胎儿脑积水的研究进展

通过对胎儿脑积水的发病原因、发病机理及其诊断治疗的研究分析,了解胎儿脑积水的预后,为临床指导提供理论依据。     

MRI在胎儿泌尿系统异常中的诊断价值

目的探讨MRI在胎儿泌尿系统异常中的诊断价值。资料与方法收集2012年8月～2014年4月超声（US）怀疑胎儿泌尿系异常孕妇57例,年龄19-38岁,平均28±3岁;孕龄23-36w,平均29±3.4w。产前超声（US）检查后72h内行MRI检查,将US、MRI结果与出生后或引产后结果对照。结果单侧肾脏缺如7例,异位肾2例,马蹄肾3例,肾囊性病变10例,输尿管上段扩张35例。结论MRI对胎儿泌尿系统异常具有较高的诊断价值。     

胎儿常见中枢神经系统畸形的MRI诊断价值

目的探讨核磁共振成像（Maganetic Imaging；MRI）对胎儿常见中枢神经系统畸形的诊断价值。方法产前超声检查诊断或怀疑中枢神经系统畸形的19例胎儿，于US检查后3d内行胎儿颅脑、脊枉及胸腹部MR扫描。结果经胎儿尸检及出生后随访检查证实中枢神经系统畸形19例，共22处（脑室扩大10处；胼胝体缺如或发育不全3处、Dandy-walker氏畸形2处，大枕大池3处．蛛网膜囊肿4处）。US准确诊断14处，准确率63．6％（14／22），误诊3处，假阳性率为13，6％（3／22），漏诊5处，假阴性率为228％（5／22）：MRI准确诊断17处，准确率77．3％（17／22），误诊2处，假阳性率殳1％（2／22），漏诊3处，漏诊率为13．6％（3／22）。结论MRI对胎儿中枢神经系统先天畸形诊断较US具有一定优势，可补充或验证胎儿畸形的超声诊断。     

外伤性脑积水的MRI表现分析

目的探讨外伤性脑积水的MRI表现特征.方法对26例外伤性脑积水患者的MRI资料进行全面的分析总结.结果外伤性脑积水的MRI表现:脑室系统扩大,且扩大程度大于脑池的扩大,脑沟正常或变窄.侧脑室周围可见间质性脑积水,T1WI呈低或等信号,T2呈高或稍高信号.开骨窗病人可见脑组织向骨窗方向移位﹑突出.结论MRI检查是确诊外伤性脑积水的重要方法.     

胎儿心肺异常MRI诊断

目的探讨MRI在胎儿心肺异常诊断中的应用价值。方法30例孕妇,年龄21～43岁．平均年龄28岁：孕龄16～36周,平均孕龄27周。产前常规行超声（US）检查后24～48h内行MRI检查,采用二维快速平衡稳态采集（2D FIESTA）序列、单次激发快速自旋回波（SSFSE）序列,非门控实时稳态采集序列,行胎儿颅脑胸腹部常规及心肺重点冠状面、矢状面及横断面扫描,将产前MRI、US表现与出生后影像表现或手术（16例胎儿）、引产后尸体解剖结果或尸体影像表现（14例胎儿）对照。结果30例胎儿心肺异常。其中肺部异常20例．心脏异常10例。全部病例产前MRI均诊断正确．产前US漏诊2例、误诊3例。结论MRI在胎儿肺异常诊断方面具有较高的应用价值,能发挥US的补充作用,在心脏畸形诊断方面目前不如US．但能提供一定的信息。MRI联合US能提高胎儿心肺异常的产前诊断准确率。     

彩色多普勒超声对胎儿畸胎瘤的诊断及预后的价值

目的探讨彩色多普勒超声对胎儿畸胎瘤的诊断及预后的价值。方法通过彩色多普勒超声对2011年1月至2012年12月产前诊断的21例胎儿畸胎瘤的影像特点进行分析并追踪胎儿预后及手术病理。结果产前共诊断21例胎儿畸胎瘤,其中12例引产,9例存活,引产者肿物大小均大于5cm。手术病理共有5例未成熟畸胎瘤,16例成熟畸胎瘤。结论彩色多普勒超声对胎儿畸胎瘤的诊断及预后有重要临床参考价值。     

MRI检查在胎儿中枢神经系统常见畸形中的诊断价值

目的探讨MRI检查在胎儿中枢神经系统常见畸形中的诊断价值。资料与方法41例孕妇,年龄19～41岁,年龄平均274±2．7岁;孕龄25～38w,平均294±3．4w。产前超声（US）检查后72h内行MRI检查,T2WI采用半傅里叶单激发快速自旋回波序列（西门子HASTE）、真稳态进动快速成像序列（西门子TrueFISP）,TlWI采用超快速小角度激发序列（FLASH）扫描,弥散加权成像选用b值选为50s／mm^2、400s／mm^2、800s／mm^2,一次扫描完成,并自动生成ADC图。将产前MRI、US表现与产后新生儿期诊断或尸检结果对照。结果产前MRI与US诊断一致并正确者23例,产前MRI正确并证实US可疑病变6例,产前MRI正确并完善产前US诊断4例,产前MRI正确并改变产前US诊断9例。结论MRI对胎儿中枢神经系统畸形的诊断具有一定的优势,与US相比,MRI可提供更全面、更准确的信息,为US检查有效的补充诊断、印证诊断,降低临床的诊断风险。     

胎儿脑积水的产前超声诊断及临床意义

目的探讨胎儿脑积水的声像图特征及超声诊断价值。方法分析总结了41例胎儿脑积水的声像图特征。结果明显脑积水35例,6例脑室轻度扩张（侧脑室后角内径在10~15mm之间）。结论明显脑室积水预后差,宜早终止妊娠。轻度脑室扩张在染色体正常,不合并其它畸形的情况下,预后大多较好。     

胎儿畸形的产前超声诊断价值分析

目的探讨超声对胎儿畸形的产前诊断价值。方法采用彩超对8616名孕妇行常规超声检查,并对其中发生胎儿畸形的资料进行分析。结果共发现胎儿畸形54例,其中无脑儿11例,脑积水10例,脊柱裂8例,脑脊膜膨出4例,胸腹腔积水4例,肾积水4例,先天性心脏病1例,软骨发育不全2例,唇腭裂4例,四肢畸形3例,死胎3例。漏诊4例,诊断符合92．59％。结论胎儿畸形的超声图像比较典型,细心检查,正确分析可避免漏诊。超声是产前诊断胎儿畸形的首选方法。     

Early non-invasive diagnosis and treatment of acute eosinophilic myopericarditis by cardiac magnetic resonance

We report a case of early non-invasive diagnosis of acute eosinophilic myopericarditis (AEM) by cardiovascular magnetic resonance (CMR) before cardiac biopsy. A 35-yr-old woman presented with a flu-like illness, followed by pleuritic chest pain and shortness of breath. Transthoracic echocardiography revealed mild left ventricular (LV) systolic dysfunction with borderline LV wall thickness and moderate pericardial effusion. The patient had peripheral eosinophilia and CMR was performed immediately at first day of visit before cardiac biopsy. CMR showed diffuse subepicardial high T2 signals and diffuse late gadolinium enhancement in LV. Steroid therapy was immediately initiated and patient's symptom was rapidly improved. Endomyocardial biopsy at hospital day 3 reported multifocal mild infiltration of eosinophils and lymphocytes. The patient was finally confirmed as acute eosinophilic myopericarditis. This presentation emphasizes on the role of CMR which enables early non-invasive diagnosis of AEM and visualize the extent of the myocarditis.     

Cardiac gating 1 in nuclear magnetic resonance imaging

In order to obtain NMR images of the heart, and to measure blood flow by NMR, the signal acquisition must be synchronized wilh the patient's cardiac cycle. Some of the problems of detecting the cardiac cycle within a strong unqorm magnetic field without introducing R F interference into the imaging system are discussed. some general applications of cardiac gated NMR imaging are presented.     

The value of preoperative magnetic resonance imaging in predicting postoperative recovery in patients with cervical spondylosis myelopathy: a meta-analysis

This meta-analysis was designed to elucidate whether preoperative signal intensity changes could predict the surgical outcomes of patients with cervical spondylosis myelopathy on the basis of T1-weighted and T2-weighted magnetic resonance imaging images. We searched the Medline database and the Cochrane Central Register of Controlled Trials for this purpose and 10 studies meeting our inclusion criteria were identified. In total, 650 cervical spondylosis myelopathy patients with (+) or without (-) intramedullary signal changes on their T2-weighted images were examined. Weighted mean differences and 95% confidence intervals were used to summarize the data. Patients with focal and faint border changes in the intramedullary signal on T2 magnetic resonance imaging had similar Japanese Orthopaedic Association recovery ratios as those with no signal changes on the magnetic resonance imaging images of the spinal cord did. The surgical outcomes were poorer in the patients with both T2 intramedullary signal changes, especially when the signal changes were multisegmental and had a well-defined border and T1 intramedullary signal changes compared with those without intramedullary signal changes. Preoperative magnetic resonance imaging including T1 and T2 imaging can thus be used to predict postoperative recovery in cervical spondylosis myelopathy patients.     

Partial epilepsy: A pictorial review of 3 TESLA magnetic resonance imaging features

Epilepsy is a disease with serious consequences for patients and society. In many cases seizures are sufficiently disabling to justify surgical evaluation. In this context, Magnetic Resonance Imaging (MRI) is one of the most valuable tools for the preoperative localization of epileptogenic foci. Because these lesions show a large variety of presentations (including subtle imaging characteristics), their analysis requires careful and systematic interpretation of MRI data. Several studies have shown that 3 Tesla (T) MRI provides a better image quality than 1.5 T MRI regarding the detection and characterization of structural lesions, indicating that high-field-strength imaging should be considered for patients with intractable epilepsy who might benefit from surgery. Likewise, advanced MRI postprocessing and quantitative analysis techniques such as thickness and volume measurements of cortical gray matter have emerged and in the near future, these techniques will routinely enable more precise evaluations of such patients. Finally, the familiarity with radiologic findings of the potential epileptogenic substrates in association with combined use of higher field strengths (3 T, 7 T, and greater) and new quantitative analytical post-processing techniques will lead to improvements regarding the clinical imaging of these patients. We present a pictorial review of the major pathologies related to partial epilepsy, highlighting the key findings of 3 T MRI.     

MnFe2O4纳米胶束合成及其应用于磁共振分子影像的可行性

BACKGROUND: Studies have shown that the saturation magnetization of nanoparticles can be increased by increasing of particle size of nanoparticles or cluster-like aggregation of multiple nanoparticles. But the increased particle size can reduce the cycle time of nanoparticles in the body. OBJECTIVE: To synthesize MnFe₂O₄  nanomicelles and explore the feasibility of its application in magnetic resonance molecular imaging. METHODS: MnFe₂O₄  nanoparticles were synthesized using thermal decomposition method and self-assembled with polyethylene glycol-polycaprolactone amphiphilic diblock copolymers (PEG-PCL) to construct PEG-PCL-MnFe₂O₄  nanomicelles. The characteristics of the MnFe₂O₄ nanoparticles and nanomicelles were tested. Then, MnFe₂O₄  nanoparticles and nanomicelles at different iron concentrations (0, 0.01, 0.02, 0.03, 0.04, 0.06, 0.08, 0.1, 0.2, 0.4, 0.6, 0.8 mmol/L) were placed into EP tubes. Relaxation rate of the nanomicelles were measured using magnetic resonance scanner. RESULTS AND CONCLUSION: (1) MnFe₂O₄  nanoparticles appeared as round under transmission electron microscopy. The size of nanoparticles was 11 nm with good monodispersion. The Zeta-particle size was (11.18±1.72) nm. The molar ratio of Fe/Mn was 2.13:1. The size of PEG-PCL-MnFe₂O₄  nanomicelles ranged from 52 to 86 nm, with a mean Zeta-particle size of (78.8±12.4) nm. (2) The signal intensity (SI) change of PEG-PCL-MnFe₂O₄  nanomicelles and PEG-PCL-Fe₃O₄ nanomicelles shared similar trend according to iron concentration. With the increasing of iron concentration, SI first increased and then decreased in T1WI, and it gradually decreased in T2WI and T2*WI. The SI changes in T2*WI were significantly stronger than that in T2WI and T1WI. Taken together, our results show that PEG-PCL-MnFe₂O₄ nanomicelles are expected to perform as a sensitive contrast agent used in T2WI as their moderate particle size, good monodisperse and strong T₂ relaxation.     

Magnetic resonance imaging and neuropsychological testing in the spectrum of normal aging

OBJECTIVE:

To understand the relationships between brain structures and function (behavior and cognition) in healthy aging.

METHOD:

The study group was composed of 56 healthy elderly subjects who underwent neuropsychological assessment and quantitative magnetic resonance imaging. Cluster analysis classified the cohort into two groups, one (cluster 1) in which the magnetic resonance imaging metrics were more preserved (mean age: 66.4 years) and another (cluster 2) with less preserved markers of healthy brain tissue (mean age: 75.4 years).

RESULTS:

The subjects in cluster 2 (older group) had worse indices of interference in the Stroop test compared with the subjects in cluster 1 (younger group). Therefore, a simple test such as the Stroop test could differentiate groups of younger and older subjects based on magnetic resonance imaging metrics.

CONCLUSION:

These results are in agreement with the inhibitory control hypotheses regarding cognitive aging and may also be important in the interpretation of studies with other clinical groups, such as patients with dementia and mild cognitive impairment.     

Tubular duplication of the esophagus. Contribution of magnetic resonance imaging in anatomical analysis before surgery

The authors report a tubular duplication of the thoracic esophagus in a 17-year-old male. This anomaly, rare in the adult, can be explained either by a failure of esotracheal compartmentalisation, or a notochordodysraphy or more probably by an error during vacuolisation of the esophagus. The anatomical characteristics of the duplication were clearly seen on MRI. This investigation showed the intramural duplication, with only a thin barrier without muscle, between the esophageal lumen and the duplication channel two communications were present between the esophageal lumen and the duplication. The esophagus was accessed by right thoracotomy. The close contact between the duplication and the esophagus did not allow them to be separated. A subtotal esophagectomy was necessary, with digestive continuity being restored by coloplasty after a left cervicotomy and a laparotomy. The anatomy seen on the MRI should have predicted that an esophagectomy was necessary and that a thoracotomy could have been avoided by performing the procedure with a closed thorax.     

Clinically low-risk prostate cancer: evaluation with transrectal doppler ultrasound and functional magnetic resonance imaging

OBJECTIVES:

To evaluate transrectal ultrasound, amplitude Doppler ultrasound, conventional T₂‐weighted magnetic resonance imaging, spectroscopy and dynamic contrast‐enhanced magnetic resonance imaging in localizing and locally staging low‐risk prostate cancer.

INTRODUCTION:

Prostate cancer has been diagnosed at earlier stages and the most accepted classification for low‐risk prostate cancer is based on clinical stage T1c or T2a, Gleason score ≤6, and prostate‐specific antigen (PSA) ≤10 ng/ml.

METHODS:

From 2005 to 2006, magnetic resonance imaging was performed in 42 patients, and transrectal ultrasound in 26 of these patients. Seven patients were excluded from the study. Mean patient age was 64.94 years and mean serum PSA was 6.05 ng/ml. The examinations were analyzed for tumor identification and location in prostate sextants, detection of extracapsular extension, and seminal vesicle invasion, using surgical pathology findings as the gold standard.

RESULTS:

Sixteen patients (45.7%) had pathologically proven organ‐confined disease, 11 (31.4%) had positive surgical margin, 8 (28.9%) had extracapsular extension, and 3 (8.6%) presented with extracapsular extension and seminal vesicle invasion.Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy values for localizing low‐risk prostate cancer were 53.1%, 48.3%, 63.4%, 37.8% and 51.3% for transrectal ultrasound; 70.4%, 36.2%, 65.1%, 42.0% and 57.7% for amplitude Doppler ultrasound; 71.5%, 58.9%, 76.6%, 52.4% and 67.1% for magnetic resonance imaging; 70.4%, 58.7%, 78.4%, 48.2% and 66.7% for magnetic resonance spectroscopy; 67.2%, 65.7%, 79.3%, 50.6% and 66.7% for dynamic contrast‐enhanced magnetic resonance imaging, respectively.Sensitivity, specificity, PPV, NPV and accuracy values for detecting extracapsular extension were 33.3%, 92%, 14.3%, 97.2% and 89.7% for transrectal ultrasound and 50.0%, 77.6%, 13.7%, 95.6% and 75.7% for magnetic resonance imaging, respectively. For detecting seminal vesicle invasion, these values were 66.7%, 85.7%, 22.2%, 97.7% and 84.6% for transrectal ultrasound and 40.0%, 83.1%, 15.4%, 94.7% and 80.0% for magnetic resonance imaging.

CONCLUSION:

Although preliminary, our results suggest that imaging modalities have limited usefulness in localizing and locally staging clinically low‐risk prostate cancer.