Prenatal Diagnosis of Placenta Accreta

Objective. The purpose of this study was to compare the accuracy of transabdominal sonography and magnetic resonance imaging (MRI) for prenatal diagnosis of placenta accreta. Methods. A historical cohort study was undertaken at 3 institutions identifying women at risk for placenta accreta who had undergone both sonography and MRI prenatally. Sonographic and MRI findings were compared with the final diagnosis as determined at delivery and by pathologic examination. Results. Thirty‐two patients who had both sonography and MRI prenatally to evaluate for placenta accreta were identified. Of these, 15 had confirmation of placenta accreta at delivery. Sonography correctly identified the presence of placenta accreta in 14 of 15 patients (93% sensitivity; 95% confidence interval [CI], 80%–100%) and the absence of placenta accreta in 12 of 17 patients (71% specificity; 95% CI, 49%–93%). Magnetic resonance imaging correctly identified the presence of placenta accreta in 12 of 15 patients (80% sensitivity; 95% CI, 60%–100%) and the absence of placenta accreta in 11 of 17 patients (65% specificity; 95% CI, 42%–88%). In 7 of 32 cases, sonography and MRI had discordant diagnoses: sonography was correct in 5 cases, and MRI was correct in 2. There was no statistical difference in sensitivity (P = .25) or specificity (P = .5) between sonography and MRI. Conclusions. Both sonography and MRI have fairly good sensitivity for prenatal diagnosis of placenta accreta; however, specificity does not appear to be as good as reported in other studies. In the case of inconclusive findings with one imaging modality, the other modality may be useful for clarifying the diagnosis.     

What Does Magnetic Resonance Imaging Add to the Prenatal Sonographic Diagnosis of Ventriculomegaly?

OBJECTIVE: The purpose of this study was to determine the contribution of magnetic resonance imaging (MRI) in evaluating fetuses with the sonographic diagnosis of ventriculomegaly (VM). METHODS: Over 4 years, consecutive fetuses with the sonographic diagnosis of VM at 1 facility who underwent prenatal MRI at a second facility were included. The roles of MRI and follow-up sonography were tabulated. The patients were analyzed in 2 groups based on the presence or absence of other central nervous system (CNS) abnormalities. RESULTS: Twenty-six fetuses with a gestational age range of 17 to 37 weeks had sonographically detected VM (atria > or =10-29 mm), including 19 with mild VM (atria 10-12 mm). In group 1, 14 had isolated VM, 6 of which reverted to normal by the third trimester. Magnetic resonance imaging showed cerebellar hypoplasia not shown by sonography in 1 fetus and an additional finding of a mega cisterna magna in a second fetus. In group 2, 12 fetuses had VM and other CNS anomalies on sonography. Additional findings were seen with MRI in 10 of these fetuses, including migrational abnormalities (n = 4), porencephaly (n = 4), and 1 diagnosis each of abnormal myelination, hypoplasia of the corpus callosum, microcephaly, a kinked brain stem, cerebellar hypoplasia, and congenital infarction. There were significantly more fetuses with additional CNS anomalies found by MRI among those in group 2 compared with those in group 1 (Fisher exact test, P = .001). CONCLUSIONS: Although sonography is an accurate diagnostic modality for the evaluation of fetuses with VM, MRI adds important additional information, particularly in fetuses in whom additional findings other than an enlarged ventricle are seen sonographically.     

脑静脉窦血栓形成的CT、MRI诊断

目的:探讨CT、MRI及MRV对脑静脉窦血栓形成(CVST)的诊断价值。材料与方法:回顾性分析15例脑静脉窦血栓形成的头颅CT、MRI及MRV表现。结果:所有患者均行头颅CT和MRI平扫,其中5例行CT增强扫描,3例行MRI增强扫描,11例行MRV检查。CT平扫显示静脉窦密度增高,急性7例(7/9),亚急性3例(3/6);MRI平扫显示13例静脉窦内有异常信号,CT及MRI增强扫描均见"空三角征"或"充盈缺损征",11例MRV均表现为受累静脉窦不显影或充盈缺损。结论:头颅CT是诊断急性CVST的重要方法;MRI对亚急性CVST具有更高敏感度与特异性;MRV可快速、无创地评价CVST。     

Prenatal Diagnosis of Isolated Tricuspid Valve Atresia

Objective. To describe the prenatal features of fetal tricuspid atresia. Methods. Four cases of fetal tricuspid atresia were prenatally diagnosed, sonographically described, and followed. Results. On the basis of this small series, the key findings for diagnosis included the demonstration of no patent tricuspid valve on the 4‐chamber view, no flow across the tricuspid valve on pulsed or color Doppler flow mapping, small right ventricles, and associated interventricular septal defects. Increased nuchal translucency thickness may give the first clue leading to follow‐up scans, resulting in a definite diagnosis. Conclusions. Tricuspid atresia can be readily diagnosed prenatally. The key findings and differential diagnoses are provided.     

产前MRI诊断胎儿中线处硬脑膜窦畸形

目的 探讨胎儿中线处硬脑膜窦畸形的产前MRI表现。方法 收集11胎中线处硬脑膜窦畸形胎儿,经产前超声检查于孕21~27周发现胎儿枕部或小脑区异常,之后1周内接受MR平扫。11胎中,9胎经引产病理证实,2胎出生后随访复查证实。分析胎儿硬脑膜窦畸形影像表现及病理特点。结果 11胎中线处硬脑膜窦畸形,MRI均表现为枕部颅板下窦汇区囊状扩张,约10 mm×15 mm~35 mm×55 mm,邻近静脉窦亦可见扩张;轴位和冠状位MRI上病灶呈楔形,矢状位上呈纺锤状或新月形;病灶T1WI呈等或稍高信号,T2WI呈稍低-等或稍高信号。其中9胎硬脑膜窦畸形内可见血栓形成,为类圆形或条块状,偏于囊性肿物一侧壁上,T1WI呈高信号,T2WI呈低、等或高信号;6胎血栓周围见含铁血黄素沉积。2胎硬膜窦横径超过30 mm,邻近脑实质及小脑受压向前移位。9胎引产后胎儿尸体解剖显示畸形扩大的静脉窦,其中7胎见偏心性血栓,周围可见分支血管。2胎出生后婴儿脑实质均发育正常。结论 产前MRI可准确诊断胎儿中线处硬脑膜窦畸形,同时可评估大脑发育状况,有助于评估胎儿预后。     

Prenatal diagnosis of pyriform sinus fistula: case report and literature review

We describe a case of prenatal diagnosis of a pharyngeal cyst as a pyriform sinus fistula on the findings of ultrasonography and magnetic resonance imaging.     

脑静脉窦血栓形成的诊断及治疗

目的:探讨脑静脉窦血栓形成(CVST)的临床特点。方法:对20例CVST患者的一般情况、病因、临床表现、脑脊液特点、影像学特征、治疗及预后等资料进行回顾性分析。结果:20例患者多表现为头痛,可伴有癫疒间发作和各种神经功能缺损的症状体征,脑脊液压力明显升高,白细胞数和蛋白质定量可正常或升高,头颅CT示静脉窦高密度改变及脑实质异常信号,MRI示静脉窦异常信号,MRV示静脉窦闭塞或充盈缺损,DSA示静脉窦狭窄、血流中断或不显影。治疗以脱水、抗凝、溶栓为主,19例好转,1例死亡。结论:对于高颅压伴或不伴神经、精神障碍的患者,须高度警惕CVST,应尽早行MRV或DSA检查,治疗以抗凝、溶栓为主。     

Prenatal diagnosis of herniated Dandy-Walker cysts.

OBJECTIVE: The purpose of this series is to describe the prenatal diagnosis and pregnancy outcome of fetuses affected with Dandy-Walker malformation in which a posterior cyst herniated through a bony defect of the occipital skull, foramen magnum, or both. METHODS: Two- and 3-dimensional sonography were used to examine 2 fetuses with poorly delineated cerebellar structures and a large posterior cystic neck mass. Fetal magnetic resonance imaging (MRI) was added to this evaluation as a complementary diagnostic modality. RESULTS: Three-dimensional sonography helped characterize the precise site of cyst herniation through the occipital skull or foramen magnum. Fetal MRI confirmed the sonographic findings. Neonatal MRI studies identified heterotopic gray matter as evidence of a neuronal migration disorder in both fetuses. The second fetus also had agenesis of the corpus callosum. Retrospective review of the fetal MRI (25.9 weeks' menstrual age) and 3-dimensional sonographic (18.7 weeks' menstrual age) studies confirmed ventricular wall nodularity involving the occipital horns of the second fetus. CONCLUSIONS: The antenatal detection of a large posterior cystic neck mass and a poorly defined or nonvisualized cerebellar vermis suggest Dandy-Walker malformation with a herniated cyst. Three-dimensional sonography and fetal MRI are important adjunctive methods that can be used to evaluate the herniation site and a possible neuronal migrational disorder.     

硬脑膜静脉窦血栓的影像学诊断对比研究

目的：探讨磁共振各序列及CT在诊断脑硬膜静脉窦血栓中的价值。方法：20例经MRI及MRV（其中15例曾行CT检查）诊断为脑静脉窦血栓的病人，着重观察静脉窦内异常信号、脑肿胀、脑实质内异常信号及有无乳突炎等。结果：15例行CT扫描病人中，7例可见脑内异常密度影，1例可见上矢状窦增宽，有高密度影充填，MRV显示上矢状窦血栓11例，上矢状窦合并横窦、直窦或乙状窦血栓7例，左横窦及乙状窦血栓1例，右侧乙状窦血栓1例。SE序列显示脑实质内异常信号8例。显示上矢状窦、横窦、乙状窦高信号影14例。结论：硬膜窦内高信号影可提示本病，而MRV与原始图像结合在诊断静脉窦血栓及随访观察中有极大的价值，T1WI在显示脑肿胀、出血等方面优于T2WI，但T2WI对于乳突炎的显示又明显优于其他序列。磁共振检查的优越性是CT及血管造影所不及的。     

产前MRI诊断胎儿软脑膜动静脉瘘1例

<正>孕妇28岁，孕1产0,孕26周产前超声筛查提示胎儿颅内发育异常；既往无特殊病史及家族史。胎儿超声：颅内见团状不规则无回声区，脑实质结构混杂，脑沟回显示不清，CDFI见无回声区内充满彩色血流信号(图1A)。胎儿MRI:快速反转恢复运动抑制序列(fast inversion recovery motion insensitive, FIRM)图像见双侧侧脑室室管膜下多发斑片状出血，主要见于侧脑室旁生发基质，左侧为著，呈T1高信号(图1B);     

产前MRI观察孕22~38周胎儿小脑体积变化

目的 探讨孕22~38周胎儿小脑体积变化规律。方法 纳入150胎孕22~38周正常胎儿颅脑MRI资料,经计算机校正处理后测量胎儿小脑横径(TCD)、小脑蚓部上下径(CC)及前后径(AP),手动校正后经计算获得小脑体积(CV)。分析小脑TCD、CC、AP及CV与孕周的相关性,观察不同孕龄胎儿小脑体积变化规律。结果 胎儿TCD、CC、AP及CV均与孕周呈高度正相关(r=0.965、0.917、0.909、0.974,P均＜0.001)。孕22~38周胎儿小脑发育迅速,CV自(1.49±0.17) cm³激增至(17.43±0.91) cm³,平均增长率为15.8%/周,孕22~25周、孕26~30周、孕31~34周及孕35~38周CV相对增长率分别为13.0%/周、19.8%/周、8.3%/周及7.5%/周。结论 孕22~38周胎儿CV发育呈先快后慢模式,其发育速度在不同孕龄存在差异,以孕26~30周增长速度最快。     

The role of magnetic resonance imaging in the evaluation of isolated mild ventriculomegaly.

OBJECTIVE: Isolated mild ventriculomegaly is defined as dilatation of the lateral ventricle from 10 to 15 mm, with no other structural abnormalities observed at the time of diagnosis. Its reported frequency is between 1 per 50 and 1 per 700 deliveries. There are no universal recommendations for evaluation of isolated mild ventriculomegaly. Targeted sonography, karyotype analysis, and viral antigen testing, particularly for cytomegalovirus, are most often used for further investigation of this finding. We studied the role of magnetic resonance imaging as part of the prenatal evaluation of isolated mild ventriculomegaly. METHODS: Thirty-six pregnant women were referred to 2 Hadassah hospitals between 1999 and 2002 for evaluation of isolated mild ventriculomegaly. They underwent targeted sonography to exclude other anomalies, genetic amniocentesis for fetal karyotype, and serologic cytomegalovirus tests. Mild ventriculomegaly was the only pathologic finding diagnosed. Fetal brain magnetic resonance imaging was performed to evaluate the correlation between sonographic and magnetic resonance imaging findings and the additional contribution of magnetic resonance imaging in evaluating isolated mild ventriculomegaly. RESULTS: Thirty-six magnetic resonance imaging studies were performed. All tests were adequate for evaluation. In 3 (8.3%) of 36 cases, magnetic resonance imaging showed additional findings: in a severely obese woman, ventricular dilatation up to 18 mm and periventricular cystic lesions with abnormal sulcation suggestive of diffuse parenchymal abnormality were diagnosed, and in 2 cases, bleeding in germinal centers was found. On subsequent sonographic examination, no other finding but isolated mild ventriculomegaly was diagnosed. In the remaining 33 women (91.7%), magnetic resonance imaging studies correlated well with sonographic findings. Further sonographic follow-up in this subgroup failed to reveal any other pathologic findings. CONCLUSIONS: Our study supports the view that magnetic resonance imaging should be considered as part of the evaluation of isolated mild ventriculomegaly, especially when objective difficulties preclude detailed sonographic examination.     

儿童大脑静脉血栓诊断:3D Brainview T1W黑血序列与3D CE-MRV序列的对比研究

目的回顾性评价3D Brainview T1W黑血序列对儿童大脑静脉血栓的诊断价值。材料与方法回顾性分析25名临床症状提示大脑静脉血栓或已被诊断大脑静脉血栓的儿童病例,25名儿童均在3.0 T磁共振仪上扫描3D Brainview T1W黑血序列和三维磁共振增强静脉血管成像序列(3D contrast-enhanced magnetic resonance venography,3D CE-MRV),其中10名儿童还扫描了颅脑常规MRI和相位对比法三维磁共振静脉血管成像(3D magnetic resonance venography,3D MRV)序列。两名高年资神经放射医生独立双盲阅读3D Brainview T1W和3D CE-MRV图像进行大脑静脉血栓诊断,诊断参考标准基于最后的临床诊断。采用Kappa一致性分析评价3D Brainview T1W序列的观察者间一致性。将3D Brainview T1W和3D CE-MRV获得的最终诊断结果与参考标准对比,分别计算3D Brainview T1W和3D CE-MRV序列诊断的敏感度、特异度及95%CI。结果3D Brainview T1W序列具有非常高的观察者间一致性(k=0.95);3D Brainview T1W序列和3D CE-MRV序列诊断的敏感度及特异度分别为97.1%/99.6%和91.4%/99.2%,差异无统计学意义,但3D Brainview T1W可直接观察血栓,提供的血栓细节及诊断信息更多。结论3D Brainview T1W能够直接观察到血栓,在儿童大脑静脉血栓诊断中具有很高的诊断效能。     

脑静脉血栓形成的临床与MRI表现

【目的】探讨脑静脉血栓形成(CVT)的临床与磁共振成像(MRI)特征。【方法】收集42例脑静脉血栓形成患者资料,详细分析其临床表现和MRI特征。【结果】90.5%的病人有头痛、呕吐等颅高压表现,50%的病人伴有局灶神经功能缺损如肢体无力、癫痫发作、视力下降等,21.4%的病人有精神异常,38.1%的病人仅表现为颅内压增高;MRI和磁共振静脉成像(MRV)能直接显示脑静脉闭塞及其血栓栓子。【结论】MRI和MRV对脑静脉血栓形成诊断起着重要作用。     

MRI、磁共振静脉造影及弥散加权成像在不同时期脑静脉窦血栓中的诊断价值

目的探讨MRI、磁共振静脉造影（MRV）及弥散加权成像（DWI）在不同时期脑静脉窦血栓中的诊断价值。方法回顾性分析本院2015年11月~2019年8月经数字减影血管造影或临床随访确诊的27例脑静脉窦血栓患者的MRI资料,其中18例患者行DWI检查,9例患者接受MRI增强检查。结果27例静脉窦血栓患者MRI平扫表现流空信号消失,静脉窦出现异常信号,3例脑静脉窦血栓患者MRI增强后表现为空三角征,MRV则显示静脉窦血流高信号不同程度缺失,局限性或阶段性血栓以血流高信号变细、中断为主。DWI对急性和亚急性脑静脉窦血栓及继发静脉性脑梗塞敏感。结论MRI、MRV联合DWI有助于静脉窦血栓的早期诊断并可以反映血栓的演变过程,为临床及时治疗静脉窦血栓具有重要意义。     

Prenatal sonographic diagnosis of hemivertebra.

OBJECTIVE: To describe our experience in prenatal diagnosis of hemivertebra. METHODS: This is a case series of patients referred to our tertiary medical center over a 3-year period. All fetuses were scanned by high-resolution real-time scanners. The apparent vertebral anomaly was assessed in a real-time manner by a joint team of obstetricians, sonographers, and pediatric orthopedic surgeons. A complete anomaly survey of other fetal organs was performed on each fetus. All patients were given proper counseling by the same joint team. All patients had detailed obstetric and neonatal follow-up. Prenatal sonograms, neonatal medical records, and clinical courses were evaluated retrospectively. RESULTS: During the 3 years, 6 cases of hemivertebra were identified in our department. Gestational age at diagnosis was 14 to 23 weeks. Two patients had conception by assisted reproductive technology. Associated anomalies included VATER syndrome (vertebral defects, imperforate anus, tracheoesophageal fistula, and radial and renal dysplasia), gastroschisis, and pyelectasis. Outcomes in fetuses without major associated anomalies were fair. CONCLUSIONS: Diagnosis of isolated hemivertebra might be associated with a favorable outcome. The 3 key factors in achieving an optimal spine at maturity, early diagnosis, anticipation, and prevention of deterioration, might be enhanced by our joint multidisciplinary approach to the diagnosis of skeletal anomalies.     

Sonographic diagnosis of plantar vein thrombosis: report of 3 cases.

OBJECTIVE: The purpose of this series is to describe sonographic findings in 3 patients with plantar vein thrombosis. METHODS: Three patients had sudden pain and swelling at the plantar side of the affected foot. Sonography of the plantar foot was performed with a broadband linear array working at 5 to 12 MHz. Gadolinium-enhanced magnetic resonance imaging was performed in 1 patient. RESULTS: Sonography showed enlarged incompressible plantar veins in all 3 cases. Magnetic resonance imaging confirmed venous thrombosis in 1 case. CONCLUSIONS: Pain and swelling at the plantar side of the foot can be caused by plantar vein thrombosis. This type of rare thrombosis can be diagnosed with sonography.     

产前MRI诊断及随访胎儿侧脑室前角旁囊肿

目的 评价产前MRI诊断胎儿侧脑室前角旁囊肿的价值,并随访观察胎儿转归.方法 回顾性分析44胎侧脑室前角旁囊肿胎儿,并跟踪随访观察其MRI特征及妊娠结局.结果 44胎中,23胎Ⅰ型、11胎Ⅱ型及10胎Ⅲ型侧脑室前角旁囊肿;T1WI见侧脑室前角旁类圆形/椭圆形、条形低信号,T2WI呈高信号,边界清晰;其中22胎合并其他颅...