磁共振弥散加权成像技术用于诊断小儿病毒性脑炎临床价值研究

目的研究磁共振弥散加权成像(DWI)在病毒性脑炎患儿中的诊断价值及与阶段分期关系。方法对中国医科大学附属盛京医院小儿神经内科2006年6月至2007年2月临床确诊的病毒性脑炎56例患儿进行传统磁共振成像(MRI)和DWI检查,异常者29例,其中13例做了2次头MRI。共42例次存在不同程度头MRI异常。依据患儿MRI传统序列与DWI的差别将其分为3组,对每组患儿患侧病灶表观弥散系数(ADC)与对侧正常脑组织进行比较。结果Ⅰ组DWI显示的病灶数目和病灶范围均优于MRI;Ⅱ组DWI与MRI相近;Ⅲ组MRI优于DWI。3组患儿病灶与对侧正常脑组织ADC值平均值分别是:Ⅰ组病灶(0.45±0.19)×10-3mm2/s,正常(0.93±0.06)×10-3mm2/s;Ⅱ组病灶(0.87±0.31)×10-3mm2/s,正常(0.97±0.06)×10-3mm2/s;Ⅲ组病灶(1.66±0.60)×10-3mm2/s,正常(1.08±0.24)×10-3mm2/s。Ⅰ组患儿ADC值较Ⅱ组明显降低,Ⅲ组患儿ADC值最高(P0.05)。结论 DWI显示早期脑炎患儿的病灶范围和数目方面优于MRI,DWI结合MRI,能判断病程阶段。     

磁共振扩散加权成像的表观弥散系数在评估新生儿缺氧缺血性脑病中的价值

目的探讨磁共振扩散加权成像（DWI）的表观弥散系数（ADC）值在新牛儿缺氧缺血性脑病（HIE）中的应用价值。方法对临床确诊的35例足月HIE患儿（男24例，女11例；轻度26例，中重度9例）在出生1～11d行常规DWI检查，在DWI上测其顶叶、额叶、枕叶、颢叶的ADC值，对HIE轻度组及中重度组的ADC值进行独立样本t检验，采用析因设计的双因素方差分析，分析不同检测时间段脑叶的ADC值信号表现是否存在差异。结果中重度组HIE患儿双侧顶叶ADC值低于轻度组HIE患儿，有显著性差异（P=0．004）；额叶、枕叶、颞叶等脑叶的ADC值，中重度组HIE患儿有低于轻度组HIE患儿的趋势，但二者无显著性差异（Pa〉0．05）。轻度组HIE患儿各脑叶ADC值不因检测日龄不同而变化（P〉0．05）；在中重度HIE患儿，日龄3～5d患儿各脑叶ADC值明显低于日龄1～2d和〉5d患儿，均有统计学差异（Pa〈0．05）。结论HIE的病情程度与各脑叶的ADC值具有相关性，即病情越重，ADC值越低；出生3～5d行MRI检查是了解HIE患儿脑水肿的较好时期。     

新生儿脑梗死早期的临床表现与磁共振成像特点

目的：磁共振成像（MRI）是目前诊断新生儿脑梗死的金标准,然而常规MRI对于2 d内的新生儿脑梗死的早期显像并不敏感。为了早期诊断新生儿脑梗死,该研究探讨了新生儿脑梗死患儿的早期临床表现及头部MRI成像学特征,包括常规MRI及弥散加权成像（DWI）,并为早期诊断提供依据。方法：回顾分析该院新生儿病房收治的16例新生儿脑梗死患儿临床资料、头部MRI检查(所有病例均于生后5 d内行常规序列扫描后接受弥散加权序列扫描),其中5例于新生儿期（生后11~18 d）进行了第2次头部MRI检查。结果：①高危因素：产前8例（50%）,产时9例（56%）,产后0例（0%）;临床表现：11例以惊厥发作为首发症状,患儿每次抽搐持续时间较短（平均为2~3 min）,9例于24 h内停止抽搐;②MRI扫描结果：初期（5 d内）病灶部位T1稍低信号,T2加权稍高信号,相同部位弥散加权影像均表现为高亮信号,且病灶边界清晰;再次扫描时（生后11~18 d）病灶部位T1低信号、T2高信号较前明显,相同部位弥散加权均表现为低信号。结论：惊厥多为新生儿脑梗死的首发表现,发作次数少且程度轻;梗死早期DWI表现为高亮信号,继之常规MRI出现T1低信号、T2高信号,并随时间逐渐明显,尤以T2表现更为敏感。［中国当代儿科杂志,2009,11（2）：96-99］     

新生猪缺氧缺血性脑病早期弥散加权像变化及热休克蛋白70表达

目的探讨早期缺氧缺血性脑病(HIE)动物模型弥散加权像(DWI)变化和热休克蛋白(HSP)70表达的演变规律。方法3日龄新生猪19只随机分为正常对照组、假手术组、缺氧缺血组。用1.5T磁共振仪行DWI和T2WI检查;用表观弥散系数(ADC)图,测量病灶中心区和周边区ADC值;应用SP法计数中心区和周边区HSP70阳性细胞。结果缺氧缺血组出现四肢抽搐、角弓反张等体征。缺氧缺血后3 h DWI有高信号,ADC图有低信号。各组中心区与周边区ADC比较有显著差异(P<0.01)。缺氧缺血后3 h出现HSP70阳性细胞,6 h达高峰,之后逐渐下降,各组中心区和周边区HSP70阳性细胞计数比较有极显著差异(P<0.01)。结论DWI结合ADC值可以敏感而准确地显示HIE病灶;HSP70表达提示早期HIE病灶周边区有可逆的脑组织区域。     

弥散加权成像早期预测新生儿缺氧缺血性脑损伤区域及其表观弥散系数值改变

目的 阐明弥散加权成像(diffusion weighted imaging,DWI)可于生后早期预测HIE患儿的损伤区域,并且评估不同区域的ADC值变化情况.方法 研究对象为2006年7月至2009年7月,我院新生儿病房收治26例HIE患儿,其临床分度为重度19例和中度7例,均于生后72 h内完成常规MRI和DWI扫描.其中,10例重度HIE患儿(ADC值组)行8个感兴趣区的ADC值测量,以同期住院的12例无神经系统疾病的足月儿为对照.8个感兴趣区分别为内囊后肢(PLIC)、腹外侧丘脑、基底节、中央沟周围皮层、枕叶皮层、半卵圆中心、脑干、额叶白质.结果 生后72 h内,26例HIE患儿的常规MRI示5例蛛网膜下腔出血、2例硬膜下出血,仅1例患儿的T2WI可见部分皮层稍高信号,此外未见其他异常.但26例HIE患儿的DWI均可见异常高信号.在19例重度HIE患儿中,17例(89%)表现为双侧腹外侧丘脑和中央沟周围皮层的异常高信号(其中6例伴有双侧基底节区异常高信号),仅2例(11%)表现为皮层及皮层下白质的异常高信号.7例中度HIE中,4例表现为皮层及皮层下自质的异常高信号,2例表现为脑室周围白质的异常高信号,仅1例表现为双侧腹外侧丘脑和中央沟周围皮层的异常高信号.ADC值组内囊后肢(PLIC)、腹外侧丘脑、基底节、中央沟周围皮层、枕叶皮层、半卵圆中心、脑干、额叶白质的平均ADC值依次为0.68(0.56～0.88),0.73±0.13,0.67±0.11,0.78±0.22,0.90±0.16,0.87±0.21,0.73±0.19,1.32±0.22×10-3 mm2/S.对照组内囊后肢(PLIC)、腹外侧丘脑、基底节、中央沟周围皮层、枕叶皮层、半卵圆中心、脑干、额叶白质的平均ADC值依次为0.96(0.95～1.02),1.02±0.90,1.15±0.99,1.08±0.07,1.09±0.08,1.39±0.20,0.96±0.05,1.58±0.18×10-3 mm2/S.与对照组相比,ADC值组8个感兴趣区的平均表观弥散系数(apparent difusion coefficient,ADC)值明显降低(P＜0.01).结论 在生后早期,重度HIE患儿的损伤区域大部分为丘脑-中央沟周围皮层,仅少数为皮层及皮层下白质.中度HIE患儿的损伤区域较多样,依次为皮层及皮层下白质、脑室周围白质和丘脑-中央沟周围皮层.HIE患儿的DWI图像异常部位及未见异常部位的ADC值均有不同程度的下降.

Abstract：

Objective To elucidate that diffusion weighted imaging (DWI) can be used to predict the injured regions of neonatal brain with hypoxic-ischemic encephalopathy (HIE) in the early phase of injury, and to measure the apparent diffusion coefficient (ADC) values in the multiple regions of the brain.Method The participants in this study were twenty-six infants with HIE from neonatology ward hospitalized between July 2006 and July 2009.Nineteen patients had severe HIE, and seven had moderate HIE.DWI and conventional magnetic resonance imaging (MRI) were performed for each case within the first 72 hrs.The ADC values of eight regions of interest (ROIs) were measured in ten cases with severe HIE ( ADC values group). ROIs included posterior limb of internal capsule (PLIC), ventrolateral thalami, basal ganglia, perirolandic cortex, occipital cortex, centrum semiovale, brainstem, and frontal white matter.Twelve neonates were enrolled as the control subjects.Results During the first 72 hfs, the conventional MR1 of 26 patients showed subarachnoid hemorrhage in 5, subdural hemorrhage in 2, and mild high signal intensity in the cortex of only one patient.In the 19 cases with severe HIE, abnormal signal intensities were seen in ventrolateral thalami and perirolandie cortex of 17 patients ( 89% ), and the remaining 2 infants showed abnormal cortex and subcortical white matter.In 7 cases with moderate HIE, 4 had abnormal signal intensity in the cortex and subcortical white matter, 2 had abnormal periventricular white matter, and only one showed abnormal signal intensity in the ventrolateral thalami and perirolandic cortex.In the ADC values group, the average ADC values of posterior limb of internal capsule ( PLIC ), ventrolateral thalami, basal ganglia, perirolandic cortex, occipital cortex, centrum semiovale, brainstem, and frontal white matterrespectively were 0.68(0.56-0.88) ,0.73 ±0.13,0.67 ±0.11,0.78 ±0.22,0.90 ±0.16,0.87 ±0.21,0.73 ±0.19,1.32 ±0.22 × 10-3 mm2/S.In the control group, the average ADC values of posterior limb of internal capsule ( PLIC ), ventrolateral thalami, basal ganglia, perirolandic cortex, occipital cortex, centrum semiovale, brainstem, and frontal white matter respectively were 0.96(0.95-1.02), 1.02 ±0.90,1.15 ±0.99,1.08 ±0.07,1.09 ±0.08,1.39 ±0.20,0.96 ±0.05,1.58 ±0.18 × 10 -3 mm2/S. There was statistically significant difference in the average ADC values between each of 8 ROIs of infants with HIE and healthy neonates( P ＜ 0.01 ).Conclusion In the first days after birth, the major injured regions of severe HIE were ventrolateral thalami and perirolandic cortex, the minor injured regions were cortex and subcortical white matter.Multiple regions of moderate HIE were injured, including cortex with subcortical white matter,periventricular white matter, and ventrolateral thalami with perirolandic cortex. The ADC values of the regions with abnormal signal intensity decreased, also some regions with the normal signal intensity.     

磁共振弥散加权成像在新生儿脑梗死早期诊断中的意义及其变化规律

目的探讨弥散加权成像（DWI）对新生儿脑梗死（NCI）早期的诊断价值。方法收集2004年6月至2005年10月,在我院新生儿科住院的6例NCI患儿的临床资料。全部病例完成了血常规、血糖、血清总钙及离子钙、C-反应蛋白、凝血酶原时间及部分凝血活酶时间、心脏彩色多普勒及头部MRI检查。并对其中4例进行MRI动态观察。结果（1）全部病例为足月儿,1例有重度窒息史,其余5例无明显宫内窘迫及出生窒息史。（2）5例以全身惊厥为首发症状。（3）全部病例无红细胞增多症,无出血及凝血机制障碍,心内结构正常。（4）MRI检查时间：发病后18h至4d。常规MRI4例异常（T1WI低信号,T2WI高信号）,2例正常;DWI6例异常（全部高信号）,随访（2周至15个月）：常规MRI6例异常（T1WI低信号,T2WI高信号）;DWI6例异常（低信号）。梗死部位：4例左侧颞叶、顶叶和枕叶,1例左侧额叶和顶叶,1例左侧基底节。结论NCI早期,常规MRI尚未出现明显异常,DWI即显示明显高信号,从而证实DWI对NCI早期诊断的价值。     

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。     

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。     

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。     

应用弥散张量成像评价支气管肺发育不良早产儿脑白质发育的研究

目的 应用磁共振弥散张量成像（DTI）的各项异性分数（FA）和表观弥散系数（ADC）评价支气管肺发育不良（BPD）早产儿的脑白质发育。方法 以2016年8月至2019年4月生后24 h内收住NICU的出生胎龄≤32周、出生体重<1 500 g,且出院前完成头颅MRI及DTI检查的96例早产儿为研究对象。根据出院诊断分为BPD组（n=48）和非BPD组（n=48）,比较两组DTI相同感兴趣区的FA值和ADC值。结果 两组早产儿脑室周围-脑室内出血、脑室周围白质软化、局灶性脑白质损伤等发生率差异无统计学意义（P > 0.05）。BPD组早产儿内囊后肢、胼胝体压部、枕叶白质、小脑、大脑脚的FA值低于非BPD组（P < 0.05）,各ADC值高于非BPD组（P < 0.05）。与非BPD组相比,BPD组早产儿呼吸暂停次数更多、肺炎发生率和机械通气比例更高、辅助通气时间更长（P < 0.05）。结论 BPD对早产儿脑白质发育具有潜在影响,可导致脑白质发育延迟,因此,需关注该类患儿的神经功能。     

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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.     

磁共振成像表观扩散系数变化对新生儿化脓性脑膜炎脑损伤纵向评估

背景：既往尚无新生儿化脓性脑膜炎在不同颅脑并发症下ADC值的纵向变化研究。 目的：回顾性总结新生儿化脓性脑膜炎在发病后不同病程阶段的头颅MR表现,在髓鞘化过程中分析不同颅脑并发症下脑组织ADC值随病程的变化规律。 设计：病例对照研究。 方法：以足月新生儿化脓性脑膜炎并行头颅MR检查者为病例组,基于颅脑并发症中有无脑实质损伤灶和脑积水分为病例1组（无脑实质损伤灶和脑积水）、病例2组（有脑实质损伤灶,无脑积水）、病例3组（有脑积水无脑实质损伤灶）和病例4组（有脑实质损伤灶和脑积水）。以发病至头颅MR检查间隔时间0~7 d、~28 d、~60 d和~120 d分为病程A~D组;根据MR检查时患儿日龄,病程A组分为A1组（0~14 d）和A2组（~28 d）,病程B组分为B1组（~28 d）和B2组（~60 d）。与病例组同期因其他疾病在同院行常规头颅MR且未观察到异常病变的儿童为对照组。 主要结局指标：相同日龄或相同病程下MR评估新生儿化脓性脑膜炎脑实质ADC值变化趋势。 结果：173例新生儿化脓性脑膜炎进入本文分析,病例组MR检查302例次,病程A~D组有241例次MR检查的ADC值进入本文分析;对照组20例。随着日龄的增加,对照组和病例组ADC值均呈降低趋势。不同病程(相同日龄)比较结果中,大脑皮层、深部白质在各个病程中,病例1~3组和对照组ADC值差异均无统计学意义（胼胝体压部的部分病程除外）;皮层下白质在病程0~60 d中,病例2和3组ADC值明显低于对照组,病例3组及部分病程中病例2组ADC值明显低于病例1组,皮层下白质在病程61~120 d中,病例2、3组和对照组ADC值差异无统计学意义,病例1组(除外顶叶白质)ADC值明显高于对照组;深部灰质核团在病程0~30 d中,病例1~3组ADC值明显低于对照组,在病程31~120 d中,病例1~3组和对照组ADC值差异均无统计学意义。 结论：在新生儿化脓性脑膜炎患儿,皮层下白质在病程1~2个月ADC值降低,病程3~4个月时ADC值正常或升高,提示髓鞘化进程受阻;深部灰质核团ADC值在病程1个月内降低,而病程2~4个月时恢复正常。MR DWI定量ADC值有助于对无脑结构损伤的新生儿脑膜炎微观损伤的评估。     

高危晚期早产儿脑损伤病因学及其磁共振发现

目的 探讨以弥散加权成像(DWI)结合常规磁共振成像(T1WI-T2WI)诊断的高危晚期早产儿脑损伤的相关危险因素及临床特点,并分析不同时间MRI序列的信号特点及DWI的早期诊断价值。方法 首先对符合纳入标准的649例晚期早产儿的MRI片重新阅片,按照脑损伤评估标准得出诊断,其次收集相关的临床资料,分析不同类型脑损伤的危险因素和临床特点,并对其中271例确诊脑白质损伤（CWMD）的MRI序列进行分析,探讨不同类型CWMD的信号特点、损伤部位及结局。结果 ①晚期早产儿发生脑损伤332例（51.2%）,其中CWMD 271例（41.8%）,以局灶性CWMD为主（62.7％,170例）;颅内出血112例（17.3%）,主要为蛛网膜下腔出血55.4%（62/112）。②非出血性脑损伤的危险因素是男性（OR=1.510,95％CI：1.067～2.136,P=0.020）、阴道分娩（OR=2.367,95％CI：0.251～22.294 ,P=0.000）、早发型败血症（OR=2.194,95％CI：1.159～4.155,P=0.016）及抢救复苏史（OR=3.784,95％CI：1.908～7.506,P=0.000）。出血性脑损伤的危险因素是阴道分娩（OR=7.195,95％CI：4.249～12.184 ,P=0.000）和早发型败血症（OR=2.692,95％CI：1.185～6.117,P=0.018）。低钙血症（OR=2.593,95％CI：1.343～5.005,P=0.005）、晚发型败血症（OR=1.533,95％CI：1.012～2.323,P=0.044）和抽搐（OR=4.006,95％CI：1.790～8.970,P=0.001）是非出血性脑损伤组的主要临床特点。出血性脑损伤组主要表现为高血糖和抽搐。③局灶性CWMD 65.3％仅累及一处损伤,主要集中在侧脑室后脚（53.5%）,有97.1%病灶消失或病灶范围减少;广泛性CWMD 79.2%累及胼胝体和内囊;弥漫性CWMD 50％合并灰质损伤,全部发生软化。④生后2周内,DWI具有较高的敏感性,98.0%表现为高信号,T1WI信号无变化或稍高信号,伴或不伴T2WI低信号。局灶性CWMD DWI高信号持续时间长达3周以上,弥漫性CWMD DWI高信号持续时间2周以内。结论 晚期早产儿仍然容易受产前产时因素影响而发生不同类型的脑损伤。对有高危因素,或早期出现临床表现或电解质紊乱的患儿应选择生后2周内（1周内最佳）进行DWI和常规MRI检查,以早期发现病变。局灶性CWMD预后较好,合并有灰质损伤或弥漫性CWMD预后极差,需要动态随访,并进行早期康复训练。     

Diffusion tensor imaging in children and adolescents with tuberous sclerosis

Background: Tuberous sclerosis (TS) is characterised by benign hamartomatous lesions in many organs. Diffusion tensor imaging (DTI) can detect microstructural changes in pathological processes. Objective: To determine apparent diffusion coefficient (ADC) and fractional anisotropy (FA) maps in children with TS and to investigate the diffusion properties in cortical tubers, white-matter lesions, perilesional white matter, and contralateral normal-appearing white matter, and to compare the results with ADC and FA maps of normal age- and sex-matched volunteers. Materials and methods: Seven children and adolescents (age range 2–20 years) suffering from TS were included. MRI was performed on a 1.5-T scanner using a transmit/receive coil with T1-W and T2-W spin-echo and FLAIR sequences. DT images were acquired by using a single-shot echo-planar pulse sequence. Diffusion gradients were applied in six different directions with a b value of 1,000 s/mm². Results: ADC was higher in cortical tubers than in the corresponding cortical location of controls. ADC values were higher and FA values were lower in white-matter lesions and perilesional white matter than in both the contralateral normal-appearing white matter of patients and in controls. There were no significant differences for both ADC and FA values in the normal-appearing white matter of patients with TS compared to controls. Conclusions: DTI provides important information about cortical tubers, white-matter abnormalities, and perilesional white matter in patients with TS.     

体素内不相干运动弥散加权成像对儿童腹部良恶性肿瘤诊断价值

目的运用体素内不相干运动(IVIM)弥散加权(DW)MRI的方法,探讨IVIM双指数参数鉴别儿童腹部良恶性肿瘤的价值。方法以儿童腹部肿瘤手术病理为金标准,术前1周内行IVIM DW-MRI检查为待测标准,对怀疑腹部肿瘤、不能完全确诊为良性肿瘤者行常规MRI(T1W、T2W和增强T1W)和DW序列。根据病理分为恶性组、良实性组、交界性组和良囊性组。选取b值范围0~800 s·mm~(-2),通过软件计算得到ADC值,使用肿瘤轮廓法勾画肿瘤的感兴趣区(ROI),计算D、D*和f值。结果 85例腹部肿瘤患儿(98个肿瘤)进入本文分析。男43例;平均年龄4.4岁;恶性组(52例,62块),交界性组(7例,7块),良实性组(21例,24块),良囊性组(5例,5块);ROI平均值12.9(1.3~26.1)cm~2。ADC、D和D~*均体现在恶性组最低,交界性组、良实性组和良囊性组依次升高,差异均有统计学意义;ADC、D和D*在恶性与非恶性肿瘤(实性+囊性)差异均有统计学意义;鉴别恶性和良实性肿瘤Cutoff(×10~(-6)mm~2·s~(-1))分别为1 367、1 056和1 605,ADC鉴别的特异度高(85.5%),D值鉴别的灵敏度高(83.3%),鉴别恶性和实性肿瘤(良实性+交界性)、恶性和非恶性肿瘤(良实性+交界性+良囊性)Cutoff(×10~(-6)mm~2·s~(-1))分别为1 173、1 014和1 634;鉴别恶性和实性肿瘤(良实性+交界性)ADC和D值特异度较好(87.1%和83.9%),鉴别恶性和非恶性肿瘤(良实性+交界性+良囊性),ADC、D和D~*值特异度均良好(88.9%、86.1%和80.6%)。结论 IVIM DW-MRI中的ADC和D值对鉴别儿童腹部良恶性肿瘤有较好的诊断价值。     

Mechanism of cerebral edema in children with diabetic ketoacidosis

OBJECTIVES: Cerebral edema during diabetic ketoacidosis (DKA) has been attributed to osmotic cellular swelling during treatment. We evaluated cerebral water distribution and cerebral perfusion during DKA treatment in children. STUDY DESIGN: We imaged 14 children during DKA treatment and after recovery, using both diffusion and perfusion weighted magnetic resonance imaging (MRI). We assessed the apparent diffusion coefficients (ADCs) and measures reflecting cerebral perfusion. RESULTS: The ADC was significantly elevated during DKA treatment (indicating increased water diffusion) in all regions except the occipital gray matter. Mean reductions in the ADC from initial to postrecovery MRI were: basal ganglia 4.7 +/- 2.5 x 10(-5) mm(2)/s (P=.002), thalamus 3.7 +/- 2.8 x 10(-5) mm(2)/s, (P=.002), periaqueductal gray matter 4.3 +/- 5.1 x 10(-5) mm(2)/s (P=.03), and frontal white matter 2.0 +/- 3.1 x 10(-5) mm(2)/s (P=.03). In contrast, the ADC in the occipital gray matter increased significantly from the initial to postrecovery MRI (mean increase 3.9 +/- 3.9 x 10(-5) mm(2)/s, P=.004). Perfusion MRI during DKA treatment revealed significantly shorter mean transit times (MTTs) and higher peak tracer concentrations, possibly indicating increased cerebral blood flow (CBF). CONCLUSIONS: Elevated ADC values during DKA treatment suggests a vasogenic process as the predominant mechanism of edema formation rather than osmotic cellular swelling.     

脑室周围白质软化早产儿出生早期MRI表现及其演变

目的 探讨最终发展为脑室周围白质软化（periventricular leucomalacia,PVL）的早产儿出生早期头部MRI表现及其演变.方法 选取2010年1月至2013年12月中国医科大学附属盛京医院新生儿科住院经MRI确诊为PVL的患儿12例,所有病例均在生后2～7d（平均5.5d）及17～23 d（平均20.3 d）完成2次常规MRI及弥散加权成像（diffusion-weighted imaging,DWI）扫描.结果 最终被确诊的12例PVL患儿,初次扫描结果：全部病例DWI显示脑室周围白质高信号,其中6例弥漫、对称性高信号,3例线状高信号,3例簇状高信号,而常规MRI仅有5例显示T1加权像稍高信号,T2加权像稍低信号,余7例无改变;再次扫描结果：全部患儿脑室周围白质出现大小不等、数量不一的病灶,常规MRI显示T1加权像低信号,T2加权像高信号,相应病变部位DWI呈低信号.结论 早产儿出生早期,DWI对发现和预测PVL优于常规MRI;弥漫性脑白质损伤易发展为PVL,较严重的局灶性脑白质损伤,如多簇状、线状损伤也有发展成PVL的可能.