Cystic mediastinal lesions in children: Evaluation by magnetic resonance and conventional imaging

The signals obtained from mediastinal cystic lesions in children by magnetic resonance imaging (MRI) have been analysed. The advantages and pitfalls in establishing the final diagnosis by MRI are compared to the conventional radiographic technique and to computed tomography.     

Muscular magnetic resonance imaging for evaluation of myopathies in children

BACKGROUND: Myopathies present with a broad diagnostic spectrum which may ultimately require muscle biopsy. MRI has been established as a non-invasive method in diagnosing adult myopathies; not only does MRI reveal characteristic findings which point in a diagnostic direction, but also aids in determining optimal biopsy sites and controlling therapeutic interventions. Muscle MRI is increasingly finding application to pediatric myopathies, especially dystrophies and myositides. The following paper serves to illustrate the use of MRI using exemplary clinical vignettes. PATIENTS/METHODS: From 1999 until 2006, 180 children with myopathies of unknown aetiology, ages 10 months to 18 years, were examined with a standardised MRI protocol (axial T1-SE and T2-weighted TIRM sequences). The protocol included imaging of the lower extremities whereas sequences displaying the upper extremities were only acquired in selected patients. Furthermore, intravenous contrast agent was only administered in selected children. RESULTS: All investigations could be performed without sedation due to an examination time of 12 to 15 minutes. The illustrated cases of limb-girdle muscular dystrophy, Duchenne's muscular dystrophy, dermatomyositis, pyomyositis, and chronic neurogenic disease with secondary myopathy all showed disease-characteristic MRI patterns which substantially helped to reach the ultimate diagnosis. CONCLUSIONS: Muscle MRI is a non-invasive and effective instrument in helping to diagnose pediatric myopathies of unknown aetiology. It may facilitate muscle biopsy and serves to control therapeutical effects and disease course. Furthermore, muscle MRI may be applicated even to children of less than 4 years of age without sedation.     

Nuclear magnetic resonance imaging of the brain in children

Nuclear magnetic resonance imaging of the hydrogen nucleus provides a unique noninvasive display of proton dynamics in biologic tissues and fluids as well as internal anatomy in a sectional imaging format. No ionizing radiation is utilized. Our experience with NMR imaging of the brain in 14 pediatric patients is presented and compared with computed tomography. The major advantages of NMR over CT include its greater sensitivity to blood flow, edema, hemorrhage, and myelinization and its lack of beam-hardening artifacts. In addition, the potential for tissue characterization exists by determination of T1 and T2 relaxation times and of mobile proton density. Disadvantages of NMR over CT include its failure to demonstrate calcification and bone detail and longer data acquisition times.     

磁共振动脉血管成像在儿童脑梗死中的应用

目的　探讨三维时间飞跃磁共振动脉血管成像法 (3D TOFMRA)对儿童脑梗死的应用价值。方法　 15例脑梗死患儿均经头MRI确诊 ,应用美国Marconi公司ECLIPSEMR仪 1.5 T ,发病 1周内做头MRA的检查。脑梗死灶均位于单侧 ,左侧 9例 ,右侧 6例 ;额叶、顶叶各 1例 ,多叶脑梗死 8例 ,基底节腔隙性梗死 5例。均予常规治疗。结果　MRA正常 4例 ,单独 /并累及大脑中动脉 (MCA) 8例 ,单独累及大脑前动脉 (ACA) 1例 ,累及双侧椎动脉 /基底动脉 2例 (但无病灶部位相应的血管受累表现 )。受累动脉末端细小分支减少、纤细 4例 ,单支动脉起始部或一级分支起始部狭窄 /闭塞 4例 ,双侧椎动脉 /基底动脉走行迂曲 2例 ,病变同侧MCA、ACA同时受累、末端细小分支减少、纤细 1例。治疗后MRA正常及受累动脉末端细小分支减少、纤细患儿平均 5±1.31d运动开始恢复 ,双侧椎动脉 /基底动脉走行迂曲、动脉起始部梗死 /分支起始部狭窄及同侧MCA、ACA均受累病人平均 10 .9± 5 .15d运动开始恢复 ,两者相比有显著差异。结论　大多数脑梗死患儿在MRA上均有相应的血管改变 ,其变化部位多为MCA系统 ,变化程度与预后有关     

Applications of magnetic resonance imaging and magnetic resonance angiography to evaluate the hepatic vasculature in the pediatric patient

Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) offer several techniques to evaluate the hepatic vasculature. These techniques are briefly reviewed with reference to the pediatric population. Examples of MRI and MRA in the evaluation of the hepatic vasculature in pediatric patients are presented. Received: 4 May 1998 Accepted: 12 October 1998     

小脑扁桃体下疝畸形的磁共振表现

目的　探讨小脑扁桃体下疝畸形 (Chiari)磁共振成像 (MRI)表现及其与临床的关系。方法　采用MRI对 4 8例Chiari患儿畸形程度及全颅腔容积和后颅窝容积进行测量分析。结果　小脑扁桃体下缘至枕大孔下缘连线距离 >10mm者 16例 ,5～ 9mm者 2 6例 ,<5mm者 6例 ,并脊髓空洞 38例 ,占 79%。小脑扁桃体下缘形态呈楔状变尖 32例 ,占 6 7%。颅腔容积 (1381.13± 76 .98)ml;后颅窝容积为 (170 .6 5± 17.39)ml。结论　MRI是Chiari畸形最重要的检查手段 ,对临床诊断及治疗具有指导意义     

Cardiac magnetic resonance imaging in children with congenital heart disease

Electrocardiogram-gated magnetic resonance imaging (MRI) was used to evaluate 36 children, ages 2 to 17 years, with congenital heart disease. With the use of multiple imaging planes, including transverse, sagittal, coronal, and 60-degree left anterior oblique views, high contrast images with excellent spatial resolution were produced. In 34 of the 36 patients the anatomic detail provided by MRI was sufficient to make the cardiac diagnosis. Electrocardiogram-gated MRI is an important new imaging technique for use in children with cardiovascular disease.     

Neonatal seizures associated with cerebral lesions shown by magnetic resonance imaging

AIM—To determine the diagnostic potential of magnetic resonance imaging (MRI) in neonatal seizures; to elucidate the aetiology, timing, and prognosis of the cerebral lesions detected.METHODS—Thirty one term neonates with clinical seizures underwent ultrasonography between days 1-7 (mean 2.5 days) and a high field spin-echo MRI scan on days 1-30 (mean 8.1 days), both of which were repeated at 3 months of age. Routine investigation excluded, as far as possible, infection, haematological, and metabolic-toxic causes as causes of the neonatal seizures.RESULTS—Brain abnormality was demonstrated by MRI in 68% of infants and ultrasonographically in 10%. Diffuse brain lesions (present in 29%) were associated with high mortality (58%) and morbidity (42%), whatever the aetiology. In contrast to a better short term prognosis for neonates with focal lesions where no infants died, 33 % had a handicap, and the rest were normal at a mean follow up age of 21/2 years. Cerebral lesions were presumed to have antepartum origin in 43% of cases. Seizure aetiology was considered to be hypoxic-ischaemic in 35%, haemorrhagic in 26%, metabolic disturbances and cerebral dysgenesis in 16% and unknown in 23%.CONCLUSIONS—MRI detected a remarkably high incidence of brain lesions in neonatal seizures. Almost half of these were of prenatal origin and pathogenesis may essentially be attributed to hypoxic and/or haemodynamic causes.     

Cardiovascular magnetic resonance imaging of hypoplastic left heart syndrome in children

Cardiovascular magnetic resonance imaging (CMR) plays an important complementary role to echocardiography and conventional angiography in the evaluation of hypoplastic left heart syndrome. This imaging modality is particularly useful for assessing cardiovascular postsurgical changes, extracardiac vascular anatomy, ventricular and valvular function, and a variety of complications. The purpose of this article is to provide a contemporary review of the role of CMR in the management of untreated and surgically palliated hypoplastic left heart syndrome in children.