MRI对双侧卵巢病变的诊断价值

目的:探讨MRI对双侧卵巢病变的诊断价值。方法:以病理结果为金标准,回顾性分析41例双侧卵巢病变患者的MRI及相关临床资料。结果:41例中,浆液性囊腺癌19例,转移瘤2例,畸胎瘤2例,无性细胞瘤1例,子宫内膜样腺癌1例,子宫内膜异位症14例,化脓性炎症2例。MRI的诊断敏感度为100%,诊断准确率为70.7%。所有病灶均表现为双侧附件区占位性病变。浆液性囊腺癌呈囊实性肿块,实性部分呈不均匀明显强化,囊性部分强化不明显;转移瘤呈类圆形囊实性肿块,增强扫描后实性部分明显强化。畸胎瘤信号混杂,内见T1高信号影,T2压脂序列呈低信号,增强扫描后实性病灶可见强化。无性细胞瘤表现为腹腔至盆腔内见一巨大软组织肿块影,T1WI呈低信号,T2WI呈不均匀高信号,DWI呈高信号,增强扫描后呈不均匀明显强化。子宫内膜样癌T1WI及T2WI压脂序列呈等高混杂信号,增强扫描后部分病灶可见轻度强化。子宫内膜异位症呈短T2或短T1信号,增强扫描后未见明显强化。化脓性炎症DWI呈明显高信号,可见多房环形强化。结论:MRI是双侧卵巢病变首选的检查方法。     

39例腹壁子宫内膜异位症的MRI表现

目的:探讨腹壁子宫内膜异位症的MRI征象及临床特点,探讨MRI的诊断价值.方法:本院39例经病理组织学证实的腹壁子宫内膜异位症患者,经盆腔MRI平扫及增强扫描,回顾性分析其影像表现及临床病理资料.结果:39例腹壁子宫内膜异位症中,大多数患者有剖宫产手术史,仅1例无腹部手术史.34例(87.2％)病灶边界模糊.22例(56.4％)病灶呈实性,T1WI呈等信号,T2WI呈混杂信号为主;15例(38.5％)病灶呈囊实性,T2WI呈高低混杂信号,T1WI以等低信号为主,其中抑脂T1WI中有高信号灶为7例;2例(5.1％)病灶呈囊性,T2WI及T1WI均呈高信号.囊性病灶增强扫描后强化不明显;实性及囊实性病灶增强扫描后病灶均可见持续性强化,病灶显示更加清晰.结论:结合临床病史及MRI表现特点,能准确诊断腹壁子宫内膜异位症,MRI能准确显示病灶位置、边界、大小及范围,对于临床治疗方案的制定有很大参考价值.     

卵巢子宫内膜样癌与高级别浆液性癌临床及MRI特征的对照分析

目的：探讨卵巢子宫内膜样癌（OEC）与高级别浆液性癌（HGSC）的临床及MRI特征表现,评价MRI对OEC与HGSC的鉴别诊断价值。方法：回顾性分析经手术病理证实的12例OEC患者（OEC组）及22例HGSC患者（HGSC组）的临床资料及MRI特征表现。临床资料包括患者年龄、体征、绝经状态、实验室检查、有无合并子宫内膜异位症等。MRI特征表现包括肿瘤形态、偏侧性、壁结节形态、囊性灶多寡特点、囊性成分信号特征、实性成分强化方式、肿瘤有无包膜、双发癌灶（合并子宫内膜癌）、腹膜种植、淋巴结转移及腹水情况等。结果：OEC与HGSC在肿瘤偏侧性、囊性灶多寡特点、部分囊性成分T1WI高信号、壁结节形态、双发癌及腹膜种植转移的组间差异均有统计学意义（均P<0.05）。相较于HGSC,OEC形态较规则,大多单侧发病,单囊为主,部分囊性成分T1WI高信号,壁结节较光滑,双发癌相对多见,腹膜种植转移相对少。结论：OEC与HGSC的病灶偏侧性、囊性灶多寡特点、部分囊性成分T1WI高信号、壁结节形态及双发癌等MRI特征表现存在差异,有助于两者的鉴别诊断。     

卵巢颗粒细胞瘤的MRI诊断

目的 分析卵巢颗粒细胞瘤的MRI特征。资料与方法 回顾性分析15例卵巢颗粒细胞瘤的MRI特征，并与手术及病理对照研究。结果 15例中，囊实性肿块8例，内有多发大小不等的囊性变，囊内壁光滑，囊内容物MRT1WI呈等低混杂信号，T2WI呈混杂高信号，囊与套间有厚壁分隔；实性肿块3例，T1WI及T2WI信号均高于肌肉；单一较大的囊性病灶4例。13例子宫均匀增大，内膜增厚，1例并有子宫内膜癌。结论 诊断卵巢颗粒细胞瘤的可靠依据为：(1)肿瘤内多发囊变，间有厚壁分隔，囊内壁光滑；(2)合并子宫体积增大，内膜增生。     

子宫内膜异位症相关性卵巢癌的MRI特征

【摘要】目的：总结、分析子宫内膜异位症相关性卵巢癌的MRI特征，提高诊断符合率。方法：回顾性分析本院15例（17个病灶）子宫内膜异位症相关性卵巢癌患者的临床及MRI资料，并与手术病理结果进行对照分析。结果：14例（93.3%）子宫内膜异位症相关性卵巢癌患者手术病理分期为卵巢癌FIGOⅠ期，1例（6.7%）为FIGO Ⅲ 期。卵巢透明细胞癌7个（41.2%），子宫内膜样癌7个（41.2%）。病灶位于左侧9个（52.9%），右侧8个（47.0%）。肿瘤大部分边缘规则16个（94.1%）。肿瘤最大径为26～244mm，平均（111.7±64.7）mm。17个病灶中呈囊实性者15个（88.2%），呈实性者2个（11.8%）。15个囊实性病灶中呈单囊者10个（66.7%），呈多囊者5个（33.3%），其中囊液含T1WI-FS高信号者8个（53.3%）。15个囊实性病灶最大壁结节表面均呈乳头状；最大壁结节及实性成分在T1WI及T2WI图像上表现多样，但均伴扩散受限，16个（94.1%）病灶壁结节或实性成分T1WI-FS增强扫描呈明显强化。11例（73.3%）患者伴有盆腔子宫内膜异位症MRI征象。结论：根据典型MRI直接征象［囊液于T1WI-FS呈高信号（出血），囊内伴强化壁结节］和重要伴随征象（盆腔内异症），可提高内异症相关性卵巢癌的术前诊断符合率。     

卵巢子宫内膜异位囊肿MRI与腹腔镜手术对照研究

目的探讨卵巢子宫内膜异位囊肿MRI表现与腹腔镜手术结果的相关性。方法回顾性研究MRI诊断的13例共22个卵巢子宫内膜异位囊肿MRI表现,全部病例均经腹腔镜手术、病理证实。结果与腹腔镜手术及病理对照,全部22个子宫内膜异位囊肿中,T1WI及T2WI均为均匀高信号6个,T1WI均匀高信号、T2WI等高混杂信号者15个,T1WI及T2WI均为混杂信号1个;5个大囊肿周围伴有小囊肿,呈"卫星囊";4个异位囊肿壁可见小破口并见高信号影向外突出。结论①卵巢子宫内膜异位囊肿的MRI信号特点、大囊肿周围伴小囊肿呈"卫星囊"、囊壁厚薄不均匀、周围粘连征象、盆腔内及卵巢表面子宫内膜异位结节征象等与腹腔镜手术结果有明显的相关性;②"囊壁缺口征"为本病的另一特征性征象。     

MRI diagnosis of granulose cell tumor of the ovary

目的:探讨MRI对卵巢颗粒细胞瘤(GCTO)的诊断价值.方法:回顾性分析经手术与病理证实的20例GCTO患者的临床和MRI资料.所有病例均行MRI平扫及增强扫描.结果:20例术前MRI诊断正确16例(80％).MRI 平扫主要表现:子宫附件区边界清楚、形态较规整、包膜完整的囊性、囊实性、实性肿块.6例为囊性肿块,其中1例为单一大囊性肿块,多囊性肿块内见厚薄不一分隔,以较厚为主,囊内壁光滑,囊内容物T1WI呈等低信号,T2WI呈高信号;9例为囊实性肿块,T1WI呈等低混杂信号,T2WI呈混杂高信号,内有多发大小不等的囊性变,囊内壁光滑;5例为实性肿块,T1WI和T2WI高于同层肌肉信号.合并症:12例子宫增大,内膜增厚,3例合并子宫内膜癌(1例同时合并子宫肌瘤)、3例合并子宫肌瘤.增强扫描20例GCTO患者的肿瘤实性部分及囊壁均明显强化.结论:卵巢颗粒细胞瘤MRI表现具有一定的特征,能清晰显示其合并症,对其诊断及鉴别诊断具有重要的临床应用价值.     

脑室毛细胞型星形细胞瘤MR诊断与鉴别诊断

目的探讨脑室内毛细胞型星形细胞瘤(pilocytic astrocytoma,PA)的MRI特征,旨在提高其术前诊断准确率。方法回顾性总结分析8例脑室内PA患者的MRI特征。8例均行MRI平扫及增强扫描。结果 4例PA位于第四脑室,2例位于侧脑室,2例位于第三脑室。实质型1例,囊实型5例,大囊伴小结节型2例。肿瘤实性部分T1WI呈低信号,T2WI呈高信号,扩散加权成像(DWI)呈低信号,表观扩散系数(ADC)均值(1.5±0.15)×10-3mm2/s,增强扫描病灶明显强化。囊实型囊性部分呈长T1、长T2信号,DWI呈低信号,液体衰减反转恢复序列(FLAIR)呈高信号,大囊伴小结节型囊液呈脑脊液样信号。结论脑室内PA的MRI表现具有一定特征,实性部分T2WI呈高信号、DWI呈低信号且显著强化的脑室内肿瘤术前鉴别诊断时应考虑到该病可能。     

DWI在脑转移瘤诊断中的应用

目的:探讨DWI在脑转移瘤诊断中的应用价值。方法:回顾性分析经手术病理或临床证实的86例脑转移瘤患者的常规MRI(包括50例MRI增强扫描)及DWI资料。结果:脑转移瘤单发30例,多发56例。在MRI上,82例病灶T1WI呈等低信号,T2WI及T2FLAIR呈不均匀高信号;4例病灶内伴出血,T1WI、T2WI呈高低不均匀混合信号。囊实型转移瘤42例,实质型24例,囊型20例。在50例增强扫描中,病灶呈不规则结节状伴环状强化、团块结节状强化、环状强化。在DWI上,转移瘤内部呈低信号或稍低信号78例(90.7%),瘤周显示环状高信号带或稍高信号带58例(67.4%),转移瘤呈均匀结节状高信号影4例(4.7%),瘤灶伴出血局部呈低信号或高信号4例(4.7%)。50例增强扫描检出转移瘤132个,而DWI检出109个病灶,检出率为82.6%。结论:脑转移瘤的确诊仍主要依靠MRI增强扫描。DWI检查是其有益的补充,对瘤周带的显示具有一定特征,对转移瘤的诊断具有一定的价值。     

子宫附件良性囊性病变的MRI诊断

目的:探讨女性附件良性囊性病变的MRI表现特点,提高其诊断及鉴别诊断水平。方法:搜集我院近三年来经手术及病理证实的110例附件区良性囊性病灶,对其MRI表现作回顾性分析,讨论其MRI表现特点。结果:110例附件良性囊性病灶中,卵巢囊性病变最多,占所有病例的89%(98/110)。其中单纯性囊肿28例(25%,28/110),卵巢囊腺瘤27例(25%,27/110),畸胎瘤22例(20%,22/110),子宫内膜异位囊肿15例(14%,15/110),占所有病例的84%(92/110)。28例单纯性囊肿信号均匀,其中26例(93%,26/28)T1WI呈低信号,T2WI呈高信号。27例卵巢囊腺瘤中,24例可见分隔,2例可见壁结节。22例囊性畸胎瘤中21例可见明显脂质信号。所有15例子宫内膜异位囊肿T1WI和T2WI均呈高信号,部分病灶内可见液液分层。结论:大多数女性附件良性可性病变的MRI表现特征性较明显,可明确诊断。     

A monitoring,feedback, and triggering system for reproducible breath-hold MR imaging

A technique is described that provides improved reproducibility of breath-holding for MR image acquisition by monitoring the superior-inferior (S/I) position of the diaphragm. The method incorporates detection of the level of inspiration using an MR signal, rapid display to the patient of diaphragm position to enable breath-hold adjustment, and triggering of image data acquisition once appropriate position is attained. The response time of the system is short, approximately 10 ms. Studies in six volunteers using this method demonstrate a considerable decrease in the S/I range of diaphragm position over 10 consecutive periods of suspended respiration. The mean range is 1.3 mm with the system, while it is 8.3 mm without using it is expected that this method will be of assistance in many abdominal and cardiothoracic studies that use breath-hold techniques.     

DSA功能性参数的提取与利用

本文介绍了在临床实际中利用功能性参数，对冠状动脉ＤＳＡ心肌血流灌注成像、冠状动脉血流量测定、左心室功能测定、肺动脉高压程度的评价等项目研究结果。重点讨论了提取ＤＳＡ功能性参数的一般方法，认为功能性参数在现代影像诊断学中的作用是对疾病做出程度、定量、动态及功能诊断。     

RARE spiral T2-weighted imaging

Spiral imaging has a number of advantages for fast imaging, including an efficient use of gradient hardware. However, inhomogeneity-induced blurring is proportional to the data acquisition duration. In this paper, we combine spiral data acquisition with a RARE echo train. This allows a long data acquisition interval per excitation, while limiting the effects of inhomogeneity. Long spiral k-space trajectories are partitioned into smaller, annular ring trajectories. Each of these annular rings is acquired during echoes of a RARE echo train. The RARE refocusing RF pulses periodically refocus off-resonant spins while building a long data acquisition. We describe both T₂-weighted single excitation and interleaved RARE spiral sequences. A typical sequence acquires a complete data set in three excitations (32 cm FOV, 192 × 192 matrix). At a TR = 2000 ms, we can average two acquisitions in an easy breath-hold interval. A multifrequency reconstruction algorithm minimizes the effects of any off-resonant spins. Though this algorithm needs a field map, we demonstrate how signal averaging can provide the necessary phase data while increasing SNR. The field map creation causes no scan time penalty and essentially no loss in SNR efficiency. Multiple slice, 14-s breath-hold scans acquired on a conventional gradient system demonstrate the performance.     

Echo-Time-Encoded Burst Imaging (EBI): A Novel Technique for Spectroscopic Imaging

A new technique for rapid spectroscopic imaging is presented. The proposed experiment enables a complete mapping of the two-dimensional reciprocal space k_x, k_o, and thus the acquisition of a 1D spectroscopic image in a single scan. The properties of the pulse sequence, based on the use of a burst of low flip angle pulses, are analyzed in the framework of linear response theory, and it is shown that chemical shift information may be introduced into the spatially encoded echoes. First experimental results are presented demonstrating that 32 x 32 proton spectroscopic images may be acquired within less than 1 min with a conventional imaging system.     

Fast imaging of phosphocreatine in the normal human myocardium using a three-dimensional RARE pulse sequence at 4 Tesla

PURPOSE: To investigate the use of a three-dimensional rapid acquisition with relaxation enhancement (RARE) pulse sequence for direct acquisition of phosphocreatine (PCr) images of the human myocardium. MATERIALS AND METHODS: A short elliptical birdcage radiofrequency (RF) body coil was constructed to produce a uniform flip angle throughout the chest cavity. In vivo images using a spectrally-selective RARE sequence with a spatial resolution of 1.2 cm x 1.2 cm x 2.5 cm (4 cm(3)) were acquired in nine minutes and 40 seconds. RESULTS: Scans of phantoms demonstrated excellent spectral selectivity. The signal-to-noise ratio in the myocardium ranged from 12.6 in the anterior wall to 5.3 in the mid septum. CONCLUSION: This study demonstrates that PCr data can be acquired using a three-dimensional RARE sequence with greater spatial and temporal resolution than spectroscopic techniques.     

Current Status of Optical Imaging for Evaluating Lymph Nodes and Lymphatic System

Optical imaging techniques use visual and near infrared rays. Despite their considerably poor penetration depth, they are widely used due to their safe and intuitive properties and potential for intraoperative usage. Optical imaging techniques have been actively investigated for clinical imaging of lymph nodes and lymphatic system. This article summarizes a variety of optical tracers and techniques used for lymph node and lymphatic imaging, and reviews their clinical applications. Emerging new optical imaging techniques and their potential are also described.     

Simultaneous multislice (SMS) imaging techniques

Simultaneous multislice imaging (SMS) using parallel image reconstruction has rapidly advanced to become a major imaging technique. The primary benefit is an acceleration in data acquisition that is equal to the number of simultaneously excited slices. Unlike in‐plane parallel imaging this can have only a marginal intrinsic signal‐to‐noise ratio penalty, and the full acceleration is attainable at fixed echo time, as is required for many echo planar imaging applications. Furthermore, for some implementations SMS techniques can reduce radiofrequency (RF) power deposition. In this review the current state of the art of SMS imaging is presented. In the Introduction, a historical overview is given of the history of SMS excitation in MRI. The following section on RF pulses gives both the theoretical background and practical application. The section on encoding and reconstruction shows how the collapsed multislice images can be disentangled by means of the transmitter pulse phase, gradient pulses, and most importantly using multichannel receiver coils. The relationship between classic parallel imaging techniques and SMS reconstruction methods is explored. The subsequent section describes the practical implementation, including the acquisition of reference data, and slice cross‐talk. Published applications of SMS imaging are then reviewed, and the article concludes with an outlook and perspective of SMS imaging. Magn Reson Med 75:63–81, 2016. © 2015 The Authors. Magnetic Resonance in Medicine Published by Wiley Periodicals, Inc. on behalf of International Society of Medicine in Resonance.     

Dynamic bioluminescence imaging for quantitative tumour burden assessment using IV or IP administration of <Emphasis Type="SmallCaps">d</Emphasis>-luciferin: effect on intensity,time kinetics and repeatability of photon emission

Introduction In vivo bioluminescence imaging (BLI) is a promising technique for non-invasive tumour imaging. d-luciferin can be administrated intraperitonealy or intravenously. This will influence its availability and, therefore, the bioluminescent signal. The aim of this study is to compare the repeatability of BLI measurement after IV versus IP administration of d-luciferin and assess the correlation between photon emission and histological cell count both in vitro and in vivo. Materials and methods Fluc-positive R1M cells were subcutaneously inoculated in nu/nu mice. Dynamic BLI was performed after IV or IP administration of d-luciferin. Maximal photon emission (PE_max) was calculated. For repeatability assessment, every acquisition was repeated after 4 h and analysed using Bland–Altman method. A second group of animals was serially imaged, alternating IV and IP administration up to 21 days. When mice were killed, PE_max after IV administration was correlated with histological cell number. Results The coefficients of repeatability were 80.2% (IV) versus 95.0% (IP). Time-to-peak is shorter, and its variance lower for IV (p < 0.0001). PE_max was 5.6 times higher for IV. A trend was observed towards lower photon emission per cell in larger tumours. Conclusion IV administration offers better repeatability and better sensitivity when compared to IP. In larger tumours, multiple factors may contribute to underestimation of tumour burden. It might, therefore, be beneficial to test novel therapeutics on small tumours to enable an accurate evaluation of tumour burden. Marleen Keyaerts is a Ph. D. fellow of the Research Foundation—Flanders (Belgium; FWO).     

Temporal resolution improvement in dynamic imaging

In some dynamic imaging applications, only a fraction, 1/n, of the field of view (FOV) may show considerable change during the motion cycle. A method is presented that improves the temporal resolution for a dynamic region by a factor, n, while maintaining spatial resolution at a cost of √n in signal-to-noise ratio (SNR). Temporal resolution is improved, or alternatively, total imaging time is reduced by reducing the number of phase encodes acquired for each temporal frame by 1/n. To eliminate aliasing, a representation of the signal from the static outer portion of the FOV is constructed using all the raw data. The k-space data derived from this representation is subtracted from the original data sets, and the differences correspond to the dynamic portion of the FOV. Improved resolution results are presented in phantom studies, and in vivo phase contrast quantitative flow imaging.