脑肿瘤的201Tl SPECT和增强MRI的融合成像研究

目的探讨图像融合影响因素及融合成像对诊断脑肿瘤的临床价值.方法对39例脑肿瘤患者201Tl-SPECT和增强MR图像进行融合成像处理.结果融合成像精度影响因素包括:体位、解剖位置融合时基准的选择是否正确、MRI矢状面视野的大小以及SPECT彩色窗的调节.融合成像可以同定201Tl集聚部位、明确201Tl在肿瘤内集聚位置、鉴别集聚灶性质以及确认小病灶,对28.2%(11/39)病例诊断有帮助.结论 201Tl-SPECT和MRI融合成像可提高脑肿瘤的诊断精度,有助于确定活检部位.     

急性脑梗死患者SPECT、CT、MRI对比分析

探讨SPECT、MRI、CT对急性脑梗死患者检查异同和优缺点 ,以指导临床早期诊断和治疗。方法　对同一患者在发病 48h内进行CT和MRI、SPECT检查。结果　CT的异常检出率为 41 1% ,MRI为 6 0 87% ,SPECT为 85 2 9%。SPECT明显高于CT、MRI(χ2 =14 2 32 ,P <0 0 0 1)。结论　SPECT与CT、MRI比较能够较早地确定病变部位和范围 ,为急性脑梗死超早期治疗提供了可靠依据。但对脑出血与脑梗死的鉴别不如CT对脑干及脑深部 ,较小病灶不如MRI显示清楚 ,因此三种检查方法不能互相取代     

SPECT／CT融合显像在距骨缺血性坏死诊断中的应用

目的评价SPECT／CT融合显像在距骨缺血性坏死诊断中的临床应用价值。方法35例临床可疑距骨缺血性坏死患者行平面骨显像及SPECT／CT同机图像融合,对平面和SPECT／CT融合显像的诊断符合率行x2检验。结果平面显像诊断符合率为59．3％;SPECT／CT融合显像诊断符合率为88．9％。融合图像对病变诊断符合率高于平面显像,差异具有显著性。结论SPECT／CT同机图像融合技术对于距骨缺血性坏死的早期诊断、鉴别诊断均有一定的临床价值。     

SPECT/CT融合图像和MRI在诊断髋关节良性病变中的比较

目的 比较SPECT/CT融合图像和MRI在髋关节良性病变中的诊断价值.方法 回顾性分析22例临床疑似股骨头缺血性坏死,并伴有髋部不适、疼痛或活动受限等症状患者的SPECT/CT融合图像和MRI.全部患者核素骨显像和MR检查均于5日内完成,并经临床随访证实.结果 22例患者的44个髋关节中,共发现股骨头坏死18髋,关节炎性病变4髋,其中1例患者为强直性脊柱炎.MRI发现股骨头坏死17髋,髋关节炎4髋;SPECT/CT融合图像发现股骨头坏死18髋,髋关节炎4髋,且核素骨显像浓聚或稀疏区与MRI征象之间均存在对应关系.结论 SPECT/CT融合图像和MRI两种显像方法在诊断髋关节良性病变中的阳性率相当,两者互为补充,且SPECT/CT融合图像可区分髋臼与股骨头病变,较单纯平面显像提高了诊断的准确率.     

SPECT/CT与MRI对鼻咽癌颅底骨侵犯诊断价值的比较

目的:探讨单光子发射计算机断层显像(single-photon emission computed tomography,SPECT)/CT及磁共振成像(magnetic resonance imaging,MRI)对鼻咽癌(nasopharyngeal carcinoma,NPC)颅底骨侵犯(skull-base bone invasion,SBBI)的诊断价值。方法:回顾性分析83例(男性57例,女性26例;年龄为16～72岁)初诊未治且由病理学检查证实的NPC患者,比较头颅~(99m)Tc-MDP SPECT/CT图像与鼻咽部MRI图像。另设正常对照10例,仅进行头颅SPECT/CT。计算SPECT/CT图像矢状面颅底异常浓集最高计数区域与高位颈椎体处比值(L/S),L/S1视为SBBI。以临床和鼻咽MRI检查结果为金标准,计算SPECT/CT及MRI判断颅底骨侵犯的灵敏度、特异度、准确率、阳性预测值、阴性预测值。结果:随访确诊为NPC SBBI的患者有64例。MRI检查真阳性64例,假阳性1例,真阴性18例;SPECT/CT检查真阳性60例,假阳性3例,真阴性16例,假阴性4例。61例患者在MRI和SPECT/CT上均表现为SBBI。MRI诊断NPC SBBI的灵敏度、特异度、漏诊率及误诊率分别为100%、94.74%、0及5.26%;SPECT/CT的相应指标分别为93.75%、84.21%、6.25%及15.79%。结论:SPECT/CT与MRI诊断NPC SBBI具有相似的诊断效能,但对各骨的诊断效能不同,尤其在颞骨诊断上有差异。     

磁共振胰胆管成像与常规扫描诊断胆系结石的对照研究

目的：对比探讨磁共振胰胆管成像及其原始图像与磁共振常规扫描诊断胆系结石的价值。方法：应用1．0T超导MRI扫描仪对55例患者（36例胆囊结石和19例胆总管结石）行重T2加权多次激发FSE序列（HT2-FSE）磁共振胰胆管成像扫描及常规轴面FSE序列MRI T1WI及T2WI扫描。结果：磁共振胰胆管成像的最大强度投影图像能清晰显示肝内、外胆管及扩张胰管的形态结构。多数较大的胆系结石在磁共振胰胆管成像原始图像及MRI常规T2WI图像上可很好地显示，但常在最大强度投影图像被掩盖；较小的胆系结石在磁共振胰胆管成像的最大强度投影图像及MRI常规T2WI图像均难以准确显示，而仅在磁共振胰胆管成像原始图像上显示。结论：磁共振胰胆管成像原始图和最大强度投影图像以及磁共振常规扫描是分析、诊断胆系结石的一个有机整体，不能仅仅依靠某一种成像技术作出诊断。     

SPECT/CT融合图像对脊柱单发病灶鉴别诊断的增益价值

目的：探讨SPECT/CT融合图像较SPECT图像在脊柱单发病灶鉴别诊断方面的增益价值。方法：193例恶性肿瘤患者在全身骨显像发现脊柱单发浓聚病灶后行SPECT/CT显像。由2名核医学科医师结合全身骨显像分别对SPECT图像和SPECT/CT融合图像进行分析,对脊柱病灶诊断分为：肿瘤骨转移、良性病变、不能确定诊断。并按SPECT/CT融合图像比SPECT图像对诊断是否具有增益价值分为：有帮助、不确定、无帮助。将观察指标分为肯定组和否定组,分别计算其百分率及95%可信区间。结果：对193处病灶的分析结果显示,SPECT图像能确定诊断（肿瘤骨转移和良性病变）的病灶共59处,占30.6%（59/193）,其95%可信区间为24.1%-37.1%;不能确定诊断的病灶共134处,占69.4%（134/193）,其95%可信区间为62.9%-75.9%。SPECT/CT融合图像能确定诊断的病灶共175处,占90.7%（175/193）,其95%可信区间为86.6%-94.8%;不能确定诊断的病灶共18处,占9.3%（18/193）,其95%可信区间为5.2%-13.4%。与SPECT图像对比,SPECT/CT融合图像对诊断有帮助者173处,占89.6%（173/193）,其95%可信区间为85.3%-93.9%;不确定18处和无帮助2处共20占10.4%（20/193）,其95%可信区间为6.1%-14.7%。结论：在对脊柱单发病灶是否为肿瘤骨转移的鉴别诊断方面SPECT/CT融合图像较SPECT图像具有增益价值,可以提供更多的诊断信息。     

SPECT/CT符合线路18F-FDG显像对肿瘤的定位诊断价值

目的：探讨SPECT/CT符合线路^18F—FDG显像对肿瘤的定位诊断价值。方法：106例恶性肿瘤患者行SPECT/CT符合线路^18F-FDG显像。患者禁食6h以上，静脉注射^18F-FDG 185～296MBq，60min后进行发射和X线CT透射扫描。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FDG SPECT的融合图像。结果：X线CT与FDG SPECT图像直观比较，X线CT能较清晰显示头颈部、胸腹部和盆腔解剖结构，FDG SPECT图像除显示肺部、心脏、肝脏较清晰外，其它解剖部位显示欠清晰。106例患者的356个病灶中，FDG SPECT 定位CT融合图像可全部检出，并能全部定位。如果不借助同机CT定位，单纯FDG SPECT图像仅有191个病灶(占53．65％)能准确定位，其它165个病灶(占46．35％)不能判断准确位置。腹腔、盆腔61个病灶中，除21个肝脏内病灶可确定部位外，其余40个病灶难以显示准确位置。8个食管病灶和2个口腔病灶均无法准确定位。结论：FDG SPECT／CT符合线路显像较单纯的FDG SPECT符合线路显像有明显优势，它在肿瘤定位、手术或放疗方案制定、评价预后等方面将发挥重要作用。     

SPECT/螺旋CT融合显像鉴别诊断颅骨良恶性病变的临床价值

目的：探讨SPECT/螺旋CT融合显像鉴别诊断颅骨良恶性病变的临床价值。方法：对19例恶性肿瘤患者全身骨扫描（WBS）显示颅骨放射性浓聚的21个病灶行SPECT/CT融合显像,由两名有经验的核医学科医生独立阅片。患者同期接受MRI和/或CT检查,各检查时间间隔不超过两周,并对所有病例进行随访,平均随访约9个月,随访结果主要根据随后的影像学检查（MRI、CT或随后的骨扫描）及临床信息。结果：根据同期影像及随访检查共10个病灶诊断为恶性病变,11个病灶诊断为良性病变。SPECT/CT融合显像检出全部10个恶性病灶及8个良性病变,诊断符合率为85.71%。1个病灶在SPECT/CT融合显像中诊断为恶性,而同期MRI及随访检查显示良性病变。另有两个病灶在SPECT/CT中难以确定其性质,同期影像及随访检查亦显示为良性。SPECT/CT融合显像在肯定性诊断为良、恶性病灶中诊断颅骨恶性病变的敏感性、特异性、阳性预测值、阴性预测值分别为100.00%、88.89%、90.91%、100.00%。结论：SPECT/螺旋CT融合显像对鉴别诊断颅骨良恶性病变有较高的敏感性和特异性。     

磁共振弥散加权成像鉴别脑脓肿和坏死囊变脑肿瘤

目的探讨磁共振弥散加权成像(DWI)鉴别诊断脑脓肿和坏死囊变脑肿瘤的价值.方法6例脑脓肿和13例脑肿瘤(8例胶质瘤和5例转移瘤),行常规MR和DWI检查.应用1.5 T磁共振机SE-EPI序列,取b*1000 s/mm2,b=0s/mm2获得DWI图像.同时测量感兴趣区的ADC值,行两个独立样本秩和检验.结果6例脑脓肿5例DWI图像表现为高信号,ADC值为(0.33±0.11)×10-3 mm2/s,13例脑肿瘤中12例坏死囊变部分DWI图像表现为低信号,ADC值为(2.46±0.49)×10-3 mm2/s.结论磁共振弥散加权成像能为鉴别诊断脑脓肿和坏死囊变脑肿瘤提供很有价值的信息,帮助提高诊断的正确性.     

^201Tl和^99mTc-HL91联合显像在诊断急性心肌梗死患者存活心肌中的初步应用

目的:研究201Tl与99mTc-H L91双核素心肌显像方法学,评价其在诊断急性心肌梗死(AM I)患者存活心肌中的临床应用价值。方法:18例AM I患者及10例对照者行静息和24h延迟201Tl与99mTc-H L91双核素心肌显像,核素显像行5分法评价图像质量,用17节段法来分析201Tl显像缺损与乏氧显影心肌节段。结果:双核素显像图像质量良好,99mTc-H L91图像质量不如201Tl(t=6.007,P<0.01);201Tl静息显像诊断AM I灵敏度为100.0%,特异度为90.0%,准确度为96.4%,24h延迟显像22.2%AM I患者多节段存活心肌显影;83.3%的AM I患者201Tl灌注缺损心肌节段在99mTc-H L91显像中显影,对照者也有部分心肌节段显影。结论:201Tl与99mTc-H L91双核素心肌显像能明确AM I患者心肌梗死部位并初步判断是否有存活心肌,具有临床应用前景。     

SPECT/CT融合显像在临床核医学中的应用现状

核医学的功能影像与传统解剖影像的有机融合大大促进了核医学设备的多模态发展方向,如SPECT/CT、SPECT/MR、PET/CT及PET/MR等。这些设备可评估脏器功能代谢,同时又可对病灶进行精确的解剖定位,大大提高了诊断效能。本文主要对SPECT/CT融合显像在各疾病中的应用现状及发展趋势进行综述。     

MR平扫和增强扫描在直肠癌分期的应用价值

目的 通过比较分析MR平扫与增强扫描在直肠癌分期及肿瘤外侵程度判断上的准确性，期望对单纯MR平扫与MR平扫加增强扫描在直肠癌的应用作出评价。方法 收集了1999年9月至2002年5月间临床诊断为直肠癌行MRI直肠检查，并有手术病理结果的病例共33例。采用MR平扫与薄层增强扫描等多个序列来观察直肠癌的外侵程度与范围。并应用直肠癌的TNM分期标准对MR成像与手术病理结果进行对照分析。结果 直肠癌的分期：在手术及病理诊断肿瘤限于黏膜下层以内的6例T1期肿瘤中MRI作出了准确诊断5例，1例高估为T2期，故其敏感性为100％、特异性为83．3％。其中在平扫T1、T2加权像时有2例认为T2期，但3D薄层增强成像1例作出了准确判断。1例仍判断错误(假阳性)。T3期的23例中，MRI平扫T1和T2加权像时诊断正确的21例。2例假阴性低估为T2期，其敏感性为91．3％，特异性为100％。而有薄层增强扫描的18例病人其诊断均与手术病理结果相符合。敏感性和特异性均为100％。T4期的病例共4例，MRI平扫与增强扫描均与手术及病理所见相符合，其敏感性与特异性均为100％。MRI总的分期准确率为90．9％。结论 MRI平扫加增强扫描对于直肠癌的术前分期及对肿瘤外侵深度的判断有较重要的临床应用价值。     

Simulation of brain tumors in MR images for evaluation of segmentation efficacy

Obtaining validation data and comparison metrics for segmentation of magnetic resonance images (MRI) are difficult tasks due to the lack of reliable ground truth. This problem is even more evident for images presenting pathology, which can both alter tissue appearance through infiltration and cause geometric distortions. Systems for generating synthetic images with user-defined degradation by noise and intensity inhomogeneity offer the possibility for testing and comparison of segmentation methods. Such systems do not yet offer simulation of sufficiently realistic looking pathology. This paper presents a system that combines physical and statistical modeling to generate synthetic multi-modal 3D brain MRI with tumor and edema, along with the underlying anatomical ground truth, Main emphasis is placed on simulation of the major effects known for tumor MRI, such as contrast enhancement, local distortion of healthy tissue, infiltrating edema adjacent to tumors, destruction and deformation of fiber tracts, and multi-modal MRI contrast of healthy tissue and pathology. The new method synthesizes pathology in multi-modal MRI and diffusion tensor imaging (DTI) by simulating mass effect, warping and destruction of white matter fibers, and infiltration of brain tissues by tumor cells. We generate synthetic contrast enhanced MR images by simulating the accumulation of contrast agent within the brain. The appearance of the the brain tissue and tumor in MRI is simulated by synthesizing texture images from real MR images. The proposed method is able to generate synthetic ground truth and synthesized MR images with tumor and edema that exhibit comparable segmentation challenges to real tumor MRI. Such image data sets will find use in segmentation reliability studies, comparison and validation of different segmentation methods, training and teaching, or even in evaluating standards for tumor size like the RECIST criteria (response evaluation criteria in solid tumors).     

Perfusion MR imaging of brain tumors

Brain tumors rank second as the cause of cancer-related deaths in children and adults younger than 34 years old, and they are seen in adults of all ages. Primary malignant brain tumors are associated with the third highest cancer-related mortality rate and a disproportionate level of disability and morbidity. Considering this, accurate diagnosis and grading of brain tumors are critical to determining prognosis and therapy. Equally important is to evaluate for tumor status during therapy to assess for therapeutic response and treatment-related complications. Brain tumors can be characterized as a heterogeneous group of neoplasm with a correspondingly wide variation in malignant phenotype and a diverse array of imaging features. Magnetic resonance (MR) imaging with intravenous contrast agent is the test of choice to diagnose and monitor brain tumors before, during, and after therapy. Recent advances in imaging methods such as diffusion-weighted imaging, perfusion imaging, and spectroscopic imaging all have in common the ability to provide quantitative cellular, hemodynamic, and metabolic information that may enhance our understanding of brain tumor biology, help us to better assess treatment response, more accurately determine tumor activity during therapy, and differentiate recurrent tumor and treatment related complications. In this article, we will review the basics of brain tumor imaging and focus on the role of perfusion MR imaging in improving accurate diagnosis and monitoring brain tumors during therapy. Both strengths and shortcomings of perfusion MR imaging over standard anatomic MR imaging will be discussed as will important pitfalls of the technique.     

99mTc-sestamibi can improve the inferior attenuation of TL-201 myocardial spect imaging

Tl-201 myocardial scintigraphy (Tl study) tends to be attenuated by soft tissues (such as the diaphragm) due to its low energy emission. 99mTc-sestamibi (2-methoxy isobutyl isonitrile) is a relatively new agent with a higher energy emission and this characteristic accounts for the higher quality of 99mTc-sestamibi images. The purpose of this study is to evaluate the ability of 99mTc-sestamibi in alleviating the inferior attenuation of Tl studies. 99mTc-sestamibi SPECT myocardial scintigraphy was performed on 13 patients with inferior wall perfusion defects as determined by Tl study (but with normal coronary artery as evidenced by cardiac catheterization). All patients underwent Tl SPECT study using a standard procedure. Same-day protocol (rest-stress sequence) was used for 99mTc-sestamibi SPECT imaging. All images were analyzed by two independent observers. The results of our study reveal that 99mTc-sestamibi produced better images. The inferior wall perfusion defects in the Tl study were noted in one case only (l/13)in the 99mTc-sestamibi study. Our study suggests that 99mTc-sestamibi can remarkably reduce the inferior attenuation of Tl study.     

口腔鳞癌前哨淋巴结融合显像检测的研究

目的:通过SPECT/CT对早期口腔鳞癌进行术前淋巴显像,评价其在前哨淋巴结(SLN)检测及定位中的意义。方法:应用带低能X线的多功能ECT对21例口腔鳞癌患者进行术前同机融合断层淋巴显像,配合术中注射蓝染法对SLN进行检测并与平面显像比较,评价其优越性。结果:断层显像更加准确地定位并纠正了部分平面显像的定位:包括发现了7例平面显像中未显示的或不同淋巴引流床中的SLN、1例平面显像拟诊为SLN的部位经断层显像及蓝染法确认为注射点的散射引起误诊、1例为因SLN接近注射点在平面显像图上未显示SLN而出现漏诊。断层显像还发现了平面显像未发现的另5个病人具有双侧淋巴引流途径。平面显像、融合显像的SLN检出率分别为95.2%和100%。对全部切除淋巴结进行病理检查发现,21例病人中共检出29个SLN,其中4个SLN病理检查为阳性,SLN隐性转移率为13.8%(4/29),未见假阴性。结论:SPECT/CT淋巴显像对局部SLN提供了较详细的解剖定位标志,有利于准确定位SLN。淋巴断层显像能检出平面显像不易发现的SLN,对局部SLN的分布提供了较多的信息,提高了SLN的检出率,减少漏检率,值得临床推广应用。     

局部脑血流SPECT显像与其他影像对癫痫定位诊断比较的研究

目的:研究癫痫发作期与发作间期同侧对照99mTc-ECD局部脑血流(rCBF)单光子发射计算机体层摄影术(SPECT)显像对癫痫灶的定位诊断价值。方法:对54例癫痫患者行发作间期显像,其中10例行发作期显像,并与皮层脑电图(EEG)、计算机断层扫描或磁共振显像(CT/M RI)、深部皮层脑电图(EcoG)结果进行对比分析。结果:癫痫发作期与发作间期rCBF SPECT显像对癫痫灶具有较高的检出率和定位率,优于EEG、CT/M RI,低于EcoG,但rCBF在发作期与发作间期的比较差异无显著性(P>0.05)。结论:发作间期rCBF SPECT显像可以成为癫痫灶方便而有效的定位方法,若加上发作期rCBF显像则定位更佳。     

Increased myocardial wall thickening as index of viability assessment: a preliminary report on delayed contrast MRI

Purpose : Regional wall thickening measurement by delayed contrast MRI may assess myocardial viability and functional recovery of ischemic cardiomyopathy. Materials and methods : Delayed contrast MRI data was used in 40 patients with significant coronary artery disease and severe left ventricular dysfunction. Regional wall thickening on follow‐up MRI served as an index of functional recovery in patients receiving revascularization. For comparison, myocardial viability was assessed by MRI and ²⁰¹Tl SPECT in 10 patients using a 17‐segment method. Results : On 480 segments, MRI hyperintensities showed positive correlation with ²⁰¹Tl reduction (r = 0.71, p < 0.0001) in the inferior wall and apex. Delayed MRI detected myocardial viability better than ²⁰¹Tl SPECT. Delayed contrast‐enhanced MRI showed diagnostic accuracy 65%, sensitivity 95%, specificity 25%, positive predictive value 65% and negative predictive value 75%, whereas ²⁰¹Tl SPECT showed diagnostic accuracy 54%, sensitivity 72%, specificity 25%, positive predictive value 52% and negative predictive value 54%. Areas under the ROC curves by MRI and ²⁰¹Tl SPECT were 0.59 ± 0.04, 0.52 ± 0.05, respectively (p = 0.07). The viability concordance was 80% between ²⁰¹Tl SPECT and MRI. Conclusion : Delayed contrast‐enhanced MRI may detect the inferior wall thickening and apex as an index of viable myocardium better than ²⁰¹Tl SPECT. Myocardial viability may predict functional recovery after revascularization in ischemic cardiomyopathy. Copyright © 2009 John Wiley & Sons, Ltd.