Search

Using the Neyman-Pearson lemma we give a method for finding the range of three nonatomic probability measures. Next we use this result to construct an explicit form of this range in the case, where the densities corresponding to these measures satisfy an additional assumption.

A retrospective study was undertaken to assess the value of three-dimensional computed tomography (3-D CT) in evaluating craniofacial abnormalities. Over a 2-year period, 145 children evaluated with routine two-dimensional (2-D) CT had 3-D CT reformatted images assessing a variety of anomalies including craniosynostosis, midface clefts, trauma, and craniofacial syndromes. There were 62 females and 83 males ranging in age from 1 month to 17 years (median: 5 months). Both soft-tissue and bone algorithms were used. In all 145 cases, the 3-D CT images confirmed or provided additional information of depth perception, contours, volumes, and extent of an abnormality. This was especially important and useful in the settings of complex anomalies and preoperative planning. We concluded that 3-D CT reconstructed images in conjunction with routine 2-D CT should be an integral part of the examination in evaluating craniofacial abnormalities.

Data collected over the past 8 years on the radiological appearance of common pediatric primary brain neoplasms are presented. An emphasis is placed on the newer radiological imaging modality of magnetic resonance imaging (MRI). Part I of this article emphasized the clinical evaluation of these brain neoplasms. Three hundred eighty-five children with known brain neoplasms ranging in age from newborn to 18 years were evaluated with one or all of the following radiological modalities: MRI, computed tomography (CT), water-soluble myelography (WSM), WSM with CT, and angiography. Contrast-enhanced MRI and CT scans both were accurate in delineating these brain neoplasms although MRI provided better resolution and delineation than CT. Angiography provided information on the vascularity of the neoplasms and their relationship to prominent arterial and venous structures. Water-soluble myelography with CT and gadolinium-enhanced MRI of the spine were equally accurate in demonstrating metastatic spread to the spinal canal and spinal cord. Magnetic resonance imaging with gadolinium was more accurate than CT with contrast in demonstrating recurrent or residual neoplasm at the operative site and metastatic spread to the brain. Magnetic resonance imaging with gadolinium is the best radiological modality to fully evaluate pediatric brain neoplasms.

In Part I of this article, we present our data collected over the past 8 years on the clinical evaluations of pediatric brain tumors with an emphasis placed on the more common neoplasms. Our data consists of 385 children ranging in age from newborn to 18 years. The majority of children presented with signs of raised intracranial pressure (including nausea, vomiting, and headaches), seizures or other focal neurologic deficits. Five percent of our children presented to outlying hospitals with symptoms that retrospectively turned out to be due to brain neoplasms but were misdiagnosed as "gastroenteritis," "viral upper respiratory tract infection," or even viral meningitis. These delays in diagnosis can cause serious negative outcomes for these patients and can be avoided through more careful neurologic and ophthalmologic examination at the time of first presentation. Central nervous system neoplasms are not uncommon in children and any child presenting with nausea, vomiting, and headaches should raise the suspicion of a primary brain tumor and should receive both a thorough neurologic exam and screening for papilledema. If papilledema is present, these children should be referred for proper neuroradiologic evaluation (which will be addressed in Part II.

This article reports the results of clinical testing in pediatric patients of a new contrast agent, gadoteridol injection (ProHance), developed by Squibb Diagnostic as a nonionic gadolinium agent for use in magnetic resonance imaging (MRI). Thirteen children (four girls and nine boys) ranging in age from 10 to 18 years were enrolled in the study. The children had MR studies of the brain and/or spine with T1-weighted, T2-weighted, and postgadoteridol injection T1-weighted sequences. Five children had primary brain or spine neoplasms, three children had metastatic disease to the central nervous system, one child had a recurrent brain neoplasm and spinal canal metastasis, one child had an arteriovenous malformation, and two children were normal on the MRI studies. No minor or major reactions to gadoteridol injection developed in the 13 patients. Gadoteridol injection provided excellent delineation and enhancement of the arteriovenous malformation and all of the primary and secondary neoplasms of the central nervous system except for one case of a grade 1 glioma of the midbrain. Gadoteridol injection is a safe and excellent contrast agent for use in MRI.

The role of MR imaging is emphasized in the evaluation of paraspinal and intraspinal soft tissue abnormalities. The technical aspects in performing a high-resolution MR image of the pediatric spine in reference to imaging parameters, sedation protocol, and the use of intravenous gadolinium are detailed. The changes in the normal pediatric spine on MR imaging are demonstrated. The diagnosis and evaluation of specific intraspinal and paraspinal neoplastic disorders in infants and children are outlined in terms of their clinical presentation and MR characteristics.