关节软骨损伤和松质骨水肿的MRI诊断和临床意义

目的探讨关节软骨损伤和松质骨水肿的MRI诊断方法及其临床意义。方法收集我院1998～2004年间行骨关节检查并确诊有关节软骨损伤和松质骨水肿的病例72例,MR扫描采用MAGNETOMVISONplus1.5T超导型磁共振成像系统。松质骨水肿的诊断均经2名影像科医师和1名副主任医师以上职称骨科医师共同读片确诊。关节软骨损伤均以关节镜检查结果为最终诊断依据。结果松质骨水肿的MRI表现:在T1WI上表现正常35例(41处);呈斑片状、地图样略低信号30例(39处)。在T2WI上表现不明显47例(54处),16例表现为明显不均匀略高信号。病变在STIR FS序列上表现最为明显,呈明显斑片状、地图样异常高信号。关节软骨损伤的MRI表现:软骨变薄且凹凸不平9例(13处);关节软骨中断不连续5例(8处),3例(3处)仅表现为局部关节软骨表面不光滑,另有6例(10处)在MR上未见明显形态结构和信号异常。MRI显示关节软骨损伤以梯度回波序列(FLASH2D)质子密度加权像上显示最为清楚。结论MR是诊断关节软骨损伤和松质骨水肿最理想的影像学方法。     

锁骨骨折手术安全性分区的MRI影像解剖学研究

目的 通过MRI影像解剖学方法研究锁骨骨折手术安全性分区. 方法用核磁共振对13例志愿者锁骨邻近结构进行矢状位和冠状位图像采集.分别测量锁骨下静脉、臂丛神经束移行至锁骨下方时在锁骨投影A点和B点至胸锁关节的距离,以确定具体位置.同时测量钻孔安全深度和安全角度. 结果 A点对应的体表标志为锁骨中内1/3交点(M点);B点对应的体表标志为锁骨全长中点(N点).将锁骨依据手术安全性分区进行如下划分,Ⅰ区为危险区:SJ点(胸锁关节)到M点;Ⅱ区为相对危险区:M点到N点;Ⅲ区为相对安全区:N点到CP'点(喙突在锁骨投影);Ⅳ区为安全区:CP'点到AJ点(肩锁关节).从Ⅰ区至Ⅳ区钻孔安全深度和安全角度数值依次递增. 结论研究锁骨手术安全性分区,可以有效避免手术时的锁骨下神经血管束损伤,降低术中风险.     

Correlation of quantitative MR imaging findings with symptoms in patients with incidentally detected inflammatory sinonasal disease

Purpose

To assess the relationships between mucosal thickness, T1-weighted, T2-weighted signals and restricted diffusion on magnetic resonance imaging (MRI) with the degree of symptoms in patients with incidentally detected inflammatory sinonasal disease.

呼吸训练对肺部感染者接受磁共振检查质量的影响

目的探讨护士提前应用呼吸训练对肺部感染者在磁共振（MRI）检查中的应用成效。 方法选取2013年1月至2015年1月本院拟接受MRI检查的肺部感染者85例。随机将患者分为观察组和对照组,其中观察组43例,对照组42例;观察组患者中男性27例,女性16例,对照组患者中男性27例,女性15例。观察组平均年龄为（56.0±3.8）岁,对照组平均年龄为（56.4±3.3）岁。两组患者均根据病情需要给予基础护理和呼吸评估,观察组在此基础上,在MRI检查前120 min开始接受呼吸训练,比较两组患者MRI的图像质量及检查耗时。 结果两组患者均完成MRI检查,观察组患者MRI检查图像质量显著优于对照组（U = 3.85、P = 0.000）;观察组患者的图像合格率显著高于对照组（97.67% vs. 76.19%,χ² = 8.704、P = 0.003）。两组患者行MRI平扫,观察组患者耗时显著短于对照组（11.3±1.7 min vs. 14.2±2.2 min,t =-6.81、P = 0.002）。行动态增强扫描,观察组患者检查时长显著短于对照组（4.1±1.0 min vs. 4.1±1.0 min,t =-3.92、P = 0.005）。 结论呼吸训练能够提高患者行MRI检查时的配合度,从而减少由自主性运动引起的MRI图像伪影,提高成像质量,减少检查时间,对小病变的检出率以及临床诊断和鉴别诊断有实际意义。     

Magnetic resonance imaging with magnetic resonance cholangiopancreatography accurately predicts resectability of pancreatic carcinoma

Accurate preoperative staging of pancreatic malignancy aids in directing appropriate therapy and avoids unnecessary invasive procedures. We evaluated the accuracy of magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP) in determining resectability of pancreatic malignancy. Twenty-one patients with suspected pancreatic malignancy underwent dynamic, contrast-en-hanced breath-hold MRI with MRCP prior to surgical evaluation. Results of this study were correlated with operative results and pathologic findings. The sensitivity, specificity, and accuracy of MRI with MRCP in detecting a mass, determining the nature of the mass, and predicting lymph node involvement and resectability were determined. MRI with MRCP correctly identified the presence of a pancreatic mass in all 21 of these patients. Following pathologic correlation, it was determined that MRI with MRCP was 81 % accurate in determining the benign or malignant nature of the pancreatic mass and 43% accurate in predicting lymph node involvement. In predicting resectability, MRI with MRCP had a sensitivity of 100%, specificity of 83%, positive predictive value of 94%, negative predictive value of 100%, and accuracy of 95%. MRI with MRCP is an accurate, noninvasive technique in the preoperative evaluation of pancreatic malignancy. Information obtained from MRI with MRCP including identification of a mass and predicting tumor resectability may be of value in staging and avoiding unnecessary invasive diagnostic procedures in patients with pancreatic cancer. Presented at the Thirty-Ninth Annual Meeting of The Society for Surgery of the Alimentary Tract, New Orleans, La., May 17–20, 1998.     

磁共振成像及其尿路造影对输尿管疾病的诊断价值

目的探讨磁共振成像（MRI）及磁共振尿路造影（MRU）对输尿管病变的诊断价值。方法对114例临床怀疑输尿管疾病的患者行磁共振成像（MRI）及磁共振尿路造影（MRU）检查,所有病例均经手术、病理或输尿管镜检证实。结果 114例输尿管疾病包括：先天性异常15例,良性狭窄21例,输尿管结石36例,输尿管癌18例,外在性病变24例。MRU对输尿管病变的定性诊断准确率为81.6%（93/114）;与常规MRI结合,定性诊断准确率提高到92.1%（105/114）。结论 MRU对输尿管病变的诊断具有良好的效果,特别适用于IVP禁忌证和肾功能丧失者;与常规MRI结合,可提高输尿管病变的定性诊断准确率。     

股骨髁负重区退变软骨基质生化成分改变与磁共振功能成像的相关性

 目的 探讨膝关节骨关节炎股骨髁负重区退变软骨基质生化成分改变与磁共振功能成像的相关性。方法 2013年12月至2014年2月行全膝关节置换术的骨关节炎患者15例,男7例,女8例;年龄62~81岁,平均70岁。利用7.0 T磁共振T2-mapping序列体外测量膝关节股骨髁负重区退变软骨的T2值,计算相同部位软骨的水含量、胶原含量,于偏振光显微镜下对胶原纤维走向进行分级。分析T2值与水含量、胶原含量和胶原纤维走向分级的相关性。结果 15例患者标本股骨髁负重区软骨的T2值平均为（50.9±2.3） ms,胶原纤维走向分级从1级至4级分别为（47.68±2.1） ms、（49.62±1.7） ms、（51.36±2.3） ms、（54.89±2.6）ms;水含量平均为72.70%±0.2%,胶原纤维走向分级从1级至4级分别为67.25%±0.3%、73.80%±0.2%、75.30%±0.2%、78.66%±0.3%;胶原含量平均为（5.74±0.2） mg,胶原纤维走向分级从1级至4级分别为（6.29±0.2） mg、（6.76±0.2） mg、（5.10±0.3） mg、（4.68±0.2） mg。从胶原纤维走向分级1级到4级,T2值逐渐增大,水含量逐渐增多,各级之间的差异有统计学意义。胶原含量呈下降趋势,但各级之间的差异无统计学意义。退变负重区软骨的T2值与其水含量呈正相关（r=0.70,P=0.000）,与胶原含量无相关性（r=0.14,P=0.200）,与胶原纤维走向分级呈正相关（r=0.56,P=0.000）。结论 人膝关节股骨髁负重区退变软骨的T2值与细胞外基质成分中水含量和胶原纤维走向分级呈正相关,磁共振T2-mapping成像序列能够在无创条件下准确地反映和评估软骨病变。     

The value of magnetic resonance imaging geometric parameters in pre-assessing the surgical approaches of pelvic fracture urethral injury

BackgroundTo investigate the correlation between the magnetic resonance urethrography and the surgical approach and complexity for the patients with pelvic fracture urethral injury (PFUI) by combining the geometry with magnetic resonance imaging (MRI).MethodsForty-three male patients with PFUI (part of the patients complicated with rectal injury) from January 2016 to December 2018 were analyzed in this retrospective research. All the patients underwent a delayed anastomotic urethroplasty and were divided into 2 groups according to the approaches (simple perineal approach or inferior pubectomy). For magnetic resonance urethrography, we measured and calculated the geometric parameters such as the gap distance between two urethral ends, the pubourethral vertical distance (PUVD), and the rectourethral median distance (RUMD).ResultsOf the 43 patients, 16 underwent inferior pubectomy and 27 underwent simple perineal approach. The numbers of patients with and without rectal injury history were 17 and 26, respectively. The operation time and intraoperative blood loss was significantly higher in the inferior pubectomy group. Multivariate logistic analysis revealed that gap distance and PUVD were independent factors of the surgical approaches. The accuracies were 83.7% and 67.4% respectively in the ROC curve analysis. In addition, the RUMD was significantly shorter in the patients with rectal injury history (1.4, 1.8 cm).ConclusionsLonger gap distance and shorter PUVD were the two independent factors of the inferior pubectomy approach. Furthermore, among the patients with rectal injury history, the tissue posterior to the urethra was often weaker and should be carefully handled during the surgery.Trial registrationThis research has been registered on the Chinese Clinical Trial Registry. The registration number is ChiCTR2000030573.     

Background parenchymal enhancement in breast magnetic resonance imaging: A review of current evidences and future trends

Background parenchymal enhancement (BPE) on breast magnetic resonance imaging (MRI) is a dynamic process, which varies among women and within the same woman over time due to different factors. BPE has profound implications for women with or at risk of breast cancer. Breast radiologist should be aware of factors that could potentially influence BPE and have to be familiar with its typical appearance. Marked BPE could indeed affect the diagnostic accuracy of breast MRI, but this shortcoming can be minimized through evaluation by dedicated radiologists, in order to correctly interpret and properly manage the additional findings. BPE shows promise as an imaging biomarker but many issues need to be addressed before it can be used either to determine screening strategy or the value of risk-reducing interventions. This review analyzes the clinical influence of BPE on breast MRI interpretation, breast cancer staging and surgical outcome and discusses current available evidences about BPE as an imaging biomarker.     

Magnetic resonance imaging (MRI) of the knee: Identification of difficult-to-diagnose meniscal lesions

This article characterizes common meniscal pathologies, reviews magnetic resonance imaging (MRI) diagnostic criteria for meniscal tears, and identifies difficult-to-detect tears and fragments and the best MRI sequences and practices for recognizing these lesions. These difficult-to-diagnose meniscal lesions that radiologists should consider include tears, meniscocapsular separation lesions, and displaced meniscal fragments. Meniscus tears are either vertical, which are generally associated with traumatic injury, horizontal, which are associated with degenerative injury, or combinations of both. MRI has a high sensitivity for tears but not for fragments; MRI performance is also better for medial than lateral meniscal lesions. Fragment detection can be improved by recognizing signs secondary to migration, especially signs of epiphyseal irritation and mechanical impingement. Radial and peripheral tears, as well as those close to the posterior horn insertion, have been traditionally difficult to detect, but improvements in arthroscopic knowledge, identification of common lesion patterns, and selection of the proper MRI sequence and plane for each lesion type mean that, when properly used, MRI is an invaluable tool in detecting all types of meniscal tears.     

Role of diffusion-weighted MR imaging in predicting the grade of nonfunctional pancreatic neuroendocrine tumors

Purpose

The purpose of this study was to describe the magnetic resonance imaging (MRI) findings including diffusion-weighted MRI of nonfunctional pancreatic neuroendocrine tumors (PanNETs) and their hepatic metastases, and investigate the relationships between MRI features and histopathological findings for each grade of PanNETs.

Magnetic resonance imaging diagnosis and new classification of the osteoporotic vertebral fracture

The purpose of this study was to investigate the usefulness of magnetic resonance imaging (MRI) in the diagnosis of, and when deciding on treatment policies for, vertebral fractures in patients with osteoporosis by comparing the diagnostic success rates for such fractures using MRI and plain radiographs. We also devised a new classification of vertebral fractures in osteoporotic patients based on MRI findings. The subjects were 34 patients with a total of 316 osteoporosis-related vertebral fractures treated in our department during the past 2 years. They consisted of 30 women and 4 men with an average age of 82 years (range 61–95 years). The site diagnostic rates of plain radiographs and MRI for the vertebral fractures were compared, and changes in signal intensity of the fractured vertebrae in MRI were examined. The areas of change in signal intensity in T1-weighted sagittal images were classified into six types: total, anterior, posterior, superior, inferior, central. The site diagnostic rate for vertebral fractures was 98% for MRI, which was better than the 87% obtained with plain radiographs. Changes in signal intensity in the vertebrae showed no intraspinal protrusion in the inferior and superior types, and neurological stability was achieved; but there was a high frequency of intraspinal protrusion in the total and posterior types.     

Standardized quantitative measurements of wrist cartilage in healthy humans using 3T magnetic resonance imaging

AIM: To quantify the wrist cartilage cross-sectional area in humans from a 3D magnetic resonance imaging (MRI) dataset and to assess the corresponding reproducibility.METHODS: The study was conducted in 14 healthy volunteers (6 females and 8 males) between 30 and 58 years old and devoid of articular pain. Subjects were asked to lie down in the supine position with the right hand positioned above the pelvic region on top of a home-built rigid platform attached to the scanner bed. The wrist was wrapped with a flexible surface coil. MRI investigations were performed at 3T (Verio-Siemens) using volume interpolated breath hold examination (VIBE) and dual echo steady state (DESS) MRI sequences. Cartilage cross sectional area (CSA) was measured on a slice of interest selected from a 3D dataset of the entire carpus and metacarpal-phalangeal areas on the basis of anatomical criteria using conventional image processing radiology software. Cartilage cross-sectional areas between opposite bones in the carpal region were manually selected and quantified using a thresholding method.RESULTS: Cartilage CSA measurements performed on a selected predefined slice were 292.4 ± 39 mm² using the VIBE sequence and slightly lower, 270.4 ± 50.6 mm², with the DESS sequence. The inter (14.1%) and intra (2.4%) subject variability was similar for both MRI methods. The coefficients of variation computed for the repeated measurements were also comparable for the VIBE (2.4%) and the DESS (4.8%) sequences. The carpus length averaged over the group was 37.5 ± 2.8 mm with a 7.45% between-subjects coefficient of variation. Of note, wrist cartilage CSA measured with either the VIBE or the DESS sequences was linearly related to the carpal bone length. The variability between subjects was significantly reduced to 8.4% when the CSA was normalized with respect to the carpal bone length.CONCLUSION: The ratio between wrist cartilage CSA and carpal bone length is a highly reproducible standardized measurement which normalizes the natural diversity between individuals.     

Artifacts in magnetic resonance imaging of the spine after surgery with or without implant

Summary Magnetic resonance (MR) imaging is often disturbed after spine surgical procedures with or without an implant. Artifacts are induced by ferromagnetic or nonferromagnetic implants and devices and by small metallic particles left by surgical instruments. All metallic artifacts can affect the quality and usefulness of postoperative spine MR examinations. The physical effects caused by the introduction of metal or other conductive materials into a magnetic field and their consequences are presented. The application to postoperative spine MR examinations and solutions to reduce artifacts are discussed.