MRCP 2D和3D FASE序列显示术后胰胆管系统的比较

目的 :评价比较磁共振胰胆管成像 (MRCP)二维高级快速自旋回波 (2DFASE)序列和三维高级快速自旋回波(3DFASE)序列对胆道术后胰胆管系统的显示及图像质量评估。方法 :对 72例胆道术后出现不明原因发热、黄疸、肝功能异常、右上腹痛等症状的患者同时行MRCP的两种序列检查 ,并分别与手术、直接胆道造影图像进行对照。结果 :MRCP的这两种序列均能很好显示术后胰胆管系统解剖 ,3DFASE序列显示肝内一、二级胆管优于 2DFASE序列 ,但差异无显著性意义 (P >0 .0 5 ) ;3DFASE序列显示胰管优于 2DFASE序列 ,差异有显著性意义 (P <0 .0 5 )。MRCP两种序列均获得了较好的图像 ,两种序列图像质量差异无显著性意义 (P >0 .0 5 )。结论 :MRCP 3DFASE序列较 2DFASE序列更适于胆道术后胰胆管系统的检查。     

快速ASE序列在MR胆胰管成像中的应用

目的评价高级转换快速自旋回波（fastadvancedspineecho,Fast-ASE）序列MR胆胰管成像（MRCP）技术的临床意义。方法用Fast-AAE序列做MRCP294例，以二维（2D）和三维（3D）技术处理图像，配置正交（QD）体线圈。结果全部成像均获得成功，其中30例胆胰管正常，264例胆胰管梗阻性病变。此技术对管腔狭窄、梗阻、扩张和充盈缺损的发现准确性高。结论Fast-ASE是在快速自旋回波（FSE）基础上开发的先进扫描技术，克服了传统FSE序列的缺点，可在较短时间内获得高质鳗的图像，为临床治疗和手术前评估提供了可靠依据。     

3D-HR sMRCP与SSh-MRCP/RAD图像质量的对比研究

目的:比较三维高分辨单次激发快速自旋回波磁共振胆胰管成像(3D-HR sMRCP)和二维单次激发厚层放射状磁共振胆胰管成像(SSh-MRCP/RAD)的图像质量。方法:30例受检者,其中男19例,女11例,年龄32~87岁,平均60.2岁,分别行3D-HRs MRCP与SSh-MRCP/RAD扫描,对所有图像均行定量和定性分析。定量比较图像相对信号强度和相对对比度;定性比较:对肝内外胆管、胆囊管、胆囊、胰管解剖显示及图像整体伪影进行评价。结果:3D-HR sMRCP的相对信号强度和相对对比信号强度要高于SSh-MRCP/RAD(P<0.001);3D-HR sMRCP显示胆囊管、肝内2级胆管、胰管效果优于SSh-MRCP/RAD(P<0.001),两种成像方式显示胆总管、胆囊、肝内一级胆管效果的差异无显著性意义(P>0.05);3D-HRs MRCP图像伪影比SSh-MRCP/RAD明显(P<0.001)。结论:3D-HR sMRCP图像整体质量优于SSh-MRCP/RAD,但其伪影较明显,两者各有优势。     

磁共振胰胆管成像对诊断胆胰系统疾病的临床应用价值

目的评价磁共振胰胆管成像(MRCP)技术在胆胰系统疾病诊断中的应用价值.方法68例患者进行了MRCP检查,其中正常对照组11例,各种胰胆管病变组57例.扫描使用ELSCINTSGR2.0T超导磁共振成像仪,体线圈及呼吸门控触发技术.平扫采用自旋回波(SE)常规成像;MRCP采用快速自旋回波(FSE)重T2加权像进行薄层扫描.所得图像用最大强度投影法(MIP)进行三维(3D)重建.结果MRCP能清晰显示胰胆管的解剖结构,对胆道梗阻程度和梗阻部位判断的确诊率达100%,梗阻原因的确诊率达91.2%.结论MRCP检查的成功率高,胰胆管解剖结构显示清晰,适应于各种胰胆管疾病的诊断,可作为该系统疾病诊断的首选方法     

3D与2D-FSE-MRCP序列比较

自90年代磁共振胰胆管成像(MRCP)开始应用以来,随着快速自旋回波序列的发展,技术和图像的质量都有着不断改善。现回顾性评估三维快速恢复自旋回波序列(3D FRFSE)与二维单次激发快速自旋回波序列(2D SSFSE)对胆道的重现及图像质量的优劣(Radiology,2006,238:549-559)。如今对于S     

应用磁共振灌注加权成像评估星形细胞肿瘤病理分级的研究

目的探讨MR灌注加权成像(PWI)评估星形细胞肿瘤病理分级的价值。资料与方法 110例经手术病理证实的星形细胞肿瘤于术前进行常规MRI平扫、增强和PWI。其中,低级别(Ⅰ～Ⅱ级)肿瘤40例,高级别(Ⅲ～Ⅳ级)肿瘤70例(Ⅲ级33例,Ⅳ级37例)。PWI采用梯度回复回波-回波平面成像(GRE-EPI)技术。盲法检测并计算肿瘤和瘤周区最高相对脑血容量(rCBV)值。比较和分析不同病理级别肿瘤间及瘤周区之间最高rCBV值的差异。两组间比较用t检验;多组间比较用方差分析,两两比较用LSD检验;检验水准α=0.05。应用受试者工作特征(ROC)曲线评估最高rCBV值的诊断效能。结果Ⅰ～Ⅱ级和Ⅲ～Ⅳ级肿瘤最高rCBV值分别为1.708±0.535,5.521±1.626;Ⅲ级和Ⅳ级分别为4.207±0.808和6.693±1.220;Ⅰ～Ⅱ级与Ⅲ～Ⅳ级间、Ⅰ～Ⅱ级与Ⅲ级和Ⅳ级间、Ⅲ级与Ⅳ级间肿瘤最高rCBV值差异均有统计学意义(均为P=0.000)。Ⅰ～Ⅱ级和Ⅲ～Ⅳ级瘤周区最高rCBV值分别为0.898±0.233和1.730±0.507,Ⅲ级和Ⅳ级分别为1.446±0.246和1.983±0.547;Ⅰ～Ⅱ级与Ⅲ～Ⅳ级...     

三维屏气梯度-自旋回波序列在MR胰胆管成像中的应用

目的:探讨三维屏气梯度-自旋回波（3D BH-GRASE）序列在MR胰胆管成像（MRCP）中的应用价值。方法:前瞻性收集2017年11月至2018年12月苏州大学附属张家港医院59名临床疑有胰胆管疾病患者,采用3D BH-GRASE和三维呼吸触发快速自旋回波（3D RT-TSE）两个序列进行MRCP成像。所得图像由3名...     

3D-SPACE联合3D-TSERT序列扫描技术在MRCP诊断结石中的价值

目的:评估可变翻转角的三维快速自旋回波（3D-SPACE）联合三维快速恢复快速自旋回波（3D-TSERT）序列扫描技术在磁共振胰胆管成像（MRCP）诊断结石中的价值。方法:选取2019年1月至9月于徐州市中心医院确诊为胰腺和胆道结石的168例患者的临床资料进行回顾性研究,其中男性93例、女性75例,年龄24~70 （4...     

3D BH-GRASE序列与3D RT-TSE序列进行MRCP的应用价值分析

目的 探讨对比分析三维屏气梯度-自旋回波（3D BH-GRASE序列）与三维呼吸触发快速自旋回波（3D RTTSE）序列进行磁共振胰胆管成像（MRCP）的应用价值。方法 选取在我院因怀疑胰胆管病变而行腹部MRI检查的患者,均接受3D RT-TSE序列与3D BH-GRASE序列MRCP扫描。比较两种序列扫描时间、图像质量评分及显示病变情况。结果 3D BH-GRASE序列的扫描时间为（16.4±1.7）s明显短于3D RT-TSE序列的（258.6±31.2）s,差异有统计学意义（P<0.05）;3D BH-GRASE序列扫描图像胆囊、肝内胆管、胆囊管、胰管、胆总管等主要分支评分均明显高于3D RTTSE序列,差异有统计学意义（P<0.05）;两种扫描序列方法对各区域病变检出率差异无统计学意义（P>0.05）。结论MRCP检查应用3D BH-GRASE序列扫描能够保证图像质量及显示病变,同时缩短扫描时间。     

探讨PROPELLER和SSFSE扫描技术在颅脑MR成像中应用价值

目的:比较螺旋浆(PROPELLER)扫描技术和单次激发快速自旋回波(SSFSE)扫描技术颅脑磁共振成像的图像质量,揭示PROPELLER这一独特的成像技术在未镇静不配合受检者颅脑磁共振成像中临床应用价值。方法:25例疑颅内病变的临床受检者,采用PROP-T2WI和SSFSE-T2WI扫描所获得的T2WI磁共振图像,由影像科医师,未告知采用扫描方法的前提下,对其图像质量进行评价,分析图像的运动伪影、病灶显示和图像优质片率状况,将影像科医师判读两种扫描技术所获得的颅脑MR图像结果供分析,采用统计学Ridit分析和χ2检验。结果:使用PROP-T2WI和SSFSE-T2WI扫描方法所获得的图像运动伪影均明显减少,颅内病灶均可以显示(Ridit分析,P=0.6664);但PROP-T2WI图像的清晰度、对比度明显优于SSFSE-T2WI图像(χ2检验,P<0.001)。结论:PROPELLER和SSFSE扫描技术具有同等消除磁共振图像运动伪影的能力,但使用PROPELLER技术所得到T2WI对脑实质的显示更为理想,显示病灶较清晰,具有较高临床实用价值。     

Spectrally selective 3D TSE imaging of phosphocreatine in the human calf muscle at 3 T

Quantitative information about concentrations of several metabolites in human skeletal muscle can be obtained through localized ³¹P magnetic resonance spectroscopy methods. However, these methods have shortcomings: long acquisition times, limited volume coverage, and coarse resolution. Significantly higher spatial and temporal resolution of imaging of single metabolites can be achieved through spectrally selective three‐dimensional imaging methods. This study reports the implementation of a three‐dimensional spectrally selective turbo spin‐echo sequence, on a 3T clinical system, to map the concentration of phosphocreatine in the human calf muscle with significantly increased spatial resolution and in a clinically feasible scan time. Absolute phosphocreatine quantification was performed with the use of external phantoms after relaxation and flip angle correction of the turbo spin‐echo voxel signal. The mean ± standard deviation of the phosphocreatine concentration measured in five healthy volunteers was 29.4 ± 2.5 mM with signal‐to‐noise ratio of 14:1 and voxel size of 0.52 mL. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.     

Contrast behavior and image quality of magnetic resonance cholangiopancreatography imaging using variable echo times at 3.0 T

Twenty-five volunteers were examined at three different echo times (TE) using magnetic resonance cholangiopancreatography (MRCP) images obtained with half-Fourier-acquired single-shot turbo spin echo (HASTE) thick-slab and multislice HASTE to identify the optimal TE at 3.0 T. No significant difference in the overall image quality was found comparing three different TEs within commonly used ranges. We observed an almost identical duct visibility with different TEs, while we found a trend toward superior visibility of the cystic duct at shorter TE.     

HASTE MRCP and MRI findings in alveolar echinococcosis of the liver

Alveolar echinococcosis is a rare mass-producing inflammatory process of the liver. Experience with MRI, and particularly magnetic resonance cholangiopancreatography (MRCP), demonstrates that features of this disease are limited. The HASTE (half-Fourier acquisition single-shot turbo spin echo) MRCP and MRI findings of alveolar echinococcosis of the liver are presented in this report. HASTE MRCP was used to define the biliary system and the biliary system-mass relationship. It was found that results were comparable with those of invasive techniques such as endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiography.     

Intracranial cerebrospinal fluid spaces imaging using a pulse-triggered three-dimensional turbo spin echo MR sequence with variable flip-angle distribution

Objective  

To assess the three-dimensional turbo spin echo with variable flip-angle distribution magnetic resonance sequence (SPACE: Sampling Perfection with Application optimised Contrast using different flip-angle Evolution) for the imaging of intracranial cerebrospinal fluid (CSF) spaces.     

SNR‐optimized phase‐sensitive dual‐acquisition turbo spin echo imaging: A fast alternative to FLAIR

Phase‐sensitive dual‐acquisition single‐slab three‐dimensional turbo spin echo imaging was recently introduced, producing high‐resolution isotropic cerebrospinal fluid attenuated brain images without long inversion recovery preparation. Despite the advantages, the weighted‐averaging‐based technique suffers from noise amplification resulting from different levels of cerebrospinal fluid signal modulations over the two acquisitions. The purpose of this work is to develop a signal‐to‐noise ratio‐optimized version of the phase‐sensitive dual‐acquisition single‐slab three‐dimensional turbo spin echo. Variable refocusing flip angles in the first acquisition are calculated using a three‐step prescribed signal evolution while those in the second acquisition are calculated using a two‐step pseudo‐steady state signal transition with a high flip‐angle pseudo‐steady state at a later portion of the echo train, balancing the levels of cerebrospinal fluid signals in both the acquisitions. Low spatial frequency signals are sampled during the high flip‐angle pseudo‐steady state to further suppress noise. Numerical simulations of the Bloch equations were performed to evaluate signal evolutions of brain tissues along the echo train and optimize imaging parameters. In vivo studies demonstrate that compared with conventional phase‐sensitive dual‐acquisition single‐slab three‐dimensional turbo spin echo, the proposed optimization yields 74% increase in apparent signal‐to‐noise ratio for gray matter and 32% decrease in imaging time. The proposed method can be a potential alternative to conventional fluid‐attenuated imaging. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.     

口服枸橼酸铁铵在胆胰系MRI中的应用价值评价

目的:评价口服枸橼酸铁铵在胆胰系MRI中的应用价值。方法:对86例怀疑有胰胆管系统疾病的患者行口服枸橼酸铁铵前、后MRCP及常规胆胰系MRI,对服用对比剂前后MRCP图像质量、邻近脏器边缘分辨力及各序列上胃十二指肠腔与肝脏的对比噪声比进行自身对照研究,由资深放射科医生对两组图像进行评价,SPSS统计软件进行统计分析。结果:服用对比剂后TrueFISP及HASTE序列均显示胃、十二指肠腔内信号显著降低,形成阴性对比;而FL2D序列胃、十二指肠腔内信号增强,形成阳性对比;胃十二指肠腔内液体造成的背景高信号被完全抑制,单层法与多层法MRCP图像质量及邻近的肝胆胰等结构边缘分辨力均明显提高。结论:口服枸橼酸铁铵能明显提高胆胰系MRI的成像质量,对诊断胆胰系病变具有重要的临床应用价值。     

Assessment of parallel acquisition techniques in adrenal magnetic resonance imaging: does increased temporal resolution significantly improve visualization of adrenal lesions?

RATIONALE AND OBJECTIVES: To compare conventional radiofrequency coil reception techniques with parallel coil array acquisition methods in adrenal tissue visualization and to evaluate the dependence of temporal resolution on image quality in adrenal magnetic resonance magnetic resonance (MR) imaging. MATERIAL AND METHODS: Using a 1.5 T MR imager, conventional and parallel sampled sequences were acquired in 10 healthy volunteers and 10 patients with adrenal lesions. The imaging protocol consisted of: conventional (TR/TE 4,730/125 ms; FA 150 degrees; NA 1; AT 25 s), and two parallel imaging SMASH techniques (TR/TE 4,090/125 ms; FA 150 degrees; NA 1 resulting in an AT of 12 s, as well as NA 2 resulting in an AT of 24 s) with generalized autocalibration T(2)-weighted turbo spin echo sequences with 5 mm slice thickness, 1.6 mm in-plane resolution, and an acceleration factor 2. Severity of breathing motion and aliasing artifact and overall image quality were rated on five-point scales and evaluated with student's t test; a differential receiver operating characteristic (DROC) analysis was performed. RESULTS: Adrenal gland findings included adenomas, metastases, and hemorrhages. Acceleration of conventional turbo spin echo sequence with one signal average led to an increase in diagnostic power (DROC 0.362) as well as significant improvement in overall image quality (P(Volunteers) =.017; P(Patients) =.042) and reduction of breathing motion artifact in patients (P(Patients) =.012) while improving the temporal resolution. Parallel imaging with two signal averages resulted in further improvement of image quality over conventional imaging (DROC 0.303), (P(Volunteers) =.045; P(Patients) =.022), in the same acquisition time as the conventional method. CONCLUSION: Parallel acceleration of sequences used for adrenal tissue visualization leads to a significant increase in diagnostic quality by significantly reducing breathing motion artifacts without sacrificing contrast indispensable for adrenal lesion characterization.     

Comparison of true FISP with turbo SE in ovarian imaging.

PURPOSE: To compare the signal pattern of True FISP (true fast imaging with steady state precession) with that of T2-weighted TSE (turbo spin echo) sequencing in several ovarian pathologies and to clarify the pathologies that may be misdiagnosed when True FISP is used as a fast T2-weighted MR (magnetic resonance) imaging technique. METHODS: A total of 56 patients with 58 ovarian lesions were prospectively studied. The histopathological diagnoses were surgically confirmed in all patients. All MR images were acquired with a 1.5T MR scanner. After routine MR examination (T2-weighted sagittal imaging with a turbo spin echo sequence and T1 and T2 transverse imaging with a spin echo and turbo spin echo sequence, respectively), True FISP was performed in the sagittal plane with a fat-saturation technique. The acquisition times for the True FISP and TSE techniques were 27 s and 4 min, 42 s, respectively. Three radiologists interpreted all images according to three grading scores and with particular reference to the difference in signal pattern between the two sequences (1=similar signal patterns in the ovarian lesions in both True FISP and TSE images; 2=partially different signal patterns in both True FISP and TSE images; and 3=conflicting signal patterns in both True FISP and TSE images). RESULTS: Those assigned a score of "1" included 30 patients with 30 ovarian lesions (12 malignant lesions and 18 benign lesions); those assigned a score of "2" included 10 patients with 10 lesions (two malignant and eight benign); and those assigned a score of "3" included 16 patients with 18 ovarian lesions (two malignant and 16 benign). With the influence of the fat-suppression technique excluded, eight ovarian lesions showed conflicting signal patterns between the two sequences and high signal intensity of hemorrhaging in the corresponding lesion in T1-weighted images. Lesions of both high and low signal intensity in TSE images appeared as lesions of high signal intensity in True FISP images. About 14% (8/56 lesions) of the True FISP and TSE signal patterns in ovarian pathology were conflicting in this study. CONCLUSION: The results indicate that the True FISP technique cannot replace the T2-weighted TSE technique in the evaluation of ovarian pathology. T1-weighted images with or without fat suppression are required for the evaluation of ovarian lesions with FISP images.     

Magnetic resonance urography: a pictorial overview

Magnetic resonance urography (MRU) can be performed on the basis of two different imaging strategies: static-fluid MRU, based on heavily T2 weighted turbo spin echo (TSE) sequences, and gadolinium-enhanced excretory MRU. Both MR urographic techniques in combination with standard MRI permit a comprehensive examination of the entire urinary tract. This pictorial review illustrates the MRU features of the a wide spectrum of pathological conditions affecting the urinary tract.     

Enhancement of BOLD-contrast sensitivity by single-shot multi-echo functional MR imaging.

Improved data acquisition and processing strategies for blood oxygenation level-dependent (BOLD)-contrast functional magnetic resonance imaging (fMRI), which enhance the functional contrast-to-noise ratio (CNR) by sampling multiple echo times in a single shot, are described. The dependence of the CNR on T2*, the image encoding time, and the number of sampled echo times are investigated for exponential fitting, echo summation, weighted echo summation, and averaging of correlation maps obtained at different echo times. The method is validated in vivo using visual stimulation and turbo proton echoplanar spectroscopic imaging (turbo-PEPSI), a new single-shot multi-slice MR spectroscopic imaging technique, which acquires up to 12 consecutive echoplanar images with echo times ranging from 12 to 213 msec. Quantitative T2*-mapping significantly increases the measured extent of activation and the mean correlation coefficient compared with conventional echoplanar imaging. The sensitivity gain with echo summation, which is computationally efficient provides similar sensitivity as fitting. For all data processing methods sensitivity is optimum when echo times up to 3.2 T2* are sampled. This methodology has implications for comparing functional sensitivity at different magnetic field strengths and between brain regions with different magnetic field inhomogeneities.