一体化PET/MRI用于直肠癌研究进展

MRI是目前可用于直肠癌局部分期的最佳影像学方法之一。一体化PET/MRI可通过同步双模态扫描获得病变的形态、功能及代谢等多方面信息,较PET/CT或单模态MRI、CT评估直肠癌分期、观察新辅助放化疗疗效及监测复发的效能更优。本文对一体化PET/MRI评估直肠癌的现状及进展进行综述。     

SPECT/MRI技术研究进展

多模态显像技术中的PET/CT和SPECT/CT现已广泛用于临床,而PET/MRI也已有商业成机。SPECT灵敏度高,应用基础广泛,其示踪剂适应面广、获取相对容易,SPECT技术与高分辨率MRI相结合的SPECT/MRI具有广泛应用前景。本文对该领域在系统结构设计、图像配准与校正及应用于动物实验的多模态纳米分子探针方面的研究进展进行综述。     

多模态磁共振成像在脑胶质瘤分级诊断及预后评估中的研究进展

脑胶质瘤是中枢神经系统中常见的恶性肿瘤,其具有弥漫性浸润生长的特点,在治疗的过程中具有较大的难度,肿瘤恶性程度高,容易复发、预后较差。多模态磁共振成像技术多用于肿瘤术前的初步诊断,在胶质瘤分级判断以及预测预后方面具有重要的价值。本文就扩散加权磁共振成像、弥散张量磁共振成像、动态磁敏感对比灌注加权成像、动态对比增强磁共振成像、动脉自旋标记成像和磁共振波谱成像等几种多模态磁共振成像技术在脑胶质瘤术前分级诊断及预后评估方面的研究进展进行综述。      

MR扩散加权成像(DWI)在预测、监测直肠癌放、化疗效果中的应用价值分析

分析MR扩散加权成像(DWI)在预测、监测直肠癌放、化疗效果中的应用价值。将本院2015年1月~2016年10月实施放、化疗的18例直肠癌患者作为分析对象,在患者放化疗前、化疗结束后实施MRI检查与MR扩散加权成像检查,基于时间点与检查结果进行比较。直肠癌患者放化疗结束后,肿瘤侵犯肠壁的厚度与放化疗前比较具有显著差异,且放化疗后患者ADC值存在显著变化,数据对比具有统计学意义(P<0.05)。MR扩散加权成像具有提前预测、全面监测以及科学评估的价值,在直肠癌患者放、化疗中的应用,能够清晰患者的临床疗效,对患者的临床治疗产生重要影响。     

术前MRI预测肝细胞癌微血管侵犯研究进展

肝细胞癌是全球常见的恶性肿瘤,最主要的治疗方法是手术切除肿瘤,但经常复发,很大一部分原因与微血管侵犯相关.因此,寻找一种无创的术前预测微血管侵犯的方法对于指导手术治疗、改善患者预后、提高患者生存率等具有重要意义.磁共振成像(magnetic resonance imaging,MRI)技术的多序列、多模态成像以及基于M...     

基于多模态磁共振成像探讨针刺治疗卒中后失语症的研究进展

卒中后失语症（post-stroke aphasia, PSA）是指因脑血管或言语中枢神经功能紊乱引起的后天性语言功能障碍。针刺治疗PSA已取得较好的临床疗效,但其作用机制尚未明确。近年来,多模态MRI飞速发展,此项技术具有无辐射、多参数、多序列成像等优点,已被众多学者应用于PSA中枢效应机制研究。本研究基于功能MRI、弥散张量成像、结构性MRI、磁共振波谱成像等多模态成像技术,从脑功能、脑结构及脑代谢等角度探讨了针刺对PSA患者中枢效应机制,旨在为针刺治疗PSA临床个体化诊疗方案提供新方向,为研究针刺治疗PSA的潜在机制提供新思路。     

CT、MRI及与PET融合显像评价宫颈癌分期及淋巴结转移中的应用进展

传统影像学检查方法(CT、MRI)在宫颈癌分期及淋巴结转移的诊断方面应用较为广泛,对制定治疗方案、改善预后和降低死亡率有重要的作用。近年来,随着分子影像技术的发展,多模态分子影像技术(PET/CT及PET/MR)被逐渐应用于宫颈癌的诊断并指导治疗。本文对CT、MRI及与PET融合显像技术在宫颈癌分期及淋巴结转移评价中的临床应用进行综述。     

多模态运动联合音乐成像在鼻咽癌放化疗患者中的应用

目的 探讨多模态运动联合音乐成像对鼻咽癌放化疗患者癌因性疲乏和负性情绪的影响。方法 便利选取江西省某三级甲等医院正在接受同步放化疗的鼻咽癌患者100例,用随机数字表分为实验组和对照组,每组各50例。实验组接受常规放化疗护理和多模态运动联合音乐成像训练,对照组接受常规放化疗护理,比较两组干预前后癌因性疲乏及激惹、抑郁和焦虑的得分情况。 结果 实验组癌因性疲乏总分及激惹、抑郁和焦虑总分均低于对照组,差异有统计学意义（P<0.05）。结论 多模态运动联合音乐成像能有效缓解鼻咽癌患者放化疗期间的疲乏,降低其负性情绪。     

胶质瘤基因预测的多模态磁共振成像及影像组学研究进展

脑胶质瘤具有高度基因异质性,术前进行胶质瘤的基因预测对患者的治疗方案及评估预后有重要的指导作用。近年来,多模态MRI、影像组学等多种影像新方法逐渐应用于胶质瘤基因信息的无创检测。本文对多模态MRI、影像组学在诊断胶质瘤基因型中的研究进展进行综述。     

一体化TOF-PET/MR的临床应用与挑战

精准化医疗是现代医学发展的趋势,而反映生命过程不同侧面信息的多模态影像学技术是实现精准化医疗的必要条件。PET及MRI的出现推动了多模态影像学的发展,特别是一体化TOF-PET/MR,可克服PET探测器与MRI强磁场相互干扰的技术难题、实现时间和空间上的同步扫描,对于从结构、功能、分子代谢等方面探索疾病的发生、发展及诊断具有重要意义。TOF技术有助于提高PET图像质量,降低假阳性或假阴性。本文就一体化TOF-PET/MR的临床应用及其面临的挑战进行综述。     

探讨DCE-MRI早期预测鼻咽癌新辅助化疗和调强放疗疗效的价值

目的探讨DCE-MRI早期预测鼻咽癌放化疗(chemoradiotherapy,CRT)疗效的应用价值。材料与方法前瞻性入组87例局部中晚期鼻咽癌患者,在新辅助化疗(nasopharyngeal carcinoma,NAC)前和调强放疗(intensity-modulated radiotherapy,IMRT)1周后(即分割照射5次)分别进行动态增强MRI(dynamic contrast-enhanced magnetic resonance imaging,DCE-MRI)扫描。获得各时间点原发肿瘤的DCE-MRI参数值(K~(trans)、K_(ep)、V_e和V_p)。比较放疗早期和放疗后的不同疗效组之间DCE-MRI参数在治疗前后变化的差异。结果在放疗早期和放疗后,有效组的K~(trans)和K_(ep)参数在放疗早期发生了明显下降。调强放疗结束后,治愈组的治疗前K~(trans)以及与放疗后早期的数学差值(△K~(trans)和△K_(ep))和变化百分比(K~(trans)_((Perc))和K_(ep(Perc)))、放疗早期的肿瘤退缩率均显著大于残留组(P0.05),上述各DCE-MRI参数早期预测IMRT的诊断效用介于0.655～0.829,联合肿瘤退缩率后的诊断效用最高,高达0.832。结论 DCE-MRI具有潜在早期预测局部中晚期鼻咽癌CRT近期疗效的价值。     

介入治疗后CT表现不典型的肝癌残留和复发病灶的早期诊断

目的探讨MRI、PET/CT早期诊断肝细胞癌(HCC)介入治疗后CT表现不典型的残留及复发病灶的价值。方法回顾性分析19例接受介入治疗的HCC患者的资料,术后定期复查发现甲胎蛋白(AFP)升高,螺旋CT三期增强扫描呈不典型表现,经MR和(或)PET/CT检查发现HCC残留和复发病灶。对所有病灶均获得病理结果。比较治疗前、后的AFP。结果对19例HCC患者行MR检查25例次,发现31个结节;PET/CT检查14例次,发现17个结节,MRI、PET/CT联合检查共发现35个结节;诊断HCC残留和复发病灶31个,直径0.90～2.50cm,平均(1.50±0.32)cm。介入治疗后1、4周,AFP明显降低,与治疗前相比差异均有统计学意义(P均<0.05)。MRI、PET/CT诊断肝内残留和复发病灶的敏感度分别为87.10%(27/31)、89.47%(17/19),MRI联合PET/CT的诊断敏感度为100%(31/31)。结论 MRI、PET/CT均能较好地早期诊断HCC患者介入治疗后CT表现不典型的残留及复发病灶;MRI联合PET/CT能进一步提高早期诊断率,减少假阴性和假阳性。     

动态增强MRI对鼻咽癌放化疗疗效的预测价值

目的探讨磁共振动态增强(DCE-MRI)序列对鼻咽癌放化疗疗效的预测评估价值。材料与方法收集经病理证实并接受放化疗的鼻咽癌患者37例,于治疗前行MRI平扫及DCE-MRI增强扫描,分别测量肿瘤高强化区、低强化区及平均的动态增强半定量参数;于放疗中期(剂量达56 Gy时)再次行磁共振扫描,计算肿瘤消退率。根据实体瘤疗效评价标准将患者分为CR组和非CR组,采用Spearman等级相关分析分别评价肿瘤不同区域半定量参数与肿瘤消退率的相关性,并采用ROC曲线计算有相关性的参数预测CR组的诊断阈值,以曲线下面积最大者预测价值最高。结果半定量参数中肿瘤高强化区TTP诊断效能最好,我们以肿瘤高强化区TTP65.53 s为诊断治疗敏感组的阈值,其敏感性为100%,特异性为43.33%,曲线下面积为0.843。结论 DCE-MRI多项半定量参数均可以预测鼻咽癌的放化疗疗效,对临床制定个体化治疗方案提供帮助。     

Relative clinical utility of simultaneous 18F-fluorodeoxyglucose PET/MRI and PET/CT for preoperative cervical cancer diagnosis

ObjectiveTo investigate the utility of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/magnetic resonance imaging (PET/MRI) for the preoperative diagnosis of cervical cancer.MethodsWe retrospectively analyzed 114 patients who were diagnosed with cervical cancer and underwent PET/MRI (n = 59) or PET/computed tomography (PET/CT) (n = 65) before surgery. The maximal standardized uptake value (SUV_max) and mean SUV (SUV_mean) were determined for regions of interest in the resultant radiographic images.ResultsRelative to PET/CT, ¹⁸F-FDG PET/MRI exhibited higher specificity and sensitivity in defining the primary tumor bounds and higher sensitivity for detection of bladder involvement. The SUV_max and SUV_mean of PET/MRI were remarkably higher than those of PET/CT as a means of detecting primary tumors, bladder involvement, and the lymph node status. However, no significant differences in these values were detected when comparing the two imaging approaches as a means of detecting vaginal involvement or para-aortic lymph node metastasis.ConclusionsThese outcomes may demonstrate the capability of ¹⁸F-FDG PET/MRI to clarify preoperative cervical cancer diagnoses in the context of unclear PET/CT findings. However, studies directly comparing SUVs in different lesion types from patients who have undergone both PET/MRI and PET/CT scans are essential to validate and expand upon these findings.     

Measuring tumor perfusion in control and treated murine tumors: correlation of microbubble contrast-enhanced sonography to dynamic contrast-enhanced magnetic resonance imaging and fluorodeoxyglucose positron emission tomography.

OBJECTIVE: The purpose of this study was to evaluate the ability of dynamic microbubble contrast-enhanced sonography (MCES), in comparison with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and fluorodeoxyglucose positron emission tomography (FDG-PET), to quantitatively characterize tumor perfusion in implanted murine tumors before and after treatment with a variety of regimens. METHODS: Seventeen mice with Lewis lung carcinoma implants were categorized to control, radiation therapy alone, antiangiogenic chemotherapy alone, and combined chemoradiation. On day 0 of each treatment regimen, MCES and DCE-MRI of each tumor were performed. On day 5 of treatment, dynamic FDG-PET, MCES, and DCE-MRI were performed. RESULTS: Microbubble contrast-enhanced sonography showed that intratumoral perfusion, blood volume, and blood velocity were highest in the untreated control group and successively lower in each of the treatment groups: radiation therapy alone resulted in a two-thirds reduction of perfusion; antiangiogenic chemotherapy resulted in a relatively larger reduction; and combined chemoradiotherapy resulted in the largest reduction. Microbubble contrast-enhanced sonography revealed longitudinal decreases in tumor perfusion, blood volume, and microvascular velocity over the 5-day course of chemoradiotherapy (all P < .01); conversely, these values rose significantly for the untreated control tumors (P < .01). Dynamic contrast-enhanced MRI showed a smaller and statistically insignificant average decrease in relative tumor perfusion for treated tumors. Dynamic PET revealed delayed uptake of FDG in the tumors that underwent chemoradiotherapy. CONCLUSIONS: Microbubble contrast-enhanced sonography is an effective tool in the noninvasive, quantitative, longitudinal characterization of neovascularization in murine tumor models and is correlative with DCE-MRI and FDG-PET. Microbubble contrast-enhanced sonography has considerable potential in the clinical assessment of tumor neovascularization and in the assessment of the response to treatment.     

Multimodal imaging of tumor response to sorafenib combined with radiation therapy: comparison between diffusion‐weighted MRI,choline spectroscopy and 18F‐FLT PET imaging

The purpose of this study was to determine the value of different imaging modalities, that is, magnetic resonance imaging/spectroscopy (MRI/MRS) and positron emission tomography (PET), to assess early tumor response to sorafenib with or without radiotherapy. Diffusion‐weighted (DW)‐MRI, choline ¹H MRS at 11.7 T, and ¹⁸F‐FLT PET imaging were used to image fibrosarcoma (FSaII) tumor‐bearing mice over time. The imaging markers were compared with apoptosis cell death and cell proliferation measurements assessed by histology. Anti‐proliferative effects of sorafenib were evidenced by ¹H MRS and ¹⁸F‐FLT PET after 2 days of treatment with sorafenib, with no additional effect of the combination with radiation therapy, results that are in agreement with Ki67 staining. Apparent diffusion coefficient calculated using DW‐MRI was not modified after 2 days of treatment with sorafenib, but showed significant increase 24 h after 2 days of sorafenib treatment combined with consecutive irradiation. The three imaging markers were able to show early tumor response as soon as 24 h after treatment initiation, with choline MRS and ¹⁸F‐FLT being sensitive to sorafenib in monotherapy as well as in combined therapy with irradiation, whereas DW‐MRI was only sensitive to the combination of sorafenib with radiotherapy. Copyright © 2013 John Wiley & Sons, Ltd.     

Main applications of hybrid PET‐MRI contrast agents: a review

In medical imaging, the continuous quest to improve diagnostic performance and optimize treatment strategies has led to the use of combined imaging modalities. Positron emission tomography (PET) and computed tomography (CT) is a hybrid imaging existing already for many years. The high spatial and contrast resolution of magnetic resonance imaging (MRI) and the high sensitivity and molecular information from PET imaging are leading to the development of this new hybrid imaging along with hybrid contrast agents. To create a hybrid contrast agent for PET‐MRI device, a PET radiotracer needs to be combined with an MRI contrast agent. The most common approach is to add a radioactive isotope to the surface of a small superparamagnetic iron oxide (SPIO) particle. The resulting agents offer a wide range of applications, such as pH variation monitoring, non‐invasive angiography and early imaging diagnosis of atherosclerosis. Oncology is the most promising field with the detection of sentinel lymph nodes and the targeting of tumor neoangiogenesis. Oncology and cardiovascular imaging are thus major areas of development for hybrid PET‐MRI imaging systems and hybrid contrast agents. The aim is to combine high spatial resolution, high sensitivity, morphological and functional information. Future prospects include the use of specific antibodies and hybrid multimodal PET‐MRI‐ultrasound‐fluorescence imaging with the potential to provide overall pre‐, intra‐ and postoperative patient care. Copyright © 2015 John Wiley & Sons, Ltd.     

一体化^(18)F-FDG PET/MRI用于诊断胰腺肿瘤北大核心CSCD

目的探讨一体化^(18)F-FDG PET/MRI鉴别胰腺良、恶性病变和检测淋巴结和/或远处转移的价值。方法回顾性分析45例临床疑诊胰腺肿瘤并接受^(18)F-FDG PET/MRI患者,包括38例胰腺恶性病变和7例良性病变,以病理或随访结果为标准,评价一体化PET/MRI诊断胰腺良、恶性病变的效能。结果取3.20为最大标准摄取值(SUV_(max))的截断值,^(18)F-FDG PET/MRI诊断胰腺癌的敏感度、特异度、准确率、阳性预测值和阴性预测值分别为89.47%(34/38)、85.71%(6/7)、88.89%(40/45)、97.14%(34/35)和60.00%(6/10);以1.78作为平均表观弥散系数(ADC_(mean))的截断值时,其敏感度、特异度、准确率、阳性预测值和阴性预测值分别为97.37%(37/38)、71.43%(5/7)、93.33%(42/45)、94.87%(37/39)和85.71%(6/7);联合应用二者则分别为100%(38/38)、71.43%(5/7)、95.56%(43/45)、95.00%(38/40)和100%(5/5)。15例检查前未发现肝、肺、骨及淋巴结转移患者中,根据^(18)F-FDG PET/MRI结果,12例的治疗方案获得修正。结论一体化^(18)F-FDG PET/MRI是检测胰腺癌淋巴结和/或远处转移的较好方法;SUV_(max)与ADC_(mean)对于鉴别胰腺良、恶性病变具有较高价值。