Magnetic resonance imaging in hypoxic-ischaemic encephalopathy

Magnetic resonance imaging of the brain is invaluable in assessing the neonate who presents with encephalopathy. Successful imaging requires adaptations to both the hardware and sequences used for adults. Knowledge of the perinatal and postnatal details are essential for the correct interpretation of the imaging findings. Perinatal lesions are at their most obvious on conventional imaging between 1 and 2 weeks from delivery. Very early imaging is useful to guide management in ventilated neonates but abnormalities may be subtle on conventional sequences. Diffusion-weighted imaging (DWI) is clinically useful for the early identification of ischaemic tissue in the neonatal brain, the pattern of which can predict outcome. DWI may underestimate the final extent of injury, particularly basal ganglia and thalamic lesions. Serial imaging with quantification of both tissue damage and structure size provides invaluable insights into the effects of perinatal injury on the developing brain.     

Early diffusion-weighted magnetic resonance imaging findings in neonatal herpes encephalitis

Neonatal herpes encephalitis is usually caused by herpes simplex virus type 2 and results in significant morbidity and mortality. Imaging diagnosis with ultrasound, computed tomography scan and conventional magnetic resonance imaging may be normal in the early course of the disease. In this case diffusion-weighted magnetic resonance imaging detected the disease process earlier and better than the conventional T2-weighted or fluid-attenuated inversion recovery imaging sequences. The use of diffusion-weighted magnetic resonance imaging in neonatal herpes encephalitis proved to be a useful tool in the early stage of the disease.     

弥散加权成像在新生儿重度缺氧缺血性脑病早期评价中的意义

目的探索新生儿重度缺氧缺血性脑病（HIE）早期弥散加权成像（DWI）动态演变规律及其意义。方法对2006年1月至2007年2月收住我院14例重度HIE患儿,分别于生后72h。7、14、21d及8个月行DWI及常规MRI扫描。结果72h内,常规MRI的T1加权（T1WI）和T2加权（T2WI）均未见异常,DWI表现为双侧腹外侧丘脑对称性的高信号;7d常规MRI表现双侧腹外侧丘脑对称性T1WI高信号,T2WI稍低信号,DWI表现为双侧基底节高信号,而初期腹外侧丘脑高信号消失;14d常规MRI双侧丘脑、基底节对称性T1WI高信号,T2WI低信号;21d常规MRI双侧丘脑及基底节T1WI高信号,T2WI高信号,DWI则未见明显异常;8个月常规MRI脑沟变深、脑室扩大及脑外间隙增宽,基底节T2WI不规则的高信号。结论重度HIE（主要因急性的完全性窒息所致）生后初期DWI显示相同的病变部位（腹外侧丘脑和基底节）和相似的病变程度,但其异常信号很快消失,而常规MRI可继之弥补DWI的不足。     

A novel mutation in the monocarboxylate transporter 8 gene in a boy with putamen lesions and low free T4 levels in cerebrospinal fluid

We describe brain lesions in a patient with a monocarboxylate transporter 8 mutation. Imaging showed a high T2 lesion in the left putamen at age 3 and a right putamen lesion at age 6. Cerebrospinal fluid free thyroxine concentrations were low, with normal 3,3',5-triiodothyronine concentrations.     

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??Abstract??Objective??The aim of this study was to evaluate the role of diffusion-weighted imaging ??DWI?? in the diagnosis of viral encephalitis and its relationship with the stage of the illness. Methods??We performed conventional magnetic resonance imaging ??MRI?? including T1WI?? T2WI sequences and DWI in 56 patients with viral encephalitis diagnosed on the basis of laboratory??clinical and radiologic findings??in which 29 patients were abnormal. Thirteen patients have received MRI two times. So ??there were 42 case-times of abnormal MRI.Based on the qualitative and quantitative comparison of the conventional MRI and DWI?? the patients were divided into three groups. Apparent diffusion coefficient ??ADC?? values of the involved and contralateral normal brain tissues were computed and compared for each group. Results ??In group ?? ??n = 23?? DWI was superior to conventional MRI in detecting the encephalitic involved sites and in depicting the borders of the encephalitic lesions. In group ?? ??n = 11?? DWI was similar to conventional MRI. In group ?? ??n = 8?? conventional MRI was superior to DWI. Mean ADC values of affected versus contralateral normal brain tissues were 0.45±0.19×10-3 mm2/s VS 0.93±0.06×10-3 mm2/s in group ??0.87±0.31×103 mm2/s VS 0.97±0.06×10-3 mm2/s in group ?? and 1.66±0.60×10-3 mm2/s VS 1.08±0.24×10-3 mm2/s in group ??. Patients in group ?? had significantly lower ADC values than those in group ?? while patients in group ?? had the highest ADC values ??P < 0.05??. The ADC values were significantly lower in the affected sites than in the unaffected sites of patients in groups I and ?? but were significantly higher in the affected sites than in the unaffected sites of patients in group ?? ??P < 0.05??. There was an excellent correlation between ADC values and duration of the disease ??r = 0.874??P = 0.01??. Conclusion??DWI is superior to other conventional diagnostic MR sequences in the detection of early viral encephalitic lesions and depiction of the lesion borders and?? in combination with other sequences?? DWI may contribute to the determination of the disease phase.     

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??Abstract??Objective??To evaluate the diagnostic value of susceptibility weighted imaging ??SWI?? in cerebral vascular malformation of children. Methods??The imaging data of MRI were retrospectively analyzed in all twenty-seven cases?? which included 16 cases of venous angioma?? 8 cases of cavernous angioma and 3 cases of arterio-venous malformation. The comparison of SWI and conventional MR sequences was obtained. Results??The dilated draining veins and medulla veins were displayed well on SWI sequence. More brain cavernous angioma lesions could be detected on SWI than those on conventional MR sequences??P < 0.05??. Conclusion??SWI can detect lesions of venous angioma?? cavernous angioma and arterio-venous malformation more sensitively than other sequences?? which is a reliable diagnostic technique for cerebral vascular malformation of children. SWI has higher clinical value?? and should be the routine sequence in the MRI examination.     

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目的探讨弥散加权成像(DWI)、常规磁共振成像(MRI)在新生儿低血糖性脑损伤不同阶段的动态变化。方法回顾分析了2005年9月至2008年9月,中国医科大学附属盛京医院新生儿科收治的经MRI确诊的20例低血糖性脑损伤患儿(病例组)的临床资料,并随机选取同期住院MRI正常的20例单纯性低血糖患儿为对照组。结果病例组平均最低血糖值低于对照组(P<0.01),低血糖持续时间长于对照组(P<0.01)。病例组于低血糖发生后3.8(1～11)d完成首次MRI检查,受累部位主要为枕叶11例、枕顶叶8例,顶叶1例,受累部位在DWI均表现为高信号,常规MRI相应部位12例表现为T1加权成像(T1WI)、T2加权成像(T2WI)正常信号,仅6例表现为T1WI低信号、T2WI高信号;11例于首次检查后11.4(8～15)d完成第2次MRI检查,首次检查受累部位DWI7例转为正常信号,4例低信号,常规MRI均表现为T1WI低信号、T2WI高信号。3例于6个月随访,提示枕叶DWI正常信号,T1WI低信号、T2WI高信号。结论新生儿低血糖性脑损伤早期DWI表现为异常高信号的部位,与晚期常规MRI表现为T1WI低信号、T2WI高信号的部...     

Neonatal hypoglycemia and occipital cerebral injury

Occipital brain injury associated with neonatal hypoglycemia can result in long-term disability, epilepsy, and visual impairment. The etiology of this pattern of injury is unclear; however, transient hyperinsulinism may be an independent risk factor. Magnetic resonance brain imaging can delineate the extent of brain injury and guide follow-up.     

新生儿低血糖性脑损伤磁共振成像动态变化研究

目的探讨弥散加权成像（DWI）、常规磁共振成像（MRI）在新生儿低血糖性脑损伤不同阶段的动态变化。方法回顾分析了2005年9月至2008年9月,中国医科大学附属盛京医院新生儿科收治的经MRI确诊的20例低血糖性脑损伤患儿（病例组）的临床资料,并随机选取同期住院MRI正常的20例单纯性低血糖患儿为对照组。 结果病例组平均最低血糖值低于对照组（P < 0.01）,低血糖持续时间长于对照组（P < 0.01）。病例组于低血糖发生后3.8（1～11）d完成首次MRI检查,受累部位主要为枕叶11例、枕顶叶8例,顶叶1例,受累部位在DWI均表现为高信号,常规MRI相应部位12例表现为T1加权成像（T1WI）、T2加权成像（T2WI）正常信号,仅6例表现为T1WI低信号、T2WI高信号;11例于首次检查后11.4（8～15）d完成第2次MRI检查,首次检查受累部位DWI 7例转为正常信号,4例低信号,常规MRI均表现为T1WI低信号、T2WI高信号。3例于6个月随访,提示枕叶DWI正常信号,T1WI低信号、T2WI高信号。结论新生儿低血糖性脑损伤早期DWI表现为异常高信号的部位,与晚期常规MRI表现为T1WI低信号、T2WI高信号的部位一致,这种一致性提示DWI异常高信号对于低血糖性脑损伤早期病情判断具有一定价值。     

Cognition and behavior at school entry in children with congenital hypothyroidism treated early with high-dose levothyroxine

OBJECTIVE: To document cognition and behavior at school entry in these patients.Study design Eighteen children with congenital hypothyroidism (CH; 9 severe and 9 moderate, based on a surface of the knee epiphyses at diagnosisor=0.05 cm(2)) treated from a median of 14 days with a median of 12.0 microg/kg per day of levothyroxine were evaluated at 5 years, 9 months, with the McCarthy Scale and the Questionnaire for Evaluation of Social Behavior, as were 40 control children. RESULTS: The global IQs at 5 years, 9 months, were similar: medians (range) were 102 (87 to 133), 102 (84 to 135), and 115 (88 to 136) (not significant) for severe CH, moderate CH, and control children, respectively. The behavioral scores of CH children were within the normal range. However, the number of times when plasma TSH was >6.0 mIU/L during treatment was correlated positively with anxiety (P=.02) and inattention (P=.05), whereas the number of times TSH was <0.8 mIU/L was correlated with lower verbal scores (P=.05). CONCLUSIONS: Children with severe CH treated early with a high dose of levothyroxine have normal global development and behavior at school entry.     

表观弥散系数在2~12岁常规颅脑MRI正常的智力障碍/全面发育迟缓患儿中的应用

目的探讨快速自旋回波弥散加权成像（TSE-DWI）表观弥散系数（ADC）在2~12岁常规颅脑MRI正常的智力障碍/全面发育迟缓（ID/GDD）患儿中的应用价值。方法选择符合ID/GDD诊断标准且常规颅脑MRI正常的578例患儿及同年龄段375例正常儿童志愿者为研究对象,并收集其影像学和临床资料。所有研究对象均行颅脑TSE-DWI序列及常规序列扫描。分析正常对照组儿童各脑区不同年龄亚组、各年龄亚组不同ID/GDD程度患儿各脑区ADC值差异,社会适应行为评分（ABAS-Ⅱ）对ID/GDD患儿各脑区ADC值的影响。结果正常对照组额颞叶白质、胼胝体、内囊、半卵圆中心、小脑齿状核、视放射、丘脑、豆状核及尾状核ADC值随年龄升高而降低（P < 0.05）。各年龄组ID/GDD患儿深、浅部白质,深部灰质核团及浅部灰质4岁~组ADC值随ID/GDD程度升高而升高（P < 0.05）。深、浅部白质及深部灰质核团,各ID/GDD组ADC值随年龄的升高而降低（P < 0.05）。ID/GDD患儿ADC值随ABAS-Ⅱ评分升高而降低（P < 0.05）。结论 ADC能反映常规颅脑MRI正常ID/GDD患儿各脑区细微结构变化,对社会适应性方面也有一定的提示作用,可为ID/GDD患儿定量诊断提供客观依据。     

Recurrent intrathecal methotrexate induced neurotoxicity in an adolescent with acute lymphoblastic leukemia: Serial clinical and radiologic findings

Systemic and intrathecal methotrexate (MTX) are integral components of acute lymphoblastic leukemia (ALL) therapy, but can be associated with neurotoxicity. We describe here the case of an adolescent male with T-cell ALL who developed recurrent episodes of subacute neurotoxicity characterized by slurred speech, emotional lability, and hemiparesis after intrathecal MTX administration. Serial magnetic resonance imaging with diffusion-weighted imaging showed recurrent areas of restricted diffusion within cerebral hemispheric white matter, which correlated chronologically with the administration of intrathecal therapy and severity of clinical symptoms. Resolution of diffusion abnormalities did not preclude further toxicity and a large lesion could cause persisting symptoms.     

MR imaging of the neonatal brain at 3 Tesla

3 Telsa MR scanners are now becoming more widely available and 3 Telsa is likely to become the filed strength of choice for clinical imaging of the brain. The neonatal brain can be safely and successfully imaged at 3 Telsa. The improved signal to noise afforded by a higher field strength may be used to improve image quality or shorten acquisition times. This may be exploited for conventional T1 and T2 weighted imaging and also for advanced techniques such as diffusion tensor imaging, angiography and functional magnetic resonance studies.     

MRI of perinatal brain injury

MRI is invaluable in assessing the neonatal brain following suspected perinatal injury. Good quality imaging requires adaptations to both the hardware and the sequences used for adults or older children. The perinatal and postnatal details often predict the pattern of lesions sustained and should be available to aid interpretation of the imaging findings. Perinatal lesions, the pattern of which can predict neurodevelopmental outcome, are at their most obvious on conventional imaging between 1 and 2 weeks from birth. Very early imaging during the first week may be useful to make management decisions in ventilated neonates but brain abnormalities may still be subtle using conventional sequences. Diffusion-weighted imaging (DWI) is very useful for the early identification of ischaemic tissue in the neonatal brain but may underestimate the final extent of injury, particularly basal ganglia and thalamic lesions. MR imaging is an excellent predictor of outcome following perinatal brain injury and can therefore be used as a biomarker in interventional trials designed to reduce injury and improve neurodevelopmental outcome.     

新生儿颅脑磁共振检查临床实践的专家共识

颅脑磁共振成像（magnetic resonance imaging,MRI）技术的迅速发展为新生儿脑发育评估、脑损伤诊断和预后判断提供了客观依据,临床应用日益广泛。中国医师协会新生儿科医师分会基于国内外现有研究证据,结合临床实践经验,为新生儿颅脑MRI的适应证和临床实践规范制定专家共识,主要内容包括：（1）疑似新生儿缺氧缺血性脑病、颅内感染、脑卒中,以及原因不明惊厥者应行颅脑MRI;颅脑MRI不纳入早产儿常规脑损伤筛查管理,当颅脑超声筛查有明确损伤证据时应行颅脑MRI进一步评估;对于颅脑超声未见异常的超早产儿和超低出生体重儿,建议在纠正胎龄足月时行颅脑MRI;（2）新生儿颅脑MRI应尽量在非镇静状态下完成;（3）过程中需密切监测生命体征,优化检查条件,保障安全,危重患儿检查需严格评估检查的必要性,可应用磁共振兼容的转运培养箱和呼吸机;（4）目前新生儿颅脑MRI检查可选1.5 T或3.0 T设备,应用新生儿颅脑专用线圈以提高信噪比;常规扫描序列选择应遵循：至少包含轴位T1加权像、轴位T2加权像、弥散加权成像,以及矢状位T1加权像或T2加权像;（5）建议采用结构化或分级报告系统,通过双人审签报告、多中心协作等方式提高报告可靠性。     

Utility of non‐enhanced magnetic resonance imaging to detect acute pyelonephritis

It has been established that enhanced computed tomography (CT) and ^99mTc‐dimercaptosuccinic acid renal scintigraphy (^99mTc‐DMSA scintigraphy) used in conjunction with single‐photon emission CT is a useful tool for the diagnosis of acute pyelonephritis (APN). The utility of non‐enhanced magnetic resonance imaging (MRI), however, has not been investigated extensively for the diagnosis of APN or renal abscess in children. We describe the case of a 23‐month‐old boy with suspected APN who received non‐enhanced MRI. Whole body diffusion‐weighted imaging (DWI) was used, and a background body‐signal suppression sequence was applied. High‐intensity focal lesions were identified on DWI and low‐intensity lesions on the apparent diffusion coefficient map in the acute phase. This case suggested that non‐enhanced MRI could be a useful tool for the diagnosis of APN in children, because it can avoid the risks of not only radiation exposure but also nephrogenic systemic fibrosis associated with gadolinium‐based contrast agents, especially in infants.     

磁敏感加权成像与常规磁共振序列诊断新生儿颅内出血的比较研究

目的 探讨磁敏感加权成像（SWI）在新生儿颅内出血的应用价值。方法 纳入2009年8月至2011年2月复旦大学附属儿科医院NICU临床疑诊脑损伤的新生儿,同时进行常规MRI和SWI扫描。分为足月儿组和早产儿组,统计常规MRI和SWI检测的出血部位、出血病灶数目和出血面积的差别。结果 596例临床疑诊脑损伤的新生儿进入分析。①常规MRI检出颅内出血117例（19.6%）,早产儿组72例（61.5%）;SWI检出颅内出血134例（22.5%）,早产儿组81例（60.4%）,包括生发基质出血40例（早产儿33例,足月儿7例）,侧脑室出血68例（早产儿54例,足月儿14例）,脉络丛出血30例（早产儿18例,足月儿12例）,第三脑室出血6例（早产儿）,中脑导水管出血3例（早产儿）,第四脑室出血27例（早产儿23例,足月儿4例）,大脑实质出血22例（早产儿14例,足月儿8例）,小脑出血20例（早产儿11例,足月儿9例）,脑干出血1例（足月儿）,蛛网膜下腔出血10例（早产儿4例,足月儿6例）,硬膜下出血36例（早产儿17例,足月儿19例）,硬膜外出血2例（足月儿）。②生发基质-脑室内出血（6个部位）中,除了中脑导水管出血外,其他5个部位的出血病灶检出数目SWI均大于常规MRI（P均＜0.05）。SWI对蛛网膜下腔出血的检出数目大于常规MRI（P＜0.05）;对硬膜下出血和硬膜外出血的检出数目上,SWI和MRI差异无统计学意义（P＞0.05）。③SWI序列81例早产儿生发基质-脑室出血主要为生发基质出血（44个）、侧脑室出血（90个）和脉络丛出血（26个）;53例足月儿生发基质-脑室出血以侧脑室出血（23个）和脉络丛出血（18个）多见。④98例在SWI和常规MR同时显示出血的病例,颅内出血（生发基质-脑室内出血、大脑和小脑实质出血）面积（cm2）SWI均大于常规MRI的T2WI序列,（0.69±0.63）vs（0.49±0.48） ,P<0.001。结论 SWI较常规MRI在检出新生儿各种类型的颅内出血和蛛网膜下腔出血的阳性率、病灶数目和出血面积方面有明显的优势, 可作为常规MRI的有力补充。     

Periventricular low intensities on fluid attenuated inversion recovery imaging in the newborn infant: Relationships to the clinical data and long-term outcome

BACKGROUND: The author's previous study showed that it is possible to predict the severity of white matter injury in early infancy by using fluid attenuated inversion recovery (FLAIR) imaging. A follow-up study was performed in order to assess the correlation between the incidence of periventricular low intensities on FLAIR imaging (F-PVLI) and the clinical data including the physiological variables at birth and the long-term outcome of the infant. METHODS: The authors reviewed MRI of 328 newborn infants, which were obtained before 2 months corrected age. Abnormal findings in the periventricular white matter and other part of the brain were recorded. Periventricular abnormal intensities were sorted into four groups according to the FLAIR grade, which comprised normal, F-PVLI 1 (focal), F-PVLI 2 (extensive), cystic periventricular leukomalacia (C-PVL), and diffused leukomalacia. RESULTS: Significantly more periventricular abnormal intensities were detected by FLAIR imaging than by conventional T1 and T2 weighted imaging. In the groups of F-PVLI 2 and C-PVL, the birth weight (BW), gestational age (GA), blood pH and base excess at birth were significantly lower than in the normal group. However, when the study population was defined into very low birth weight infants, F-PVLI 2 had significantly larger BW and GA than normal. The FLAIR grade had a strong correlation with the developmental outcome at 12 and 36 months corrected age. CONCLUSIONS: F-PVLI is a silent but very important white matter injury, which has many features in common with C-PVL. FLAIR imaging could be a strong tool in screening newborn infants at high risk of neurological impairment.     

Transient seizure‐related MRI abnormalities in a child with primary Epstein–Barr virus infection

We describe the case of a 6‐year‐old girl with typical infectious mononucleosis syndrome complicated by clustered right hemiconvulsions and disturbed consciousness. Diffusion‐weighted magnetic resonance imaging on admission demonstrated reduced diffusion in the left temporo‐posterior cortex and pulvinar of the ipsilateral thalamus. Her neurological symptoms resolved completely by the next day, with complete disappearance of abnormal signal intensities on magnetic resonance imaging (MRI). Elevated cerebrospinal fluid interleukin (IL)‐6 with normal IL‐10 might indicate a neuroprotective role of IL‐6 rather than injury. We concluded that the MRI abnormalities could have been due to the seizure activity itself rather than Epstein–Barr virus‐associated encephalitis. The recognition of transient seizure‐related MRI abnormalities may help in the diagnostic approach to MRI changes in suspected encephalopathy.     

Routine magnetic resonance imaging of the spine in children with Gaucher disease: does it help therapeutic management?

Background Routine magnetic resonance imaging (MRI) surveillance of bone marrow change in patients with Gaucher disease (GD) is recommended, but interpretation of imaging findings in the developing skeleton may be difficult.Objectives To assess the agreement between routine spinal MRI findings and clinical course in paediatric GD patients receiving enzyme replacement therapy (ERT).Materials and methods A retrospective institutional review of all GD patients on ERT who had had repeated routine spinal MRI in accordance with national recommendations (n=14) was carried out. Vertebral body bone marrow MRI T1 signal was assessed relative to intervertebral discs. MRI findings were then compared with recorded date(s) of ERT initiation and possible therapy changes.Results Nine patients had spinal MRI both before and after the start of ERT. MRI T1 marrow signal was normal in two and abnormal in three of the nine patients both before and after the start of ERT. Two of the nine patients had normalization and one had conversion from normal to abnormal T1 signal. Interpretation was uncertain in one. Seven episodes of treatment intensification occurred. MRI T1 marrow signal was normal before five and uncertain before two of the seven episodes.Conclusion Routine spinal MRI had low accuracy for predicting clinically indicated therapy intensification.