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:值得期待的分子影像未来

PET-CT实现了功能和解剖结构显像的融合,在临床和科研中均获得了巨大成功.MRI是另一种解剖显像方法,与CT相比它具有更好的软组织对比度和空间分辨率,如果能实现PET和MRI的同机融合,将可能对分子影像学产生更深远的影响.主要综述目前PET-MRI研制存在的问题和进展情况,并展望其潜在的临床和科研价值.     

18F-FDG PET/CT在肺癌疗效评估中的价值

肺癌的精准分子靶向及免疫治疗的研究和临床应用已成为当前肺癌治疗领域的热点。18F-FDG PET/CT是结合形态学与分子代谢的影像学技术,与传统的影像学检查如CT、MRI相比,18F-FDG PET/CT能够及时反映肿瘤细胞的活性,对指导肺癌的精准放化疗及监测疗效有重要价值。笔者主要就18F-FDG PET/CT在肺癌病灶的靶区勾画、疗效评估及预后评价中的价值进行探讨。     

PET/CT显像联合融合图像纹理特征分析在肺癌鉴别诊断中的应用价值探讨

目的:探讨~(18)F-FDG PET/CT显像医师先验知识、PET/CT融合图像纹理特征参数联合应用对肺癌的诊断价值.方法:130例患者行PET/CT检查,分别由医师先验知识和4项融合图像纹理特征参数(粗糙度、对比度、频度、角二阶矩)判断肺部病灶的良恶性.经病理检查或治疗后影像学随访确诊肺部良恶性病变.计算每种方法及联合应用诊断肺癌的灵敏度和特异性.结果:130例中,77例诊断为肺癌.医师先验知识诊断肺癌的灵敏度为87.0%、特异性为81.1%,纹理特征参数诊断肺癌的灵敏度为80.5%、特异性为71.7%,两者联合的灵敏度为97.4%、特异性为60.4%.结论:基于PET/CT,两者联合应用在判断肺部病灶良恶性中起到积极作用.     

68Ga/18F标记PSMA在非前列腺癌肿瘤诊疗中的应用进展

前列腺特异性膜抗原(prostate-specific membrane antigen,PSMA)最早在前列腺癌细胞中发现,是前列腺癌诊疗的重要靶点。⁶⁸Ga/¹⁸F-PSMA正电子发射体层成像(positron emission tomography,PET)/计算机体层成像(computed tomography,CT)或PET/磁共振成像(magnetic resonance imaging,MRI)在前列腺癌的诊疗中发挥着重要作用。随着研究和应用的不断深入和拓展,研究者发现肝癌、肺癌、肾癌等其他实体肿瘤均摄取⁶⁸Ga/¹⁸F-PSMA,因此,⁶⁸Ga/¹⁸F-PSMA PET/CT在这些肿瘤诊疗中的价值也逐渐体现出来。本文就⁶⁸Ga/¹⁸F-PSMA PET/CT或PET/MRI在非前列腺癌肿瘤诊疗中的应用进行述评。     

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。     

基于体表定位的PET/CT/MRI"二机三维"图像融合的数字化对照

目的:尝试一种基于体表定位的二维图像配准方法,逐一实现PET、MRI和CT异机图像之间的精确三维融合.方法:输入PET/CT/MRI原始数据后采用数字化格式转换,设计"9点3面"立体定位法进行配准,在实时工作站Mimics按照信息交互自动融合模式,通过讯号叠加技术完成图像融合.结果:以肺癌患者的头、胸、膝为实例交叉试验CT+MRI、PET+MRI和PET+CT立体图像的异机融合,生成了分辨软、硬组织病变性质和位置的清晰互补影像.结论:这种先进的数字化融合算法对提高早期诊断和鉴别诊断具有临床意义,虽然异机融合工序目前尚未像PET+CT的同机融合那样完全成熟,但这一实验将为医学成像厂家进一步研制CT+MRI或PET+MRI同机融合设备提供经验借鉴.     

PET/CT在肺癌精准放疗中的应用进展

PET/CT作为重要的分子成像手段之一,已广泛应用于肿瘤的精准放疗中。其用于肺癌的放疗计划及疗效评估时,对影像质量的要求往往较诊断性成像更高。目前,随着PET/CT新技术在放疗应用中的不断深入,基于PET/CT影像评估肿瘤异质性的生物适形放疗及靶区勾画已初步用于临床,不仅可以提高放疗的准确性,更可以进一步减少辐射诱导损伤,在肺癌的放射治疗中具有重要意义。就PET/CT新技术在肺癌放射治疗中的应用进展予以综述。     

乳腺癌18F-FDG PET/CT和3.0T MRI联合显像评分与Ki-67表达水平的相关性分析

目的 探讨18F-FDG PET/CT和3.0T MRI联合显像评分与Ki-67（一种增殖细胞核抗原）表达水平的相关性。 方法 18例经病理确诊的原发性乳腺癌患者术前行18F-FDG PET/CT和3.0T MRI联合显像,对显像结果进行评分并与Ki-67的表达水平进行相关性分析。联合显像和术后病理标本的免疫组化检测在一周内完成。 结果 ① 乳腺癌最大标准化摄取值与Ki-67的表达水平呈正相关（r=0.473,P＜0.05）;②PET/CT和3.0T MRI联合显像评分与Ki-67的表达水平呈明显正相关（r=0.674,P＜0.01）。 结论 18F-FDG PET/CT和3.0T MRI联合显像在乳腺癌的预后判断中可能具有重要的潜在价值。     

PET和PET/MRI在阿尔茨海默病中的应用

阿尔茨海默病(AD)是老年痴呆最常见的原因,AD的早期诊断有利于改善病人预后。PET和PET/MRI技术在AD的早期诊断和病情评估方面有重要的临床应用价值。现就~(18)F-FDG PET、淀粉样蛋白PET、Tau PET以及PET/MRI在AD方面的发展现状、优势和局限性,以及发展趋势的预测进行综述。     

Recent technological and application developments in computed tomography and magnetic resonance imaging for improved pulmonary nodule detection and lung cancer staging

This review compares the emerging technologies and approaches in the application of magnetic resonance (MR) and computed tomography (CT) imaging for the assessment of pulmonary nodules and staging of malignant findings. Included in this review is a brief definition of pulmonary nodules and an introduction to the challenges faced. We have highlighted the current status of both MR and CT for the early detection of lung nodules. Developments are detailed in this review for the management of pulmonary nodules using advanced imaging, including: dynamic imaging studies, dual energy CT, computer aided detection and diagnosis, and imaging assisted nodule biopsy approaches which have improved lung nodule detection and diagnosis rates. Recent advancements linking in vivo imaging to corresponding histological pathology are also highlighted. In vivo imaging plays a pivotal role in the clinical staging of pulmonary nodules through TNM assessment. While CT and positron emission tomography (PET)/CT are currently the most commonly clinically employed modalities for pulmonary nodule staging, studies are presented that highlight the augmentative potential of MR.     

Bildgebende Methoden in der onkologischen Diagnostik

Cross-sectional imaging techniques, such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) CT are an integral part of the modern oncological workup. They are used for tumor detection and staging as well as for treatment evaluation and monitoring. Due to pathophysiological and histological differences there is no universal imaging protocol for the assessment of different forms of cancer. For instance, CT is still the standard technique for the detection and staging of lung cancer supplemented by PET which aids the exclusion of nodal involvement and the detection of distant metastases. For hepatocellular carcinoma on the other hand, MRI is the preferred imaging technique, particularly when used in conjunction with liver-specific contrast media - PET/CT is only of limited value. Finally, for neuroendocrine tumors there is a focus on special radiotracers, which, in the context of PET/CT, enable a highly specific whole-body assessment. Thus, knowledge of the pathophysiological and imaging characteristics of different tumors is essential for a personalized, state-of-the art management of oncology patients.     

孤立性肺结节检测的影像学研究进展

孤立性肺结节检测多采用X线、CT扫描,而MRI很少被应用于其中.随着MRI新技术的发展,MRI可利用其独特的优势,对肺部进行多序列成像扫描,然后利用其强大的图像后处理功能,可以更加清晰多方位、直观、立体显示肺结节的大小和位置.因此作为一种新的方法,MRI在孤立性肺结节的检测中具有很好的应用前景.本文就孤立性肺结节检测的影像学研究进展及展望进行了综述.     

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.     

PET/CT versus MRI for diagnosis,staging, and follow‐up of lung cancer

Positron emission tomography / computed tomography (PET/CT), with its metabolic data of ¹⁸F‐fluorodeoxyglucose (FDG) cellular uptake in addition to morphologic CT data, is an established technique for staging of lung cancer and has higher sensitivity and accuracy for lung nodule characterization than conventional approaches. Its strength extends outside the chest, with unknown metastases detected or suspected metastases excluded in a significant number of patients. Lastly, PET/CT is used in the assessment of therapy response. Magnetic resonance imaging (MRI) in the chest has been difficult to establish, but with the advent of new sequences is starting to become an increasingly useful alternative to conventional approaches. Diffusion‐weighted MRI (DWI) is useful for distinguishing benign and malignant pulmonary nodules, has high sensitivity and specificity for nodal staging, and is helpful for evaluating an early response to systemic chemotherapy. Whole‐body MRI/PET promises to contribute additional information with its higher soft‐tissue contrast and much less radiation exposure than PET/CT and has become feasible for fast imaging and can be used for cancer staging in patients with a malignant condition. J. Magn. Reson. Imaging 2015;42:247–260.     

Sensitivity of PET/MR images in liver metastases from colorectal carcinoma

Our aim was to evaluate the sensitivity of positron emission tomography/magnetic resonance image (PET/MRI) in the detection of liver metastases in patients from colorectal cancer as compared with computed tomography (CT), magnetic resonance imaging (MRI), PET and PET/CT images. From April 2008 to April 2010, twenty-four patients (mean age 56.5±10.5 years) with liver metastases from colorectal cancer diagnosed by pathology were retrospectively studied as above. All image data were respectively collected and fused. PET/CT and PET/MRI fusion images were successfully performed with a PET-MR-CT robot transmission-fusion imaging system. Pathologic findings and clinical follows-up were performed as referenced standards. Images were reviewed independently by at least three experts. We found a total number of 121 metastatic lesions and 35 of them, with a maximum diameter less than 1cm. According to a per-lesion analysis, the sensitivity on liver metastases was 64.5%, 80.2% and 54.5% on CT, MRI and PET, respectively. Based on reconstruction imaging analysis, PET/CT and PET/MRI showed sensitivities of 84.2% and 98.3%. Sensitivity comparison of PET/MRI had superior sensitivity of 98.08%. Paired data analysis (McNemar) resulted a type I error which equated to 0.05. There was a statistically significant difference between CT and MRI or PET for the detection of patients with liver metastatic lesions (P<0.05). However, PET/MRI can efficiently detect more metastatic lesions than PET/CT (P<0.05) among those with diameter <1cm. In conclusion, PET/MRI was a quite efficient diagnostic modality compared to conventional imaging modalities and should be considered the procedure of choice in the detection of liver metastatic lesions from colorectal cancer.     

Liver metastases: Detection and staging

The liver is more often involved with metastatic disease than primary liver tumors. The accurate detection and characterization of liver metastases are crucial since patient management depends on it. The imaging options, mainly consisting of contrast-enhanced ultrasound (CEUS), multidetector computed tomography (CT), magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI), extra-cellular contrast media and liver-specific contrast media as well as positron emission tomography/computed tomography (PET/CT), are constantly evolving. PET/MRI is a more recent hybrid method and a topic of major interest concerning liver metastases detection and characterization. This review gives a brief overview about the spectrum of imaging findings and focus on an update about the performance, advantages and potential limitations of each modality as well as current developments and innovations.     

FDG–PET imaging findings of a pulmonary sclerosing hemangioma

Pulmonary sclerosing hemangiomas are generally regarded as benign lung lesions arising from type II pneumocytes and bronchial epithelium. In some cases malignant features may be present. There are several case reports describing the radiographic, computed tomography (CT), and magnetic resonance imaging (MRI) characteristics of pulmonary sclerosing hemangiomas. Given the potential for low-grade malignancy 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging may be useful in the diagnostic work up and therapeutic planning in these patients, however the FDG–PET imaging features of pulmonary sclerosing hemangiomas are not well defined. We report a case of histopathologically diagnosed sclerosing hemangioma of the lung which demonstrated intermediate uptake of FDG on the preoperative PET/CT evaluation.     

Staging of untreated nasopharyngeal carcinoma with PET/CT: comparison with conventional imaging work-up

Purpose  We prospectively compared PET/CT and conventional imaging for initial staging of nasopharyngeal carcinoma (NPC). Methods  A total of 111 patients with histologically proven NPC were investigated with PET/CT and conventional imaging (head-and-neck MRI, chest X-ray, abdominal ultrasound, and bone scan) before treatment. The respective findings were reviewed independently and then compared with each other. Results  With regard to T staging, PET/CT showed a discrepancy with head-and-neck MRI in 36 (32.4%) of the study subjects. With regard to N staging, PET/CT showed a discrepancy with head-and-neck MRI in 15 (13.5%) patients. Among the discordant cases, MRI was superior in demonstrating tumor involvement in the parapharyngeal space, skull base, intracranial area, sphenoid sinus, and retropharyngeal nodes while PET/CT was superior in demonstrating neck nodal metastasis. PET/CT disclosed 13 of 16 patients with distant malignancy compared with four patients disclosed by conventional imaging work-up. The false-positive rate of PET/CT was 18.8%. PET/CT correctly modified M staging in eight patients (7.2%) and disclosed a second primary lung malignancy in one patient (0.9%). Conclusion  In NPC patients, MRI appears to be superior to PET/CT for the assessment of locoregional invasion and retropharyngeal nodal metastasis. PET/CT is more accurate than MRI for determining cervical nodal metastasis and should be the better reference for the neck status. PET/CT has an acceptable diagnostic yield and a low false-positive rate for the detection of distant malignancy and can replace conventional work-up to this aim. PET/CT and head-and-neck MRI are suggested for the initial staging of NPC patients. An erratum to this article can be found at     

肺癌脊椎骨转移（18）F-FDG PET/CT与MRI的对比分析

目的：比较分析18 F-FDG PET/CT与MRI在肺癌脊椎骨转移诊断方面的敏感性、特异性。方法：28例肺癌PET/CT疑脊椎转移患者行MRI检查,比较两种方法对脊椎转移的显示征象。统计学方法采用配对四格表资料2检验,P〈0.05被认为差异有显著性。结果：经病理或随访确诊脊椎骨转移22例。以受累椎体病灶个数为统计单位,脊椎范围内共700个椎体,153个为真阳性,574个为真阴性。PET/CT诊断正确143个病灶,假阴性10个,假阳性24个,其敏感性93.4%,特异性95.6%。MRI诊断正确145个病灶,假阴性8个,无假阳性,其敏感性94.7%,特异性100%。结论：在显示脊椎骨转移方面,MRI较PET/CT具有更高的敏感性、特异性。