Noninvasive assessment of coarctation of the aorta: Comparative measurements by two-dimensional echocardiography,magnetic resonance,and angiography

Summary Fifteen patients, aged between 9 and 21 years (mean, 15.1), with native coarctation of the aorta (CoA) or suspected recoarctation after surgical repair, underwent three different diagnostic procedures. Two-dimensional echocardiography (2D echo) and magnetic resonance imaging (MRI) of the thoracic aorta were performed in all patients; 14 patients underwent aortography, and digital subtraction angiography of the aorta was performed in one (after injection via a central venous catheter). Conventional electrocardiographic (ECG) gated MRI was performed, using the sagittal plane, a 256×256 acquisition matrix, multi-slice technique and a slice thickness of 10 mm. Diameters at the coarctation site were determined by all methods. Additional diameters of the descending aorta and the aortic arch were measured by MRI and echocardiography, respectively. All noninvasively obtained diameters were compared with angiographic data. Ultrasound imaging of the aortic isthmus was achieved in seven of 15 patients and of the aortic arch in nine of 15. The mean difference compared with angiographically determined diameters was 1.7 (0–7) mm, being greater for the coarctation site [mean, 2.2 (0–4)]. MRI images of the aortic isthmus were obtained in all patients, but the difference to angiographically determined diameters was slightly higher [mean, 3.2 mm (0–8)] than the ultrasound results. This deviation was presumably due to technical conditions, such as slice thickness and orthogonal imaging planes. Including all diameters, the correlation to invasive measurements wasr=0.82 (SEM=3.1) for MRI andr=0.89 (SEM=2.3) for echo recordings. It is concluded that MRI gives a reliable estimate of the severity of coarctation in a higher percentage of investigated patients. However, in patients in whom ultrasound imaging is successful, results are as reliable as those obtained by MRI.     

The Range of Normal Values of Cardiovascular Structures in Infants, Children, and Adolescents Measured by Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is a powerful diagnostic technique and research tool for assessment of congenital heart disease due to its ability to accurately assess anatomy, function, and flow in any orientation in the thorax. However, little data exist on normative reference values for cardiac structures, except in small study populations, and even fewer data exist for pediatric populations. In this review, MRI acquisition and analysis methods for assessment of aortic size, pulmonary artery size, and right and left ventricular function, volume, and mass are presented along with reference data obtained in pediatric populations by MRI. Where MRI data are not available, reference data obtained by echocardiography or angiography are included.     

Partial Anomalous Pulmonary Venous Drainage in Young Pediatric Patients: The Role of Magnetic Resonance Imaging

Studies of larger patient groups for systematic assessment of the anatomical accuracy of magnetic resonance imaging (MRI) for partial anomalous pulmonary venous drainage (PAPVD) have been performed so far only in adults. This study was undertaken to evaluate whether MRI can precisely depict pulmonary venous anatomy in infants and young children. Data on 26 children under 10 years old that underwent MRI over the past 2 years for suspected PAPVD were assessed. The MRI protocol included shunt quantification by velocity-encoded cine as well as morphological and functional assessment by multislice multiphase and contrast-enhanced MR techniques. MRI was performed in the compliant patient in breath-hold (n = 8; age range, 4.6–9.5 years) and in the noncompliant patient in conscious-sedation free breathing (n = 18; age range, 0.4 to 7.5 years). In 22 patients, PAPVD was diagnosed with MRI and confirmed during surgery. In four patients with large atrial septal defects not accessible to percutaneous closure, normal pulmonary venous return was demonstrated by MRI and confirmed during surgery. MRI under conscious sedation accurately specifies the anatomy of pulmonary veins in infants and small children. Therefore, we suggest performing MRI in patients with inconclusive transthoracic echocardiographic results in the preoperative assessment of PAPVD.     

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。     

Assessment of Cardiovascular Anatomy in Patients with Congenital Heart Disease by Magnetic Resonance Imaging

The following discussion addresses the assessment of cardiovascular anatomy in patients with congenital heart disease by magnetic resonance (MR). The focus of this review is on the techniques of performing the MR examination. In particular, individual pulse sequences are described and illustrated with their strengths and weaknesses. Imaging strategies using the described pulse sequences are proposed. The pulse sequences described are widely available on most MR scanners. Therefore, the proposed imaging strategies are clinically proven to be simple and effective ways to perform cardiac MR examination for the assessment of cardiovascular anatomy in patients with congenital heart disease. Functional imaging, such as flow analysis and ventricular function assessment, are discussed elsewhere in this issue.     

Cardiac tumour in a neonate with tuberous sclerosis: echocardiographic demonstration and magnetic resonance imaging

In a neonate with tuberous sclerosis, cardiac tumours were diagnosed by two-dimensional echocardiography and evaluated by electrocardiogram-gated magnetic resonance imaging (MRI). The tumour size, shape and mobility in the ventricular cavities were more precisely determined by two-dimensional echocardiography than electrocardiogramgated MRI, while the extent of tumour mass at the apex was more clearly delineated by MRI. As two-dimensional echocardiography provides real-time imaging of cardiac anatomy without sedation, it is useful for initial evaluation of cardiac masses in neonates with genetic predisposition to tuberous sclerosis.Abbreviation MRI magnetic resonance imaging     

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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.     

Magnetic resonance imaging of absent pulmonary valve syndrome

A neonate with absent pulmonary valve syndrome was examined by means of echocardiography and magnetic resonance imaging (MRI). MRI provided an excellent evaluation of the intracardial morphology, vessel anatomy, mediastinal structures, and shunt flow; and it was superior to echocardiography for detection of aortopulmonary collaterals and vessel abnormalities. This case report of an uncommon cardiac abnormality confirms that MRI is a useful complementary modality to echocardiography in neonates and is recommended for problems with central pulmonary vessels and their relation to tracheobronchial structures.     

Non-gated fetal MRI of umbilical blood flow in an acardiac twin

Currently, the standard method of diagnosis of twin reversed arterial perfusion (TRAP) sequence is ultrasound imaging. The use of MRI for flow visualization may be a useful adjunct to US imaging for assessing the presence of retrograde blood flow in the acardiac fetus and/or umbilical artery. The technical challenge in fetal MRI flow imaging, however, is that fetal electrocardiogram (ECG) monitoring required for flow imaging is currently unavailable in the MRI scanner. A non-gated MRI flow imaging technique that requires no ECG monitoring was developed using the t-test to detect blood flow in 20 slices of phase-contrast MRI images randomly scanned at the same location over multiple cardiac cycles. A feasibility study was performed in a 24-week acardiac twin that showed no umbilical flow sonographically. Non-gated MRI flow images clearly indicated the presence of blood flow in the umbilical artery to the acardiac twin; however, there was no blood flow beyond the abdomen. This study leads us to conjecture that non-gated MRI flow imaging is sensitive in detecting low-range blood flow velocity and can be an adjunct to Doppler US imaging.     

磁共振弥散加权成像在早产儿脑室周围白质软化早期的预测价值

目的 探讨磁共振弥散加权成像(DWI)早期评价和预测早产儿脑室周围白质软化(PVL)的作用及意义.方法 回顾分析2005年8月至2007年4月,在我院新生儿科住院,且经头部MRI确诊的12例PVL早产儿生后7 d内、2 w和4 w的DWI及常规MRI资料.结果 初次检查(平均生后4.5 d)全部病例DWI均显示双侧脑室周围脑白质对称性、弥漫性高信号,常规MRI基本正常;出生后2周DWI示脑白质内不规则高、低混杂信号,而常规MRI则显示相应部位小片状或点状T1WI高信号,T2WI稍低信号;出生后4W DWI示侧脑室后角、枕部三角区大小不等的囊性低信号,常规MRI显示相应病灶的T1WI低信号,T2WI高信号(即囊性PVL改变);出生后4个月常规MRI示囊腔逐渐变小、消失,脑白质减少、脑室扩大.结论 DWI显示的双侧脑室周围白质对称性弥漫性高信号是PVL的最早期表现;所提供的影像学异常变化与晚期常规MRl所证实PVL发生的高度相关性,表明了DWI可能是早期评价脑白质损伤及预测早产儿PVL发生的重要检测手段.     

Cardiovascular Magnetic Resonance Imaging for Intensive Care Infants: Safe and Effective?

Background Cardiac magnetic resonance imaging (MRI) is an important diagnostic tool for congenital heart disease (CHD), as reflected by class 1 recommendations for the use of cardiac MRI by various consensus panels. However, little is known about the safety and clinical utility of cardiac MRI for these critically ill infants with CHD, whose further management cannot be directed by echocardiography. This study aimed to assess the safety, the potential hemodynamic side effects, and the clinical benefits of cardiac MRI for infants with complex CHD during their intensive care unit stay. Methods Infants referred from the pediatric cardiac intensive care unit (PCICU) to the authors’ cardiac MRI program in the past 2 years were retrospectively analyzed using the electronic chart system available at their institution. Data collected included age, diagnosis, inotropic support, urine output, diuretic medication, body temperature and lactate levels, length of MRI examination, adverse effects during and after the procedure, clinical implications of MRI, length of stay in the PCICU, and mean blood pressure and heart rate before, during, and after MRI. Results Among 592 patients in the past 2 years, 20 (3.4%) were referred for MRI testing during their stay in the PCICU. The mean age of the infants was 4.8 ± 3.2 months. Four of the patients were neonates, and eight were postoperative patients. Intracardiac malformations were present in 16 of the infants, vascular rings causing tracheal stenosis in 3 patients, and cardiomyopathy in 1 patient. The mean stay in the PCICU was 28 ± 43 days. Eight of the infants were ventilated, with a mean fraction of inspired oxygen (FiO₂) of 0.30 ± 0.15. Four were receiving inotropic support. All the nonventilated children were intubated for the MRI and extubated in the MRI laboratory. The mean duration of the MRI (door-to-door time) was 110 ± 27 min. All except one patient were hemodynamically stable, and no increase in catecholamine support was necessary during or after the scans. A 10-month-old girl receiving inotropic support needed a single dose of epinephrine due to a short episode of bradycardia after a breathhold for a contrast agent MRI angiography. Mean body core temperature at arrival to the PCICU was 36.8 ± 0.7°C. The mean serum lactate level after the MRI was 1.2 ± 0.4 mmol/l. The mean blood pressure and heart rate before, during, and after MRI were unchanged. The mean diuresis on examination day was insignificantly lower (2.4%) than the day before with unchanged medication (5.09 ± 1.58 vs 5.53 ± 1.77 ml/kg/h). For 14 (70%) of the 20 patients, surgical or catheter interventional procedures were initiated based on novel MRI information. Conclusion Cardiac MRI can be performed safely with low risk and limited hemodynamic changes for infants during their stay in the PCICU. Cardiac MRI provides key information for invasive management decisions in this subset of patients.     

Elevated CNS average diffusion constant in Fabry disease

Aims : Evaluation of the average brain diffusion constant in Fabry disease. Introduction : Fabry disease is an X-linked recessive lysosomal storage disorder secondary to deficiency of α-galactosidase A and resulting in excess tissue globotriaosylceramide, particularly in cerebral blood vessels. This has been associated with cerebral hyperperfusion. Increased tissue perfusion should increase interstitial water by the Starling relationship. This hypothesis was examined by measuring the average CNS diffusion constant (D_av) in patients with Fabry disease using diffusion-weighted magnetic resonance imaging (DWI). Methods : Axial DWI was performed at b = 1000 seconds/mm² and b = 1000 seconds/mm² (TR (pulse repetition time), 10 000; TE (time to echo), 100; FOV (field of view), 22 cm; 3 mm interleaved slices; image matrix, 128 × 128; GE Signa, 1.5T). Eight healthy male volunteers (age range, 21–47 years) and 17 hemizygous patients with Fabry disease (age range, 19–49 years) were examined. Following DWI acquisition, the trace image and the diffusion distribution map were calculated. The diffusion distribution curve was then fitted by a multi-modal Gaussian curve, allowing estimation of D_av. Results : The D_av was 0.743 ±; 0.024 ±; 10^-5 cm²/second (mean ±; SD) for patients with Fabry disease and 0.726 ±; 0.014 ±; 10^-5 cm²/second for the control group. D_av was significantly increased in the patients with Fabry disease compared with the controls ( p = 0.029)
Conclusions : The elevated D_av indicates increased brain tissue water diffusivity in patients with Fabry disease, a finding consistent with increased extracellular water and increased cerebral blood flow.     

Tracheobronchography and angiocardiography of paediatric cardiac patients with airway disorders

OBJECTIVE: We report our experience in combining tracheobronchography and angiocardiography in the assessment of a selected cohort of paediatric cardiac patients with problematic airway disorders. METHODOLOGY: The clinical records of 11 patients who underwent 17 studies at a median age of 5.5 months (range 3 months to 10.8 years) were reviewed. Tracheobronchography and angiocardiography were performed under general anaesthesia using a non-ionic contrast agent. The findings were compared with those of flexible bronchoscopy and magnetic resonance imaging (MRI). RESULTS: Seven patients had cardiac lesions associated with vascular anomalies potentially compressing the airway, while four had no identifiable aberrant or enlarged vessels. All examinations but one were performed without complications. Tracheobronchography demonstrated extrinsic vascular compression with secondary airway malacia in three (27%), intrinsic tracheobronchial stenosis in five (45%), and airway malacia in three patients (27%). Precise measurement of the airway calibre and real-time fluoroscopic monitoring facilitated transcatheter tracheobronchial interventions (six balloon dilations, three stent implantations) in four patients. In conjunction with angiocardiography, cine-tracheobronchography provided detailed information on the spatial relationship between vascular and airway structures in all patients; allowed dynamic assessment of airway malacia; and facilitated preoperative planning in six patients. In contrast, bronchoscopy failed to differentiate malacia from extrinsic compression in four patients (36%), while MRI, performed in six patients, was unsatisfactory in one due to a motion artefact and failed to diagnose airway malacia and extrinsic compression in three patients. CONCLUSIONS: Tracheobronchography is relatively safe in paediatric cardiac patients. Combined tracheobronchography and angiocardiography, a less operator-dependent imaging modality compared to bronchoscopy and MRI, delineated the airway and vascular anatomy in detail; facilitated preoperative planning; and permitted transcatheter tracheo-bronchial interventions. The dynamic capability of tracheobronchography supplements that of flexible bronchoscopy and MRI in the diagnosis of airway malacia.     

Predictors of Successful Transcatheter Closure of Atrial Septal Defect by Cardiac Magnetic Resonance Imaging

The location, size, and rim of an atrial septal defect (ASD) are major determining factors for transcatheter closure. We compared the measurements of ASD size and the characteristics of atrial septal rim using cardiac magnetic resonance imaging (MRI) with those obtained using transesophageal echocardiography (TEE). Patients with an ASD that met established criteria were selected for evaluation by cardiac MRI and TEE. There were 66 patients who underwent both TEE and cardiac MRI. Bland–Altman comparative analysis was performed to demonstrate agreement between measurement of ASD by MRI and balloon sizing compared to measurement of ASD by TEE and balloon sizing. Twelve patients were excluded from transcatheter closure of ASD. TEE did not demonstrate an adequate measurement of the posterior inferior rim in 10 of 66 patients. Fifty-four patients underwent transcatheter closure using the Amplatzer septal occluder. Of these, 52 patients had successful closure (ASD measurements of 25.9 ± 5.6 mm using MRI and 21.9 ± 5.8 mm using TEE). The median device size was 28 mm (range, 11–38). Patients who had successful closure had a significantly smaller major axis of ASD and larger posterior inferior rim compared to those of patients who were excluded from the closure procedure. Cardiac MRI showed a better correlation of ASD diameter measurement to balloon sizing compared to TEE. We believe that the most important predictive factor for successful transcatheter closure of an ASD is an adequate posterior inferior rim, which is best visualized using cardiac MRI.     

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。     

Evaluation of pulmonary artery anatomy using magnetic resonance: The importance of multiplanar and oblique imaging

Summary Pulmonary artery anatomy was studied in 36 patients (age range 12 days to 12.83 years, mean 2.9 years) with right ventricular outflow tract obstruction over a 3-year period using a 1.5 Tesla Magnetic Resonance system. Gated spin-echo sequences were obtained in each patient. Image planes used were straight and oblique transverse, oblique coronal, and oblique sagittal. The studies were analyzed retrospectively and comparative angiographic, surgical, and postmortem data was available in all cases. As previously noted with other imaging modalities, multiple views and oblique cuts were found to increase significantly the quality and accuracy of the information acquired. In 12 of the 15 patients who had axial and coronal imaging of both branch pulmonary arteries, the pulmonary arteries were unequivocally demonstrated to at least the first hilar branch. However, early in our experience we missed a number of branch stenoses that developed following surgical anastomoses. These mistakes were caused by inadequate or inappropriate slice acquisition. Magnetic resonance is an important technique for imaging pulmonary arteries. Careful use of the appropriate imaging planes is essential for accurate demonstration of the anatomy.     

Time-course changes in the liver of biliary atresia patients on magnetic resonance imaging

Background:  Using magnetic resonance imaging (MRI), changes in the livers of postoperative biliary atresia (BA) patients were investigated.
Methods:  Periodic MRI was performed in 32 postoperative BA patients. The findings were evaluated by calculating the near-normal liver tissue area that corresponded with normal- or high-signal regions on T1-weighted imaging. The patients were divided into three groups based on the extent of near-normal liver tissue on the final MRI: group A, n  = 14; group B, n  = 13; and group C, n  = 5, included patients with >40%, 20–40%, and <20% area of near-normal liver tissue, respectively. The relationship among the macroscopic and histological findings in the liver at orthotopic living donor liver transplantation (OLDLT), patient outcomes, and MRI findings were investigated.
Results:  In group A, 11 patients had no evidence of liver dysfunction. In group B, six patients either had undergone or were awaiting OLDLT. In group C, all patients had undergone OLDLT. All patients had either adequate or impaired bile drainage in each liver segment. The segmental changes corresponded with the liver architecture at OLDLT. The changes could be evaluated on MRI at 1–2 years after surgery.
Conclusions:  Adequate and restricted areas of liver tissue with near-normal structure were indicative of good and poor prognoses, respectively. Shortly after portoenterostomy, these segmental changes occurred and/or developed in each liver segment and could be detected on MRI. It is emphasized that patients with >40% area of near-normal liver architecture at the initial stages did not require OLDLT, while those with <20% area did require OLDLT.     

磁共振中脑导水管脑脊液流动成像在正常小儿的研究分析

目的 分析正常小儿中脑导水管处脑脊液磁共振流动成像表现,并进一步了解脑脊液的循环过程及原理.方法 使用3T超导磁共振机器(西门子verio)对正常小儿中脑导水管进行磁共振脑脊液流动成像检查.按其年龄分为＜1.5岁(14例)和1.5～14岁(25例)两组.磁共振检查序列包括经过中脑导水管的横断位、矢状位和冠状位T2WI像,经过中脑导水管的矢状位3D-CISS序列和相位对比-电影序列(PC-Cine),以及垂直中脑导水管截面的相位对比-电影序列.观察各组的影像学改变和脑脊液电影循环情况,并测定每组小儿中脑导水管的截面积、脑脊液不同方向峰流速及净流量,比较两组数据有无统计学差异.结果 在经过中脑导水管矢状位和垂直中脑导水管截面的PC-Cine序列上均可观察到在一个心动周期内脑脊液信号呈明暗交替变化,心脏收缩期峰流速方向向下,舒张期方向向上.1.5～14岁组脑脊液向下峰流速为(8.371±1.511)cm/s显著高于＜1.5岁组(6.538±1.264) cm/s,差异有统计学意义(P=0.000 5);1.5～14岁组向上峰流速为(7.163±1.806)cm/s略高于＜1.5岁组(6.073±1.096) cm/s,差异亦有统计学意义(P=0.047 5),小儿中脑导水管的截面积和净流量在两组间差异无统计学意义(P＞0.05).结论 磁共振脑脊液流动成像能清晰的显示中脑导水管脑脊液循环过程,为了解小儿脑脊液循环特点及疾病进展提供准确的影像依据.     

足月新生儿低血糖22例磁共振表现与临床特征

目的 探讨足月新生儿低血糖病例的MRI表现及临床特征的相关性。方法 回顾性分析2008年6月1日至2011年6月30日复旦大学附属儿科医院新生儿科收治的22例足月低血糖新生儿的病例资料,根据MRI检查结果分为低血糖MRI-组（n=9）和低血糖MRI+组（n=13）,分析两组低血糖新生儿的临床特征并描述低血糖MRI+组的MRI表现。结果 MRI-组和MRI+组在有无围生期高危因素中的差异无统计学意义（P=0.054）;MRI-组和MRI+组低血糖首次发现时间分别为1(0.5~17)h和46.6(12.7~78.3)h,两组差异有统计学意义P=0.000;MRI-组和MRI+组血糖正常并稳定的时间分别为（54.1±18.2）h和（71.6±15.1）h,两组差异有统计学意义P=0.023。出现症状的比例MRI+组高于MRI-组（P=0.000）。MRI+组中10例低血糖新生儿的MRI表现以累及双侧枕顶叶为主,3例不伴双侧枕顶叶损伤（1例累及单侧顶枕叶,2例为侧脑室旁和半卵圆中心斑点状白质损伤）。 结论 对于存在高危因素的低血糖新生儿,应早期筛查,定期监测;生后12 h内发现的低血糖新生儿可无症状,MRI可无脑损伤性改变;血糖正常并稳定的时间指标提示对低血糖脑损伤更要注意远期随访。双侧顶枕叶是新生儿低血糖脑损伤的主要受累部位。