Real-time magnetic resonance imaging aids prenatal diagnosis of isolated cleft palate.

OBJECTIVE: Cleft of the secondary palate without cleft lip is difficult to visualize sonographically. This study was performed to assess the utility of sonography, standard magnetic resonance (MR) imaging, and real-time MR imaging in the diagnosis of isolated cleft palate. METHODS: We prospectively assessed 5 fetuses at risk for isolated cleft palate on the basis of family history, micrognathia, or both, using sonography and standard and real-time single-shot fast spin echo MR sequences. Written informed consent was obtained under our Institutional Review Board-approved Health Insurance Portability and Accountability Act-compliant protocol. Images were assessed for confidence in a diagnosis of cleft or normal palate. Prenatal and postnatal diagnoses were compared. RESULTS: In 3 fetuses, micrognathia was visualized by sonography and MR imaging with standard and real-time sequences. One fetus at 19 weeks had a wide cleft of the entire secondary palate, and another fetus at 33 weeks had a cleft of the soft palate; these defects were seen only with real-time MR imaging. One 35-week gestational age fetus had a cleft soft palate that was visualized on standard and real-time MR imaging. Two fetuses with no abnormalities had the normal midline secondary palate seen only on real-time MR imaging. In all fetuses, real-time images were helpful in assessing the secondary palate because the entire midline naso-oropharynx could be visualized. CONCLUSIONS: Real-time MR imaging allows for rapid assessment of the midline structures, providing accurate diagnosis of isolated cleft palate.     

Fetal magnetic resonance imaging in the evaluation of fetuses referred for sonographically suspected abnormalities of the corpus callosum.

OBJECTIVE: Fetal magnetic resonance imaging (MRI) has been shown to be useful in assessing the developing central nervous system. However, its utility in specific brain disorders has not been well investigated. We hypothesized that fetal MRI can better assess the integrity of the brain in cases with sonographically suspected callosal abnormalities. METHODS: We retrospectively reviewed fetal MRI and prenatal sonographic studies of 10 fetuses referred for MRI for sonographically suspected callosal abnormalities. RESULTS: An abnormal corpus callosum was identified on fetal MRI in 80% of cases. The type of callosal abnormality (complete or partial agenesis) was similar on both prenatal sonography and fetal MRI in all cases. All sonographically identified additional brain abnormalities were detected on fetal MRI, with the exception of choroid plexus cysts. Furthermore, in 63% (5 of 8) of cases with a callosal abnormality on both sonography and fetal MRI, additional brain abnormalities were detected on fetal MRI that were not apparent on sonography. These sonographically occult findings were confirmed on postnatal MRI or autopsy in 3 of 5 patients. CONCLUSIONS: Fetal MRI is an important adjunct to sonography in assessing the corpus callosum and other aspects of brain development when agenesis of the corpus callosum is suspected. It can identify frequent additional findings that are not visible on sonography such as abnormal sulcation. In light of the association between additional brain abnormalities and worse neurodevelopmental outcome, the potential of fetal MRI as an important adjunctive prognostic imaging test in fetuses with callosal agenesis can now be tested.     

遗忘型轻度认知障碍近十年磁共振成像研究进展

随着我国社会老龄化的不断加速,老年痴呆的发病率不断增高,其也是中老年群体的重要死因之一。轻度认知障碍是介于正常脑老化与老年痴呆的一种认知功能障碍状态,遗忘型轻度认知障碍作为其主要分型,是老年痴呆的高危因素。在老年群体中,遗忘型轻度认知障碍发病率高达10%以上。与认知正常的老年人相比,轻度认知障碍患者患痴呆的风险高4~10倍,在此阶段对患者进行有效诊治,可极大延缓患者病情向痴呆转化的进程。目前,遗忘型轻度认知障碍诊断主要依靠临床神经电生理检查及神经影像学检查,近年来随着磁共振成像技术的不断发展,极大提高了遗忘型轻度认知障碍的早期诊断效能,本文对扩散张量成像、基于体素的形态学测量、动脉自旋标记成像、磁共振波谱、酰胺质子转移成像、静息态功能磁共振成像几种磁共振成像技术在遗忘型轻度认知障碍中的应用现状进行综述,以期为临床医生提供帮助。     

扩散加权成像评价胎儿轻度侧脑室扩张

目的 探讨ADC值对胎儿轻度侧脑室扩张的诊断价值。方法 对15胎轻度侧脑室扩张胎儿（侧脑室扩张组）及15胎侧脑室无扩张的胎儿（对照组）行DWI扫描,测量双侧额叶、顶叶、颞叶、枕叶白质、基底核、丘脑及小脑ADC值,比较2组各脑区ADC值差异及轻度侧脑室扩张胎儿左侧及右侧各脑区ADC值的差异。分析所有胎儿各脑区ADC值与孕周的相关性、侧脑室扩张胎儿侧脑室宽度与孕周的相关性。结果 与对照组比较,轻度侧脑室扩张组双侧额叶、双侧顶叶白质ADC值下降（P均<0.05）。侧脑室扩张胎儿左侧与右侧各脑区ADC值差异均无统计学意义（P均>0.05）。相关分析显示所有胎儿双侧枕叶、双侧基底核区、双侧丘脑、双侧小脑及左侧颞叶ADC值与孕周呈负相关,侧脑室扩张胎儿侧脑室宽度与孕周呈正相关（r=0.635,P=0.011）。结论 轻度侧脑室扩张胎儿额叶、顶叶ADC值下降,ADC值对检测潜在脑部损伤较敏感,有助于诊断胎儿侧脑室扩张。     

Fetal lung volume estimated by 3-dimensional ultrasonography and magnetic resonance imaging in cases with isolated congenital diaphragmatic hernia.

OBJECTIVE: To assess the agreement of 3-dimensional ultrasonography and magnetic resonance imaging in estimating fetal lung volume in cases with isolated congenital diaphragmatic hernia. METHODS: Fetal lung volume was measured in 11 cases of congenital diaphragmatic hernia (10 left and 1 right) by 3-dimensional ultrasonography and magnetic resonance imaging. These examinations were performed during the same week. The operators were blinded to each other's results. Intraclass correlation was used to evaluate the agreement between 3-dimensional ultrasonography and magnetic resonance imaging estimations of the ipsilateral, contralateral, and total fetal lung volume. A Bland-Altman graph was plotted to detect possible discordant observations. RESULTS: The global intraclass correlation coefficient between magnetic resonance imaging and 3-dimensional ultrasonographic measurement of fetal lung volume was 0.94 (95% confidence interval, 0.78-0.98) with no outliers observed on the Bland-Altman plot. CONCLUSIONS: There is a good agreement between 3-dimensional ultrasonography and magnetic resonance imaging for fetal lung volume estimation in cases with congenital diaphragmatic hernia.     

Ultrasound and fetal magnetic resonance imaging: Clinical performance in the prenatal diagnosis of orofacial clefts and mandibular abnormalities

Cleft lip, with or without cleft palate, is the most common congenital craniofacial anomaly and the second most common birth defect worldwide. Micrognathia is a rare facial malformation characterized by small, underdeveloped mandible and frequently associated with retrognathia. Second- and third-trimester prenatal ultrasound is the standard modality for screening and identification of fetal orofacial abnormalities, with a detection rate in the low-risk population ranging from 0% to 73% for all types of cleft. The prenatal ultrasonography detection can also be performed during the first trimester of pregnancy. Given the potential limitations of obstetric ultrasound for examining the fetal face, such as suboptimal fetal position, shadowing from the surrounding bones, reduce amniotic fluid around the face, interposition of fetal limbs, umbilical cord and placenta, and maternal habitus/abdominal scars, the use of adjunct imaging modalities can enhance prenatal diagnosis of craniofacial anomalies in at-risk pregnancies. Fetal magnetic resonance imaging (MRI) is a potentially useful second-line investigation for the prenatal diagnosis of orofacial malformations with a pooled sensitivity of 97%. In this review, we discuss the role of ultrasound and fetal MRI in the prenatal assessment of abnormalities of the upper lip, palate, and mandible.     

磁共振扩散成像技术在轻度认知障碍的研究进展

轻度认知障碍(mild cognitive impairment,MCI)被认为是正常老龄化和阿尔茨海默病(Alzheimer'disease,AD)以及其他类型痴呆的中间状态。给予MCI患者积极的干预治疗,有助于改善认知功能并减缓MCI向AD的转变。因此,寻找MCI诊断和进展监测的敏感影像标记物是非常必要的。磁共振扩散成像技术能够通过描述脑组织中水分子的扩散运动来检测微观结构的变化,可以为MCI的病理机制研究和认知障碍严重程度的评估提供重要的信息。近年来,新型磁共振扩散成像技术的不断发展为MCI的研究提供了额外的价值。作者对扩散张量成像(diffusion tensor imaging,DTI)、扩散峰度成像(diffusion kurtosis imaging,DKI)、自由水扩散磁共振成像(free-water diffusion magnetic resonance imaging,FW diffusion MRI)、神经突方向离散度和密度成像(neurite orientation dispersion and density imaging,NODDI)技术在MCI中的研究进行综述。     

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.     

Fetal magnetic resonance imaging enhances detection of spinal cord anomalies in patients with sonographically detected bony anomalies of the spine.

OBJECTIVE: Although fetal magnetic resonance imaging (MRI) is being increasingly used to evaluate sonographically suspected abnormalities, its utility in the evaluation of the spinal canal is not well studied. Because it is not susceptible to the limitations of fetal position, oligohydramnios, and shadowing from bony structures, we hypothesize that fetal MRI is better suited to assess the contents of the spinal canal compared with prenatal sonography. The purpose of this investigation was to determine whether fetal MRI could detect spinal abnormalities in cases in which they had not been originally suspected on prenatal sonography. METHODS: Fetal spine MR images were retrospectively reviewed over a 42-month period. Corresponding sonographic images were then rereviewed to determine whether there were findings in retrospect that might have suggested the cord abnormalities. Cases of myelomeningocele were counted as a spinal cord abnormality only if fetal MRI showed a cord anomaly other than the myelomeningocele. RESULTS: Of 33 cases referred for bony anomalies of the spine, fetal MRI showed additional abnormalities involving the spinal cord in 3 patients. These included diastematomyelia in 2 cases and segmental spinal dysgenesis in the third case. One case of diastematomyelia occurred in association with a lumbosacral myelomeningocele. The spinal cord anomalies were not visible on any of the prenatal sonograms, even in retrospect. CONCLUSIONS: Additional spinal cord anomalies were detected in 10% of cases reviewed. Fetal MRI can be useful in assessing the spinal cord in fetuses with bony spinal anomalies. Our findings suggest that fetuses with sonographically diagnosed bony abnormalities of the spine may benefit from further evaluation with fetal MRI.     

Magnetic resonance imaging of the kinked fetal brain stem: a sign of severe dysgenesis.

OBJECTIVE: Magnetic resonance imaging (MRI) allows visualization of the fetal brain stem in a manner not previously possible. A "kinked" brain stem is a sign of severe neurodysgenesis. The purpose of this series was to describe cases of a kinked brain stem detected on prenatal MRI and to discuss the possible genetic and syndromic etiologies. METHODS: Seven cases of a kinked brain stem on fetal MRI (gestational age range, 18-34 weeks) were reviewed and correlated with other clinical, genetic, imaging, and autopsy findings. RESULTS: In all cases, there was associated cerebellar hypogenesis. Additional findings were ventriculomegaly (4 cases), cerebral hypogenesis (3 cases), microcephaly (4 cases), schizencephaly (1 case), cephalocele (1 case), hypogenesis of the corpus callosum (1 case), and hydrocephalus (1 case). In 2 cases, prenatal sonography misidentified the kinked brain stem as the cerebellum. CONCLUSIONS: A kinked brain stem is an indicator of severe neurodysgenesis arising early in gestation. Magnetic resonance imaging provides the necessary resolution to detect this sign and delineate any associated anomalies in utero to assist with further genetic evaluation, management, and counseling.     

Prenatal diagnosis of periventricular nodular heterotopia in borderline ventriculomegaly using sonography and magnetic resonance imaging

Periventricular nodular heterotopia (PNH) is usually missed on prenatal sonographic examinations, even on targeted scans. Irregular ventricular walls on axial view and irregular square‐shaped lateral ventricles on coronal view are suggestive of PNH in the early third trimester. To achieve an early prenatal diagnosis, it is important to keep in mind the possible coexistence of PNH with brain malformations such as ventriculomegaly, posterior fossa anomalies, or agenesis of corpus callosum. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44 :510–513, 2016     

经超声诊断的孤立性轻度侧脑室增宽胎儿的临床预后

目的 探讨超声诊断的胎儿孤立性轻度侧脑室增宽的临床特点及预后.方法 回顾性分析我院产前诊断的22胎孤立性轻度侧脑室增宽(IMV)的资料,并进行产后追踪随访,重点观察胎儿神经系统发育情况.结果 产前超声诊断并成功随访IMV22胎,侧脑室宽度10.3～14.1 mm,平均宽度12.5 mm.2名孕妇选择引产(其中1胎证实为21-三体),其余20胎活产(男胎12例,女胎8例).活产病例中,1例于出生后10天死亡,19例存活,其中1例发生神经系统发育迟滞,余18例发育正常.6胎于妊娠晚期及生后复查IMV自然消退.结论 超声检查是胎儿IMV产前诊断的有效方法,IMV胎儿总体预后较好,但应重视出生后随诊.     

脑静息态功能磁共振局部一致性分析在轻度认知障碍患者中的初步研究

目的利用局部一致性(regional homogeneity,ReHo)分析方法来探讨轻度认知障碍(mild cognitive impairment,MCI)患者局部自发脑活动特点,并进一步探讨相应脑区ReHo值改变与认知功能及临床生理指标的相关性。材料与方法39例被试入组,其中临床诊断的MCI患者17例,年龄、性别及受教育年限相匹配的健康志愿者22例,所有受试者均行静息态功能磁共振成像(resting-state fMRI,rs-fMRI)扫描,采用rs-fMRI的ReHo分析方法,比较静息状态下MCI患者与健康志愿者ReHo值存在差异的脑区,对存在显著差异脑区的ReHo值与认知评估量表及临床生理指标进行相关分析。结果与正常对照比较,MCI组右侧岛叶、左侧小脑半球、旁扣带回、颞下回、左右梭状回ReHo值升高;而左侧颞上回、右侧背外侧额上回ReHo值降低。所有被试蒙特利尔认知评估量表(montreal cognitive assessment scale,MoCA)评分与右侧脑岛区(r=-0.487,P=0.002)ReHo值呈负相关,与左侧颞上回(r=0.610,P<0.001)及右侧背外侧额上回(r=0.475,P=0.002)呈正相关。所有被试简易智能状态检查量表(mini mental status examination,MMSE)评分与左侧小脑上回(r=-0.407,P=0.010)呈负相关,与左侧颞上回(r=0.466,P=0.003)呈正相关。MCI组右侧岛叶ReHo值与血浆果糖胺浓度呈负相关(r=-0.630,P=0.007),左侧小脑半球ReHo值与血清肌酐浓度呈负相关(r=-0.579,P=0.015)。结论轻度认知障碍患者rs-fMRI的ReHo值有明显改变,并与认知功能改变及临床生理指标存在一定的相关性。     

Brain and heart magnetic resonance imaging/spectroscopy in duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is an X‐linked muscle disorder characterized by progressive and irreversible loss of muscular function. As muscular disease progresses, the repair mechanisms cannot compensate for cellular damage, leading inevitably to necrosis and progressive replacement by fibrous and fatty tissue. Cardiomyopathy and respiratory failure are the main causes of death in DMD. In addition to the well‐described muscle and heart disease, cognitive dysfunction affects around 30% of DMD boys. Myocardial fibrosis, assessed by late gadolinium enhancement (LGE), using cardiovascular magnetic resonance imaging (CMR), is an early marker of heart involvement in both DMD patients and female carriers. In parallel, brain MRI identifies smaller total brain volume, smaller grey matter volume, lower white matter fractional anisotropy and higher white matter radial diffusivity in DMD patients. The in vivo brain evaluation of mdx mice, a surrogate animal model of DMD, showed an increased inorganic phosphate (P(i))/phosphocreatine (PCr) and pH. In this paper, we propose a holistic approach using techniques of magnetic resonance imaging, spectroscopy and diffusion tensor imaging as a tool to create a “heart and brain imaging map” in DMD patients that could potentially facilitate the patients’ risk stratification and also future research studies in the field.     

多模态磁共振成像在脑胶质瘤分级诊断及预后评估中的研究进展

脑胶质瘤是中枢神经系统中常见的恶性肿瘤,其具有弥漫性浸润生长的特点,在治疗的过程中具有较大的难度,肿瘤恶性程度高,容易复发、预后较差。多模态磁共振成像技术多用于肿瘤术前的初步诊断,在胶质瘤分级判断以及预测预后方面具有重要的价值。本文就扩散加权磁共振成像、弥散张量磁共振成像、动态磁敏感对比灌注加权成像、动态对比增强磁共振成像、动脉自旋标记成像和磁共振波谱成像等几种多模态磁共振成像技术在脑胶质瘤术前分级诊断及预后评估方面的研究进展进行综述。     

Sonographic and magnetic resonance imaging findings in uterine incarceration

We show the sonographic and magnetic resonance imaging features of uterine incarceration. Clinical data and imaging findings were retrospectively reviewed for 8 confirmed cases identified by sonography from 2000 to 2010. Two patients had magnetic resonance imaging. Seven of 8 patients (87.5%) presented with abdominal pain; 4 of 8 (50.0%) also had urinary symptoms. All had a retroverted uterus with an elongated anterosuperiorly displaced or poorly visualized cervix on sonography. Magnetic resonance imaging showed similar features, but in both cases, the placental position was misinterpreted because of severe uterine retroversion. Radiologists should be aware of this condition and its imaging features to reduce associated morbidity and mortality.     

Sonographic findings of pectoralis major tears with surgical, clinical, and magnetic resonance imaging correlation in 6 patients.

OBJECTIVE: The purpose of this research was to describe the sonographic findings of pectoralis major injuries with clinical, surgical, and magnetic resonance imaging (MRI) correlation. METHODS: Images from sonographic examinations of the pectoralis major muscle of 6 patients were retrospectively evaluated and characterized. The sonographic findings were compared with clinical, surgical, and MRI findings. RESULTS: The 6 patients were male (mean age, 30 years) with injuries sustained during weight lifting, football, and shotgun firing. Two of the 6 patients had MRI correlation; 1 had surgical correlation; 2 had both surgical and MRI correlation; and 1 had clinical follow-up. The sternal head was injured in 5 patients; 4 involved the musculotendinous junction, and 1 involved the distal tendon. The sonographic findings of muscle fiber retraction and surrounding hemorrhage allowed identification of the affected muscle. Direct impact injury causing hematoma involved the clavicular head in 1 patient. In total, 5 cases were partial-thickness pectoralis major tears, whereas complete distal tendon disruption was found in 1. CONCLUSIONS: Sonographic imaging longitudinal to the pectoralis muscle fibers showed fiber disruption, retraction, and possible hypoechoic or anechoic hematoma, most commonly involving the musculotendinous junction of the sternal head. Distal tendon assessment is important to evaluate for a full-thickness pectoralis major tear.     

Adenomyosis:common and uncommon manifestations on sonography and magnetic resonance imaging.

OBJECTIVE: The purpose of this presentation is to show the imaging findings of the common and uncommon variants of adenomyosis as seen on sonography and magnetic resonance imaging (MRI). METHODS: A 3-year database search was performed to identify women who had pelvic sonography and pelvic MRI within a 6-month interval. Images of these cases were retrospectively reviewed. RESULTS: Eighty women were identified. Adenomyosis was diagnosed on MRI, which was used as the reference standard, in 45 of these women. The correct diagnosis was made on sonography in 73% of the cases. CONCLUSIONS: Awareness of the spectrum of imaging features of adenomyosis is important to use sonography effectively for diagnosing this entity and to help avoid misdiagnosis.     

静息态脑功能磁共振成像在急性轻型脑外伤中的应用

目的 分析静息态脑功能磁共振成像在急性轻型脑外伤临床中的应用效果。 方法 选取北京博爱医院2019年5月至2021年5月收治的急性轻型脑外伤患者47例为观察组,同期行常规体检的健康人50例为对照组,采用静息态脑功能磁共振成像采集低频震荡幅度(ALFF),采用简易精神状态检查(MMSE)、蒙特利尔认知评定(MoCA)、Rivermead行为记忆功能测试(RBMT)进行评定。 结果 与对照组相比,观察组MMSE、MocA、RBMT评分均显著降低(t > 18.138, P < 0.001);观察组ALFF降低的脑区包括小脑后叶、小脑扁桃体、下半月小叶、右侧颞上回、右侧颞中回、右侧顶叶和右侧中央后回等,ALFF升高的脑区包括边缘叶、扣带回、楔前叶、左侧小脑、右侧颞上回、右侧颞中回、右侧额上回、右侧额中回和右侧额下回等。 结论 急性轻型脑外伤患者存在多个脑区异常改变,可能与认知障碍有关。