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Biomedical subjects

R S Boyer

Publications and source records attributed to R S Boyer.

At least 19 recordsLinked to original sources
PubMed1999

Bilateral hippocampal encephalitis caused by enteroviral infection.

Nonpolio enteroviral encephalitis usually presents as a diffuse, generalized encephalitis. Focal cerebral involvement by nonpolioviruses is uncommon, and neuroradiologic studies in these cases are usually normal. The authors present a case of a 5-year-old male with an acute encephalitic illness and bilateral lesions of the hippocampi on magnetic resonance imaging. Enteroviral nucleic acids were detected in the cerebrospinal fluid by the reverse transcription polymerase chain reaction. The findings suggest that enteroviral infection should be considered in the differential diagnosis of acute bilateral hippocampal encephalitis in patients in whom polymerase chain reaction fails to demonstrate the presence of herpes simplex virus.

Child, Preschool↗
PubMed1999

Neuroimaging of postnatal pediatric central nervous system infections.

Pediatric neuroimaging plays an important role in the timely diagnosis of postnatal central nervous system (CNS) infections, and in some patients the imaging findings are sufficiently specific to suggest a cause. The sequela of CNS infection, including hydrocephalus, subdural collections, ischemia/infarction, cerebral abscess, demyelination, and vascular thrombosis, can be accurately depicted and serially followed with current imaging techniques. The purpose of this review is to describe the spectrum of pediatric postnatal CNS infections, emphasizing key pathological and neuroimaging features, and to outline the strengths, weaknesses, and applications of current neuroimaging technology. The prenatal and perinatal infections falling under the designation of TORCH (toxoplasmosis, other [e.g., syphilis, HIV], rubella, cytomegalovirus, and herpes simplex II) are not covered.

Brain↗
PubMed1997

Choroid plexus papilloma and cysts in the Aicardi syndrome: case reports.

Two female infants with callosal agenesis, infantile spasms, chorioretinal lacunae, optic disc colobomas and cortical heterotopias were diagnosed with Aicardi syndrome. A choroid plexus papilloma was found in one patient, and choroid plexus cysts were found in the other. Choroid plexus lesions are common findings in the Aicardi syndrome and are discussed in this paper.

Agenesis of Corpus Callosum↗
PubMed1994

Neuroimaging of premature infants.

Neuroimaging of babies born prematurely challenges each member of the imaging team. This article reviews the commonly used modalities for neuroimaging in premature infants (ultrasonography, CT, and MR imaging) and makes recommendations for their optimal implementation based on the imaging literature and the author's experience. Special care of the premature neonate in the imaging department is discussed. Suggestions are made for the proper application of current imaging technology to the frequently encountered problems of intracranial hemorrhage and periventricular leukomalacia in the neonate.

Brain↗
PubMed1993

Pneumatization of the paranasal sinuses: normal features of importance to the accurate interpretation of CT scans and MR images.

CT and MR imaging of the paranasal sinuses in infants and children reveal a spectrum of findings associated with the normal pneumatization process, both inside the sinus cavities and in the adjacent marrow spaces. These normal findings must be understood and recognized so that CT scans and MR images may be accurately interpreted. If such normal developmental radiologic findings are not appreciated, misinterpretation may occur and lead to inappropriate treatment. In this pictorial essay, the normal process of pneumatization for each paranasal sinus group will be described from the first stages of the process to its completion. CT scans and MR images will illustrate the range of normal radiologic findings associated with the developmental process, with emphasis placed on the types of findings that, although normal, create potential interpretive difficulties.

Child↗
PubMed1993

Magnetic resonance angiography in pediatric neuroradiology.

Magnetic resonance angiography (MRA) is a novel technique that uses gradient echo pulse sequences and computer postprocessing technology to create vascular-flow images. The technique is easy to apply, noninvasive, and frequently yields information not available by other noninvasive means. The utility and benefits of MRA are amply documented by clinical studies in the neuroimaging literature. This article reviews the techniques of MRA and the current literature in the application of MRA in pediatric imaging. Illustrative cases demonstrating the use of MRA in pediatric neuroradiology are presented. The utilization of MRA in congenital lesions such as aberrant internal carotid artery and arteriovenous malformation and in differing causes of ischemic disease is highlighted. There is an ever-expanding number of applications of MRA in pediatric neuroimaging. Despite the lack of standardized protocols, with a thorough knowledge of the basic principles, MRA can be successfully applied in many imaging situations. The ease of use and noninvasive nature of MRA make it an ideal tool in the evaluation of the pediatric neurovasculature.

Brain Diseases↗
PubMed1992

Cerebral MR angiography with multiple overlapping thin slab acquisition. Part II. Early clinical experience.

In a prospective, multicenter study of 164 patients, cerebral magnetic resonance (MR) angiography with multiple overlapping thin slab acquisition was evaluated for image quality and diagnostic accuracy. Of the 164 patients, 87 (53%) underwent either correlative cut-film angiography or surgery. The overall image quality was excellent in 90% of patient studies. Eighteen of 19 aneurysms were detected with MR angiography. The parent artery, the anatomy of the neck and dome, and the size were correctly shown in 17 of the 19 aneurysms. All 19 vascular malformations were seen with MR angiography. Venous malformations and single pedicle arteriovenous malformations were completely defined with MR angiography, while complete definition of complex arteriovenous malformations was frequently difficult. In cerebral tumors, the arteries and veins important in surgical planning were accurately shown in all cases. In ischemic cerebrovascular disease, MR angiography depicted all stenoses and occlusions of first- and second-order cerebral arteries. The inability to depict intraluminal filling defects in any but the large central arteries limited the ability of MR angiography to enable the specific diagnosis of embolic stroke.

Brain Ischemia↗
PubMed1990

Multiple sclerosis in adolescents: CT and MR findings.

The MR and CT findings in 12 adolescents with multiple sclerosis were compared with reported findings in adults. The adolescent group showed a more striking female predominance, more severe disease characteristics, and more frequent infratentorial involvement. Cortical atrophy and abnormal iron accumulation in the basal ganglia were uncommon in the adolescents. Neither group demonstrated a correlation between symptom severity and either extent or location of disease as delineated by MR imaging. MR was more sensitive than CT in detecting demyelinating plaques.

Adolescent↗