Diagnostic accuracy of myocardial perfusion imaging with single photon emission computed tomography and positron emission tomography: a comparison with coronary angiography

Objective The aim of this study was to compare the diagnostic accuracy of myocardial perfusion imaging (MPI) by positron emission tomography (PET) with the diagnostic accuracy of MPI by single photon emission computed tomography (SPECT) in two comparable patient cohorts, using coronary angiography (CA) as the standard of reference. Methods A “SPECT-group” of 80 patients (15 female, 65 male; mean age 60 ± 9 years) and a “PET-group” of 70 patients (14 female, 56 male; mean age 57 ± 10 years) underwent a one day stress/rest examination either with attenuation-corrected ¹³N-ammonia PET or attenuation-corrected ²⁰¹TlCl SPECT or ^99mTc-hexakis-methoxy-isobutyl-isonitril (MIBI) SPECT. PET and SPECT results were semiquantitatively graded using a 6-segment heart model. All patients underwent CA, and stenoses were graded as a diameter reduction ≥50%. Results Coronary findings between both groups did not significantly differ at CA. For the SPECT-group overall sensitivity and specificity for localisation of stenoses was 77% and 84%. Respective values for the PET-group were 97% and 84%. The specificity of MPI by SPECT in the detection of ischemia was 74% and 91% for MPI by PET. The diagnostic accuracy of MPI improves when the individual coronary dominance and previous coronary revascularisations are taken into account. Conclusion MPI by ¹³N-ammonia PET is more sensitive in the detection and localisation of coronary stenoses, and more specific in the detection of ischemia than MPI by ²⁰¹TlCl/^99mMIBI SPECT.     

18F-前列腺特异性膜抗原-1007 PET/CT显像、11C-胆碱PET/CT显像及单光子发射计算机断层成像术骨显像对前列腺癌骨转移的诊断价值比较

目的探讨¹⁸F-前列腺特异性膜抗原(PSMA)-1007标记的正电子发射体层显像融合计算机体层显像技术(PET/CT)显像、11C-胆碱(11C-CHO)PET/CT显像及单光子发射计算机断层成像术(SPECT)骨显像在前列腺癌骨转移诊断上的差异。方法回顾性分析2018年9月至2020年7月北部战区总医院核医学科收治的43例男性前列腺癌患者的临床资料,年龄(77.47±11.87)岁,年龄范围为55~89岁。所有患者行¹⁸F-PSMA-1007 PET/CT显像、11C-CHO PET/CT显像及SPECT骨显像检查。分别统计¹⁸F-PSMA-1007 PET/CT显像、11C-CHO PET/CT及SPECT骨显像诊断骨转移的阳性例数和阴性例数,计算三种方法各自的灵敏度、特异度、准确性、阳性预测值、阴性预测值,绘制受试者工作特征(ROC)曲线,计算并比较各自曲线下面积(AUC),评价三种检查方法对前列腺癌骨转移的诊断效能。结果 43例前列腺癌患者中,27例患者出现骨转移。¹⁸F-PSMA-1007 PET/CT显像示26例患者发生骨转移,漏诊1例;11C-CHO PET/CT显像示24例患者发生骨转移,误诊1例,漏诊4例;SPECT骨显像示23例患者发生骨转移,误诊3例,漏诊7例,三者诊断前列腺癌骨转移的灵敏度、特异度、准确性分别为96.3%(26/27)、100%(16/16)、97.7%(42/43);85.2%(23/27)、93.8%(15/16)、88.4%(38/43);74.1%(20/27)、81.3%(13/16)、76.7%(33/43)。¹⁸F-PSMA-1007 PET/CT显像、11C-CHO PET/CT和SPECT骨显像ROC曲线的AUC和95%CI分别为0.981(0.885~1.000)、0.913(0.763~0.967)、0.777(0.624~0.889)。三种检查的AUC曲线下面积进行两两比较,差异均有统计学意义(P<0.05)。采用Wilcoxon秩和检验对27例患者三种方法检出的骨转移灶的数量进行两两比较发现,¹⁸F-PSMA-1007 PET/CT显像与SPECT骨显像比较,差异有统计学意义(Z=-2.484,P=0.013),¹⁸F-PSMA-1007 PET/CT显像与11C-CHO PET/CT显像比较,差异无统计学意义(Z=-0.160,P=0.873);11C-CHO PET/CT显像与SPECT骨显像比较,差异有统计学意义(Z=-2.085,P=0.037)。结论 PET/CT显像较SPECT骨显像能发现更多的骨转移灶。¹⁸F-PSMA-1007 PET/CT显像对前列腺癌骨转移诊断的灵敏度、特异度及准确性高于其他两种检查方式。在低前列腺特异性抗原(PSA)的情况下,能够精确地对前列腺癌骨转移做出诊断。     

Magnetic resonance imaging with computed tomography of a renal leiomyoma

Renal leiomyoma are rare, benign tumors of the kidney. There is little information about the imaging of these tumors with modern modalities. We present a case of computed tomographic (CT) and magnetic resonance (MR) imaging of a large renal leiomyoma.     

超顺磁性纳米氧化铁颗粒标记胰腺癌细胞的MR分子成像

目的 探讨超顺磁性纳米氧化铁颗粒（SPION）靶向标记胰腺癌细胞（BxPC-3）行MR分子成像的可行性。方法 制备黏蛋白1（MUC1）靶向修饰的探针MUC1-SPION（靶向组）,并以牛血清蛋白（BSA）制备非靶向探针BSA-SPION（非靶向组）。采过噻唑蓝（MTT）法测试不同MUC1-SPION浓度下（铁浓度为0、6.25、12.50、25、50、100、200 μg/ml）的细胞毒性。并分别于铁浓度为50、100、200 μg/ml条件下,对靶向组及对照组与BxPC-3细胞共同孵育2 h后的细胞悬液进行MR成像,测定横向弛豫时间（T2）,计算T2强化率。以普鲁士蓝染色观察靶向探针与细胞结合情况。结果 MTT法细胞毒性实验显示,不同MUC1-SPION浓度下BXPC-3细胞增殖率差异无统计学意义（F=1.74,P=0.183）。铁浓度50、100、200 μg/ml条件下,2组间T2值和T2强化率的差异均有统计学意义（P均<0.05）。普鲁士蓝染色显示靶向组的蓝染颗粒更多。结论 MUC1-SPION对BxPC-3细胞具有良好的靶向性,以SPION靶向标记BxPC-3细胞进行MRI安全、可行。     

B超、CT与MRI诊断胆管结石的比较研究

目的 比较B超、CT与MRI各成像序列对胆管结石的诊断价值.方法 23例临床拟诊胆管结石的患者行B超和MRI检查,其中10例行同期CT扫描.最后诊断均经手术或经内镜逆行胰胆管造影(ERCP)证实.依据影像诊断报告结果总结B超、CT与MRI诊断胆管结石的准确性,并通过回顾性分析CT与MRI脉冲序列图像探讨各种技术的优缺点.结果 23例病人中,22例有胆管结石,1例手术中未见胆管内结石.B超诊断结石12例,其中1例假阳性,诊断准确度48%(11/23).CT诊断结石8例,假阴性2例,诊断准确度80%(8/10).MRI诊断结石20例,其中1例假阳性,诊断准确度83%(19/23).在MRI各序列中,磁共振胰胆管造影(MRCP)显示胆管结石最直观,轴位T2WI与T1WI是MRCP的有益补充.结论 诊断胆管结石时,B超可作为初步筛查方法.CT与MRI的诊断准确性较高,且后者多序列多方向的成像能力可补充B超与CT的不足.     

叶酸介导APTMS包被的超小超顺磁性氧化铁的制备及体外MR成像

目的探究叶酸介导的超小超顺磁性氧化铁(USPIO)对于人乳腺癌MCF-7细胞表面叶酸受体的靶向性及MR成像的可行性。方法①制备叶酸介导的耦联3-氨基丙基-三甲氧基硅烷(APTMS)的USPIO(FA-APTMS-US-PIO),通过TEM、FTIR等技术对其进行表征。②USPIO组、竞争抑制组(FA-APTMS-USPIO+叶酸)及叶酸介导的耦联APTMS的靶向组(FA-APTMS-USPIO)分别与MCF-7细胞孵育不同时间,通过普鲁士蓝染色观察不同组别铁颗粒的摄取情况。③对与纳米铁孵育后的细胞采用3.0TMR仪进行体外MR成像。④采用MTT法进行细胞活性检测。结果透射电镜照片显示FA-APTMS-USPIO外形较规则。普鲁士蓝染色观察,靶向组细胞摄取的氧化铁较多,可见大量蓝色沉淀。竞争抑制组与USPIO组细胞内蓝色颗粒较少。体外MRI结果显示,与MCF-7孵育的靶向组T2信号降低显著,竞争抑制组和USPIO组无明显变化。MTT实验显示,靶向组不同时间对细胞生存能力无显著影响。结论 FA-APT-MS-USPIO对MCF-7细胞有良好的靶向性,对早期诊断乳腺癌具有重大应用潜力。     

MR imaging of human pancreatic cancer xenograft labeled with superparamagnetic iron oxide in nude mice

The aim of this work was to investigate the MRI findings on tumor xenografts induced in nude mice by the inoculation of human pancreatic cancer cells labeled with superparamagnetic iron oxide (SPIO), and to monitor the kinetics of SPIO distribution in tumor xenografts. The labeled cancer cells were subcutaneously inoculated into 11 nude mice to induce tumor xenograft. The unlabeled cancer cells served as a control inoculated into nine nude mice. MR imaging was performed with a 1.5 T MR scanner for the tumor xenograft at the first, second and third week after the inoculation. We found that the tumor xenograft was induced in 100% nude mice on MR imaging for both groups in the first week after the inoculation. In the SPIO group, the tumors showed homogeneous hypointensity on T₁‐ and T₂‐weighted and FIESTA images 1 week after inoculation. Two and 3 weeks after inoculation, the center of the tumors was still hypointense on all the above sequences. The tumor periphery was isointense on T₁‐weighted, and hyperintense on T₂‐weighted and FIESTA images. The tumors in control group were homogeneously hypointense or isointense on T₁‐weighted, and hyperintense on T₂‐weighted and FIESTA images in the first, second and third week after the inoculation. The size and signal‐to‐noise ratio of the tumor center in the SPIO group had decreased subsequent to the inoculation in all T₁‐ and T₂‐weighted images and FIESTA. Our results showed the human pancreatic cancer cells labeled with SPIO can induce tumor xenograft in nude mice and MRI can monitor the kinetics of SPIO distribution in tumor xenografts. Copyright © 2012 John Wiley & Sons, Ltd.     

超顺磁性氧化铁标记骨髓间充质干细胞的磁共振成像研究

目的明确顺磁性氧化铁纳米粒子(SPIO)体外标记兔骨髓间充质干细胞(MSCs)的适当浓度和不同标记浓度对细胞的生物学活性影响,以及经MR成像的特征和可成像的最低标记细胞量等。方法分离、纯化、培养兔MSCs,体外不同浓度SPIO标记,荧光显微镜观察铁颗粒在细胞内的位置、不同标记浓度下的最佳孵育时间、不同标记浓度细胞形态的改变、细胞内铁颗粒的分布及标记率;测量并绘制未标记细胞和标记细胞的MTT生长曲线;选取适当浓度标记量,对不同细胞量组进行标记后MR成像,测量不同扫描序列标记细胞管的信号强度改变,并进行统计学分析。结果标记后的铁颗粒均位于细胞质内;20～50μgFe/ml培养液是SPIO标记干细胞的适当浓度阈值,超过50μgFe/ml培养液浓度可使细胞的变形增殖能力受到不同程度的抑制;在此浓度阈值标记后孵育18～24h即可有效标记细胞97%～100%;细胞对铁颗粒的吸收与细胞的数量、标记浓度和孵育时间呈正相关;SPIO标记的MSCs在T2WI尤其是FFE(T2WI)序列信号明显降低;在35μgFe/ml培养液标记浓度下,MR可成像的最低细胞量为5×104;35μgFe/ml培养液浓度时,标记细胞1×105和5×104MR成像可使T2WI、FFE图像信号均降低,而且没有使靶灶扩大的磁敏感伪影。结论SPIO可以简便标记MSCs并且在适当浓度下对MSCs的生物学活性没有影响,MRT2WI和T2WI序列可敏感显像磁性标记的干细胞。     

采用自制超小超顺磁性氧化铁行兔VX2肿瘤MR成像

目的 观察自制USPIO在兔VX2肿瘤MR成像中的价值.方法 以一步法实现葡聚糖对Fe_3O_4纳米粒子的表面包裹,制备USPIO.7只新西兰大白兔双侧大腿肌肉内接种VX2肿瘤;6只于接种后2周分别行Gd-DTPA和USPIO T2~*WI增强扫描.1只未注射对比剂的实验兔留电镜和元素分析作对照研究.计算不同对比剂的病灶对比度噪声比(CNR)和增强对比度.MR成像结束后,行普鲁士蓝染色、电镜及元素分析.结果 经傅立叶变换红外光谱仪证实,葡聚糖成功包裹到Fe_3O_4磁性纳米粒子的表面;且合成USPIO大小在10～20 nm,分散性较好.增强扫描中两种对比剂的CNR差异有统计学意义(P<0.005).病理、电镜及元素分析共同证实肿瘤组织与正常肌肉USPIO的含量有显著差异.结论 VX2肿瘤血管基底膜对USPIO具有高通透性.USPIO T2~*WI增强扫描可以提高肿瘤组织的增强效果.自制USPIO可被肿瘤细胞吞噬,是用于肿瘤成像的理想对比剂.     

Hepatic metastases of soft tissue angiosarcoma: CT and MR imaging findings

Background: We describe the computed tomographic (CT) and magnetic resonance imaging (MRI) findings of hepatic metastases caused by soft tissue angiosarcomas to clarify the relation between radiologic appearances and clinicopathologic features.Methods: CT and MR examinations of 13 patients with hepatic metastases of soft tissue angiosarcoma were retrospectively analyzed.Results: Contrast-enhanced CT images showed multiple hypoattenuating lesions relative to the adjacent liver parenchyma. Lesions contained peripheral areas of enhancement in eight patients (62%). Tumors showed cystic attenuation with fluid–fluid levels, which were suggestive of hemorrhage in five patients (38%). In one patient (8%) with cystic attenuation and fluid–fluid levels, lesions also contained marked enhanced nodular portions located centrally or peripherally. On T1-weighted MR images, all four liver tumors appeared heterogeneous and hypointense relative to adjacent liver parenchyma. Fluid–fluid levels were identified on T2-weighted MR images in five patients (38%). After an intravenous bolus of gadolinium-based contrast material was administered, slight peripheral enhancement was seen in three patients (75%).Conclusion: The common CT findings of metastatic angiosarcoma in our series were multiple hypoattenuating lesions often associated with nodular enhancement and cystic lesions with hemorrhagic change.     

F-18 fluorodeoxyglucose positron emission tomography/computed tomography image of gastric mucormycosis mimicking advanced gastric cancer: A case report

BACKGROUND Mucormycosis is a very rare fungal infection,and its prognosis is poor.Most common sites of infection are the sinuses,lung,or skin,and gastric involvement is uncommon.The standard antifungal therapy is the treatment of choice for gastric mucormycosis.However,the symptoms of gastric mucormycosis are varied and the early diagnosis is not easy.CASE SUMMARY I report a 53-year-old alcoholic man,who was admitted due to epigastric pain.The upper gastrointestinal endoscopy revealed a huge ulcer lesion in the stomach,which was suspected to be gastric cancer.F-18 fluorodeoxyglucose positron emission tomography/computed tomography(F-18 FDG PET/CT)showed diffusely intense FDG uptake at the ulcer lesion of the stomach,and several enlarged hypermetabolic lymph nodes were noted at the left gastric chain.Although,endoscopy and F-18 FDG PET/CT findings suggested advanced gastric cancer with regional lymph node metastases,there was no cancer cells in the biopsy results and multiple fungal hyphae were noted in the periodic acid-Schiff stained image.CONCLUSION He was diagnosed with gastric mucormycosis and successfully underwent amphotericin B and posaconazole treatment.     

背部弹力纤维瘤的多排螺旋CT及MRI诊断

目的探讨多排螺旋CT(multidetector spiral computed tomography,MSCT)及磁共振成像(magnetic resonance imaging,MRI)诊断背部弹力纤维瘤(elastofibroma dorsi,EFD)的影像学特点。材料与方法收集我院20例经手术病理证实的EFD患者资料,所有患者均行CT检查,其中8例行CT增强检查,4例行MRI检查,1例同时行MRI增强检查,3例MRI平扫检查,并分别测量EFD、前锯肌及周围脂肪CT平扫及增强后CT值进行比较,分析EFD的临床特点及CT、MRI表现。结果 20例患者中,13例病灶位于双侧,4例病灶位于右侧,3例病灶位于左侧,CT共发现33处病灶,并均位于背部肩胛下角肌肉深面,均呈扁丘状或半圆形肿块,主要以肌肉样密度为主,病灶内见条纹状脂肪密度沿病灶长轴间隔排列;病灶边缘毛糙不整,周围脂肪间隙模糊不清,CT增强扫描3例轻度强化,5例无强化;EFD与前锯肌、EFD与周围脂肪间平扫及增强CT值差异均存在统计学意义(P0.05);MRI平扫信号不均匀,呈等信号为主的肌组织与高信号的脂肪组织交错排列,MRI增强扫描1例呈不均匀中度强化。结论背部弹力纤维瘤具有典型的发病部位,根据CT及MRI影像表现均可做出明确诊断。     

Role of cardiac computed tomography and magnetic resonance imaging in the evaluation of acute chest pain in the emergency department

Evaluation of patients presenting with chest pain to the emergency department remains a challenging task because of a variety of etiologies that range from benign to potentially fatal. Although majority of patients do not have myocardial ischemia as the cause of their presentation, the clinical work up can be time consuming, costly and inconclusive. Recent technical advances in cardiac computed tomography and magnetic resonance imaging have led to better diagnostic accuracy in evaluating patients with chest pain. In this paper, we review the role of cardiac computed tomography and magnetic resonance imaging in evaluating patients with chest pain in the emergency department.     

非典型性、恶性脑膜瘤的CT、MRI与良性脑膜瘤对比研究

目的　探索恶性脑膜瘤的ＣＴ、ＭＲＩ特征以提高临床影像学的诊断正确率。方法　对比分析了１５ 例经病理证实的恶性脑膜瘤和２０ 例良性脑膜瘤的ＣＴ、ＭＲＩ表现。结果　恶性脑膜瘤的结构非均质性（７／１５）、分叶及结节特征（１０／１５） 和短粗的硬膜尾征形态（４／１５） 均明显高于良性组（ Ｐ＜ ００５）。结论　良、恶性脑膜瘤在影像学表现方面存在某些明显差异性,认识恶性脑膜瘤的影像特征可以减少术前误诊。     

叶酸靶向超顺磁性氧化铁-多巴胺-叶酸纳米复合物的制备及体外MR成像

目的 探讨叶酸靶向超顺磁性氧化铁-多巴胺-叶酸(NP-DPA-FA)纳米复合物对叶酸受体(FR)阳性肝癌细胞的靶向性及利用MRI对其进行监测的可行性。方法 ①制备NP-DPA-FA纳米复合物。②对Bel-7402细胞进行普鲁士蓝染色及体外竞争抑制试验。③将NP-DPA-FA复合物与Bel-7402人肝癌细胞及HL-7702正常人肝细胞孵育2 h后,进行普鲁士蓝染色及体外MR成像,观察其T2WI信号强度变化,并计算信号强度变化率。结果 普鲁士蓝染色显示Bel-7402细胞内可见大量铁颗粒沉积,HL-7702细胞内铁颗粒沉积少见。Bel-7402细胞抑制竞争试验显示细胞内铁颗粒极少。铁浓度不同的NP-DPA-FA复合物分别与Bel-7402细胞及HL-7702细胞孵育后,MRI显示Bel-7402细胞的信号强度随NP-DPA-FA复合物铁浓度的升高而明显减低,HL-7702细胞信号强度减低相对不明显。结论 叶酸介导的磁性纳米颗粒复合物对Bel-7402人肝癌细胞具有靶向性,应用MRI可对其进行监测。     

Categorical and correlational analyses of baseline fluorodeoxyglucose positron emission tomography images from the Alzheimer's Disease Neuroimaging Initiative (ADNI)

In mostly small single-center studies, Alzheimer's disease (AD) is associated with characteristic and progressive reductions in fluorodeoxyglucose positron emission tomography (PET) measurements of the regional cerebral metabolic rate for glucose (CMRgl). The AD Neuroimaging Initiative (ADNI) is acquiring FDG PET, volumetric magnetic resonance imaging, and other biomarker measurements in a large longitudinal multi-center study of initially mildly affected probable AD (pAD) patients, amnestic mild cognitive impairment (aMCI) patients, who are at increased AD risk, and cognitively normal controls (NC), and we are responsible for analyzing the PET images using statistical parametric mapping (SPM). Here we compare baseline CMRgl measurements from 74 pAD patients and 142 aMCI patients to those from 82 NC, we correlate CMRgl with categorical and continuous measures of clinical disease severity, and we compare apolipoprotein E (APOE) 4 carriers to non-carriers in each of these subject groups. In comparison with NC, the pAD and aMCI groups each had significantly lower CMRgl bilaterally in posterior cingulate, precuneus, parietotemporal and frontal cortex. Similar reductions were observed when categories of disease severity or lower Mini-Mental State Exam (MMSE) scores were correlated with lower CMRgl. However, when analyses were restricted to the pAD patients, lower MMSE scores were significantly correlated with lower left frontal and temporal CMRgl. These findings from a large, multi-site study support previous single-site findings, supports the characteristic pattern of baseline CMRgl reductions in AD and aMCI patients, as well as preferential anterior CMRgl reductions after the onset of AD dementia.