磁共振扩散张量成像定量参数对脑胶质瘤分级的诊断价值

目的:探讨磁共振扩散张量成像（diffusion tensor imaging，DTI）定量参数，是否可以对脑胶质瘤进行分级。方法:选取抚矿总医院2015年2月至2017年11月，经病理证实的脑胶质瘤患者60例，依据WHO肿瘤分级标准，分为高级别组（A组）27例，低级别组（B组）33例，分别给予患者磁共振平扫、增强扫描及DTI，观察图像信号变化规律，并测量DTI定量参数FA值与ADC值。结果:ADC值组间比较，A组病人瘤体和瘤周水肿带的ADC值，与B组病人瘤体和瘤周水肿带的ADC值对比，差异有统计学意义（P<0.05）。A、B组内对比，周围水肿带ADC值大于瘤体ADC值，差异有统计学意义（P<0.05）。FA值组间对比，A、B两组肿瘤主体和瘤体周围水肿带对比，差异无统计学意义（P>0.05）。A、B组内对比，瘤周水肿带的FA值大于肿瘤主体FA值，差异有统计学意义（P<0.05）。结论:DTI定量参数可以对脑胶质瘤进行分级，并获得满意效果。     

正电子发射计算机断层成像及核磁共振弥散张量成像对脑胶质瘤复发与放射性脑损伤的鉴别诊断价值

目的探讨正电子发射计算机断层成像(PET/CT)及MRI弥散张量成像对脑胶质瘤复发与放射性脑损伤的鉴别诊断价值。方法选取2015年6月至2018年6月间中国人民武装警察部队海警总队医院收治的145例脑胶质瘤手术后放疗患者,所有患者放疗3～6个月后行PET/CT及MRI弥散张量成像复查。比较患者的临床资料、PET/CT指标及MRI弥散张量成像指标,通过绘制受试者工作特征(ROC)曲线分析各指标鉴别诊断脑胶质瘤复发与放射性脑损伤的价值。结果脑胶质瘤复发患者标准摄取值(SUV)、病灶正常组织比(L/N)、局部脑血容量(r CBV)、局部脑血流量(r CBF)、胆碱/肌酸比值(Cho/Cr)及Cho/N-乙酰天门冬氨酸比值(Cho/NAA)均高于放射性脑损伤,差异均有统计学意义(均P <0. 05); SUV、L/N、r CBV、r CBF、Cho/Cr及Cho/NAA鉴别脑胶质瘤复发与放射性脑损伤的ROC曲线下面积(AUC)分别为0. 874、0. 828、0. 952、0. 928、0. 853及0. 905; r CBV鉴别脑胶质瘤复发与放射性脑损伤的AUC高于L/N和Cho/Cr,差异有统计学意义(P <0. 05); r CBV鉴别脑胶质瘤复发与放射性脑损伤最佳截点为1. 458,敏感度和特异度分别为90. 8%和94. 1%。结论脑胶质瘤复发患者SUV、L/N、r CBV、r CBF、Cho/Cr及Cho/NAA等指标明显升高,高于放射性脑损伤患者,MRI弥散张量成像指标鉴别脑胶质瘤复发与放射性脑损伤优于PET/CT,尤其是r CBV指标,更具临床价值。     

MRI弥散张量成像在颅内肿瘤切除术术前评估中的应用价值

目的 探讨MRI弥散张量成像(DTI)在颅内肿瘤切除术术前评估中的应用价值.方法 74例颅内肿瘤患者均接受MRI常规及DTI扫描.评价自动生成表观扩散系数(ADC)、各向异性分数(FA)、相对各向异性分数(rFA)、相对表观扩散系数(rADC)对良恶性肿瘤及不同级别脑胶质瘤的诊断价值.结果 74例颅内肿瘤患者中,良性脑...     

氢质子磁共振波谱联合磁共振成像对脑胶质瘤的诊断价值

目的探讨氢质子磁共振波谱(1H-MRS)联合磁共振成像(MRI)对脑胶质瘤的诊断价值。方法选取2015年10月至2016年10月间哈尔滨医科大学附属第二医院收治的48例脑胶质瘤患者,其中低级别脑胶质瘤30例,高级别脑胶质瘤18例。均在行MRI基础上行1H-MRS检查,检测N-乙酰天门冬氨酸(NAA)、肌酸(Cr)和胆碱(Cho),分析患者肿瘤实质区与瘤周水肿区的低级别脑胶质瘤和高级别脑胶质瘤Cho/Cr和Cho/NAA的差异。结果 MRI扫描显示低级别脑胶质瘤和高级别脑胶质瘤的瘤周水肿区的水肿和肿瘤实质区的强化程度对比,差异均无统计学意义(均P>0.05)。1H-MRS扫描显示高级别脑胶质瘤的肿瘤实质区的Cho/Cr和Cho/NAA值与瘤周围水肿区的Cho/Cr值均高于低级别脑胶质瘤,差异均有统计学意义(均P<0.05)。而高级别脑胶质瘤和低级别脑胶质瘤瘤周水肿区的Cho/NAA值比较,差异无统计学意义(P>0.05)。结论在传统MRI扫描的基础上联合使用1H-MRS,可以提供定量的检测结果来评价肿瘤的恶性度,为脑胶质瘤做出准确的分级诊断。     

DWI联合ADC在脑肿瘤鉴别诊断中的价值

目的探讨磁共振扩散成像(DWI)联合表观弥散系数(ADC)对脑肿瘤鉴别诊断的价值。方法选取2012年5月至2018年2月间西安市第四医院收治的81例实施磁共振检查的脑部分肿瘤患者,均行头颅MRI常规平扫、常规增强扫描及DWI联合ADC检查。比较良恶性脑肿瘤间、肿瘤侧与对照侧间及高低级别脑胶质瘤间的DWI信号强度和ADC值,比较DWI信号强度、ADC值及DWI联合ADC对恶性脑肿瘤的诊断灵敏度、特异度和准确度。结果当b=400s/mm2、600s/mm2和1 000s/mm2时,恶性组患者DWI信号强度高于良性组,ADC值低于良性组,高级别组患者DWI信号强度高于低级别组,ADC值低于低级别组,差异均有统计学意义(均P <0. 05)。良性组和恶性组的DWI信号强度均高于对照组,ADC值均低于对照组,差异均有统计学意义(均P <0. 05)。DWI联合ADC的灵敏度、特异度和准确度均高于DWI信号强度和ADC值诊断(P <0. 05); DWI信号强度和ADC值诊断效能比较,差异无统计学意义(P> 0. 05)。结论 DWI信号强度和ADC值可用于鉴别脑肿瘤的良恶性及高、低级别胶质瘤,而取不同b值时得到不同的DWI信号强度和ADC值,且DWI联合ADC可明显提高DWI信号强度和ADC值对脑肿瘤的诊断效能。     

脑胶质瘤MR弥散加权成像与病理对照研究

目的:通过MR DWI 技术分析评估脑胶质瘤ADC值与微观病理状态的关系,探讨ADC值在脑胶质瘤中的临床应用价值.方法:采用美国GE公司1.5T HDMR机,对30例胶质瘤进行了常规MRI及弥散加权成像,测量肿瘤实质部分的ADC值,分析不同级别胶质瘤的ADC值的差异性,并比较ADC值与细胞构成和核质比的相关性.结果:低级别胶质瘤(11.74±1.32)与高级别胶质瘤肿瘤实质ADC值(9.55±1.21)相比差异有统计学意义(P<0.05),低级别胶质瘤较高级别胶质瘤ADC值高.胶质瘤的ADC值与细胞构成(r=-0. 80,P<0. 01) 和核质比(r=-0.73,P<0. 01) 成负相关,与细胞构成的相关性较核质比高;胶质瘤的ADC值与肿瘤级别也呈明显负相关(r=-0.73,P<0.001).结论:弥散加权图像中胶质瘤的ADC值可预测肿瘤的级别,并有助于在活体上对胶质瘤的病理微观状态进行判断,为MRI从微观角度观察胶质瘤的结构变化提供了基础,并为临床诊断和治疗提供了新的评价指标.     

磁共振弥散加权成像在胶质瘤分级中的价值

目的 探讨磁共振弥散加权成像(DWI)及表观弥散系数(ADC)在鉴别胶质瘤瘤体区、瘤周区和正常组织中的应用及鉴别胶质瘤良、恶性的价值.方法 采用Philips 1.5T Achieva超导型磁共振成像仪,对46例胶质瘤患者行常规MRI及DWI,弥散系数b值分别取0和1 000 s/mm2,测量瘤体区、瘤周区及对侧正常组...     

弥散张量成像在脑肿瘤中的应用

目的 探讨脑肿瘤弥散张量成像(DTI)的特点及其在脑肿瘤中的诊断和鉴别诊断价值.方法 对39例经病理证实的脑肿瘤患者(脑膜瘤10例,胶质瘤17例,转移瘤12例),采用PhilipsAchieva 1.5 T磁共振行常规MRI和DTI,在工作站上重建部分各向异性(FA)图、表观弥散系数(ADC)图和三维白质纤维束图,选择...     

弥散张量成像在脑胶质瘤放疗中的应用价值

[目的]利用弥散张量成像探讨脑胶质瘤放疗后的早期变化.[方法]31例诊断明确的脑胶质瘤部分切除术后患者,在放疗前后1周内分别行MRI平扫+增强+DTI检查,分析肿瘤瘤体区及剂量相关区域的FA、ADC值变化.[结果]肿瘤瘤体区放疗后FA及ADC值均升高,放疗前后差异均有统计学意义(P＜0.05).剂量＞60Gy时正常白质FA值放疗后升高,50～60Gy、30～40Gy、20～30Gy区域的正常白质放疗后FA值均下降,差异均无统计学意义(P＞0.05);剂量＞60Gy、50～60Gy、40～50Gy、30～40Gy、20～30Gy区域的ADC值升高,但放疗前后的差异亦无统计学意义(P＜0.05).[结论]放疗前、后肿瘤瘤体区FA、ADC值变化能较早提供肿瘤对放疗反应评估.     

磁共振功能成像在脑胶质瘤侵袭性行为评价中的作用

脑胶质瘤的侵袭常沿着有髓神经纤维和血管基底膜途径进行。MR功能成像包括MRS、PWI和DWI．具有一定的分子成像的能力。MRS代谢物浓度变化可以明确瘤体和瘤周的代谢物变化。Cho／Cr值自近瘤周区向远瘤周区有逐渐降低的趋势．而NAA／Cr则有升高趋势．符合胶质瘤沿白质纤维自近向远侵袭性生长的特点。MRI灌注成像rCBV对胶质瘤分级的预测具有一定价值。MRI弥散成像通过反映组织内水分子的扩散特性反映脑内肿瘤的病理变化,常以扩散张量成（DTI）、表观扩散系数（ADC）和白质纤维柬追踪~（V13来间接反映胶质瘤的生物学侵袭性特点。MR功能成像在评价脑胶质瘤侵袭性上具有一定价值,临床医生应把传统MRI与多种功能成像技术联合应用来提高MRI对胶质瘤侵袭性的认识。     

Microwave imaging of the breast

Microwave imaging for medical applications has been of interest for many years. Recently, microwave imaging for breast cancer detection has gained attention due to advances in imaging algorithms, microwave hardware and computational power. The breast is relatively translucent to microwaves, accessible for imaging, and there appears to be a significant electromagnetic property contrast between tumors and healthy tissues. Therefore, breast imaging may be the first clinically viable application of microwave imaging. This paper reviews recent developments in passive, hybrid, and active approaches to microwave breast cancer detection.     

Immunotherapy and the role of imaging

Significant advances in the genetic and molecular characterization of cancer have led to the development of effective immunotherapies. These therapeutics help the host immune system recognize cancer as foreign, promote the immune system, and relieve the inhibition that allows growth and spread of tumors. Experience with various immunotherapies, particularly the immunomodulatory monoclonal antibody ipilimumab, has demonstrated that unique patterns of response may be encountered that cannot be adequately captured by traditional response criteria, such as the World Health Organization (WHO) criteria and Response Evaluation Criteria in Solid Tumors (RECIST), which have been used primarily with cytotoxic chemotherapies. In response to these observations, several novel response criteria have been developed to evaluate patients who receive immunotherapy, including immune‐related response criteria (irRC), immune‐related RECIST (irRECIST), and immune RECIST (iRECIST). These criteria are typically used in conjunction with RECIST version 1.1 in the clinical trial setting, because approval of new therapeutics by the US Food and Drug Administration relies on the responses derived from RECIST version 1.1. Finally, a wide variety of immune‐related adverse events may affect patients who receive immunotherapy, many of which can be identified on imaging studies such as computed tomography, magnetic resonance imaging, and 2‐deoxy‐2‐(fluorine‐18)fluoro‐D‐glucose–positron emission tomography/computed tomography. In this review, the authors present the role of imaging in the evaluation of patients treated with immunotherapy, including the background and application of irRC, irRECIST, and iRECIST; the imaging of immune‐related adverse events; and future directions in advanced imaging of immunotherapy. Cancer 2018;124:2906‐22 . © 2018 American Cancer Society.     

Radiologic imaging of the fallopian tubes

Aim of the present article is to illustrate the radiologic findings which afford the most reliable diagnosis with hysterosalpingography, in the evaluation of tubes in infertile patients. Based on the more regular anatomical patterns with details of minor anatomical variants, a common cause of infertility, the signs of the various types of tubal obstruction, are examined. The nature of the latter is not always organic: the implementation of simple albeit often resolutive technical devices as change of position or the use of more sophisticated but well-tolerated maneuvers as the interventional ones, may help detect normal patterns hidden by false (functional) obstruction. Careful analysis of tubal morphology down to the obstructed portion allows the identification of true pathologic patterns, making this exam even more valid in the diagnostic approach to the infertile patient.     

Noninvasive imaging of the abdominal vessels

Color Doppler ultrasound, computed tomography (CT), multi detector CT, CT-angiography, magnetic resonance imaging (MRI), MR-angiography are playing an increasingly important role for noninvasive examinations of the abdominal vessels. The most frequently studied abdominal vessels are the aorta and the renal arteries. The most common abdominal vascular diseases include: renal artery stenosis, renovascular hypertension, ischemic nephropathy and end-stage renal disease. Scintigraphy, color Doppler US, CT-angiography and MR-angiography have been used for the evaluation of patients. The mesenteric artery and celiac axis are less frequently studied; however some important information is provided by these imaging procedures.     

Current status of body MR imaging: fast MR imaging and diffusion-weighted imaging

The recent technical advances in fast MR imaging have greatly enhanced the clinical value of MR imaging of the body. Advances in T₁-weighted images have enabled the acquisition of dynamic contrast-enhanced MR imaging, which is currently central to hepatic MR imaging for detection and characterization of liver tumors and is also useful for the evaluation of myometrial invasion in uterine cor-pus cancer. Advances in rapid T₂-weighted MR imaging with single-shot fast spin-echo images have enabled MR cholangiopancreatography and MR urography. Application of respiratory triggering can also provide T₂-weighted images of high quality. Cine MR imaging utilizing ultrafast MR sequences enables the assessment of the respiratory motion of the lung for evaluating thoracic wall invasion by tumors. Diffusion-weighted images can provide excellent tissue contrast based on molecular diffusion and have the potential to demonstrate malignant tumors. Quantitative measurement of apparent diffusion coefficient values may also be valuable in distinguishing malignancies from benign lesions.     

Metastatic cutaneous malignant melanoma: Spectrum of imaging findings and the role of multimodality imaging

Cutaneous malignant melanoma is one of the most lethal and widely metastasising cancers with unpredictable pathways of spread. One of the most significant factors associated with survival in patients who have distant metastases is the number of organ sites involved. Innovative treatment options are now available for metastatic melanoma, and diagnostic imaging has become crucial for accurate staging and restaging of disease. The objective of this pictorial review is to illustrate the imaging spectrum of metastatic cutaneous malignant melanoma including both the common and the relatively ubiquitous sites of involvement using both conventional cross‐sectional and metabolic molecular imaging. This review also highlights the importance of combining multiple imaging methods for accurate staging of metastatic melanoma.     

Advancement of the imaging for hepatic malignancies

The development of CT and MR imaging technology represents a significant advancement. On CT imaging,the advent of multi-detector row CT (MDCT) scanners enables an increase in both scanning speed and spatial resolution. Multiphasic dynamic study is useful for the detection of hepatocellular carcinomas (HCCs) which are demonstrated as hyperattenuated lesions during the hepatic arterial phase. Many investigators assess the optimal timing for detection of HCCs by using the evolving MDCT, and have demonstrated the high detection rate for HCCs. Thanks to the increase in spatial resolution along the z-axis,we are now able to generate high-quality CT angiography and multiplanar reformations without complicated interpolation steps. These CT angiography and MPR images of patients with malignant hepatic tumors (e.g., HCCs, cholangiocellular carcinomas) are very useful for preoperative evaluation. On the other hand, the development of MR fast imaging techniques allows rapid breath-hold, whole-liver imaging. Superparamagnetic iron oxide (SPIO) is a liver-specific particulate magnetic resonance (MR) imaging contrast agent that is taken up by the reticuloendothelial system of the liver. SPIOenhanced MR imaging is useful for the detection of hepatic metastases. The advent of parallel imaging techniques improves the quality of images obtained with diffusion weighted (DW) imaging of the liver. DW imaging demonstrates high accuracy in the detection of hepatic metastases. Recently, in Japan, positron emission tomography (PET)-CT has also been employed for evaluation of hepatic metastases.