肺癌脑转移的MRI诊断

背景与目的：在颅内转移瘤中以来自于肺癌为最多。本文观察肺癌脑转移的MRI征象，比较不同病理类型肺癌脑转移病灶的差异。方法：分析32例病理证实的肺癌脑转移病例MRI图像，观察转移瘤的部位、数目、形态、信号、水肿、增强表现及脑膜和颅骨的受侵等情况。结果：32例患者，共检出88个病灶，57个为囊实性。31个为实性。病灶多数位于灰白质交界区。病灶周围Ⅱ-Ⅲ度水肿共47个病灶(腺癌20个，鳞癌26个。小细胞癌1个)，Ⅰ度水肿41个(腺癌21个，鳞癌9个，小细胞癌11个)。有15个病灶内可见不同范围的短T1WI信号(腺癌12个，鳞癌2个，小细胞癌1个)；颅骨破坏4例，均见于腺癌。结论：肺癌脑转移瘤具有相对特征性的MRI征象，肺腺癌和鳞癌脑转移瘤MRI表现有一定差异，主要表现在转移瘤发生率、病灶数目、水肿范围以及短T1信号出现率和颅骨转移等方面。     

磁共振改良DIXON定量技术在椎体转移瘤中的诊断价值

目的 探讨磁共振改良DIXON定量技术（mDIXON Quant）在椎体转移瘤中的诊断价值。方法 回顾性分析152例经病理确诊为恶性肿瘤并椎体转移患者的MRI图像。扫描序列包括T1WI、STIR、mDIXON Quant及T1WI压脂增强。分析T1WI、FF图像在椎体转移瘤中的诊断效能;比较正常椎体与椎体转移瘤FF值的差异,应用ROC曲线评估FF值的诊断效能。结果 FF图像诊断椎体转移瘤的敏感度、假阳性率、假阴性率、阴性预测值、准确性均高于T1WI。椎体转移瘤的FF值明显低于正常椎体（Z=-21.792, P<0.05）,其中ROC曲线下面积为0.987,截断值为9.87%,诊断敏感度99.6%,特异性92.0%。结论 mDIXON Quant能够定量测定椎体转移瘤的脂肪含量,对椎体转移瘤的诊断具有较高的诊断效能。     

富血供肝转移瘤的MRI表现和特点

背景与目的：肝脏是血源性转移癌最好发的器官，正确判断富血供肝转移瘤具有重要的临床价值，本研究探讨富血供肝转移瘤的MRI特征。方法：回顾性分析122例有明确原发肿瘤病史并伴有肝脏转移的病例。根据强化程度，当病灶显示出明显的早期强化（强化程度与胰腺或肾皮质相仿）时，肝转移瘤被认为是富血供的，据此，共有31例符合人选标准，其中男性8例，女性23例，年龄29～77岁，平均年龄51．9岁。所有31例均行上腹部MRI检查（采用1．5T超导MR扫描仪），扫描序列包括T2WIFSE序列，T1WISPGR序列（用于增强前后扫描）。对比剂为钆喷酸葡胺注射液（Gd—DTPA），注射剂量为0．1mmol/kg，注射速率为2ml／s，注射后行Ⅲ期扫描，扫描时间分别为：20、45、90S。所有MR图像由两位有经验的放射科高年主治医师分析并达成一致。结果：31例患者共发现239个肝转移灶，分布于两叶，无特别好发肝段。其中21例转移灶为多发，其余10例为单发转移灶。病灶小于9．5cm。MR图像显示所有病灶于T1WI均为低信号。在T2WI图像上，127个病灶（53％）显示为中等高信号，65个病灶（27％）为中等高信号伴病灶中央更高信号区。增强动脉期显示183个病灶（77％）呈明显的边缘强化，41个病灶（17％）呈弥漫均匀的结节样强化，15个病灶（6％）呈弥漫不均匀强化。增强门脉期，131个病灶表现为与动脉期相仿的强化方式与程度，其中33个病灶表现为较动脉期稍增厚的强化环。结论：根据富血供肝转移瘤的主要特征．大多数病灶可以和肝脏其他富血供病变（如HCC．血管瘤，FNH等）能正确鉴别。     

磁共振扩散加权成像在肾细胞癌脑转移诊断中的应用

目的:探讨磁共振扩散加权成像（MRI DWI）在肾细胞癌（RCC）脑转移诊断中的应用价值。方法:采用回顾性研究方法分析2014年2月至2016年5月在我院诊治的140例RCC患者,所有患者都给予常规MRI T1WI与T2WI序列诊断,同时给予DWI序列的ADC值测定与诊断价值判定。结果:所有患者的MRI图像均显示清晰,病理确诊为RCC脑转移40例,RCC 100例。39例RCC脑转移患者的T2WI序列表现为高信号,36例T1WI序列表现为高信号;78例RCC患者的T2WI序列表现为高信号,72例T1WI序列表现为高信号,对比差异都有统计学意义（P＜0.05）。140例患者肾实质ADC值是（2.21±0.32）×10-3 mm2/s,同时,患者肾脏实性肿瘤ADC值是（1.54±0.37）×10-3 mm2/s,对比差异有统计学意义（t=4.298,P＜0.05）;RCC患者的ADC 值为（1.26±0.21）×10-3 mm2/s,RCC脑转移患者的ADC 值为（1.59±0.30）×10-3mm2/s,RCC脑转移的ADC 值明显高于RCC患者（P＜0.05）。将阈值设定为1.355×10-3 mm2/s,通过DWI对RCC患者的脑转移进行诊断,得出其特异性为92.1%,敏感性为85.0%。结论:在诊断RCC患者的脑转移时,ADC值和DWI可以提供重要依据,两者有很好的应用价值。     

鼻咽癌放疗后放射性脑干损伤的MRI表现

目的分析鼻咽癌患者放疗后发生放射性脑干损伤的MRI表现特征。方法对37例鼻咽癌放疗后发生放射性脑干损伤患者的MRI资料进行复阅,对MRI检查序列包括T1WI、T2WI、FLAIR以及增强扫描序列进行分析,明确放射性脑干损伤的病变部位、范围、信号强度和增强后病灶强化等的形态。结果37例放射性脑干损伤患者,病变位于脑桥19例,中脑1例,延髓3例,脑桥＋中脑6例,脑桥＋延髓5例,中脑＋脑桥＋延髓3例。病灶在MRI上TIWI表现为等信号或低信号,TaWI表现为高信号,FLAIR表现为低、高混杂信号,增强后无明显强化者9例,强化者28例。强化方式：均匀斑片状强化者12例、不均匀环形强化者16例。结论MRI可以清晰地显示放射性脑干损伤的病灶,MRI对于诊断放射性脑干损伤有着重要价值,为临床治疗提供参考。     

MRI三期增强扫描对脑转移瘤的诊断价值

目的:对比MRI三期增强扫描对脑转移瘤的敏感性及诊断价值，评估最佳增强扫描时间。方法:对40例临床拟诊为脑转移瘤患者，均行磁共振T1WI轴位即时增强扫描、5 min增强扫描及10 min增强扫描，据此分为三组，统计并比较三组图像中脑转移瘤的数量、体积、信号强度比。结果:40例患者中，三组分别显示病灶136个、163个、173个。整个肿瘤体积的中位数在三组分别为79.2 mm3、102.4 mm3、116.8 mm3，延迟5 min和10 min的肿瘤体积明显大于即时增强的肿瘤体积（P<0.000 1）。病灶信号强度比在三组分别为0.16、0.19、0.20，延迟10分钟图像肿瘤增强部分信号强度比明显大于即时增强图像肿瘤的信号强度比（P<0.05），延迟5 min和10 min的图像之间没有显著差异（P=0.65）。结论:注射钆造影剂后的10分钟左右行MRI增强扫描对脑转移瘤的检测具有较高的敏感性。     

SPIO增强MRI成像在大鼠脾脏荷 VX2 肿瘤模型的实验研究

目的:建立大鼠脾脏VX2肿瘤模型,研究大鼠脾VX2肿瘤超顺磁性氧化铁(SPIO)增强MRI上信号强度变化与病理学改变之间的关系.探讨SPIO在大鼠脾脏转移瘤的应用价值.方法:对8只脾脏荷VX2肿瘤模型鼠;静脉注射SPIO后行MRI扫描,扫描序列采用T1WI(450/12 ms )和T2WI(4 000/128 ms ).结果:平扫SET1WI上肿瘤-脾脏的对比噪声比极差,所有病灶均不能很好显示.SPIO增强T2WI上正常脾实质信号强度明显降低,信号强度下降百分比(PSIL)为55.04%;脾脏VX2肿瘤信号强度无明显下降,PSIL为0.87%,与正常脾实质信号强度下降程度差异有统计学意义,t= 3.879,P<0.001.脾VX2肿瘤的CNR较增强前显著提高,t= 6.963,P<0.001.结论:SPIO增强T1WI 上正常脾实质与VX2肿瘤组织的对比差,病灶的检出率低,不利于描述病灶的特征.SPIO增强T2WI 上脾脏-肿瘤的对比显著,提高了病灶的检出率,改善了病灶影像学特征的描述.     

基于多序列MRI与多体系影像组学模型预测子宫颈癌淋巴结转移的研究

背景与目的：术前寻找可早期用于准确评估淋巴结转移与否的生物标志物极具临床应用价值。探讨MRI影像组学参数预测子宫颈癌淋巴结转移的价值,建立和验证用于术前预测子宫颈癌淋巴结转移的影像组学模型。方法：回顾性分析2015年6月—2019年9月在复旦大学附属肿瘤医院经术后病理学检查证实的子宫颈癌非淋巴结转移患者和子宫颈癌淋巴结转移患者共202例的临床资料,所有患者均经过术前MRI检查。选用MRI图像分别为T2加权图像（T2 weighted image,T2WI）和T1增强图像（T1 contrast +,T1C+）。使用ITK-SNAP软件进行三维手动分割子宫颈癌肿瘤区域。通过开源的python包Pyradiomics和python编程平台jupyter notebook,经过10种图像类型体系和6种特征体系来提取影像组学特征,选取子宫颈癌患者202例,其中未发生淋巴结转移的104例,发生淋巴结转移的98例。T2WI序列和T1C+序列模型分别提取1 923个特征,T2WI联合T1C+序列提取3 846个特征。通过建立影像组学标签,经过机器学习模型验证影像组学标签。最后将训练集和测试集的曲线下面积（area under curve,AUC）、准确率、阳性预测值（positive predictive value,PPV）和阴性预测值（negative predictive value,NPV）作为评估影像组学标签的定量表现。结果：T2WI序列选取特征排序前14名的特征进行分类器训练,训练集AUC=0.810,测试集AUC=0.773。对于T1C+序列选取了特征排序前16名的特征进行分类器训练,训练集AUC=0.819,测试集AUC=0.781。在T2WI联合T1C+序列中选取了特征排序前16名的特征进行分类器训练,训练集AUC=0.841,测试集AUC=0.803。结论：T2WI联合T1C+序列影像组学模型对早期子宫颈癌淋巴结转移有较好的预测能力。     

肺癌脑转移瘤CT-MR融合对靶区勾画体积影响的观察

目的:将CT与MR图像进行融合,比较融合前后勾画的靶区体积,探讨融合技术在放射治疗应用中的价值。方法:收集20例肺癌脑转移患者。增强CT静脉高压注射碘帕醇(30mgI/mL)造影剂,扫描层厚5mm,扫描10.6s;增强MR静脉高压注射Gd-DTPA(0.1mmol/kg体质量)显影剂,行矢状位T1WI和横断位T1WI、T2WI和FLAIR扫描,扫描参数T1WI:TR 440ms,TE 14ms;T2WI:TR 3 200ms,TE 280ms;FLAIR IR:IR 2 000ms;层厚5mm。将CT和MR图像传输至Eclipse工作站并进行CT-MR图像融合,在3种图像上分别勾画GTVCT、GTVMR和GTVCT-MR,比较3种GTV体积,并对比体外标记点法和解剖点法的融合精度。结果:GTVCT、GTVCT-MR和GTVMR体积平均值分别为(25.24±4.73)、(21.8±5.31)和(19.03±3.04)cm3,F=9.709,q=6.21,P=0.001;其中融合组勾画的GTVCT-MR准确度要明显优于CT组GTVCT,q=3.44,P<0.05;融合组GTVCT-MR体积与核磁组GTVMR体积差异无统计学意义,q=2.77,P>0.05。体外标记点法融合精度(1.39±0.64)mm要好于解剖点法(1.97±1.0)mm。结论:CT-MR融合技术能够更准确的确定肺癌脑转移瘤病灶范围;体外标记点法可减少人为误差,融合结果要好于解剖点法。     

颞叶放射性脑病磁共振成像的特征分析

背景与目的：鼻咽癌(nasopharyngeal carcinoma,NPC)放疗后放射性脑病(radiation encephalopathy,REP)的表现形式多样,对其多样性表现的报道并不多,本研究观察NPC放射性脑病的磁共振成像(magnetic resonance imaging,MRI)形态学表现特征并探讨其诊断价值。方法：对104例NPC患者共160处病灶经MRI诊断为颞叶REP的MRI资料进行回顾性分析。在NPC放射治疗8个月～13年进行MRI检查,成像序列包括T1WI,T2WI,111处病灶作了T1WI Gd—DTPA增强,37处病灶有水抑制反转恢复(fluid attented inversion recovery FLAIR)检查,其中2例有磁共振脑血流灌注成像(MR perfusion weighted imaging,MR PWI)。结果：104例REP中累及单侧颞叶48例,双侧颞叶56例,共160个病灶。脑白质病变在T2WI为高信号,信号可均匀一致,但其中59个病灶在高信号区内出现不均匀低信号影;有91个病灶同时伴有灰质病变,表现为T1WI低信号,T2WI高信号;在111个病灶T1WI Gd—DTPA检查中91个病灶出现强化灶;有5个病灶出现出血及含铁血黄素沉着。结论：鼻咽癌放射性脑病表现具有多样性,除了常见的脑白质病变外,脑灰质病变、脑出血及含铁血黄素沉着及血脑屏障破坏等均比较常见;MRI能清楚地显示这些病变。     

T1‐weighted fluid‐attenuated inversion recovery and T1‐weighted fast spin‐echo contrast‐enhanced imaging: A comparison in 20 patients with brain lesions

T1‐weighted fluid‐attenuated inversion recovery (FLAIR) sequence is a relatively new pulse sequence for intracranial MR imaging. This study was performed to compare the image quality of T1‐weighted FLAIR with the T1‐weighted FSE sequence. Twenty patients with brain lesions underwent T1‐weighted fast spin‐echo (FSE) and T1‐weighted FLAIR during the same imaging session. Four quantitative and three qualitative criteria were used to compare the two sequences after contrast. Two of four quantitative criteria pertained to lesion characteristics: lesion to white matter (WM) contrast‐to‐noise ratio (CNR) and lesion to cerebrospinal fluid (CSF) CNR, and two related to signals from normal tissue: grey matter to WM CNR and WM to CSF CNR. The three qualitative criteria were conspicuousness of the lesion, the presence of image artefacts and the overall image contrast. Both T1‐weighted FSE and FLAIR images were effective in demonstrating lesions. Image contrast was superior in T1‐weighted FLAIR images with significantly improved grey matter‐WM CNRs and CSF‐WM CNRs. The overall image contrast was judged to be superior on T1‐weighted FLAIR images compared with T1‐weighted FSE images by all neuroradiologists. Two of three reviewers considered that the FLAIR images had slightly increased imaging artefacts that, however, did not interfere with image interpretation. T1‐weighted FLAIR imaging provides improved lesion‐to‐background and grey to WM contrast‐to‐noise ratios. Superior conspicuity of lesions and overall image contrast is obtained in comparable acquisition times. These indicate an important role for T1‐weighted FLAIR in intracranial imaging and highlight its advantage over the more widely practiced T1‐weighted FSE sequence.     

多模态MR图像测量鼻咽癌GTV一致性评价

目的 探讨多模态MR图像测量鼻咽癌GTV的一致性。方法 回顾分析 45例经病理证实的鼻咽癌初诊病例,均行MRI平扫、增强和扩散加权成像检查。在轴位增强T₁WI、轴位T₂WI、ADC图像上手动勾画原发肿瘤轮廓,通过面积求和法计算GTV,将不同图像测量的GTV分成T₁+C、T₂WI组和ADC组。采用单因素方差分析3个组平均值,Bland-Altman法通过两组差值平均值和95%分布范围评价不同模态图像测量GTV结果的一致性。结果 T₁+C、T₂WI、ADC组GTV分别为(20.8±18.1)、(21.5±17.2)、(24.4±20.8) cm³(P=0.617)。T₂WI和T₁+C组、ADC和T₂WI组、ADC和T₁+C组差值的平均值和95%一致性界限分别为0.74(-5.97~7.44)、2.94(-8.25~13.69)、3.68(-3.34~10.70) cm³。结论 多模态MR图像测量鼻咽癌GTV一致性不佳,尚不能相互替代,增强T₁WI联合T₂WI、DWMRI可更准确地判断鼻咽癌靶区范围。     

A surgical strategy using a fusion image constructed from 11C-methionine PET, 18F-FDG-PET and MRI for glioma with no or minimum contrast enhancement

The objective of this study was to investigate the distribution of 11C-methionine (MET) and F-18 fluorodeoxyglucose (FDG) uptake in positron emission tomography (PET) imaging and the hyperintense area in T2 weighted imaging (T2WI) in glioma with no or poor gadolinium enhancement in magnetic resonance imaging (GdMRI). Cases were also analyzed pathologically. We prospectively investigated 16 patients with non- or minimally enhancing (<?10% volume) glioma. All patients underwent MET-PET and FDG-PET scans preoperatively. After delineating the tumor based on MET uptake, integrated 3D images from FDG-PET and MRI (GdMRI, T2WI or FLAIR) were generated and the final resection plane was planned. This resection plane was determined intraoperatively using the navigation-guided fencepost method. The delineation obtained by MET-PET imaging was larger than that with GdMRI in all cases with an enhanced effect. In contrast, the T2WI-abnormal signal area (T2WI+) tended to be larger than the MET uptake area (MET+). Tumor resection was >?95% in the non-eloquent area in 4/5 cases (80%), whereas 10 of 11 cases (90.9%) had partial resection in the eloquent area. In a case including the language area, 92% resection was achieved based on the MET-uptake area, in contrast to T2WI-based partial resection (65%), because the T2WI+/MET? area defined the language area. Pathological findings showed that the T2WI+/MET+ area is glioma, whereas 6 of 9 T2WI+/MET? lesions included normal tissues. Tissue from T2W1+/MET+/FDG+/GdMRI+ lesions gave an accurate diagnosis of grade in six cases. Non- or minimally enhancing gliomas were classified as having a MET uptake area that totally or partially overlapped with the T2WI hyperintense area. Resection planning with or without a metabolically active area in non- or minimally enhancing gliomas may be useful for accurate diagnosis, malignancy grading, and particularly for eloquent area although further study is needed to analyze the T2WI+/MET? area.     

Comparative Study of Images with Pathology： Superparamagnetic Iron Oxide-enhanced Magnetic Resonance Image （MRI） of Splenic VX2 Tumor in Rats

Objective： To establish a rodent model of VX2 tumor of the spleen, to analyze relationship between the change of the signal intensity on superparamagnetic iron oxide enhanced magnetic resonance image （MRI） and pathologic change to evaluate the ability of superparamagnetic iron oxide enhanced MRI for detection of splenic metastases. Methods： 8 rodent models of VX2 tumor of spleen were established successfully. The images were obtained before and after administration of superparamagnetic iron oxide. T1-weighted spin-echo （SE） pulse sequence with a repetition time （TR） of 450 msec, and echo time （TE） of 12 msec （TR/TE=450/12） was used. The imaging parameters of T2-weighted SE pulse sequence were as follows： TR/TE=4000/128. Results： On plain MR scanning T1-weighted splenic VX2 tumor showed hypointensity or isointensity which approximated to the SI of splenic parenchyma. Therefore all lesions were not displayed clearly. On superparamagnetic iron oxide enhancement T2WI sequence the SI of splenic parenchyma decreased obviously with percentage of signal intensity loss （PSIL） of 55.04%, But the SI of tumor was not evidently changed with PSIL of 0.87%. Nevertheless the SNR of normal splenic parenchyma around the lesions had obvious difference （P〈0.001） comparatively. Therefore the contrast between tumor and spleen increased, and tumor displayed more clearly. Moreover the contrast-to-noise （CNR） between VX2 tumor and splenic parenchyma had an evident difference before and after admininstration of superparamagnetic iron oxide （P〈0.001）. Conclusion： On superparamagnetic iron oxide enhancement T1WI sequence the contrast of tumor-to-spleen is poor. Therefore it is not sensitive to characterize the lesions in spleen. On superparamagnetic iron oxide enhanced T2WI the contrast degree of lesions increases obviously. Consequently, superparamagnetic iron oxide -enhanced T2WI MRI scanning can improve the rate of detection and characterization for lesions of spleen.     

Imagerie des métastases cérébrales

The therapeutic management of brain metastases depends upon their diagnosis and characteristics. It is therefore imperative that imaging provides accurate diagnosis, identification, size and localization information of intracranial lesions in patients with presumed cerebral metastatic disease. MRI exhibits superior sensitivity to CT for small lesions identification and to evaluate their precise anatomical location. The CT-scan will be made only in case of MRI's contraindication or if MRI cannot be obtained in an acceptable delay for the management of the patient. In clinical practice, the radiologic metastasis evaluation is based on visual image analyses. Thus, a particular attention is paid to the imaging protocol with the aim to optimize the diagnosis of small lesions and to evaluate their evolution. The MRI protocol must include: 1) non-contrast T1, 2) diffusion, 3) T2* or susceptibility-weighted imaging, 4) dynamic susceptibility contrast perfusion, 5) FLAIR with contrast injection, 6) T1 with contrast injection preferentially using the 3D spin echo images. The role of the nuclear medicine imaging is still limited in the diagnosis of brain metastasis. The Tc-sestamibi brain imaging or PET with amino acid tracers can differentiate local brain metastasis recurrence from radionecrosis but still to be evaluated.     

不同MR序列测量宫颈癌放疗靶区的一致性比较

目的 比较不同MR序列测量宫颈癌放疗靶区的一致性。方法 回顾性分析38例经病理学证实的宫颈癌患者MR资料，均行MRI平扫、增强和扩散加权成像检查。分别在轴位T2WI、T1WI增强扫描（T1+C）以及表观扩散系数（apparent diffusion coefficient，ADC）图上手动勾画肿瘤轮廓，通过面积求和法计算大体肿瘤体积（gross tumor volum，GTV），将不同序列测算的GTV分为T2WI组、T1+C组和ADC组。采用One-way ANOVA计算各组GTV的平均值，Bland-Atlman法计算各组GTV的95%一致性界限（95% limits of agreement，95% LoA）。 结果 T2WI、T1+C和ADC 组GTV平均值分别为（46.35±28.04） cm³、（44.27±26.66） cm³和（47.50±28.55） cm³，组间差异无统计学意义（F＝0.132，P＝0.877）。Bland-Atlman结果显示，T2WI组与T1+C组、T2WI组与ADC组以及T1+C组与ADC组的95% LoA分别为（-16.43～20.59） cm³、（-19.01～25.47） cm³和（-20.13～22.44） cm³，不同组Bland-Atlman散点图比较均存在5.26%（2/38）位于95% LoA范围外，超出临床可替代范围。结论 不同MR序列测量宫颈癌放疗靶区的一致性欠佳，尚不能相互取代，综合分析T2WI、T1+C以及ADC更有利于宫颈癌放疗靶区的准确勾画。     

MRI在诊断宫颈癌复发中的价值

目的：探讨MRI在评估诊断宫颈癌复发中的价值。方法：36例经病理证实宫颈癌复发患者,均行盆腔的MRI轴位T1WI、T2WI、SPIR以及GD-DTPA增强扫描后T1WI轴位、矢状位扫描。在不同序列MRI图像上观察复发肿瘤的形态、大小及信号改变。结果：326例病人中出现复发36例,发生率为11%。25例宫颈癌手术后复发病例,MRI可见在阴道残端或盆腔内出现软组织信号肿块影,增强扫描可见肿块明显强化。其中5例可见肿块侵及一侧输尿管,其上方输尿管扩张积水。11例宫颈癌放化疗后复发病例,MRI可见宫颈较前明显增厚,肿块T1WI为略低信号,T2WI为略高信号,增强扫描可见肿块呈不均匀强化。其中2例可见肿块侵及膀胱壁。结论：由于MRI具有非常好的软组织分辨率,MRI成像已成为宫颈癌手术前后或放化疗前后检查和随访最重要的手段,它能够准确判断宫颈癌临床分期,并且可以早期、及时发现肿瘤复发;在评估宫颈癌复发诊断中有重要价值。