Pediatric radiology
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Pediatric radiology · Oct 1996
Fundamentals of transorbital sonographic evaluation of optic nerve sheath expansion under intracranial hypertension. I. Experimental study.
The optic nerve, ontogenetically part of the central nervous system, is surrounded by subarachnoidal cerebrospinal fluid (CSF) and dura mater. Because of the connection with the intracranial subarachnoidal space, CSF pressure variations influence the optic nerve sheath (ONS) diameter. Histologic studies revealed a segment of the optic nerve in which maximal diameter fluctuations could be expected, namely the bulging dura mater region approximately 3 mm behind the papilla. ⋯ Under clinical conditions, however, only axial sections can be obtained using anterior probe positions with transbulbar sound directions. Using such axial projections the 3 mm position proved reliably reproducible. The reduced resolution of the optic nerve itself, allowing it to be distinguished from its surrounding sheath, proved to be somewhat disadvantageous from this projection angle.
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Pediatric radiology · Oct 1996
Radiographic skeletal survey and radionuclide bone scan in Langerhans cell histiocytosis of bone.
The lack of a consensus in the literature on the imaging strategy in Langerhans cell histiocytosis (LCH) bone lesions in childhood. ⋯ In the initial work-up both RSS and RBS should be carried out, while in the follow-up only RSS should be performed.
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This paper reviews the techniques that we employ to perform musculoskeletal magnetic resonance imaging in the pediatric patient. We examine the procedures for preparation and screening of the patient and the protocols for sedation. The selection of imaging coils and sequences for the evaluation of the pediatric musculoskeletal system is also addressed, followed by a summary of scanning protocols.
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Pediatric radiology · Oct 1996
Fundamentals of transorbital sonographic evaluation of optic nerve sheath expansion under intracranial hypertension II. Patient study.
Up to now, the presence of elevated intracranial pressure (ICP) in acute neurological disorders is suspected by clinical and neuroimaging findings, but its verification depends on invasive techniques. Based on our experimental findings of rapid dilatation of human optic nerve sheaths (ONS), we investigated whether this phenomenon not only happens under chronic, but also under acute conditions of intracranial hypertension. Using optic nerve sonography the ONS was measured at 3 mm behind the papilla in axial transbulbar view. ⋯ Considering the error of measurement (0.35 mm), the ONSD is regarded as definitely enlarged when 5 mm is exceeded in children above age 4. In younger children, smaller ONSD have to be taken into consideration. We conclude that ultrasound studies of the optic nerve may contribute information about the acutely increased ICP in critically ill patients.