胎儿羊膜带综合征所致四肢畸形的MRI诊断

目的:探讨快速MRI对胎儿羊膜带综合征所致四肢先天畸形的诊断价值。方法:搜集本院行产前超声检查(US)和MRI检查的68例孕妇中发现并经引产后胎儿尸检证实的胎儿四肢畸形病例资料12例。这12例孕妇年龄22~34岁,平均27.3岁;其12例胎儿,胎龄20~38周,平均26.8周。US检查后3天内行胎儿肢体轴面、冠状面、矢状面MRI扫描。MRI扫描采用单次激发快速自旋回波(SSFSE)序列。观察胎儿四肢骨骼及软组织的形态、结构,并与US及尸检结果进行比较。结果:快速MRI视野大,运动伪影少,组织分辨力高,能清楚显示四肢骨骼、软组织等解剖结构。引产后尸检发现12例四肢畸形(左前臂缺失3例,右前臂残端畸形4例,左侧手指缺失1例,下肢狭窄环2例,马蹄内翻足畸形2例);US诊断10例,误诊、漏诊各1例;MRI诊断11例,漏诊1例。比较两者正确诊断数及误漏诊数,采用四格表的确切概率法检验,P>0.05,差异无统计学意义。结论:MRI对胎儿四肢先天畸形具有较高的诊断价值,是胎儿肢体先天畸形影像学诊断的重要手段之一。     

胎儿三维磁共振成像技术的初步应用

目的：探讨三维磁共振成像（3D-MRI）技术在显示胎儿体表正常解剖和先天畸形方面的应用价值。方法：对40例18~37周的胎儿在超声检查后1~2d内行MRI检查,应用单次激发快速自旋回波序列（SSFSE）行胎儿轴面、矢状面和冠状面二维MRI（2D-MRI）,三维稳态进动快速成像（3D-FIESTA）序列MRI,均使用并行采集技术（ASSET）,在工作站对原始数据进行多平面重组（MPR）、容积重组（VR）和磁共振仿真内窥镜技术（MRVE）等三维图像后处理。将MRI和随访、尸检结果进行比较。结果：36例孕妇3D-MRI检查成功率为94.4%（34/36）,34例胎儿经随访和尸检证实46处畸形。胎儿体表先天畸形2D-MRI正确诊断37处,诊断符合率80.4%（37/46）;误诊1处,假阳性率为2.1%（1/46）;漏诊8处,漏诊率17.4%（8/46）。3D-MRI正确诊断43处,诊断符合率93.5%（43/46）;误诊1处,假阳性率2.1%（1/46）;漏诊2处,漏诊率为4.3%（2/46）。两种方法诊断胎儿体表先天畸形差异无统计学意义（χ2=2.40,P〉0.05）,但3D-MRI对于面部畸形如唇裂和其他复杂畸形如体蒂异常、骶尾部畸胎瘤、联体双胎等显示更直观清楚。结论：3D-MRI一次扫描可直观反映胎儿体表结构的表面特征、立体形态及相互间的位置关系,VR、MRVE对胎儿正常面部、外生殖器、脐带、肢体等的评价有较高价值,MPR可对兴趣区进行多角度观察。磁共振三维成像对显示胎儿正常体表结构和病变及产前咨询和围产期手术具有重要的临床价值。     

快速MRI技术与超声在胎儿Dandy-Walker 综合征中诊断价值的对比研究

目的：探讨快速 MRI 技术对胎儿 Dandy-Walker 综合征（DWS）的诊断价值,并与超声结果对照。方法：回顾性分析13例经尸检或随访证实为 DWS 胎儿的病例资料,所有胎儿均于行超声检查后72h 内行快速 MRI 检查。结果：13例 DWS 中快速 MRI 明确诊断13例,并正确诊断合并的其它中枢神经系统畸形7例,与产后尸检及 MRI 检查结果一致。超声明确诊断6例,可疑3例,漏诊4例;明确诊断合并畸形3例,可疑2例,漏诊2例。结论：快速 MRI 技术对胎儿 Dan-dy-Walker 综合征及合并畸形的诊断优于超声,可作为超声检查的重要补充手段。     

MRI在胎儿中枢神经系统畸形的应用价值

目的 评价MRI在胎儿中枢神经系统畸形中的应用价值.资料与方法 22例孕妇,年龄23～40岁,年龄平均28岁;孕龄23～40周,平均30周.产前超声(US)检查后48 h内行MRI检查,T2WI采用半傅里叶单激发快速自旋回波序列(HASTE)、真稳态进动快速成像序列(True FISP),T1WI采用超快速小角度激发序列(FLASH)(Turbo FLASH)扫描,将产前MRI、US表现与产后诊断或尸检结果对照.结果 产前MRI与US诊断一致并正确者9例,产前MRI正确并证实US可疑病变2例,产前MRI正确并完善产前US诊断1例,产前MRI正确并改变产前US诊断7例,产前US正确MRI不正确1例,产前US正确且完善MRI诊断2例.结论 MRI对胎儿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,甚至更正US诊断,可作为胎儿中枢神经系统畸形的一种重要检查方法和补充手段.     

MRI在胎儿泌尿系统畸形诊断中的价值

目的评估MRI在胎儿泌尿系统畸形诊断中的价值。方法对34例泌尿系统畸形的胎儿MRI结果，结合超声诊断以及部分产后或术后结果进行分析。结果胎儿肾脏积水12例，包括7例随访积水消失；2例失访；产前MRI诊断的1例梗阻性右肾发育不良正在随访中，1例右双肾盂输尿管畸形在产后MRI随访中证实，1例肾盂输尿管连接处异常产后超声随访证实。双侧性泌尿系统畸形胎儿7例，显示羊水量减少，肺信号减低，其中双侧性多囊性肾发育不良3例（均引产），双肾发育不良2例（1例失访，1例尸检），双侧肾不发育1例（引产后尸检证实），右肾缺如伴左肾发育不良1例（失访），1例尸检胎儿产前MRI诊断正确，1例MRI上清晰显示双侧下肢合并成团块状。单侧性泌尿系统畸形胎儿15例，包括单侧肾发育不良9例（3例随访中，2例引产，1例失访，3例产后超声或MRI证实），单侧肾脏不发育4例（2例引产，2例产后超声或MRI证实），异位肾1例产后经超声证实，脐尿管囊肿1例引产，产前MRI对于得到随访结果的6例胎儿均诊断正确。结论MRI可以不受羊水量的影响，多方位清晰显示各类泌尿系统畸形及其伴发的其他系统畸形，并作出准确诊断，作为产前超声的重要补充检查手段具有很高的临床应用价值。     

MRI对胎儿胼胝体缺如的诊断价值

目的 探讨MRI对胎儿胼胝体缺如的诊断价值. 资料与方法 超声（US）怀疑胎儿胼胝体缺如的孕妇9例,平均年龄25岁（18～29岁）,平均孕周32周（28～36周）,所有患者均在US检查后2天内行MRI检查.将US、MRI结果与出生后或引产后结果对照. 结果 MRI与US比较,胎儿胼胝体缺如基本一致者3例;US可疑、MRI肯定者6例,其中出生后随访证实者2例,引产后证实者4例;对于其伴发畸形,两者基本一致者5例,MRI多于US者4例. 结论 MRI对胎儿胼胝体缺如有较高的诊断价值,可作为US有利的补充及验证手段.     

磁共振成像在胎儿产前诊断中的临床应用价值

目的 探讨磁共振成像（MRI）在胎儿产前检查中的临床应用价值。方法 回顾性分析我院2020年11月至2021年12月间经院内外超声产前筛查发现异常而行针对性胎儿MRI检查252例胎儿的影像及相关资料。结果 中枢神经系统（脑部）MRI检查206例，主要以胎儿脑部发育及畸形为主；腹盆部MRI检查31例，主要以泌尿及生殖系异常为主，部分为腹部肿瘤性病变；胸部MRI检查7例，主要以肺部先天畸形为主；脊柱MRI检查6例，颌面部及颈部MRI检查各1例。结论 在胎儿产前影像学检查中，针对性胎儿MRI检查属Ⅳ级产前影像诊断，可以确认超声检查结果或提供比超声更多的诊断信息，对于明确产前诊断、促进优生优育有重要价值。     

羊水过少致胎儿肺发育不良的MRI评价

目的:探讨MRI对羊水过少致胎儿肺发育不良的定性和定量诊断价值。方法:病例组包括26例因羊水过少致胎儿肺发育不良的孕妇,年龄21～43岁,平均28岁;孕龄22～36周,平均25周。另选取26例相应孕周胎儿肺发育正常的孕妇作为对照组,产前常规行超声(US)检查后24～48h内行MRI检查,采用稳态自由进动(SSFP)序列和单次激发快速自旋回波(SSTSE)序列T2WI以及快速T1WI序列,将产前MRI、US表现与胎儿出生后影像学或尸检结果进行对照。结果:26例孕妇均诊断为羊水过少,其中泌尿系异常所致22例、胎膜早破所致4例。羊水过少组胎儿肺肝信号强度比(LLSIR)为1.34±0.27,显著低于正常对照组(2.14±0.70),2组间差异有高度统计学意义(P<0.01)。26例胎儿US均未提示双肺发育不良;对于羊水过少的病因诊断,US漏诊2例、诊断不完全正确3例,MRI均诊断正确。结论:MRI可以量化评价羊水过少致胎儿肺发育不良程度,准确诊断羊水过少病因,是诊断羊水过少合并胎儿异常的较理想的评价方法。     

婴幼儿脑外积液的MRI研究:脑外间隙发育性与病理性的扩大

目的 分析婴幼儿脑外积液的MRI特征，明确脑外积液的病因及与脑发育的关系。方法 选择经MRI确诊的46例年龄〈2岁的脑外积液患儿，分析其MRI特征。并按月龄分7组，在T2WI上测量脑外间隙宽度并与正常值对照。结果 引起婴幼儿脑外积液的主要原发病有感染性疾病、硬膜下或蛛网膜下出血、缺氧缺血性脑病（HIE）占67．4％（31／46例），原因不明占26．1％（12／46例）。脑外积液主要发生在大脑凸面的前部，以蛛网膜下腔积液多见，占80．4％（37／46例），硬膜下积液8．7％（4／46例），硬膜下和蛛网膜下积液并存10．9％（5／46例）。其中，化脓性脑膜炎可致硬脑膜或软脑膜的信号在T1WI或T2WI上增高，常引起硬膜下积液或与蛛网膜下腔积液并存。硬膜下和（或）蛛网膜下腔出血常为硬膜下和蛛网膜下腔积液并存，并常见大脑表面静脉（皮质静脉）增粗、淤滞和出血，在T1WI上信号增高。HIE所致脑外积液为蛛网膜下腔积液，可见HIE所致的特征性改变，常有髓鞘化落后占63．6％（7／11例）。原因不明者多为双侧对称性的蛛网膜下腔积液。脑室扩大主要见于HIE和硬膜下或蛛网膜下出血。结论 婴幼儿脑外积液多有明确病因，以出血、感染和HIE为多见，积液的部位与脑发育的特性有关，MRI对明确脑外积液的性质，判断病因有帮助。     

MRI在显示胎儿中枢神经系统发育畸形中优势的初步探讨

目的:探讨MRI在检出胎儿中枢神经系统发育异常中的优势。方法:对42例超声检查发现胎儿异常的孕妇进行胎儿MRI检查(超声检查48h内完成),孕妇年龄22~35岁,胎龄16~35周。MRI检查采用半傅立叶单激励快速自旋回波(HASTE)序列获得T2WI,其中8例还行快速小角度激励(fastlowangleshot,FLASH)T1WI成像,4例行扩散加权成像。将超声结果、MRI与尸体解剖、手术或/和出生后随访MRI比较。结果:产前超声漏诊的病例共20例,MRI的T2WI仅漏诊1例。超声漏诊病例多数为脑实质及脊髓病变,且多种中枢神经系统发育畸形的声像图可表现相同,缺乏特异性。结论:MRI可直接显示脑实质、脊髓以及病变与脑脊髓的关系,在超声检查基础上进行胎儿磁共振成像,有助于弥补超声之不足,进一步完善、验证、甚至更正超声诊断。     

Contribution of MRI to ultrasound in the diagnosis of fetal anomalies

Purpose:

To evaluate the contribution of MRI to ultrasound (US) in the diagnosis of fetal anomalies.

Materials and Methods:

After informed consent and institutional review board approval, concomitant US and MR imaging were performed for 184 fetuses with suspected anomalies in university hospital. Postnatal final diagnoses were obtained for 183 anomalies in 151 fetuses either by radiological examination, surgery, autopsy, or inspection. The prenatal US and MR diagnoses were compared with respect to postnatal diagnoses. Sign test was used to determine the statistical significance.

Results:

Both ultrasound and MR imaging correctly diagnosed 93 (50%) cases and failed in 12 (7%) cases. Ultrasound was superior in 7 (4%) cases. MR imaging was superior in 71 (39%) cases (P < 0.001). MR contributed to the prenatal diagnosis by the confirmation of the suspected US diagnosis in 13%, by demonstration of additional findings in 31% and by changing the diagnosis in 56% of the cases. The contribution rates were 55% for the central nervous system (CNS) (P < 0.001), 44% for thorax (P = 0.016), 38% for gastrointestinal system (GIS) (P = 0.031) and 29% for genitourinary system (GUS) (P = 0.003) anomalies. In facial, cardiac and extremity‐skeletal system anomalies, there was not a significant contribution of MR imaging over US.

Conclusion:

MR imaging can be used as an adjunct to US in the prenatal diagnosis of fetal anomalies of not only the CNS but also the non‐CNS origin especially those involving the GIS, GUS and thorax. J. Magn. Reson. Imaging 2012;35:882–890. © 2011 Wiley Periodicals, Inc.     

MRI快速扫描序列在胎儿前腹壁缺损诊断中的应用

目的：通过分析3l例胎儿前腹壁缺损在快速磁共振扫描序列中的表现,探讨MRI在胎儿前腹壁缺损诊断中的价值及其对临床治疗的指导作用。方法：回顾性分析31例胎儿前腹壁缺损的MRl图像,并与产前超声或分娩后结果进行比较。结果：MRI正确诊断所有31例胎儿前腹壁缺损,其中脐膨出19例,腹裂12例。19例脐膨出胎儿中伴发畸形7例(...     

Truncus arteriosus communis in a midtrimester fetus: comparison of prenatal ultrasound and MRI with postmortem MRI and autopsy

Different techniques are used in fetal cardiology, and their accuracy has been demonstrated on several occasions. Color Doppler US has proved to be a reliable and valuable tool in the diagnosis of fetal cardiac abnormalities. Magnetic resonance imaging (MRI) of the fetal heart has, so far, played no role in prenatal diagnostics. We report on a truncus arteriosus communis diagnosed prenatally during a screening ultrasound at 22 weeks of gestation. In addition to real-time ultrasound and color Doppler echocardiography, fetal MRI was performed. Fetal echocardiography arose suspicion of a type I common trunk. Fetal MR showed solely a widened vessel coursing retrocardially and additionally an inhomogeneous fluid distribution of the lung not shown on prenatal US. After termination of pregnancy at 23 weeks of gestation, MR fetography and autopsy were performed, and both found a type II common trunk. MR autopsy of the heart was very reliable in this case and could be an alternative when fetal pathology is not available for different reasons. Postmortem MRI was also able to demonstrate the inhomogeneous fluid distribution in the lung, which was confirmed by autopsy. Fetal and postmortem MR was reliable in the detection of an inhomogeneous fluid distribution in the lung not shown on prenatal US, providing a relevant additional finding to US. Therefore, MRI should be used more often in fetal cardiology, although it still must be further developed.     

Fetal anomalies: comparison of MR imaging and US for diagnosis

PURPOSE: To compare prenatal ultrasonography (US) and magnetic resonance (MR) imaging for the diagnosis of fetal anomalies. MATERIALS AND METHODS: Images of 27 fetuses (28 diagnostic cases) with anomalies diagnosed at US were evaluated; in these fetuses, prenatal MR imaging was performed within 15 days of US. Prenatal US and MR imaging findings were compared with postnatal diagnoses. Postnatal evaluation included US, MR imaging, autopsy, surgery, voiding cystourethrography, computed tomography, angiography, and physical examination. RESULTS: In seven diagnostic cases, US and MR imaging findings were in complete agreement with postnatal diagnoses. MR imaging correctly provided additional information to the US-determined diagnosis in another seven and correctly changed the US diagnosis in three. The MR imaging-determined diagnosis was incorrect and the US diagnosis was correct in four cases. In seven cases, the diagnoses at both US and MR imaging were incorrect when correlated with the postnatal outcome. MR imaging was most valuable in the assessment of anomalies of the central nervous system. CONCLUSION: MR imaging may have a place as an adjunct to US in evaluation of fetal anomalies, particularly those involving the central nervous system.     

胎儿先天性膈疝MRI诊断的探讨

目的 探讨MRI在胎儿先天性膈疝诊断中的应用价值.方法 14名孕妇,孕龄16～39周.产前常规行超声(US)检查怀疑胎儿先天性膈疝后在24-48 h内行MR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)序列以及快速反转恢复运动抑制(FIRM)序列,行胎儿颅脑、胸、腹部常规及胸腹部重点冠状面、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(13例胎儿)、引产后尸体解剖(1例胎儿)结果对照.结果 12例为单胎,2例为双胎之一.膈疝位于左侧12例,右侧2例.随访结果与产前MRI诊断完全一致,产前US误诊2例、漏诊2例.12例左侧疝中1例为左胸部被巨大结肠占据,1例仅整个胃泡疝入,5例仅部分肠管疝入,5例整个胃泡和部分肠管同时疝入;2例右侧疝中1例仅部分肠管疝入,1例为肝脏部分和部分肠管同时疝入.结论 MRI对胎儿先天性膈疝诊断具有较高的应用价值.     

Fetal MRI of the central nervous system: State-of-the-art

Prenatal ultrasonographic (US) examination is considered as the first tool in the assessment of fetal abnormalities. However, several large-scale studies point out that some malformations, in particular central nervous system (CNS) anomalies, are not well characterized through US. Therefore, the actual malformation severity is not always related to prenatal ultrasound (US) findings.Over the past 20 years, ultrafast Magnetic Resonance Imaging (MRI) has progressively increased as a prenatal 3rd level diagnostic technique with a good sensitivity, particularly for the study of fetal CNS malformations. In fact, CNS anomalies are the most common clinical indications for fetal MRI, representing about 80% of the total examinations.This review covers the recent literature on fetal brain MRI, with emphasis on techniques, safety and indications.     

产前超声及磁共振成像在胎儿肺隔离症诊断中的价值探讨

目的 探讨超声及MRI诊断胎儿肺隔离症的临床应用价值.方法 对12例产前超声怀疑胎儿肺隔离症者,24h内进行MRI检查,诊断结果均经尸检病理及产后随访证实.对12例胎儿的超声和MRI图像资料进行分析,并与随访结果对照.结果 产前超声诊断的12例胎儿肺隔离症,超声诊断符合率83.3％,误诊2例,（1例为隔疝,1例为肺囊腺瘤）;产前MRI检查诊断准确率为91.7％,误诊1例（隔离肺误诊为腹腔肿瘤）.结论 产前超声检查是诊断胎儿肺隔离症主要筛选方法,MRI可以作为胎儿超声检查的重要补充,二者联合应用,可进一步提高该病的诊断率.