MRI和PET显像在阿尔茨海默病早期诊断中的应用

阿尔茨海默病(AD)是一种最常见的进行性神经退行性疾病, 严重威胁患者的生命和健康, 早期诊断和干预可以减缓甚至逆转该疾病的病情进展。目前, MRI和PET显像已被应用于AD的诊断, 其在AD的早期诊断方面均有独特的优势。笔者重点介绍了结构性MRI、功能性MRI和PET显像在AD早期诊断中的应用。     

阿尔茨海默病及轻度认知障碍PET/MR研究进展

阿尔茨海默病(AD)是一种进行性发展的神经退行性疾病,轻度认知障碍(MCI)被认为正常衰老和AD之间的过渡阶段.目前AD的治疗主要是延缓病情和预防并发症,因此早期诊断与干预尤为重要.新型大型影像设备PET/MR实现了对AD及MCI代谢、结构以及功能的多模态研究融合.本文就目前PET/MR在AD及MCI的研究现状做一综述...     

PET/MRI在胰腺肿瘤中的应用

PET/MRI是一种将PET和MRI融合的新型影像诊断技术,其整合了PET提供的人体生理代谢、分子信息和MRI提供的功能及解剖形态信息。相较于CT,MRI具有更高的软组织对比度,可多参数成像,且无辐射。PET/MRI在胰腺癌病灶检测、术前分期和预后评估方面优于PET/CT。~(68)Ga标记的生长抑素受体显像剂PET/MRI能够提高胰腺神经内分泌肿瘤的检测和诊断能力。新型显像剂的研发和应用能够提高胰腺肿瘤PET/MRI的特异性和精准性。就PET/MRI在胰腺癌的诊断、分期及疗效监测的应用价值及其对胰腺神经内分泌肿瘤的研究进展予以综述。     

PET/MRI在肿瘤研究中的新进展

PET/MRI成像整合了PET提供的人体生理代谢、分子信息和MRI提供的功能、解剖形态信息,在肿瘤诊断、评估肿瘤生物学行为(包括分期、分级、浸润深度、远处转移)、评价治疗疗效及预后方面具有较高的准确性、敏感性、特异性,实现了PET及MR成像设备的优势互补。就PET/MRI在肿瘤中的应用现状及其发展前景进行回顾和展望。     

PET/MRI在肺癌中的潜在临床应用价值

PET/MRI作为新出现的融合影像技术,其临床应用价值尚未得到充分证实。与CT相比,MRI具有软组织对比分辨力高、无辐射、多参数成像、能够提供更多功能信息的优势,PET与MRI的融合对于肺癌的潜在应用价值可能要优于PET/CT。简述不同的PET/MRI系统的设计,并从肺结节的检出、鉴别诊断、TNM分期、预后/早期疗效评价/肿瘤复发4个方面介绍PET/MRI在肺癌中的潜在临床价值。     

PET分子探针在阿尔茨海默病中的应用

阿尔茨海默病(AD)是最常见的一种痴呆.最新的正电子发射断层(PET)分子探针可特异和灵敏地检测临床AD患者β淀粉样肽(Aβ)和Tau蛋白,这对提高AD临床诊断的准确性和实现早期干预十分重要.目前世界上已有3种针对Aβ的PET分子探针获得美国FDA批准用于临床实践,而针对Tau的PET分子探针尚处于研发阶段.该文就Aβ和Tau的PET分子探针的研究现状进行综述.     

PET在阿尔茨海默病中的应用价值

阿尔茨海默病是老年痴呆中最常见的原因.FDG PET可以探测AD与不同类型痴呆葡萄糖代谢的早期变化,用于AD的早期诊断与鉴别诊断.神经炎性斑块和神经纤维缠结是AD主要的病理学特征.淀粉样斑块PET显像可以提供AD早期的诊断信息.本文主要介绍FDG与淀粉样斑块PET显像在AD中的应用价值.     

前列腺癌的影像学诊断方法及PET/CT显像剂应用进展

近些年,我国前列腺癌(PCa)的发病率及病死率逐渐增高,并且PCa的早期诊断及准确分期仍是一大难题,多数患者确诊时已为晚期,生存预后较差。目前,MRI、CT、PET/CT等影像学检查方法是对PCa进行诊断及分期的主要手段,但这些方法在应用的过程中亦被发现存在一定的局限性,因此需要不断进行探索和优化。尤其是PET/CT各种显像剂的应用,大大提高了对PCa的诊断灵敏度及特异度,在PCa的早期诊断、及时治疗、临床分期及预后评估等各方面均展示出良好的前景。笔者就这几种常用影像学方法及PET/CT显像剂的应用展开综述,总结它们的优势、不足及新的应用进展,旨在能为临床医师提供参考。     

非小细胞肺癌术前淋巴结分期采用联合MRI和PET/CT解释标准的建议

摘要目的联合利用MRI及PET/CT为非小细胞肺癌术前淋巴结分期确定阳性的恶性淋巴结判读标准。方法49例经活检证实的非小细胞肺癌病人,同时接受PET/CT及胸部MRI(DWI)检查。在MRI联合PET/CT解释时应用纳入法(任一项判断为阳性即为阳性)及排除法(两者均为阳性者)评估每个淋巴结部位是否存在转移。淋巴结分期由病理证实。以结节分区及病人为分析单位评价MRI联合PET/CT诊断的准确性,并与单独利用PET/CT诊断的准确性比较。     

18F-FDG PET/MRI在胰腺癌中的临床应用及新进展

胰腺癌是一种恶性程度高、易转移、进展快、预后差的恶性肿瘤,早期诊断、准确分期和及时的疗效评估对胰腺癌患者至关重要。一体化的PET/MRI作为一种新型的多模态成像技术,集合了MRI对软组织分辨率高、多序列、多参数和PET代谢显像的高灵敏度等优势,在胰腺癌患者的肿瘤分期、疗效评估、预后预测、复发监测等方面具有潜在的应用价值。因此,笔者就18F-氟脱氧葡萄糖（FDG）PET/MRI的优势及其在胰腺癌中的临床应用及新进展进行综述。     

Feasibility and acceptance of simultaneous amyloid PET/MRI

Purpose

Established Alzheimer’s disease (AD) biomarker concepts classify into amyloid pathology and neuronal injury biomarkers, while recent alternative concepts classify into diagnostic and progression AD biomarkers. However, combined amyloid positron emission tomography/magnetic resonance imaging (PET/MRI) offers the chance to obtain both biomarker category read-outs within one imaging session, with increased patient as well as referrer convenience. The aim of this pilot study was to investigate this matter for the first time.

Methods

100 subjects (age 70?±?10 yrs, 46 female), n?=?51 with clinically defined mild cognitive impairment (MCI), n?=?44 with possible/probable AD dementia, and n?=?5 with frontotemporal lobe degeneration, underwent simultaneous [¹⁸F]florbetaben or [¹¹C]PIB PET/MRI (3 Tesla Siemens mMR). Brain amyloid load, mesial temporal lobe atrophy (MTLA) by means of the Scheltens scale, and other morphological brain pathologies were scored by respective experts. The patients/caregivers as well as the referrers were asked to assess on a five-point scale the convenience related to the one-stop-shop PET and MRI approach.

Results

In three subjects, MRI revealed temporal lobe abnormalities other than MTLA. According to the National Institute on Aging-Alzheimer’s Association classification, the combined amyloid-beta PET/MRI evaluation resulted in 31 %, 45 %, and 24 % of the MCI subjects being categorized as “MCI-unlikely due to AD”, “MCI due to AD-intermediate likelihood”, and “MCI due to AD-high likelihood”, respectively. 50 % of the probable AD dementia patients were categorized as “High level of evidence of AD pathophysiological process”, and 56 % of the possible AD dementia patients as “Possible AD dementia - with evidence of AD pathophysiological process”. With regard to the International Working Group 2 classification, 36 subjects had both positive diagnostic and progression biomarkers. The patient/caregiver survey revealed a gain of convenience in 88 % of responders as compared to a theoretically separate PET and MR imaging. In the referrer survey, an influence of the combined amyloid-beta PET/MRI on the final diagnosis was reported by 82 % of responders, with a referrer acceptance score of 3.7?±?1.0 on a 5-point scale.

Conclusion

Simultaneous amyloid PET/MRI is feasible and provides imaging biomarkers of all categories which are able to supplement the clinical diagnosis of MCI due to AD and that of AD dementia. Further, patient and referrer convenience is improved by this one-stop-shop imaging approach.

     

~(18)F-FDGPET显像诊断老年性痴呆初步研究

目的　探讨18F 脱氧葡萄糖 (FDG)PET显像诊断老年性痴呆 (AD)的影像特征和诊断标准。方法　静脉注射18F FDG后行脑断层显像 ,获得顶叶、颞叶、额叶单位面积放射性计数与小脑计数的比值 ,以此作为半定量指标。结果　 12例正常人可见大脑皮质各叶、基底神经节、丘脑及小脑放射性分布均匀对称。 12例AD影像分为 3种 :双侧顶叶放射性减低 5例 ,双侧颞顶叶减低 4例 ,单侧颞顶叶减低 3例。半定量分析显示AD患者顶颞叶代谢显著低于正常人 ,并与痴呆程度相关。 11例非AD痴呆影像也分 3种 :多发性非对称性放射性减低 8例 ,双侧颞顶叶伴其他多灶性放射性减低 2例 ,显像正常 1例。MRI检查 10例AD可见颞叶、杏仁核、海马体积缩小 ;2例轻度AD虽有代谢减低 ,但MRI未见海马体积缩小。 10例非AD痴呆MRI可见脑内陈旧出血、梗死、软化灶等病灶 ,而这些表现AD患者未见到。结论　在MRI除外脑内结构损害病灶基础上 ,18F FDGPET发现双侧或单侧顶叶或颞顶叶代谢减低可诊断AD ;半定量分析有助于痴呆程度的评价。     

18F-FDG PET/CT结合MRI在癫（癎）外科治疗中的应用

目的 探讨18F-脱氧葡萄糖（FDG）PET/CT结合MRI定位致（癎）灶,指导癫（癎）外科治疗的意义.方法 67例癫（癎）外科治疗患者术前均行18F-FDG PET/CT和MRI检查,根据术前评估以及术中皮质脑电图监测结果进行致（癎）灶切除术.术后长期随访,根据Engel分级将患者分为癫（癎）发作完全控制组（Engel Ⅰ）和癫（癎）发作未完全控制组（Engel Ⅱ～Ⅳ）,采用x2检验或Fisher精确检验对数据进行分析.结果 67例中48例患者术后癫（癎）发作完全控制（Engel Ⅰ,71.6%）,11例Engel Ⅱ,5例Engel Ⅲ,3例Engel Ⅳ.18F-FDG PET/CT定位定侧结果与MRI检查结果一致或基本一致者63例,其中71.4%（45/63）术后癫（癎）发作完全控制;18F-FDG PET/CT与MRI检查结果不一致者4例,其中3例术后癫（癎）发作完全控制,2组差异无统计学意义（Fisher精确检验,P＞0.05）.63例中MRI与18F-FDG PET/CT均发现局限性异常者为41例,其中80.5%（33/41）术后癫（癎）发作完全控制;MRI发现局限性病变,但18F-FDG PET/CT呈更广泛性代谢异常者20例,其中55.0%（11/20）术后癫（癎）发作完全控制,2组差异有统计学意义（x2=4.34,P＜0.05）.结论 18F-FDG PET/CT结合MRI可为致（癎）灶定位及预后评估提供重要信息.     

18F-FDG PET/CT与PET/MRI在结直肠癌肝转移诊断中的比较分析

目的:比较 18F-氟脱氧葡萄糖（FDG） PET/CT与PET/MRI显像对结直肠癌肝转移的诊断价值。 方法:回顾性分析2018年9月至2019年9月于宁波明州医院行全身 18F-FDG PET/CT显像及上腹部 18F-FDG PET/MRI显像,并疑似有结直肠癌肝转移...     

Improving liver lesion characterisation using retrospective fusion of FDG PET/CT and MRI

AimTo compare retrospectively fused FDG PET/CT and MRI (PET/MRI) to FDG PET/CT and MRI for characterisation of indeterminate focal liver lesions as malignant or benign in patients with a known primary malignancy.Materials and methodA retrospective review of 70 patients (30 females, 40 males; mean age 56 ± 14 years) with 150 indeterminate lesions after FDG PET/CT and MRI (mean scan time interval 21 ± 11 days). HERMES® software was used to fuse PET/CT and MRI scans which were reviewed by 2 readers using the Likert score (scale 1–5) to characterise lesions as benign (1–3) or malignant (4–5). Final diagnosis was determined by histopathology or follow up imaging. Results for fused PET/MRI were compared to PET/CT and MRI alone.ResultsFor detection, MRI and fused PET/MRI detected all the lesions while PET/CT detected 89.4%. Characterisation of liver lesions as malignant on PET/CT alone yielded sensitivity, specificity, accuracy, PPV and NPV of 55.6%, 83.3%, 66.7%, 83.3%, 55.6% respectively and 67.6%, 92.1%, 80%, 89.3%, 74.5% for MRI, respectively. The sensitivity, specificity, accuracy, PPV and NPV for characterising lesions as malignant increased to 91.9%, 97.4%, 94.7%, 97.1%, 92.5% with PET/MRI fusion. The sensitivity, specificity, accuracy, PPV and NPV of fused PET/MRI for characterising lesions as malignant remained superior to PET/CT and MRI.ConclusionRetrospective fusion of PET with MRI has improved characterisation of indeterminate focal liver lesions compared to MRI or FDG PET/CT alone.     

FDG Whole-Body PET/MRI in Oncology: a Systematic Review

The recent advance in hybrid imaging techniques enables offering simultaneous positron emission tomography (PET)/magnetic resonance imaging (MRI) in various clinical fields. ¹⁸F-fluorodeoxyglucose (FDG) PET has been widely used for diagnosis and evaluation of oncologic patients. The growing evidence from research and clinical experiences demonstrated that PET/MRI with FDG can provide comparable or superior diagnostic performance more than conventional radiological imaging such as computed tomography (CT), MRI or PET/CT in various cancers. Combined analysis using structural information and functional/molecular information of tumors can draw additional diagnostic information based on PET/MRI. Further studies including determination of the diagnostic efficacy, optimizing the examination protocol, and analysis of the hybrid imaging results is necessary for extending the FDG PET/MRI application in clinical oncology.     

An update on the role of PET/CT and PET/MRI in ovarian cancer

This review article summarizes the role of PET/CT and PET/MRI in ovarian cancer. With regard to the diagnosis of ovarian cancer, the presence of FDG uptake within the ovary of a postmenopausal woman raises the concern for ovarian cancer. Multiple studies show that FDG PET/CT can detect lymph node and distant metastasis in ovarian cancer with high accuracy and may, therefore, alter the management to obtain better clinical outcomes. Although PET/CT staging is superior for N and M staging of ovarian cancer, its role is limited for T staging. Additionally, FDG PET/CT is of great benefit in evaluating treatment response and has prognostic value in patients with ovarian cancer. FDG PET/CT also has value to detect recurrent disease, particularly in patients with elevated serum CA-125 levels and negative or inconclusive conventional imaging test results. PET/MRI may beneficial for tumor staging because MRI has higher soft tissue contrast and no ionizing radiation exposure compared to CT. Some non-FDG PET radiotracers such as ¹⁸F-fluorothymidine (FLT) or ¹¹C-methionine (MET) have been studied in preclinical and clinical studies as well and may play a role in the evaluation of patients with ovarian cancer.     

一体化PET/MR结合统计参数图辅助^11C-PIB显像的半定量分析及其临床应用

目的 研究一体化PET/MR结合统计参数图(SPM)辅助^11C-匹兹堡化合物B(PIB)用于β-淀粉样蛋白(Aβ)PET显像半定量分析的准确性,探索其用于认知障碍的诊断及鉴别诊断的可行性.方法 回顾分析2018年1月至2019年9月在华中科技大学同济医学院附属协和医院PET中心进行^11C-PIB PET/MR扫描,临床最终确诊的13例阿尔茨海默病(AD)患者[男4例,女9例;年龄(59.2±5.8)岁]和10例血管性认知障碍(VCD)患者[男9例,女1例;年龄(59.5±11.5)岁].结合三维T1加权成像(3D T1WI)对^11C-PIB PET图像分别进行脑区手动勾画和SPM辅助半自动分割,获得8个关键脑区(大脑白质、纹状体、丘脑、后扣带回、额叶皮质、后顶叶皮质、颞叶外侧皮质和枕叶皮质)与小脑皮质的标准摄取值比值(SUVR).对2种方法所获结果进行Pearson相关分析;采用两独立样本t检验、配对t检验分析数据.结果 AD组与VCD组患者的年龄和简易精神状态检查量表(MMSE)评分[(19.7±4.7)和(21.7±3.8)分]差异均无统计学意义(t值:0.095和1.098,均P>0.05).除丘脑外(r=0.179,P=0.413),分割法和勾画法在其余7个关键脑区获得的SUVR均有良好的相关性(r值:0.678~0.893,均P<0.05).AD组8个关键脑区的SUVR均明显高于VCD组(1.519~2.055与1.105~1.618;t值:2.799~11.582,均P相似文献   

Competitive advantage of PET/MRI

Multimodality imaging has made great strides in the imaging evaluation of patients with a variety of diseases. Positron emission tomography/computed tomography (PET/CT) is now established as the imaging modality of choice in many clinical conditions, particularly in oncology. While the initial development of combined PET/magnetic resonance imaging (PET/MRI) was in the preclinical arena, hybrid PET/MR scanners are now available for clinical use. PET/MRI combines the unique features of MRI including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most evidence for the potential clinical utility of PET/MRI is based on studies performed with side-by-side comparison or software-fused MRI and PET images. Data on distinctive utility of hybrid PET/MRI are rapidly emerging. There are potential competitive advantages of PET/MRI over PET/CT. In general, PET/MRI may be preferred over PET/CT where the unique features of MRI provide more robust imaging evaluation in certain clinical settings. The exact role and potential utility of simultaneous data acquisition in specific research and clinical settings will need to be defined. It may be that simultaneous PET/MRI will be best suited for clinical situations that are disease-specific, organ-specific, related to diseases of the children or in those patients undergoing repeated imaging for whom cumulative radiation dose must be kept as low as reasonably achievable. PET/MRI also offers interesting opportunities for use of dual modality probes. Upon clear definition of clinical utility, other important and practical issues related to business operational model, clinical workflow and reimbursement will also be resolved.