甲基丙二酸血症3 例报告并文献复习

目的探讨甲基丙二酸血症(MMA)伴同型半胱氨酸血症(cbl C)的临床及基因突变特点。方法回顾性分析经基因检测确诊的3例MMA患儿的临床资料及基因检测结果,并复习相关文献。结果 3例患儿均为男性。例1患儿26日龄,间断抽搐3 d入院;血甲基丙二酸175.8μmol/L,丙酰肉碱/乙酰肉碱比值(C3/C2)1.363,同型半胱氨酸65μmol/L,脑电图异常,MMACHC基因外显子1缺失,del EXON1未见文献报道。例2患儿12岁,因肢体抖动、抽搐、呕吐入院,血甲基丙二酸334.3μmol/L,C3/C2比值0.37,同型半胱氨酸65μmol/L,脑电图异常,MMACHC基因c.482GA、c.609GA突变。例3患儿3个月,因间断抽搐20 d入院,血甲基丙二酸154.3μmol/L、C3/C2 0.84,MMACHC基因c.394CT、c.540del8突变,其中c.540del8未见报道。文献复习发现,部分MMA患者合并癫痫发作,进一步验证MMACHC基因c.482GA突变可能与晚发型的cbl C相关。结论基因检测有助于MMA的诊断,MMACHC基因c.482GA突变可能与晚发型cbl C相关;del EXON 1、c.540 del 8为新突变。     

Imaging of the brain,including diffusion-weighted imaging in methylmalonic acidemia

Methylmalonic acidemia (MMA) is a multifactorial autosomal recessive inborn error of organic acid metabolism, often presenting with neurologic findings. We report the imaging findings in a case of a child with classic neurological and laboratory findings for MMA. Imaging studies demonstrated abnormalities within the basal ganglia, particularly the globi pallidi (GP). Diffusion-weighted abnormalities seen in patients with MMA during an acute episode of metabolic acidosis and at follow-up are discussed. The authors are aware of only one prior report of serial examinations demonstrating resolution of restricted diffusion in the GP. The biochemical and pathophysiologic basis of the imaging findings of MMA are explained.     

Pilomatricomas in children: imaging characteristics with pathologic correlation

Background Although pilomatricoma commonly occurs in children, there is still a poor understanding of the imaging characteristics of pilomatricoma and lack of agreement regarding its imaging findings and histopathologic features. Objectives To characterize the radiologic appearance of pilomatricomas on US, CT, and MR and to correlate the imaging findings with histopathologic features. Materials and methods The imaging findings of 47 pilomatricomas on US (n = 17), CT (n = 31), and MR (n = 5) were retrospectively evaluated. Pathologic specimens of all cases were reviewed and compared with imaging findings. Results All lesions were well-circumscribed, subcutaneous nodules with partial attachment to the overlying skin. On US, the lesions were mostly hyperechoic with posterior acoustic shadowing and hypoechoic rim. On CT, they appeared as enhancing soft-tissue masses with varying amounts of calcification. MR findings were internal reticulations and patchy areas on T2-weighted images and contrast-enhanced T1-weighted images, corresponding to edematous stroma on pathology. Peritumoral inflammatory changes and connective capsule on pathology were well correlated with imaging findings. Conclusion Pilomatricoma should be considered when US or CT shows a well-defined hyperechoic or calcific nodule in subcutaneous fat attached to the skin in children. MR images may be helpful in diagnosis. Pathologic findings are well correlated with imaging findings.     

Round pneumonia: imaging findings in a large series of children

Background Although round pneumonia is a well-known clinical entity, there have been no large case reviews, with most knowledge based on case reports and small series from the 1960s and 1970s. Objective To review the imaging findings of a large series of children with round pneumonia. Materials and methods A retrospective review of radiographic and CT findings in all children reported to have round pneumonia at a large children’s hospital from 2000 to 2006 was performed. Children with underlying medical conditions were excluded. Epidemiologic characteristics, radiographic and CT findings, and follow-up imaging were reviewed. Results The review identified 109 children (mean age 5 years, range 4 months to 19 years). Round pneumonias tended to be solitary 98% (107/109), have well-defined borders 70% (77/109), and be posteriorly located 83% (91/109), with the following lobar distribution: left lower lobe (36), right lower lobe (33), right upper lobe (28), left upper lobe (7), right middle lobe (4), and lingula (2). Round pneumonia tended to resolve on follow-up imaging (95%, 41/43) as compared to progression to lobar pneumonia (4.6%, 2/43). Three patients (2.6%, 3/112) originally suspected to have round pneumonia were later shown to have other diagnoses: cavitary necrosis in pneumonia (two) or pleural pseudocyst (one). Conclusion Round pneumonia occurs in young children (mean age 5 years), tends to be a solitary lesion, and is most commonly posteriorly located. Misdiagnosis of other pathology as round pneumonia is uncommon.     

Adamantinoma in childhood: report of six cases and review of the literature

Background Adamantinoma is a rare slow-growing malignant bone tumour. Objective To describe the imaging appearances of six childhood cases and review the published literature. Materials and methods The database of the Working Group on Paediatric Oncology, Academic Medical Centre/Emma Children’s Hospital Amsterdam, was searched for cases of adamantinoma. Additionally a literature study was performed to identify cases of adamantinoma in childhood. Results We identified six local cases of adamantinoma of the long bones, two boys (age 3 and 8 years) and four girls (mean age 8.8 years, range 3.0–14.0 years). The location of the tumour was the tibia in five and the tibia and fibula in one patient. In two patients initially a different diagnosis was made, which led to a delay in appropriate treatment. None of the children showed pulmonary metastases and all underwent total gross resection. On follow-up (mean 6.1 years, range 1.6–12.0 years) all children remained disease-free. Besides a discussion of our six patients, imaging features, histopathology, surgical approach and a literature review of childhood adamantinomas is presented. Conclusion Although the incidence of adamantinoma is low, it is important to recognize this rare bone tumour, since in the early stages of the disease adequate treatment will result in an excellent prognosis. Part of this paper was presented at the Annual Meeting of the Radiological Society of North America, 2004, Chicago, USA.     

Post-contrast FLAIR MR imaging of the brain in children: normal and abnormal intracranial enhancement

Objective To describe the normally enhancing intracranial structures on fluid-attenuated inversion recovery (FLAIR) MRI and evaluate the usefulness of postcontrast FLAIR images of the brain in the assessment of enhancing lesions by comparing postcontrast FLAIR imaging with postcontrast T1-weighted (T1-W) imaging in children.Materials and methods In 218 children, 249 pre- and postcontrast FLAIR MRI examinations of the brain were obtained consecutively between August 2001 and April 2002. The normally enhancing intracranial structures on FLAIR imaging were assessed in 77 MRI studies of 74 children who showed normal intracranial imaging findings. In 86 MRI studies in 68 children who showed enhancing intracranial lesions, lesion conspicuity on postcontrast FLAIR imaging was compared with that on postcontrast T1-W imaging for all lesions (n=107), intra-axial lesions (n=40), or extra-axial lesions (n=67).Results The normally enhancing intracranial structures on FLAIR MRI were the choroid plexus (99%, 76/77), pituitary stalk (84%, 65/77), pineal gland (71%, 55/77), dural sinuses (26%, 20/77), and cortical veins (9%, 7/77). Of all the enhancing lesions, lesion conspicuousness on postcontrast FLAIR imaging was better than postcontrast T1-weighted imaging in 42, equal in 28, and worse in 37. Of 40 intra-axial lesions, lesion conspicuousness on postcontrast FLAIR imaging was better in 6, equal in 10, and worse in 24. Of 67 extra-axial lesions, lesion conspicuity on postcontrast FLAIR imaging was better in 36, equal in 18, and worse in 13. Conspicuousness of extra-axial lesions was significantly better than that of intra-axial lesions on postcontrast FLAIR imaging (P<0.001).Conclusions The choroid plexus, pituitary stalk, pineal gland, dural sinuses, and cortical veins show normal enhancement on postcontrast FLAIR MRI in children, and postcontrast FLAIR imaging appears better than postcontrast T1-W imaging in the assessment of extra-axial enhancing lesions in children.Presented at the 46th Annual Meeting of the Society for Pediatric Radiology, San Francisco, California, USA, May 2003     

Narrow duplicated internal auditory canal: radiological findings and review of the literature

Narrow duplicated internal auditory canal (IAC) is a rare malformation of the temporal bone that is associated with ipsilateral congenital sensorineural hearing loss. This may be an isolated finding or a part of a syndrome. Radiological examination should demonstrate aplasia or hypoplasia of the neural components of the narrow IAC, to guide the surgical approach. We report a 7-year-old boy with Klippel-Feil syndrome with a narrow double IAC with no sensorineural hearing loss but with conductive hearing loss. In this patient, the IAC consisted of two separate narrow bony canals clearly seen on 3D temporal bone CT and one nerve that was delineated on MRI. The contralateral external auditory canal was stenotic and the ossicles were dysplastic.     

Assessment of lung function in children by cross-sectional imaging: techniques and clinical applications

Imaging techniques are indispensable for diagnosis and follow-up of paediatric pulmonary diseases. In the past, interest was focused on morphological aspects of pulmonary tissue. With the development of novel CT and MRI techniques, functional pulmonary imaging became available. In this review, the new techniques of cross-sectional functional imaging of the lung are presented and the value of these methods for investigating paediatric pulmonary diseases and their potential clinical applications are discussed.     

CT and MRI in haemolytic uraemic syndrome with central nervous system involvement: distribution of lesions and prognostic value of imaging findings

Background: Central nervous system (CNS) involvement is a common complication in haemolytic uraemic syndrome (HUS). Various imaging findings have been described, mostly as case reports. Although there are a few retrospective studies on larger patient groups there is no report that focuses on MRI. Objective: To analyse the CT and MRI studies of patients with neurological complications of HUS, to describe the typical imaging findings, and to evaluate their predictive character with regard to follow-up examinations and clinical outcome. Materials and methods: Of 57 patients with clinically proven HUS who were referred to our hospital between 1995 and 2003, 17 had signs of serious CNS involvement and 10 underwent neuroimaging. Nine MRI and seven CT studies were performed in the acute phase and five MRI and two CT studies were done for follow-up. Results: In six patients, pathological imaging findings were seen on CT or MRI performed in the acute phase of the disease whereas CT and MRI scans were completely normal in four patients. All patients with positive imaging findings had pathological changes within the basal ganglia. Additional findings were seen in the thalami (n=2), cerebellum (n=2) and brain stem (n=1). On follow-up imaging performed in five cases, the pathological imaging findings had resolved completely in two and partially in three patients. All patients had a good neurological outcome. Comparing the various MRI findings, a haemorrhagic component within an acute lesion was the most reliable parameter predicting residual pathologic findings on follow-up imaging. Conclusions: Basal ganglia involvement is a typical finding in patients with neurological complications of HUS. Even in patients with severe CNS involvement on acute imaging studies, prognosis was favourable for clinical outcome and resolution of pathological imaging findings.     

甲基丙二酸血症14例诊断及治疗分析

目的 探讨甲基丙二酸血症(MMA)的临床特征和治疗方法。方法 对14例MMA患儿的临床资料进行总结分析。结果 14例中男4例,女10例,发病年龄自出生～9岁,生后1个月内发病者7例(50％),1岁以内发病者共10例(71％)。主要临床表现有嗜睡(6例)、智力体力发育落后或倒退(7例)、惊厥(6例)、发作性呕吐(4例)、喂养困难(4例)、肌张力异常(低下5例,增高3例)、毛发黄(4例)等。血气分析提示代谢性酸中毒6例,高氨血症5例,酮尿4例,气相色谱-质谱法(GC/MS)尿有机酸分析显示14例患儿尿甲基丙二酸浓度均明显高于正常,头颅CT检查6例中5例异常,MRI检查5例全部异常,4例肌电图中2例提示有周围神经病变。3例在确诊前死亡,11例确诊患儿中10例接受维生素B12(VitB12)治疗,辅以低蛋白饮食及左旋肉碱治疗。对治疗的7例进行3个月～1年6个月(平均8.5个月)的随访,1例临床症状完全消失,4例明显好转,2例死于严重代谢性酸中毒。结论 嗜睡、智力体力发育落后或倒退、惊厥、发作性呕吐、喂养困难、肌张力异常、毛发黄、代谢性酸中毒、高氨血症、酮尿是MMA的主要临床特征,GC/MS法尿有机酸分析是早期诊断MMA的重要依据,确诊后坚持长期合理治疗是改善预后的有效方法。     

Inborn errors of metabolism for the diagnostic radiologist

Inherited metabolic disorders are becoming more important with the increasing availability of diagnostic methods and therapies for these conditions. The radiologist has become an important link in making the diagnosis or collaborating with the specialist centre to diagnose these disorders and monitor effects of therapy. The modes of presentation, disease-specific groups, classic radiological features and investigations are explored in this article to try and give the general radiologist some crucial background knowledge. The following presentations are covered: acute intoxication, hypoglycaemia, developmental delay and storage features. Specific groups of disorders covered are the abnormalities of intermediary metabolism, disorders of fatty acid oxidation and ketogenesis, mitochondrial disorders, lysosomal storage disorders, and, briefly, other groups such as peroxisomal disorders, disorders of glycosylation, and creatine synthesis disorders. New advances and the demands for monitoring are also briefly explored.     

Malonyl coenzyme A decarboxylase deficiency. Clinical and biochemical findings in a second child with a more severe enzyme defect

A second child with a more severe deficiency of malonyl CoA decarboxylase is described. He is mildly mentally retarded and presented with vomiting, a seizure, hypoglycaemia and mild metabolic acidosis during a urinary tract infection. The urine contained increased, amounts of malonic, methylmalonic, succinic, adipic, glutaric and suberic acids. Mitochondrial malonyl CoA decarboxylase activity in cultured fibrobast extracts was 4% of the mean control value. A high fat, low carbohydrate diet led to symptomatic hypyglycaemia, a moderate metabolic acidosis and excretion in the urine of large amounts of the same organic acids and 3-hydroxybutyrate. Only relatively small quantities of malonic, methylmalonic and succinic acid were excreted in the urine when the boy was fed an isocaloric low fat, high carbohydrate diet. Acute fat and lysine loads led to increased excretion of malonic acid in the urine without affecting the excretion of the other organic acids.Experience with this patient, suggests that malonyl CoA decarboxylase serves an important function in the mitochondrion by preventing accumulation of malonyl CoA. The importance of the enzyme is best seen when fat is the main metabolic fuel. The mechanisms by which malonyl CoA produces its complex metabolic effects remain to be elucidated.     

Pediatric renal leukemia: spectrum of CT imaging findings

Background The kidneys are a site of extramedullary leukemic disease that can be readily detected by CT. Objective To demonstrate the spectrum of CT findings in children with renal leukemic involvement. Materials and methods Twelve children were identified retrospectively as having renal leukemic involvement by contrast-enhanced CT of the abdomen. Contrast-enhanced CT images through the kidneys of each patient were reviewed by two pediatric radiologists. Pertinent imaging findings and renal lengths were documented. The electronic medical record was accessed to obtain relevant clinical and pathologic information. Results Five patients with renal leukemic involvement presented with multiple bilateral low-attenuation masses, while three patients demonstrated large areas of wedge-shaped and geographic low attenuation. Four other patients presented with unique imaging findings, including a solitary unilateral low-attenuation mass, solitary bilateral low-attenuation masses, multiple bilateral low-attenuation masses including unilateral large conglomerate masses, and bilateral areas of ill-defined parenchymal low attenuation. Two patients showed unilateral nephromegaly, while eight other patients showed bilateral nephromegaly. Two patients had normal size kidneys. Two patients had elevated serum creatinine concentrations at the time of imaging. Conclusion Renal leukemic involvement in children can present with a variety of CT imaging findings. Focal renal abnormalities as well as nephromegaly are frequently observed. Most commonly, renal leukemic involvement does not appear to impair renal function.     

甲基丙二酸血症伴同型半胱氨酸血症患儿基因突变分析

目的 检测甲基丙二酸血症伴同型半胱氨酸血症患儿的MMACHC基因突变类型及突变频率.方法 依据串联质谱检测血中的酰基肉碱、气相色谱-质谱检测尿甲基丙二酸、血清同型半胱氨酸测定及维生素B12负荷试验等,对28例甲基丙二酸血症伴同型半胱氨酸血症患儿进行诊断;应用聚合酶链反应(PCR)对这些患儿及其部分直系亲属、健康对照组的MMACHC基因外显子进行扩增,通过DNA直接测序进行基因突变分析.结果 在28例患儿中27例检测到突变,共10种,其中2例仪检测到1个杂合突变,3例仅检测到多态性.突变集中在外显子3和4上(91.3%),以609G>A(W203X)最常见,突变频率为53.6%,其中10例为纯合突变,10例为杂合突变,其次为658_660delAAG(K220del),突变频率为8.9%,均为杂合突变.另外检测到6种未报道突变,分别为1A>G、365A>T、658_del660AAG、301-3_327del 30、567_568insT和625_626insT.3种基因多态性分别为-302T>G(rs3748643)、-234A>G(rs3728644)和321G>A(rs2275276).结论 揭示了中国甲基丙二酸血症伴同型半胱氨酸血症患儿的部分基因突变谱,其中609G>A(W203X)可能为热点突变.     

儿童肱动脉假性动脉瘤一例并文献复习

目的:报道1例儿童肱动脉假性动脉瘤的诊疗,并回顾相关文献总结此类疾病的病因、诊治及预后。方法:回顾性分析了2019年6月1例16天新生儿的左上肢肱动脉假性动脉瘤的临床资料。本例患儿出生后6d发现逐渐增大的左肘部包块。B型超声、左上肢MRI及CTA提示左肱动脉假性动脉瘤。经局部加压包扎治疗,包块持续增大并出现表面皮肤坏死...     

代谢性疾病相关脑病的诊治

脑病是脑功能障碍的总称,由各类代谢紊乱引起的脑功能障碍称之为代谢性脑病,如维生素代谢异常性疾病、叶酸代谢障碍、尿素循环障碍及线粒体疾病等均可引起脑功能障碍。一些先天代谢性疾病相关脑病,可以通过特殊饮食、补充相关辅酶等得到良好控制,因此,在不可逆的脑功能损害发生前,早期诊断和治疗非常重要。癫痫是代谢性脑病的最常见表现。代谢性脑病的病因多源,起病隐匿,诊断代谢性脑病对临床医生是个很大的挑战。对于临床表现为癫痫伴生长发育迟缓、智力障碍和多系统受累的患儿,均应及时进行代谢性疾病的相关检查,如尿有机酸分析、血氨基酸分析、血酰基肉碱分析、脑脊液的相关代谢产物检测以及基因诊断。     

Cystic mediastinal lesions in children: Evaluation by magnetic resonance and conventional imaging

The signals obtained from mediastinal cystic lesions in children by magnetic resonance imaging (MRI) have been analysed. The advantages and pitfalls in establishing the final diagnosis by MRI are compared to the conventional radiographic technique and to computed tomography.     

Celiac disease in children: A review of the literature

Celiac disease is an immune-mediated systemic disease triggered by intake of gluten in genetically susceptible individuals. The prevalence of celiac disease in the general population is estimated to be 1% in the world. Its prevalence differs depending on geographical and ethnic variations. The prevalence of celiac disease has increased significantly in the last 30 years due to the increased knowledge and awareness of physicians and the widespread use of highly sensitive and specific diagnostic tests for celiac disease. Despite increased awareness and knowledge about celiac disease, up to 95% of celiac patients still remain undiagnosed. The presentations of celiac disease have significantly changed in the last few decades. Classical symptoms of celiac disease occur in a minority of celiac patients, while older children have either minimal or atypical symptoms. Serologic tests for celiac disease should be done in patients with unexplained chronic or intermittent diarrhea, failure to thrive, weight loss, delayed puberty, short stature, amenorrhea, iron deficiency anemia, nausea, vomiting, chronic abdominal pain, abdominal distension, chronic constipation, recurrent aphthous stomatitis, and abnormal liver enzyme elevation, and in children who belong to specific groups at risk. Early diagnosis of celiac disease is very important to prevent long-term complications. Currently, the only effective treatment is a lifelong gluten-free diet. In this review, we will discuss the epidemiology, clinical findings, diagnostic tests, and treatment of celiac disease in the light of the latest literature.     

Embryonal rhabdomyosarcoma of the omentum: two cases occurring in children

Rhabdomyosarcoma is a soft-tissue malignancy that represents approximately 4–8% of all solid tumours in children and commonly arises from the head and neck and genitourinary system. Intraperitoneal rhabdomyosarcoma, in particular with omental involvement, has been rarely reported in the literature. Furthermore, reports of omental rhabdomyosarcoma of embryonal origin do not exist, to our knowledge. We report two cases of omental embryonal rhabdomyosarcoma affecting children and illustrate the imaging characteristics of this rare tumour.