Magnetic resonance imaging in occult spinal dysraphism

The value of magnetic resonance imaging (MRI), compared to myelography and computerized tomography, is illustrated in six patients with occult spinal dysraphism. MRI proved to be the diagnostic tool of choice.     

Magnetic resonance imaging of lymphomas in children

Magnetic resonance imaging has been used to evaluate 10 children with lymphomas and was able to identify disease in all 10 cases and monitor response to therapy in all three patients with follow-up studies. It could not distinguish between the different histological types of lymphoma. The image intensity of a diseased spleen in one case was different from that of five other normal spleens in six children with Hodgkins disease. Magnetic resonance imaging compared well with computed tomography and it was especially good at identifying blood vessels.     

Magnetic resonance imaging in children with kernicterus

The magnetic resonance (MR) findings of three children with severe neonatal jaundice who were suspected to be suffering from kernicterus were examined. In all children high intensity areas in the globus pallidus were demonstrated bilaterally on T2-weighted imaging. The posteromedial border of the globus pallidus was shown to be the most sensitive area to kernicterus by MR findings. D Athetosis, cerebral palsy, globus pallidus, kernicterus, magnetic resonance imaging
K Yokochi, Ohzora-no-iye Hospital, 7448 Nakagawa, Hosoe, Inasa, Shizuoka 431-13, Japan     

Magnetic resonance imaging of knee injuries in children

The purpose of this study was to evaluate the significance of meniscal appearances and determine the frequency of abnormalities seen on magnetic resonance (MR) imaging in children with knee injuries. We reviewed 78 consecutive MR imaging studies of 74 children aged 5–16 years with unfused epiphyses. Menisci were evaluated using conventional grading techniques. We used ² to compare the frequencies of medial and lateral meniscus and anterior cruciate ligament (ACL) tears with each other and with published data for children. Similarly, we compared the proportions of tears of these structures with published data. Arthroscopy results from 26 children were used to calculate sensitivity and specificity of MR imaging for meniscal tears, which were 100 % (8/8) and 89 % (16/18), respectively. The majority of studies (82 %) had grade I or II signal intensity in one or both menisci. Arthroscopy results available in 33 % of this group revealed normal menisci. Tears of the medial and lateral menisci were significantly more common than of the ACL. Injuries of the ACL were seen significantly less frequently than previously reported. Grade I or II meniscal signal intensity in children with knee injuries is consistent with a normal meniscus. Tears of the menisci are more common than ACL tears. MR imaging in this context appears reliable.     

Magnetic resonance imaging of renal osteodystrophy in children

Background. Improved life expectancy of children with chronic renal failure (CRF) has increased the number of patients with renal osteodystrophy and has brought to light novel and severe forms of the disease. These factors have contributed to the need to evaluate new, noninvasive imaging modalities for the detection of bone involvement. Objectives. To evaluate the potential of MRI in the detection of the bone changes of renal osteodystrophy as compared to conventional X-rays. Materials and methods. Fourteen children with CRF were examined with a 0.5-T MR unit using TI-weighted and STIR sequences and conventional radiographs. The following features were reviewed in a nonblinded study: skeletal deformities, thickening of cortical bone, trabecular pattern, intraosseous soft-tissue masses, osteonecrosis, extraskeletal calcifications and bone marrow signal changes. Results. MRI adequately demonstrated skeletal deformities, cortical thickening and irregular trabecular pattern. It showed osteonecrosis and intraosseous soft-tissue masses more conspicuously than X-ray. In addition, it revealed diffuse nonspecific signal changes in the bone marrow. Conclusion. MRI is a potentially useful tool for evaluating the bone changes of renal osteodystrophy. Received: 28 February 1997 Accepted: 23 June 1997     

Magnetic resonance imaging of lung infections in children

The advantages and limitations of MRI in lung infections in children have not been well established. This article illustrates the MRI findings in children with pneumonia caused by Mycoplasma pneumoniae, Streptococcus pneumoniae, and other pathogens. Lung parenchymal, pleural, and lymph node abnormalities are well characterized by MRI. Loculation of pleural fluid is detected in children with empyema. Contrast enhancement may be useful in the differentiation of active inflammation from noninflammatory changes. MRI can be particularly useful in the follow-up of children with chronic pulmonary diseases.     

Magnetic resonance imaging of spinal cord disease of childhood

Correct diagnosis of spinal cord disease in childhood is often delayed, resulting in irreversible neurologic deficits. A major reason for this delay is the lack of a reliable means to noninvasively visualize the spinal cord. Magnetic resonance imaging (MRI) should be useful in the evaluation of diseases of the spinal cord. A 1.5 Tesla MRI unit with a surface coil was used to study 41 children, including eight patients with intrinsic spinal cord lesions, eight patients with masses compressing the cord, 12 patients with congenital anomalies of the cord or surrounding bony structures, three patients with syrinxes, and three patients with vertebral body abnormalities. Intrinsic lesions of the cord were well seen in all cases as intrinsic irregularly widened, abnormally intense cord regions. MRI was helpful in following the course of disease in patients with primary spinal cord tumors. Areas of tumor were separable from syrinx cavities. Extrinsic lesions compressing the cord and vertebral body disease were also well visualized. Congenital anomalies of the spinal cord, including tethering and lipomatous tissue, were better seen on MRI than by any other radiographic technique. MRI is an excellent noninvasive "screening" technique for children with suspected spinal cord disease and may be the only study needed in many patients with congenital spinal cord anomalies. It is also an excellent means to diagnose and follow patients with other forms of intra- and extraspinal pathology.     

Magnetic resonance imaging in athetotic cerebral palsied children

The magnetic resonance findings in 22 children with athetotic cerebral palsy were studied. Sixteen had perinatal asphyxia, two had neonatal jaundice, and four had no association with predisposing conditions. In six of the children, symmetrical high intensity areas were found in both the thalamus and putamen in T2-weighted images. In five children they were seen only in the thalamus, and in another one only in the putamen. In six children, symmetrical periventricular high intensity areas were seen. In seven of the subjects, no abnormal magnetic resonance findings were seen. Magnetic resonance lesions, possibly caused by asphyxia, were found in the basal ganglia, thalamus and/or cerebral white matter in 14 of 16 children. Three children with lesions only in the cerebral white matter had mild motor abnormality, and six children with lesions in both the thalamus and putamen did not have mild abnormality.     

Magnetic resonance imaging in the assessment of medullary compression in achondroplasia

Children with achondroplasia may be at increased risk of developing apneic episodes and of dying unexpectedly. The risks seem to be related to neural axis compression by an abnormal cranial base and may be complicated by the development of hydrocephalus. We used magnetic resonance imaging to study five children with achondroplasia. All of them demonstrated a discrepancy between the size of the brain stem and the foramen magnum. Comprehensive prospective assessment of infants with achondroplasia, including the use of new imaging techniques, will provide important information concerning the natural history of the relationship of the neural axis to the bony posterior fossa and upper cervical spine in this condition. It may also help to identify those patients at risk before the development of life-threatening medullary compression.     

Magnetic resonance imaging of obstructive sleep apnea in children

Sleep-disordered breathing has a spectrum of severity that spans from snoring and partial airway collapse with increased upper airway resistance, to complete upper airway obstruction with obstructive sleep apnea during sleeping. While snoring occurs in up to 20% of children, obstructive sleep apnea affects approximately 1–5% of children. The obstruction that occurs in obstructive sleep apnea is the result of the airway collapsing during sleep, which causes arousal and impairs restful sleep. Adenotonsillectomy is the first-line treatment of obstructive sleep apnea and is usually effective in otherwise healthy nonsyndromic children. However, there are subgroups in which this surgery is less effective. These subgroups include children with obesity, severe obstructive sleep apnea preoperatively, Down syndrome, craniofacial anomalies and polycystic ovarian disease. Continuous positive airway pressure (CPAP) is the first-line therapy for persistent obstructive sleep apnea despite previous adenotonsillectomy, but it is often poorly tolerated by children. When CPAP is not tolerated or preferred by the family, surgical options beyond adenotonsillectomy are discussed with the parent and child. Dynamic MRI of the airway provides a means to identify and localize the site or sites of obstruction for these children. In this review the authors address clinical indications for imaging, ideal team members to involve in an effective multidisciplinary program, basic anesthesia requirements, MRI protocol techniques and interpretation of the findings on MRI that help guide surgery.     

脑性瘫痪儿童的MRI特征

目的 探讨脑性瘫痪(脑瘫)患儿脑MR／的表现及其与出生胎龄和脑瘫类型的关系。方法 回顾性分析104例脑瘫患儿的病史、l临床与MR／表现。结果 早产与足月儿脑瘫类型构成显著不同,早产儿以痉挛性双瘫多见(占66．O％),而足月儿偏瘫和失调型高于早产儿。104例脑瘫患儿MR／异常率为84．7％,早产和足月儿组MHI异常率差异无显著性。痉挛型双瘫、四肢瘫、偏瘫、手足徐动型和失调型脑瘫MR／异常率分别为89．4％、100％、100％、54．5％和90．O％。31／42例痉挛性双瘫表现为脑室周围白质软化症(PVL),而以早产儿双瘫更多见(90％);各类型脑瘫的MR／异常表现不同,双瘫以PVL为主,徐动型表现为基底节病变或．PVL失调型绝大部分存在先天性小脑发育不全,偏瘫型突出表现为单侧脑损伤。出生胎龄与MRI特点有关,早产儿组以PVL为特征,见于除失调型外的其他脑瘫类型;足月儿脑瘫MR／异常表现变化多且病变广泛。结论MR／有助于评价各型脑瘫的病理特点及其与出生胎龄的关系．对脑瘫病因的推测有帮助。     

Magnetic resonance imaging in children with acute hip pain

45 children presenting with acute hip pain were prospectively evaluated with conventional radiography, radioisotope bone scan, and magnetic resonance imaging (MRI). The final diagnoses were transient synovitis (n = 17), septic arthritis (n = 2), Legg-Calve-Perthes disease (LCPD, n = 13), epiphyseal dysplasia (n = 2), other conditions (n = 4), and normal findings (n = 7). In the work-up MRI provided more morphologic information than other techniques and enlarged the diagnostic possibilities. It was the only imaging technique able to give an early indication of bone marrow involvement in systemic diseases. For the early diagnosis of LCPD, MRI was as sensitive as isotope bone scan and more precise than conventional radiography. In the follow-up of LCPD patients MRI was not able to indicate the start of revascularisation of the necrotic area, which bone scans showed reliably in six patients: but MRI provided excellent evaluation of the position, form and size of the femoral head and the surrounding soft tissues.     

Spinal dysraphism: use of magnetic resonance imaging in evaluation

Three cases of children with spinal dysraphism are reported. Magnetic resonance imaging (MRI) was used as a primary diagnostic examination. The ages of the patients were 2 days, 4 years, and 16 years. In all instances the scan gave a precise diagnosis as well as well as an accurate delineation of the structural abnormalities before surgical treatment. Plain radiographs and ultrasound analysis may not be helpful, and invasive procedures can be associated with morbidity. Technical ease, safety, and anatomic precision suggest that MRI should be performed as a primary radiologic examination in the diagnostic workup of spinal dysraphism.     

Magnetic resonance imaging of children with Duchenne muscular dystrophy

Eight children representing a spectrum of clinical states of biopsy-proven Duchenne muscular dystrophy (DMD) underwent magnetic resonance (MR) scans to assess the degree of muscular involvement and disease progression. Five muscle groups (neck, shoulder girdle, pelvic girdle, thigh and calf) were evaluated. In each case, involved muscles were clearly demarcated. Image estimates of disease severity by degree of muscle involvement correlated well with clinical staging. In our experience MR is useful for assessment of disease stage, selection of appropriate muscles for biopsy and planning for courses of physical and rehabilitation therapy.