新生儿缺氧缺血性脑病MRI表现及其与预后的关系

目的 探讨足月新生儿缺氧缺血性脑病（HIE）的早期MRI表现及其与临床分度及预后的关系。资料与方法 以9例无窒息史的正常新生儿作对照,观察46例HIE患儿初期的MRI表现及28例复查病例的MRI表现。结果 （1）MRI能显示HIE患儿的12种早期异常征象,其中T1WI皮层高信号、侧脑室周围深部白质高信号以及蛛网膜下腔出血（SAH）或硬膜下出血（SDH）3种征象在轻度组与中、重度HIE组差异无显著性（P〉0．05）;而另外6种征象（弥漫性脑水肿、T1WI双侧基底节高信号伴内囊后肢高信号消失、弥漫性脑实质出血、脑回征、灰白质分界不清及胼胝体水肿）,在中、重度与轻度HIE组差异有显著性（P〈0．05）,说明这些征象是脑损伤严重的表现。（2）双侧基底节区广泛高信号伴内囊后肢高信号消失,弥漫性脑水肿。大面积脑梗死,脑回征以及脑实质广泛出血5种早期征象提示预后不良。常常会留下神经系统后遗症。结论 MRI可以客观反映新生儿HIE早期脑损伤的严重情况,并可早期评估预后。     

新生儿低血糖脑损伤MRI表现

目的 :探讨新生儿低血糖脑损伤的MRI特征,为低血糖性脑损伤患儿的诊断及治疗提供依据。方法 :回顾性分析我院收治的11例临床诊断为低血糖脑损伤患儿的MRI表现。结果:本组中,累及双侧顶枕叶11例,胼胝体压部7例,侧脑室旁白质2例,1例伴脑室旁点状出血。首次MRI检查表现为病变部位长T1长T2信号,DWI高信号11例,2例内囊后肢T1WI高信号消失,1例伴脑室旁点状出血呈短T1短T2信号。1个月后MRI复查3例,2例显示双侧顶枕叶软化灶,1例胼胝体仍显示稍长T1长T2信号,DWI稍高信号。结论:新生儿低血糖脑损伤主要部位为大脑半球顶枕叶皮层及皮层下白质,其次为胼胝体;急性期MRI表现主要为损伤部位的水肿,慢性期则表现为受累脑组织出现软化、萎缩等。颅脑MRI是目前诊断低血糖脑损伤影像学检查最佳的选择。     

妊娠高血压综合征致脑后部可逆性脑病综合征的MRI表现

目的:探讨妊娠高血压综合征(PIH)致脑后部可逆性脑病综合征(PRES)的MRI表现。方法:回顾性分析9例临床诊断为PIH致PRES患者的MRI平扫及扩散加权扫描(DWI)表现。结果:9例PRES患者MRI均可见双侧顶枕区皮质及皮层下白质多发病灶,在T1WI上病灶呈等信号或略低信号,FLAIR及T2WI上呈高信号,6例DWI显示病灶呈等信号或低信号,扩散系数(ADC值)升高,3例病灶DWI上呈高信号,ADC值不变。治疗后随访MRI显示所有患者病灶逐渐减小、消失。结论:PIH妊娠晚期发生的PRES病好发于顶枕叶皮质及皮层下白质,治疗及时可逆转,采用MRI平扫及DWI成像结合临床特征,可做出较为明确诊断。     

磁共振弥散加权成像在新生儿缺氧缺血性脑病的诊断价值

目的:以磁共振弥散加权成像(DWI)技术并与常规MR T1WI、T2WI结合应用,探讨DWI对新生儿缺氧缺血性脑病(HIE)的早期诊断价值。方法:对我院2004年1月~2010年1月临床确诊缺氧缺血性脑病的新生儿62例(4h~15天)进行DWI和常规T1WI、T2WI检查。结果:DWI出现高信号病灶59例,T1WI信号异常32例,T2WI信号异常13例。DWI高信号病灶多见于大脑皮层、侧脑室周围白质区及室管膜下,T1WI高信号以脑室周围白质区多见。出血性病变,在T1WI呈高信号,而DWI表现为无信号。结论:DWI适用于早期HIE,T1WI及T2WI在亚急性期、恢复期或随访应用显示病灶较好。     

用MR扩散加权成像评价新生儿缺氧缺血性脑病的初步研究

目的应用扩散加权成像(DWI)方法评价新生儿缺氧缺血性脑病(HIE)，并同常规MRI对照，以了解扩散成像的价值及限度。方法对临床确诊的36例缺氧缺血性脑病的新生儿(年龄3h至22d，平均8．44d)，进行常规MRT，WI和DWI检查(b=700s／mm^2)。观察皮层及皮层下白质、深部白质、基底节及丘脑、脑室及脑外间隙等部位。结果缺血缺氧所致脑损害在DWI表现为弥漫性损害：区域性皮层、皮层下及深部白质较广泛的高信号19．4％(7／36)；局灶性损害：沿侧脑室壁和三角部白质的高信号27．8％(10／36)，额叶深部白质点状高信号5．6％(2／36)。相应部位的T1WI分别为16．7％(6／36)，36．1％(13／36)，30．6％(11／36)。出血性病变，在T1WI上为高信号，而在DWI上表现为无信号。结论MR DWI适于早期检查HIE，T1WI适于亚急性期和慢性期。     

结节性硬化症脑部CT和MRI表现(附12例报告)

目的:分析结节性硬化症脑部CT和MRI表现,以提高对本病的认识。方法:回顾性分析12例经临床证买为结节性硬化症患者的CT和MRI脑部影像学表现。结果:TSC脑部主要影像学改变包括:①室管膜下结节(12例),CT 上表现为多发高密度钙化结节,MRI上表现为T1WI高信号、T2WI低信号7例,T1WI和T2WI上均为低信号1例,T1WI 上呈等信号、T2WI上呈低信号4例;②皮层及皮层下结节(9例),其CT表现为高密度钙化灶3例、低密度灶6例,MRI上呈T1WI低信号、T2WI高信号9例;③脑白质异常(6例),CT上表现为多发低密度灶4例,MRI上表现为T1WI低信号、 T2WI高信号6例。5例行MRI增强扫描,示室管膜下结节呈中等强化,皮层及皮层下结节和脑白质异常信号均未见强化。结论:CT和MRI能较好显示结节性硬化脑部改变,CT对显示钙化结节较敏感,MRI对显示皮层及皮层下结节和脑白质改变较敏感。     

儿童髓鞘少突胶质细胞糖蛋白抗体相关疾病首次发作的MRI分析

目的 探讨儿童髓鞘少突胶质细胞糖蛋白抗体相关疾病（MOGAD）首次发作的MRI特点。资料与方法 回顾性分析2018年5月—2021年2月湖南省儿童医院临床诊断为MOGAD的40例患儿首次发作时头颅、脊髓及视神经MRI表现,患儿首次发作年龄1.2～13.8岁。结果 40例患儿中,37例（92.5%）头颅MRI可见异常病灶,30例为多脑叶受累,24例皮层、皮层下白质及深部白质均受累,额叶（78.4%,29/37）、顶叶（75.7%,28/37）为最常累及的脑叶,扩散加权成像及磁敏感成像无异常,增强扫描无强化或轻度强化。14例（38.9%）脊髓MRI异常,表现为脊髓长节段、不连续稍长T1稍长T2信号影,主要位于中央灰质部位,增强扫描无强化或轻度强化;其中13例胸髓受累,8例颈髓受累。31.0%(9/29)视神经MRI异常,主要表现为单侧（4例）或双侧（4例）视神经稍增粗,T2WI信号增高,1例累及视交叉,增强扫描以视神经鞘及周围脂肪组织强化为特征。结论 MOGAD患儿头颅、脊髓及视神经MRI表现多样,在头颅多表现为皮层、皮层下白质及深部白质的多发稍长T1稍长T2信号影,在脊髓表现为颈胸髓内长...     

新生儿缺氧缺血性脑病:前10天的MRI和CT表现对比分析

目的：比较新生儿缺氧缺血性脑病前10d的MRI和CT征象，探讨更适合的检查方法。方法：回顾性分析和记录32例新生儿HIE的MRI和CT异常征象。结果：32例HIE患儿MRI均有不同程度的异常征象，主要表现为脑水肿28例，皮层下及深部脑白质斑点状和弯曲条状高信号（T1WI)15例，基底节及丘脑斑点状高信号（T1WI）9例，蛛网膜下腔出血或硬膜下血肿15例；CT仅27例有异常表现，以脑水肿为主要表现，仅见9例伴有蛛网膜下腔出血或硬膜下血肿。结论：新生儿HIE前10d MRI比CT能发现更多有价值的诊断征象，有助于早期准确诊断。     

局灶性脑皮层发育不良的MRI诊断

目的 研究局灶性脑皮层发育不良(focal cortical dysplasia,FCD)的MRI表现特点.资料与方法 回顾性分析23例经手术病理证实的FCD患者的MRI表现.常规行横断位、矢状位及垂直于海马长轴的斜冠状位扫描,获得T1 WI、T2WI及液体衰减反转恢复序列(FLAIR)图像.结果 23例FCD病灶均表现为一侧大脑半球内局限性病变.病灶区域皮质增厚18例,灰白质分界模糊20例,皮层下白质异常信号22例,脑回、脑沟形态异常14例,邻近蛛网膜下腔局限性扩大4例.T1WI、T2WI及FLAIR显示灰白质分界模糊分别为6例、20例及18例;皮层下白质异常信号分别为3例、16例及19例;脑回、脑沟形态异常分别为12例、10例及11例.结论 FCD的MRI表现为皮质增厚、灰白质分界模糊、皮层下白质异常信号、脑回、脑沟形态异常及邻近蛛网膜下腔局限性扩大.T2WI及FLAIR显示灰白质界限、白质内异常信号较T1WI敏感,T1WI显示脑回、脑沟形态有一定的价值.     

新生儿缺血缺氧性脑病的MRI表现

目的:分析新生儿缺血缺氧性脑病(hypoxic ischemic encephalopathy,HIE)的常规MRI T1WI、T2WI、T2FLAIR及DWI表现,探讨各序列在不同类型损伤中的诊断价值。方法:对出生15d内临床诊断为HIE的新生儿行3.0T MRI颅脑检查,扫描序列包括轴位T1WI、T2WI、T2FLAIR及DWI。分析图像并根据图像所显示的病变部位及信号特点对HIE脑损伤进行分型,计算不同序列显示各型损伤的病灶数目及显示率。结果:MRI共检出病灶240个。T1WI对基底节及丘脑损伤、皮质及皮质下白质损伤、脑出血显示较好,显示率分别为46.15%、41.30%、35.71%。T2WI对深部白质损伤显示较好,且脑出血的显示率与T1WI相同。T2FLAIR检测深部白质损伤最佳,显示率为36.36%;对皮质及皮质下白质损伤也较为敏感,显示率为29.35%。DWI对胼胝体及内囊后肢损伤的显示率分别为80.00%、50.00%,优于其他序列。结论:T1WI、T2WI、T2FLAIR及DWI对不同类型HIE的显示各有优势。常规MRI序列对新生儿HIE有重要诊断价值。     

足月新生儿缺氧缺血性脑病的MRI研究

目的：通过对足月新生儿缺氧缺血性脑病（ＨＩＥ）的ＭＲＩ分析,找出ＨＩＥ的ＭＲＩ特点。材料和方法：对４５例临床确诊为ＨＩＥ的足月新生儿行ＭＲ检查。采用０．３５Ｔ磁共振仪,选自旋回波序列（ＳＥ）,在Ｔ１ＷＩ及Ｔ２ＷＩ上对脑皮层及皮层下白质,深部白质;基底节及丘脑;脑室及蛛网膜下腔等部位进行观察。结果：在Ｔ１ＷＩ上见皮层沿脑回分布点的及条状高信号,深部白质沿侧室壁的条状高信号,基底节及丘脑高信号,幕上及幕下蛛网膜下腔出血呈现的高信号,其发生率分别为８４．４４％,３７．７８％,４２．２２％,１３．３３％与４８．８９％。此外,额叶深部白质内对称的点状高信号也相当特殊,发生率４４．４４％,其它改变有皮层下坏死软化,占２０％,脑室内出血占８．８９％。结论：本文主要描述了足月新生儿ＨＩＥ的ＭＲＩ特点并对其相关的病理基础进行探讨。     

新生儿缺氧缺血性脑病的MRI评价

目的：评价MRI对新生儿缺氧缺血性脑病（HIE）的诊断价值。资料与方法：采用SE序列对61例（65例次）HIE患儿进行了MRI检查，分析MRI表现。结果：56例新生儿期检查中脑水肿42例，内囊后肢信号异常22例，脑出血11例，脑室出血4例，脑室旁白质软化2例。9例婴儿期检查者中表现有脑室扩大7例，脑外间隙增宽9例，髓鞘发育延迟3例。结论：MRI有助于明确HIE的脑损伤情况，对于预后的评估有价值。     

Neonatal hypoxic-ischemic encephalopathy: detection with diffusion-weighted MR imaging

BACKGROUND AND PURPOSE: Although diffusion-weighted imaging has been shown to be highly sensitive in detecting acute cerebral infarction in adults, its use in detecting neonatal hypoxic-ischemic encephalopathy (HIE) has not been fully assessed. We examined the ability of this technique to detect cerebral changes of acute neonatal HIE in different brain locations. METHODS: Fifteen MR examinations were performed in 14 neonates with HIE (median age, 6.5 days; range, 2-11 days). Imaging comprised conventional T1-weighted, proton density-weighted, and T2-weighted sequences and echo-planar diffusion-weighted sequences. The location, extent, and image timing of ischemic damage on conventional and diffusion-weighted sequences and apparent diffusion coefficient (ADC) maps were compared. RESULTS: Although conventional sequences showed cerebral changes consistent with ischemia on all examinations, diffusion-weighted imaging showed signal hyperintensity associated with decreased ADC values in only seven subjects (47%). All subjects with isolated cortical infarction on conventional sequences had corresponding hyperintensity on diffusion-weighted images and decreased ADC values, as compared with 14% of subjects with deep gray matter/perirolandic cortical damage. The timing of imaging did not significantly alter diffusion-weighted imaging findings. CONCLUSION: Diffusion-weighted imaging, performed with the technical parameters in this study, may have a lower correlation with clinical evidence of HIE than does conventional MR imaging. The sensitivity of diffusion-weighted imaging in detecting neonatal HIE appears to be affected by the pattern of ischemic damage, with a lower sensitivity if the deep gray matter is affected as compared with isolated cerebral cortex involvement.     

Cerebellar vermian atrophy after neonatal hypoxic-ischemic encephalopathy

BACKGROUND AND PURPOSE: Although pathologic evidence of cerebellar injury due to birth asphyxia is well described, neuroimaging evidence is sparse. The primary purpose of this retrospective study was to evaluate the early and late imaging findings in the cerebellum of patients who had neonatal hypoxic-ischemic encephalopathy with thalamic edema shown by neonatal CT. The secondary aims were to validate thalamic edema shown by neonatal CT as a marker of thalamic injury and to assess the late cerebral cortical abnormalities associated with neonatal thalamic edema. METHODS: Fifty-five neonates with thalamic edema shown by CT performed when patients were 3 days old were identified from a cohort of full-term neonates with hypoxic-ischemic encephalopathy. Twenty-six of the 55 underwent follow-up neuroimaging. All sonograms, CT scans, and MR images of the brains of the 55 neonates were retrospectively reviewed by two pediatric neuroradiologists. The examinations were reviewed for evidence of hemorrhage, edema, atrophy, and CT attenuation or MR signal intensity abnormalities in the cerebellum, basal ganglia, and cerebral cortex. The neonatal autopsy findings in four cases were reviewed separately by a pediatric neuropathologist. RESULTS: Of the 55 neonates with thalamic edema shown by neonatal CT, 28 (51%) had thalamic edema with diffuse cerebral cortical edema, and 27 (49%) had thalamic edema without diffuse cortical edema. The cerebellar vermes appeared normal on all neonatal sonograms, CT scans, and MR images. However, atrophy of the cerebellar vermis was found in 12 (46%) of 26 patients by use of follow-up studies (95% CI, 27-65%). One of the 12 patients also had cerebellar hemispheric atrophy. Cerebellar vermian atrophy was shown at follow-up in eight (67%) of 12 patients who had neonatal thalamic edema with cortical sparing, compared with four (29%) of 14 patients who had thalamic edema with diffuse cortical edema. The difference did not reach statistical significance. The thalami appeared abnormal on follow-up neuroimages in 25 of 26 cases. Different patterns of cortical atrophy were observed on the images of patients who had thalamic edema with cortical sparing compared with those obtained in patients who had thalamic edema with cortical involvement. CONCLUSION: Cerebellar vermian atrophy is a frequent finding on follow-up images of patients in whom neonatal CT showed hypoxic-ischemic encephalopathy with abnormal thalami.     

新生儿缺氧缺血性脑病SPECT显像研究

目的：探讨新生儿缺氧缺血性脑病SPECT显像的特点。方法：对30例符合新生儿缺氧缺血性脑病诊断和分度标准的患儿和10例正常新生儿进行SPECT脑血流灌注断层显像，并与CT，MRI进行比较，结果：22例同时做SPECT，CT和MRI的患儿中，轻度组7例，SPECT，CT和MRI阳性数分别为7例，3例和5例，中度组10例中，3种方法的阳性数分别为10例，8例和9例；重度组5例，3种方法均为阳性；SPECT，CT和MRI总的阳性检出率分别为100％，72．7％，和86．4％，结论：SPECT显像是诊断该病较灵敏的方法，与CT，MRI结合能对脑组织的生理，病理及代谢，功能状态作出诊断。     

MR T1WI纹状体高信号表现分析

目的探讨纹状体MRT1WI高信号病变的影像表现,并结合文献讨论其发生机制及病理改变。资料与方法回顾性分析32例纹状体MRT1WI高信号病变的影像表现,包括亚临床性肝性脑病,钙化、脑梗死及CO中毒性脑病。结果亚临床性肝性脑病患者表现为多个部位的T1WI高信号,主要累及部位有苍白球,壳核,中脑红核周围,T2WI及CT上未见异常,T2WI梯度回波上呈明显或较低信号;钙化表现为纹状体对称的T1WI高信号,其信号强度不均匀,T2WI上表现为稍低、等或高信号,CT表现为高密度;脑梗死后病变表现为纹状体点片状T1WI高信号,T2WI上可见比,T1WI上范围大的高信号;CO中毒性脑病表现为双侧纹状体对称性T1WI高信号,其信号强度不均匀,主要累及苍白球,T2WI上其周围深部白质可见大片状高信号。结论纹状体T12I高信号主要与金属顺磁性物质（锰、钙、铁等）的沉积有关。结合临床表现及实验室检查可以做出正确地诊断与鉴别诊断。     

应用低场磁共振成像诊断高血压脑出血的探讨

讨论了２６３例高血压脑出血超急性期及急性期血肿在低磁场磁共振成像中的信号特征，在Ｔ１加权像表现为高信号，Ｔ２加权像为混杂信号，与中、高磁场ＭＲＩ图像有所不同。低磁场ＭＲＩ对显示超急性期及急性期脑出血有较高的诊断敏感性和准确性。     

Temporal evolution of MR perfusion in neonatal hypoxic-ischemic encephalopathy

PURPOSE: To illustrate the evolution of brain perfusion-weighted magnetic resonance imaging (PWI-MRI) in severe neonatal hypoxic-ischemic (HI) encephalopathy, and its possible relation to further neurodevelopmental outcome. MATERIALS AND METHODS: Two term neonates with HI encephalopathy underwent an early and a late MRI, including PWI. They were followed until eight months of age. A total of three "normal controls" were also included. Perfusion maps were obtained, and relative cerebral blood flow (rCBF) and cerebral blood volume (rCBV) values were measured. RESULTS: Compared to normal neonates, a hyperperfusion (increased rCBF and rCBV) was present on early scans in the whole brain. On late scans, hyperperfusion persisted in cortical gray matter (normalization of rCBF and rCBV ratios in white matter and basal ganglia, but not in cortical gray matter). Diffusion-weighted imaging (DWI) was normalized, and extensive lesions became visible on T2-weighted images. Both patients displayed very abnormal outcome: Patient 2 with the more abnormal early and late hyperperfusion being the worst. CONCLUSION: PWI in HI encephalopathy did not have the same temporal evolution as DWI, and remained abnormal for more than one week after injury. This could be a marker of an ongoing mechanism underlying severe neonatal HI encephalopathy. Evolution of PWI might help to predict further neurodevelopmental outcome.