺癌(NSCLC)患者区域肺功能的意义.方法 选择Ⅲ期NSCLC患者32例,治疗前行肺功能测试和胸部CT扫描,并在相同体位下行SPECT肺灌注显像,两套图像均传至Philips Pinnacle3放射治疗计划系统,依据外标记点进行手动异机图像融合.参考CT与SPECT肺灌注融合图像,按灌注缺损区与肿瘤病灶的大小关系分为4级:0级为无灌注受损;1级为肿瘤及其周围局部肺灌注受损;2级为1叶肺灌注受损;3级为超过1叶肺灌注受损.采用SPSS 13.0软件,行PearsonX2检验.结果 32例Ⅲ期NSCLC患者中,31例有程度不等的肺灌注缺损,其中1级13例,2级8例,3级10例.中央型NSCLC患者肺灌注缺损较周围型NSCLC患者严重,差异有统计学意义(X2=10.495,P＜0.05).8例患者肺功能测试有不同程度的异常.CT与SPECT肺灌注融合图像阳性率96.9%(31/32),较肺功能测试阳性率25.0%(8/32)高,差异有统计学意义(X2=34.724,P＜0.05).结论 SPECT肺灌注与CT异机融合图像能更好显示Ⅲ期NSCLC患者区域肺组织的功能状况,为此类患者制订手术方案、预测术后肺功能、优化放疗计划等提供更多的信息.     

~(99m)Tc-MIBI潘生丁负荷心肌灌注断层显像评价冠状动脉支架术后血管再狭窄的价值

目的: 通过对冠状动脉(简称冠脉)支架植入前后进行静息和潘生丁负荷99mTc-MIBI断层显像(R-MPTI、P-MPTI),以了解SPECT在支架置入术前筛选、术后再狭窄评价中的价值.材料和方法: 95例冠心病患者在冠状动脉介入治疗前、术后3～6个月行R-MPTI和P-MPTI.潘生丁最大剂量时注射740MBq99mTc-MIBI,1h后行心肌断层显象;24h后重复静态心肌显象.与术后复查冠脉造影(CAG)对比,分析心肌灌注显像对支架术后再狭窄的诊断效果.结果: 95例冠心病患者共有855个心肌血流灌注节段,术前R-MPTI发现196个心肌血流灌注缺损,P-MPTI发现351个.支架置入后R-MPTI检查发现62个心肌血流灌注缺损病变节段,P-MPTI检查发现145个心肌血流灌注缺损病变节段.术后CAG随访92例,18例(18/92,19.6%)共29支血管发生再狭窄.按再狭窄冠脉支数计算,R-MPTI、P-MPTI对再狭窄的诊断准确性、阳性预测值和阴性预测值分别为84.5%、92.6%; 59.5%、75.7%;95.7%、98.9%,所有指标均有显著差异(χ~2＝15.54)(P<0.01).结论: P-MPTI可以早期发现冠状动脉内支架术后再狭窄,诊断效率高于R-MPTI,有利于准确判断病情和指导治疗.     

64排128层螺旋CT冠状动脉成像与冠脉造影比较分析

目的 探讨64排1 28层螺旋CT在冠状动脉病变中的应用价值.方法 选择2011年6月～2012年10月间在我院影像中心接受螺旋CTA检查的冠心病患者100例为研究对象,所有患者均于入院3d内完成冠状动脉螺旋CTA检查及冠脉造影.观察冠状动脉螺旋CTA图像特征,以冠脉造影为金标准,分析64排128层螺旋CTA对冠脉狭窄诊断的敏感性、特异性、阳性预测率及阴性预测率.结果 100例患者64排128层螺旋CT冠脉成像均取得满意的检查图像.以冠脉造影为金标准,64排128层螺旋CT冠脉成像显示轻度冠脉狭窄数量多于冠脉造影,中度及重度冠脉狭窄数量少于冠脉造影,经卡方检验,无统计学差异（P＞0.05）.64排128层螺旋CT冠脉成像共显示146处冠状动脉狭窄（≥50％）.以冠脉造影为金标准,64排128层螺旋CT冠脉成像对冠状动脉狭窄（≥50％）诊断的敏感性为96.4％（137/142）,特异性为96.8％（274/283）,阳性预测率为93.8％（137/146）,阴性预测率为98.2％（274/279）.结论 64排128层螺旋CT冠脉成像可以与冠脉造影相媲美,具有很高的敏感性、特异性、阳性预测率及阴性预测率,值得临床推广应用.     

冠状动脉CT血管成像在缺血性狭窄诊断中的应用价值

目的 探讨冠状动脉CT血管成像在缺血性狭窄诊断中的应用价值。方法 选取150例冠心病患者，行冠状动脉CTA、MPI与常规冠状动脉造影(CCA),按照心肌灌注缺损部位评估冠状动脉病变血管。结果 150例患者中，CCA检出90例存在狭窄≥50%的冠状动脉共有165支，255个节段，其中有125个节段处于冠状动脉远端和分支。冠状动脉CTA检出狭窄≥50%节段的灵敏度、特异性、PPV和NPV在所有节段是47%、90%、55%、94%,在可评估节段为57%、93%、56%、98%。MPI一共检出了可逆性缺损患者25例，CCA检出可逆性缺损灵敏度、特异性、PPV与NPV分别是95%、71%、19%以及100%,CTA检出可逆性缺损灵敏度、特异性、PPV与NPV分别是52%、85%、10%、93%。结论 冠状动脉CTA异常的患者需要率先使用MPI,然后按照MPI的结果有选择性的行CCA。     

负荷心肌灌注显像与双源CT冠脉成像诊断冠心病的对比研究

目的:通过对心肌灌注显像(MPI)与心脏双源CT(DSCT)检查结果进行对比分析,探讨两者对冠心病的临床诊断价值.方法:对38例拟诊为冠心病的患者行MPI及心脏DSCT检查;分别对MPI图像及DSCT图像进行分析处理,其中29例经冠状动脉造影(CAG)证实为冠心病.结果:DSCT显示有29例冠脉狭窄程度＞50％,其中大...     

Inadequacy of motion correction algorithms in functional MRI: Role of susceptibility-induced artifacts

Functional MR (fMR) has been useful in providing insight into the localization and detection of neural cortical activity. However, patient head motion is inevitable over the course of most fMR experiments. Although methods to align the control and activation fMR images may correct for some of this motional error, they will be incomplete in correcting for those that depend on spatial orientation. MR signal amplitude of structures that lie along air-tissue interfaces, for example, are sensitive to susceptibility errors introduced by their reorientation with respect to the main magnetic field. This analysis, using phantoms, cadaver brain, and volunteers, has shown that this reorientation between control and activation images can create regions of “false activation” that increase in area with rotation. Anatomic regions that are expected to be most affected by these susceptibility-induced magnetic field homogeneity variations are those adjacent to bone or air, such as the mesial and inferior temporal lobes and the inferior and anterior frontal lobes. Interpretation of “activation” in these areas on fMR studies must be performed with careful consideration of this important source of error.     

Registration of images from sequential MR studies of the brain

For sequential studies of patients with brain tumors, the authors have designed an automated registration procedure for intra- and interexamination alignment of magnetic resonance images. This was evaluated with artificially misregistered data and data from repeat studies of six healthy volunteers and six brain tumor patients. In a subset of cases, a manual procedure based on matching of neuroanatomic landmarks was also applied for comparison. The results showed that the technique is robust and reproducible, giving an accuracy in the range of 1–2 mm, which corresponded to the spatial resolution of the images. Subject motion between imaging sequences within the same study was negligible, although adjustments (one to two section thicknesses) were required in the z direction to correlate multisection and volume images and to allow accurate image segmentation. For alignment between sequential volunteer and patient examinations, translations of up to 22 mm and rotations in the x, y, and z axes of up to 9° were required. This alignment procedure may be valuable in numerous aspects of treatment planning and patient follow-up.     

Bidirectional elastic image registration using B-spline affine transformation

A registration scheme termed as B-spline affine transformation (BSAT) is presented in this study to elastically align two images. We define an affine transformation instead of the traditional translation at each control point. Mathematically, BSAT is a generalized form of the affine transformation and the traditional B-spline transformation (BST). In order to improve the performance of the iterative closest point (ICP) method in registering two homologous shapes but with large deformation, a bidirectional instead of the traditional unidirectional objective/cost function is proposed. In implementation, the objective function is formulated as a sparse linear equation problem, and a sub-division strategy is used to achieve a reasonable efficiency in registration. The performance of the developed scheme was assessed using both two-dimensional (2D) synthesized dataset and three-dimensional (3D) volumetric computed tomography (CT) data. Our experiments showed that the proposed B-spline affine model could obtain reasonable registration accuracy.     

Dose accumulation during vaginal cuff brachytherapy based on rigid/deformable registration vs. single plan addition

PurposeTo compare dose summation using a single plan (SP) approach for vaginal cuff brachytherapy (VBT) against dose summation after a rigid or deformable registration for each VBT fraction, in women with early stage endometrial cancer receiving postoperative VBT.Methods and MaterialsA retrospective analysis of 19 patients who received VBT as the sole adjuvant treatment was undertaken. For the purposes of the study, every VBT fraction was re-segmented and re-planned under the same conditions. CT-planning images were registered, initially following a rigid method and then using deformable registration. The transformation vectors were reused to warp the dose files, followed by the dose summation. Three dose accumulation scenarios were studied: (1) an SP approach, (2) a rigid dose warping summation (RDWS), (3) a deformable dose warping summation (DDWS). Each scenario was analyzed for 3 and 5 fractions to evaluate the effect of fractionation. D0.1cc, D1cc, D2cc, D5cc, D5%, and Dmean values were compared for organs at risk, such as the rectum and bladder.ResultsNo statistical significances were observed in rectal parameters between SP and RDWS or between SP and DDWS. Significant SP, RDWS and DDWS Dmean, D0.1cc, and D2cc metric differences for the 5 fractions bladder scenario were observed (p = 0.0242, 0.0196, and 0.0242, respectively).ConclusionsA multi-image planning procedure for a VBT course leads to limited differences between different summation methods. SP is an effective and acceptable surrogate for absorbed doses in organs at risk.     

自动追踪冻结联合智能边缘修复技术在宝石能谱CT冠状动脉成像诊断心肌桥中的应用价值

目的 探究自动追踪冻结(SSF)联合智能边缘修复(IBR)技术在宝石能谱CT冠状动脉成像诊断心肌桥(MB)中的应用价值.方法 选取本院2017年1月～2019年12月期间178例疑似冠心病患者行宝石能谱CT冠状动脉检查图像及临床资料进行分析,其中诊断MB患者57例.根据SSF和IBR技术重建图像,并由经验丰富的CT诊断...     

医学图像融合的临床应用与新进展

医学图像融合是医学图像后处理的研究热点,它充分利用多模态图像,获得互补信息,使临床的诊断和治疗更加准确完善。本文综述了近年来医学图像融合研究的临床应用与最新进展,认为多模态医学图像融合是一个发展趋势,在临床疾病的早期诊断、治疗定位中将发挥重要的作用。     

基于形变配准的鼻咽癌调强放射治疗计划剂量学研究

目的 探讨形变配准技术在鼻咽癌患者治疗过程中靶区、正常组织的几何改变及相应的剂量学改变。方法 选取12例采用IMRT-SIB治疗的鼻咽癌患者,针对首次定位CT制定放疗计划为计划1(CT1), 治疗20~25次后,针对复位CT制定放疗计划为计划2(CT2)。将 CT1中的剂量分布形变配准至图像CT2上,为计划1(CT2);同时将患者CT1中25次治疗剂量和 CT2中的剩余5次治疗剂量进行剂量叠加,为计划1+2(CT2)。比较计划1(CT1)、计划1(CT2)和计划1+2(CT2)中的剂量分布。结果 图像CT2和CT1相比,右侧和左侧腮腺体积明显缩小(24.6±11.9)%、(35.1±20.1)%。与计划1 (CT1)相比,在计划1 (CT2)中靶区(D₉₅)和PGTV、PTV2(Dmean)明显降低,计划1+2 (CT2)中数据表明,如果25次后修改计划会提高靶区剂量。在12例患者中有5例患者如果不重新修改计划则脑干脊髓受量会超过剂量限制,如果修改计划则会降低。结论 鼻咽癌患者在治疗中靶区及腮腺体积有明显缩小,重新定位修改计划可确保靶区足够剂量,并且使危及器官受量控制在安全范围之内。     

Assessing the reliability of MRI-CBCT image registration to visualize temporomandibular joints

Objectives:

To evaluate image quality of two methods of registering MRI and CBCT images of the temporomandibular joint (TMJ), particularly regarding TMJ articular disc–condyle relationship and osseous abnormality.

Methods:

MR and CBCT images for 10 patients (20 TMJs) were obtained and co-registered using two methods (non-guided and marker guided) using Mirada XD software (Mirada Medical Ltd, Oxford, UK). Three radiologists independently and blindly evaluated three types of images (MRI, CBCT and registered MRI-CBCT) at two times (T₁ and T₂) on two criteria: (1) quality of MRI-CBCT registrations (excellent, fair or poor) and (2) TMJ disc–condylar position and articular osseous abnormalities (osteophytes, erosions and subcortical cyst, surface flattening, sclerosis).

Results:

75% of the non-guided registered images showed excellent quality, and 95% of the marker-guided registered images showed poor quality. Significant difference was found between the non-guided and marker-guided registration (χ² = 108.5; p < 0.01). The interexaminer variability of the disc position in MRI [intraclass correlation coefficient (ICC) = 0.50 at T₁, 0.56 at T₂] was lower than that in MRI-CBCT registered images [ICC = 0.80 (0.52–0.92) at T₁, 0.84 (0.62–0.93) at T₂]. Erosions and subcortical cysts were noticed less frequently in the MRI-CBCT images than in CBCT images.

Conclusions:

Non-guided registration proved superior to marker-guided registration. Although MRI-CBCT fused images were slightly more limited than CBCT alone to detect osseous abnormalities, use of the fused images improved the consistency among examiners in detecting disc position in relation to the condyle.