Tumor-induced rickets: usefulness of MR gradient echo recall imaging for tumor localization

An 11-year-old boy presented with a femur fracture, bone hypomineralization, and hypophosphatemia, suggesting tumor-induced rickets. Conventional radiologic techniques including magnetic resonance skeletal survey did not identify a tumor. Magnetic resonance gradient echo recall imaging demonstrated a 3-cm iliac tumor, the resection of which rapidly reversed metabolic abnormalities. This technique may be useful in identifying elusive tumors associated with tumor-induced rickets.     

Magnetic resonance and ultrasound brain imaging in preterm infants

Cranial ultrasonography has been used to identify brain injury in preterm neonates for more than two decades. More recently, magnetic resonance imaging has been used to evaluate brain development and pathology in these infants. In this review we describe how well findings from these two imaging modalities agree with histology findings and neuro-developmental outcome. In addition, we discuss studies comparing ultrasound and magnetic resonance imaging findings.     

磁共振磁敏感加权成像在早产儿脑损伤中的应用价值

<正>早产儿是一组易发生不同程度神经系统发育障碍的高危人群,其常见的脑损伤主要为脑室周围-脑室内出血(PVH-IVH)和脑室周围白质软化(PVL)[1-3]。由于脑损伤早产儿在早期常无明显的临床症状,易被忽视,因此影像学诊断显得非常重     

脑电图在早产儿脑损伤早期诊断中的应用价值

目的 研究早产儿脑电图及头颅CT检查结果的相关性,探讨脑电图在早产儿脑损伤早期诊断中的应用价值.方法 所有患儿在出生24~72h行脑电图检查,根据检查结果分为脑电图正常组,脑电图轻度异常组和脑电图重度异常组.患儿于纠正胎龄40周行头颅CT检查,以了解其脑损伤情况,比较脑电图与头颅CT结果的相关性.结果 对两种检查结果进行行×列表的χ2检验,χ2=9.432,P<0.05,提示早产儿脑电图结果与头颅CT检查结果差异具有统计学意义.结论 脑电图对于早产儿脑损伤的早期诊断具有临床价值,加之脑电图检查方便、经济、实用、无创伤,并且易于重复,值得临床推广.     

Parotid haemangioma in infants: MR imaging at 1.5T

Parotid gland neoplasms are uncommon and account for less than 2% of human tumours. Haemangiomas account for about 50% of parotid tumours in infants and children compared to only 2% in adults. As the clinical course of infantile haemangiomas may be self limiting and the initial treatment is expectant, early and accurate diagnosis is essential. We report 3 cases of paediatric parotid haemangioma and discuss the Magnetic Resonance (MR) characteristics of these tumours. In two cases the diagnosis was proven histologically and in one case Computed Tomography (CT) was also performed.     

振幅整合脑电图对早产儿脑损伤的诊断价值及其影响因素

目的　探讨振幅整合脑电图(aEEG)对早产儿脑损伤(BIPI)的诊断价值及其影响因素。方法　将116例胎龄27~36+6周早产儿纳入研究, 对所有早产儿生后 6 h 内aEEG进行评分; 依据BIPI诊断结果将116例早产儿分为BIPI组(n=63)和非BIPI组(n=53), 采用logistic回归分析对导致BIPI发生的危险因素进行评估; 依据aEEG检测结果再将116例早产儿分为aEEG正常组(n=58)和aEEG异常组(n=58), 对影响早产儿aEEG结果的因素行单因素分析。结果　BIPI组中aEEG异常52 例(83%); 非BIPI组中aEEG 异常6例(11%), 两组aEEG异常率比较差异有统计学意义(P<0.05)。将早产儿依据胎龄27~33+6周和34~36+6周进行划分, BIPI组aEEG评分明显低于同胎龄非BIPI组(P<0.01)。Logistic回归分析显示：小胎龄(<32周)、低出生体重(<1 500 g)、胎盘胎膜及脐带异常和母孕期高血压是导致BIPI发生的高危因素(P<0.05)。aEEG异常组与aEEG正常组在胎龄、出生体重、胎盘胎膜及脐带异常和母孕期高血压4方面比较差异有统计学意义(P<0.05)。结论 导致BIPI发生的危险因素与影响早产儿aEEG结果的因素相一致, 提示aEEG有助于BIPI的早期诊断。     

Prognostic factors for walking attainment in very low-birthweight preterm infants

The purpose of this study was to compare the age of walking attainment between very low-birthweight (VLBW) preterm infants and normal term infants, and to determine the variables that affect the walking attainment in VLBW infants. Ninety-six VLBW preterm infants and 82 normal term infants were prospectively followed to determine their age of walking attainment and to monitor gross motor development with sequential clinic visits at 6, 9, 12 and 18 months corrected age. Perinatal and sociodemographic data were collected through review of medical records. The VLBW infants were significantly older at attainment of walking (median 14 months) than the term infants (median 12 months) after correction for prematurity. By the age of 18 months, all term infants had attained walking ability; while 11% of VLBW infants were still unable to walk. Multivariate proportional hazards regression analysis revealed that low gestational age was significantly associated with late attainment of walking in VLBW infants. With the adjustment for gestational age, prolonged ventilation (or oxygen therapy) and severe retinopathy of prematurity were significant predictors of late walking attainment. Our findings indicate that VLBW preterm infants have an increased risk of delayed attainment of walking. Furthermore, the contribution of low gestational age to the delayed walking attainment in VLBW infants may occur via the plausible pathways of neonatal respiratory distress and severe retinopathy of prematurity.     

影响早产儿脑损伤的相关因素分析

目的分析早产儿不同类型脑损伤的发生情况及影响因素。方法收集239例早产儿的临床资料及头颅磁共振检查结果,分析产前、产时、产后因素对早产儿脑损伤的影响。结果早产儿脑损伤的发生率为25.5%,其中出血性脑损伤占10.5%,缺血性脑损伤占10.5%,出血+缺血性脑损伤占4.6%。胎龄越小,出血性脑损伤及总脑损伤发生率越高(P0.01),缺血性脑损伤及出血+缺血性脑损伤的发生率与胎龄无关(P0.05)。出血性、缺血性及总脑损伤发生率均与出生体重无关(P0.05)。胎龄34周早产儿脑损伤的保护因素是经产(OR=0.292,95%CI:0.088~0.972)和剖宫产(OR=0.075,95%CI:0.015~0.368);胎龄≥34周早产儿脑损伤的保护因素是剖宫产(OR=0.296,95%CI:0.131~0.672),危险因素是严重感染(OR=8.176,95%CI:1.202~55.617)。结论在临床工作中,应尽量延长早产儿的胎龄、掌握剖宫产指征,积极有效地预防及治疗感染,以期预防或减少早产儿脑损伤的发生。     

Magnetic resonance imaging in preterm infants

MR imaging of the premature infant poses a number of challenges with regard to safety, sequence optimization and recognition of the normal appearances of the developing brain. In this paper we discuss these challenges, and review the common intracerebral abnormalities associated with premature birth. Although the outcome for very-low-birth-weight babies has improved over the last decade, there remains a significant risk of subsequent development of neurological disability. The relationship between MRI abnormalities and long-term outcome is considered.     

Visual performance in preterm infants with brain injuries compared with low-risk preterm infants

Background

Neonatal brain injuries are the main cause of visual deficit produced by damage to posterior visual pathways. While there are several studies of visual function in low-risk preterm infants or older children with brain injuries, research in children of early age is lacking.

Aim

To assess several aspects of visual function in preterm infants with brain injuries and to compare them with another group of low-risk preterm infants of the same age.

Study design and subjects

Forty-eight preterm infants with brain injuries and 56 low-risk preterm infants.

Outcome measures

The ML Leonhardt Battery of Optotypes was used to assess visual functions. This test was previously validated at a post-menstrual age of 40 weeks in newborns and at 30-plus weeks in preterm infants.

Results

The group of preterm infants with brain lesions showed a delayed pattern of visual functions in alertness, fixation, visual attention and tracking behavior compared to infants in the healthy preterm group. The differences between both groups, in the visual behaviors analyzed were around 30%. These visual functions could be identified from the first weeks of life.

Conclusion

Our results confirm the importance of using a straightforward screening test with preterm infants in order to assess altered visual function, especially in infants with brain injuries. The findings also highlight the need to provide visual stimulation very early on in life.     

Magnetic resonance imaging of the brain in a cohort of extremely preterm infants.

To define magnetic resonance imaging (MRI) appearances of the brain in extremely preterm infants between birth and term, a sequential cohort of infants born at a gestational age <30 weeks was studied with a dedicated neonatal magnetic resonance scanner. Images of infants (n = 41) with a median gestational age of 27 weeks (range 23 to 29 weeks) were initially obtained at a median age of 2 days (range 1 to 20 days) and then repeatedly studied; 29 (71%) infants had MRI at a median gestational age of 43 weeks (range 38 to 52 weeks) (term MRI). On the initial MRI scan 28 of 41 infants had abnormalities: either intraventricular hemorrhage, germinal layer hemorrhage, ventricular dilatation, or diffuse and excessive high signal intensity in the white matter on T(2)-weighted images. When magnetic resonance images for preterm infants at term gestation were compared with those of infants in the control group born at term, 22 of 29 infants had dilatation of the lateral ventricles, 24 of 29 had squaring of the anterior or posterior horns of the lateral ventricles, 11 of 29 had a widened interhemispheric fissure or extracerebral space, and 22 of 29 had diffuse and excessive high signal intensity in the white matter. There were no cases of cystic periventricular leukomalacia. We conclude that MRI abnormalities are commonly seen in the brain of preterm infants on whom images are obtained within 48 hours of birth and that further abnormalities develop between birth and term. A characteristic appearance of diffuse and excessive high signal intensity in the white matter on T(2)-weighted images is associated with the development of cerebral atrophy and may be a sign of white matter disease. These MRI appearances may help account for the high incidence of neurodevelopmental impairment in extremely preterm infants.     

Optimized T1- and T2-weighted volumetric brain imaging as a diagnostic tool in very preterm neonates

Background  

T1- and T2-W MR sequences used for obtaining diagnostic information and morphometric measurements in the neonatal brain are frequently acquired using different imaging protocols. Optimizing one protocol for obtaining both kinds of information is valuable.     

Physiologic brain dysmaturity in late preterm infants

Neonatal EEG sleep was used to determine whether differences are expressed between healthy late preterm and full-term (FT) groups. Twenty-seven 24-channel multihour studies were recorded at similar postmenstrual ages (PMA) and analyzed for eight asymptomatic late preterm infants (LPT) compared with 19 healthy FT infants as a preliminary analysis, followed by a comparison of a subset of eight FT infants, matched for gender, race, and PMA. Z scores were performed on data sets from each group pair comparing each of seven EEG/Sleep measures for entire recordings, active sleep (AS) and quiet sleep (QS) segments and artifact-free intervals. Six of seven measures showed differences between the eight LPT and eight matched FT cohort pair comparisons of >0.3; rapid eye movements, arousals during QS, spectral correlations between homologous centrotemporal regions during QS, spectral beta/alpha power ratios during AS and QS, a spectral measure of respiratory regularity during QS, and sleep cycle length. Quantitative neurophysiologic analyses define differences in brain maturation between LPT and FT infants at similar PMA. Altered EEG/Sleep behaviors in the LPT are biomarkers of developmental neuroplasticity involving interconnected neuronal networks adapting to conditions of prematurity for this largest segment of the preterm neonatal population.     

Electroencephalography and brain damage in preterm infants

Electroencephalography (EEG) is a sensitive method for detection of brain injury in preterm infants. Although the acute and chronic EEG changes are mainly non-specific regarding type of damage, they correlate with later neurological and cognitive function. In infants developing brain white matter damage, acute EEG findings include depression of background activity and presence of epileptic seizure activity. The chronic EEG changes associated with white matter injury and abnormal neurological development include delayed maturation, and presence of abundant Rolandic sharp waves. Cognitive limitations in preterm infants have been associated with changes in various sleep measures in EEG's recorded at full term. Continuous EEG-monitoring during neonatal intensive care shows that cerebral electrical activity during this vulnerable period can be affected by several extracerebral factors, e.g. cerebral blood flow, acidosis and some commonly used medications. For diagnosis of brain damage in preterm infants with neurophysiological methods, a combination of early continuous EEG monitoring during the initial intensive care period and full EEG, performed at later stages, is probably optimal.     

Safety of magnetic resonance imaging in preterm infants

Aim: As we progress in our knowledge of preterm brain injury, cohort studies are focusing in neuroimaging preterm infants in the first days of life. Magnetic resonance (MR) is the most powerful neuroimaging modality and valuable in understanding perinatal brain injury. The main purpose of the study is to evaluate the safety of MR imaging in very low birth weight (VLBW) infants at our hospital settings where the scanner is located at some distance from the neonatal intensive care unit (NICU). Subjects and methods: This is a prospective study of 33 VLBW infants who underwent early MR imaging (MRI), within 10 days after birth and term corrected age MRI. The study period included June to December 2008. Results: A total of 46 MRI were performed on 33 preterm infants. The mean total time the infants stayed in the bore of the magnet was 13.04 min. No incidences occurred during transfer or during the scans, and no significant changes were found in heart rate, oxygen saturation and temperature. Conclusions: At our hospital settings, the process of transport and MR imaging have been proven to be safe and not to disturb any of the variables measured. MRI should not be restricted to centres with neonatal MR system or MR‐compatible incubator, as long as the process is coordinated and supervised by a multidisciplinary team.