Age-related changes of the MR appearance of CNS involvement in neurocutaneous melanosis complex

We report a case of giant congenital melanocytic nevi (GCMN) at risk of developing neurocutaneous melanosis (NCM) with age-related changes observable on MRI of the brain. However, although the usefulness of MR imaging in NCM is well known, age-related changes on MRI have rarely been reported. The prevalence of positive MRI findings and prognosis in GCMN accompanied by epilepsy and/or mental retardation awaits clarification. This case report may suggest the importance of serial brain MRI in cases of GCMN in assessing the risk of NCM. Received: 22 April 1999/Accepted 20 March 2000     

Rapid response to therapy of neurocutaneous melanosis with leptomeningeal melanoma

Leukocyte adhesion deficiency‐III (LAD‐III) is a rare disorder characterized by abnormal signaling to β integrins, leading to defective leukocyte adhesion and chemotaxis and platelet aggregation. Here we present the first case of an African‐American female infant with this disorder. She had history of multiple infections, bleeding, and leukocytosis since birth. She was successfully treated with allogeneic bone marrow transplant using a reduced intensity‐conditioning regimen. Mutations in KINDLIN‐3 have been described in LAD‐III but the mutations in KINDLIN‐3 in her case are unique. Pediatr Blood Cancer 2010;55:180–182. © 2010 Wiley‐Liss, Inc.     

Rapidly progressive and fatal neurocutaneous melanosis presenting as recurrent headache

Neurocutaneous melanosis is an extremely rare disease characterized by large or multiple congenital melanocytic nevi and benign or malignant proliferation of melanocytes in the central nervous system. Neurological manifestations usually develop during the first three years of life and the prognosis of patients with NCM who manifest neurological symptoms is very poor. Here we describe a 9‐year‐old girl who manifested neurological symptoms caused by communicating hydrocephalus and died of proliferation of melanocytes in the central nervous system 11 months after the initial symptoms. Serum and cerebrospinal fluid 5‐S‐CD levels could be a useful marker of disease progression, even in patients with NCM without apparent malignant findings at initial biopsy.     

Functional hepatobiliary MR imaging in children

Background  

Clinical application efforts for the hepatocyte-specific MRI contrast agent gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) have mainly been directed toward detection and characterization of various hepatic masses in the adult population.     

MR imaging characteristics of soft tissue vascular anomalies in children

Accurate classification of soft tissue vascular anomalies is critical since treatment options and morbidity differ significantly for the various groups of vascular anomalies (VA). A classification system introduced by Mulliken and Glowacki in 1982 explained the biology of VA, thus resulting in improved management and communication between different disciplines taking care of children with soft tissue vascular anomalies. This classification has been updated by the International Society for the Study of Vascular Anomalies in 1996 and forms the basis for the current nomenclature. Although the majority of vascular anomalies can be accurately classified by their clinical history and a physical exam, imaging is necessary to determine the full anatomical extent of the anomaly, to follow up treatment response, to confirm diagnosis, and to provide correct classification in challenging cases when necessary. This article will review the key magnetic resonance imaging (MRI) features of most common soft tissue vascular anomalies in children. MRI and dynamic contrast-enhanced magnetic resonance angiography are crucial for the evaluation of vascular anomalies in children because of lack of radiation, high soft tissue resolution, and the capability of dynamic contrast-enhanced images to reflect the hemodynamics of the anomalies.     

MR imaging surface display of the cerebral cortex in children

The purpose of this study was to introduce the use of three-dimensional (3D) surface MR imaging display for clinical use. Surface display was created using images acquired with T1 magnetization prepared rapid acquisition gradient echo (MPRAGE) in 24 cases of migrational defects, cortical dysplasia and prenatal asphyxia. Schizencephaly and cortical dysplasia were pathologically confirmed. The precise configurations of cortical abnormalities, and their relation to the adjacent gyri and sulci were demonstrated. The topography of schizencephalic clefts was clearly defined. The appearance of ulegyria was characteristic and it was sometimes possible to differentiate polymicrogyria from pachygyria. Received: 27 November 1995 Accepted: 7 June 1996     

Gamma-hydroxybutyric acid sedation in neonates and children undergoing MR imaging

BACKGROUND: Insufficient sedation in pediatric magnetic resonance imaging (MRI) results in prolonged examination time. To describe the efficacy and side effects of sedation with Phenobarbital short-time infusion followed by continuous gamma-hydroxybutyric acid (GHB) infusion in neonates and children for MRI examinations in a retrospective study. PATIENTS: With Institutional Review Board approval 94 children (Group I: 1-4 weeks; Group II: >1 to 6 months; Group III: >6 months) were sedated with phenobarbital 10 mg/kg (maximum 200 mg) intravenously 30 min prior to examination. Than intravenous sedation was maintained with GHB 10 mg/kg/h after a priming dose of 30 mg/kg in 20 min. RESULTS: In group 1 all neonates (n=8) were well sedated without side effect. One of 21 infants in group 2 showed restlessness and the MRI failed. Two of 65 patients of group 3 were not sufficiently sedated and one of them vomited. CONCLUSIONS: Non-invasive diagnostic procedures in neonates and children may be managed by phenobarbital and GHB sedation with side effects or failure of 3%.     

Early diagnosis of asymptomatic neurocutaneous melanosis (60 month follow‐up)

Neurocutaneous melanosis (NCM) is a rare, sporadic, congenital neuroectodermal dysplasia. Large congenital melanocytic nevi (CMN) can evolve in a certain percentage of patients to NCM. Meningeal deposits are benign, but can be prone to malignant transformation in some cases. We describe the case of an infant with asymptomatic NCM, and typical magnetic resonance imaging (MRI) findings. The diagnosis was established shortly after delivery, and the patient was followed for 60 months. At that time, the girl did not have any neurologic symptoms; she reached normal developmental milestones and did not show mental retardation and did not develop malignant melanoma; further follow‐up will be needed, although there are no reliable guidelines as to the time range of follow up of asymptomatic NCM in the literature. We report the typical MRI signal abnormalities of the brain, and present a review of the literature regarding this rare and mysterious congenital disorder.     

Application of a three-point method for water-fat MR imaging in children

Background. Effective fat suppression is desirable in clinical magnetic resonance imaging. Conventional frequency selective fat suppression is dependent on accurate prescan shimming and is subject to artifacts due to magnetic field inhomogeneity. Quadrature three-point water-fat imaging with direct phase encoding is an alternative technique for fat suppression that has been previously described in adult volunteers and patients. Objective. To evaluate the use of three-point water-fat imaging with direct phase encoding for fat-suppressed MR scans in children. Materials and methods. Sixty-two three-point water-fat imaging studies were performed in 55 children 2 months to 18 years old. T 1-weighted fat-suppressed (water) images from this sequence were compared with frequency selective fat-suppressed images obtained in 15 patients. The reliability and subjective quality of the sequence were assessed in the remaining 47 cases. Results. High-quality fat suppression was achieved in all anatomic sites studied, even where frequency selective fat-suppression failed due to magnetic susceptibility artifact. The three-point water-fat sequence was visually preferred to the frequency selective fat saturation technique in 15/15 cases. Conclusion. Three-point water-fat imaging has replaced the conventional frequency selective technique for fat suppression on T 1-weighted MR imaging at our institution. Received: 27 July 1998 Accepted: 23 December 1998     

MR imaging evaluation of subacute and chronic bone abscesses in children

Objective. The aim of the present study was to assess the value of magnetic resonance (MR) imaging in subacute and chronic bone abscesses in children. ¶Materials and methods. Seventy-four patients underwent MR imaging because of suspected musculoskeletal infections between January 1996 and January 1999 in Montreal Children's Hospital. The clinical, radiographic, scintigraphic and MR imaging features of patients with a bone abscess were studied. ¶Results. Eleven patients had osteomyelitis with no bone abscess and six had osteomyelitis with a subacute or chronic bone abscess. Although the lucency was eventually seen on plain radiographs in all cases, MR imaging made a significant contribution, as it helped narrow the differential diagnosis and showed better delineated medullary involvement and extension into the epiphysis. ¶Conclusion. MR imaging is valuable in the diagnostic evaluation of children with bone infection and abscess. It reveals the extent of subperiosteal and epiphyseal involvement not seen on plain radiographs. The extent of the medullary involvement around the abscess is best visualized with MR imaging, which can also distinguish between isolated soft tissue infection adjacent to bone and true bone infection.     

MR imaging of glioblastoma in children: usefulness of diffusion/perfusion-weighted MRI and MR spectroscopy

Background Glioblastoma is relatively uncommon in childhood and maybe difficult to differentiate from other brain tumors such as primitive neuroectodermal tumor, ependymoma, or benign astrocytoma. Objective To describe the characteristic MR features in children with glioblastoma and to evaluate the usefulness of diffusion and perfusion MR imaging and MR spectroscopy in pediatric glioblastoma. Materials and methods MR imaging in 11 children (12 tumors) with biopsy-proven glioblastoma was reviewed retrospectively. In one patient, there was a recurrent glioblastoma. We reviewed CT and MRI imaging for tumor location, density/signal intensity, and enhancement pattern. Routine MR imaging was performed with a 1.5-T scanner. In six patients, diffusion-weighted MR images (DWIs) were obtained with a single-shot spin echo EPI technique with two gradient steps, and apparent diffusion coefficients (ADCs) were calculated. Using the gradient EPI technique, perfusion-weighted MR images (PWIs) were obtained in four patients from the data of dynamic MR images. The maximum relative cerebral blood volume (rCBV) ratio was calculated between the tumor and contralateral white matter in two cases. In three patients, proton MR spectroscopy was performed using a single voxel technique with either STEAM or PRESS sequences. The locations of the tumor were the thalamus and basal ganglia (n=8), deep white matter (n=3), and brain stem (n=1).Results Intratumoral hemorrhage was seen in four tumors. The tumors showed high-signal intensity or DWIs, having a wide range of ADC values of 0.53–1.30 (mean ±SD=1.011±0.29). The maximum rCBV ratios of glioblastoma were 10.2 and 8.5 in two cases. MR spectroscopy showed decreased N-acetylaspartate (NAA) and increased choline in three cases. The MR findings of glioblastoma in children were: a diffusely infiltrative mass with hemorrhage involving the deep cerebral white matter, thalami, and basal ganglia. Conclusion Diffusion/perfusion MR imaging and MR spectroscopy are very helpful in diagnosing glioblastoma, determining the biopsy site, and evaluating tumor recurrence.This paper was presented as a scientific contribution at the 39th Annual Congress of the European Society of Paediatric Radiology, Bergen, Norway, June 2002     

Importance of sagittal MR imaging in nontraumatic femoral head osteonecrosis in children

Background  In nontraumatic femoral head osteonecrosis, characterization of femoral head collapse is important in staging disease progression and planning treatment. Few prior studies have quantitatively compared the ability of sagittal and coronal MR images to detect femoral head collapse. Objective  We hypothesized that sagittal MR images show a greater degree and angular span of femoral head collapse than coronal images. Materials and methods  We reviewed 38 hip MRI scans of nontraumatic femoral head osteonecrosis from 34 pediatric patients. In both sagittal and coronal images, the maximal extent and angular location along with the angular span of the femoral head collapse were measured. Differences were evaluated using a paired t-test. The extent of bone and cartilage loss from the femoral head was evaluated. Results  Sagittal MR images showed 29% maximal femoral head radius collapse, whereas coronal images showed 16% collapse (P<0.001). Sagittal images showed a larger angular span of collapse (115°) than coronal images (55°, P<0.001). Sagittal images showed greater epiphyseal bone loss in the anterior than in the posterior portion (P<0.001), whereas coronal images did not show a significant difference in bone loss between the medial and lateral portion (P=0.32). Conclusion  Sagittal images show greater femoral head collapse than coronal images in nontraumatic femoral head osteonecrosis.     

4例儿童肺吸虫脑病的CT与MRI诊断

例1,男,9岁,因间断胸痛2月余,咳嗽1周,头痛、呕吐1 d入院。患儿为云南人,有半生食溪蟹史。体查:体温38.4℃,脉搏63次/min,呼吸27次/min。嗜睡状,能简单回答问题,精神差,眼眶稍凹,右肺呼吸音偏低。余无异常。辅助检查:血常规示WBC 9.29×109/L(参考值5~12×109/L),嗜酸性粒细胞计数1.561×109/L(参考值0~0.1×109/L),嗜酸性粒细胞相对值0.168(参     

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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.     

MR imaging of simple bone cysts in children: not so simple

Objective. The unicameral bone cyst (UBC) is a common cystic bone lesion seen in children. We review and summarize its MR findings, focusing on their appearance following contrast enhancement, and correlating them to known histologic features of UBC. Subjects and methods. A retrospective review of 20 cases (13 boys, 7 girls; age range, 1–17 years; mean age, 8.9) diagnosed as UBC was conducted. Clinical histories, radiographic and MR features, follow-up data, and available pathologic findings were noted. Results. At initial presentation 18 (90 %) of the patients with UBC had a history of acute or remote pathologic fracture. Cysts with history of fracture displayed heterogeneous fluid signals on T1- (n = 9, 50 %), and T2-weighted (n = 15, 83 %) MR images. Gadolinium-enhanced images were obtained in 15 of the 18 UBC cases with history of previous fracture. All showed enhancement with focal, thick peripheral, heterogeneous, or subcortical patterns. Focal nodules of homogeneous enhancement (diameter > 1 cm) within the UBC (n = 5) correlated with areas of ground-glass opacification on plain film. Other interesting MR features were fluid-fluid levels (n = 11), “fallen-leaf” sign (n = 1), soft-tissue changes (n = 2), and detection of septations not seen on plain film (n = 2). Conclusion. UBCs frequently appear complicated on MR imaging, with heterogeneous fluid signals and regions of nodular and thick peripheral enhancement related to previous pathologic fracture and early healing. Received: 27 December 1999 Accepted: 6 March 2000     

MR imaging of capitellar ossification: a study in children of different ages

Background

The capitellar ossification center is used routinely to evaluate elbow alignment on radiography. However, whether capitellar ossification is central and concentric to support this practice is unknown.

Objective

To define the pattern of capitellar ossification at different ages of childhood.

Materials and methods

This HIPAA-compliant study was IRB approved. MR imaging examinations from 81 children (ages 1–13 years, at least 3 boys and 3 girls in each age group) were included. We determined the center points of the ossified capitellum and the cartilaginous capitellum on the sagittal and coronal sequences that best showed differentiation between cartilage and bone. Percentage offset of the center of the ossified capitellum from the center of the cartilaginous capitellum was calculated in anterior–posterior, proximal–distal and medial–lateral dimensions, and compared across age groups and between genders. Linear regressions were used to ascertain the effect of age on percentage offset for all patients and for each gender.

Results

Capitellar ossification begins eccentrically with sagittal anterior proximal offset and coronal medial offset. With age, ossification proceeds posteriorly, distally and laterally. Percentage offset gradually diminishes with age. The ossified capitellum centralizes in the sagittal plane by 12–13 years. In the coronal plane, the capitellum ossifies medially beyond the proximal radioulnar joint and remains eccentric at 12–13 years. Centralization in boys lags in the anterior–posterior dimension.

Conclusion

Capitellar ossification is an eccentric process, with lag in anterior–posterior centralization in boys. Medial offset persists at 12–13 years. Recognition of this eccentric ossification may allow for more accurate assessment of elbow alignment on radiographs, especially in younger children.     

MR imaging of osteonecrosis of the knee in children with acute lymphocytic leukemia

This essay illustrates various patterns of progression of osteonecrosis of the knee and the relationship between early MR imaging findings and radiologic outcome in children with acute lymphocytic leukemia. It also includes a review of nonosteonecrosis signal abnormalities, which are common in the knee region and are often transient. Such abnormalities must be distinguished from osteonecrosis, which can lead to joint collapse and predispose to secondary arthritis.     

Assessment of airways compression by MR imaging in children with aneurysmal pulmonary arteries

Magnetic resonance imaging (MRI) has an established role in the accurate and non invasive assessment of airways compression by congenital vascular rings and pulmonary artery slings, making angiography of these lesions unnecessary [1, 2]. This role can be broadened to encompass other vascular compressive lesions, as in the two pediatric patients described here with aneurysmal pulmonary arteries of different etiology, one congenital and the other acquired.