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Biomedical subjects

D C Harwood-Nash

Publications and source records attributed to D C Harwood-Nash.

At least 19 recordsLinked to original sources
PubMed1996

Neuroradiology of pediatric posterior fossa medulloblastoma.

Medulloblastoma of the cerebellum is a common intracranial neoplasm in children and presents many faces in medical imaging. Characteristic or classic features, such as increased attenuation on unenhanced CT, midline location and well defined margins, are commonly present in childhood cases of posterior foassa medulloblastoma, although atypical imaging features are being noted more frequently with the increased dependence on MR as the diagnostic modality of choice. Carefully performed CT and MR both initially provide suitable geography and characteristics, but MR is superior in the detection of pre- or post-operative neoplastic spread elsewhere in the subarachnoid space. Accurate establishment of disease extent is essential in planning both surgical resection and adjuvant therapy.

Adult↗
PubMed1994

Neuroimaging of childhood craniopharyngioma.

The imaging of craniopharyngioma may include plain skull x-rays, computer tomography (CT) scans, magnetic resonance imaging (MRI) and angiography. Coronal studies are essential to properly define the regional anatomy. The solid or cystic character of the lesion is especially apparent with contrast enhancement. MRI adds a sagittal projection which is useful, and its increasing sophistication may eventually make angiography superfluous in these tumours. The appearance of craniopharyngiomas in each modality is described, including 3D, and an ideal imaging strategy presented. Postoperative imaging is best done with both MRI and CT, and enhanced studies done within 48 h to avoid the effect of surgical trauma.

Calcinosis↗
PubMed1993

Edward B. D. Neuhauser Lecture. Pediatric neuroradiology: its evolution as a subspecialty.

Pediatric neuroradiology emerged as the first formal subspecialty of pediatric radiology during the late 1960s. The history of its development as an unusual and effective combination of an age-related and a specific organ-directed clinical subspecialty, and the considerable technical adaptation and innovation within the diagnostic imaging so required, merits its inclusion within the history of the modern matrix of radiology. This Neuhauser Lecture outlines the odyssey of this subspecialty until the present: the adaptation of techniques and equipment to accommodate imaging of patients of all sizes--from 1-kg infants to young adults--and the understanding of the wide spectrum of CNS diseases, many often extremely complex. The evolution of this special body of knowledge and experience, the established and productive fellowship programs, and the significant part pediatric neuroradiology now plays in major scientific and professional associations and societies have led to this subspecialty becoming a lifelong persuasion for a growing number of radiologists.

Child↗
PubMed1992

Radiology of the developing central nervous system.

Functional and anatomical imaging of the developing central nervous system continue to engender considerable interest. Structural anomalies have been further defined and catalogued, aiding in the diagnosis and genetic counseling of children with developmental delay. Anomalous development of the brain has recently been linked to certain neuropsychiatric disorders. The natural course of many of the metabolic brain disorders has now been chronicled with imaging studies, rendering standards on which to evaluate efficacy of treatment.

Brain↗
PubMed1991

Primary neoplasms of the central nervous system in children.

Modern diagnostic imaging techniques are able to detect primary neoplasms of the central nervous system (CNS) in children safely and accurately but with less specificity as to cell type or degree of malignancy. These neoplasms, often peculiar in cell type and size, mediated by hydrocephalus in their clinical presentation, demand careful and often extensive imaging techniques best to evaluate their geography and character. Added to these basic observations, determination of the neoplasm from surrounding edema, detection of possible spread, and evaluation of residual or recurrent neoplasm are prime responsibilities of the pediatric neuroradiologist toward the child, neurosurgeon, and oncologist.

Angiography↗
PubMed1991

Benign intrinsic tectal "tumors" in children.

A specific group of intrinsic dorsal midbrain tumors was identified in six children by computerized tomography (CT) and magnetic resonance (MR) imaging. Each patient presented with raised intracranial pressure as a result of hydrocephalus due to obstruction of the sylvian aqueduct. No patient had brain-stem signs referable to the tectal tumor initially or subsequently. All six children underwent cerebrospinal fluid (CSF) diversionary procedures. The radiological features were consistent and specific, with all patients showing tectal calcification or primary increased attenuation of the tectal plate on CT scans. In addition, lack of contrast enhancement was noted initially in four patients and eventually in all six patients. In all patients MR imaging showed a focal tectal tumor distorting the collicular plate with no cystic component and increased signal intensity on T2-weighted images. There has been no evidence of progression in these six patients in the follow-up period ranging from 8 months to 17 years (8 months and 2 1/2, 4 1/2, 8, and 17 years). Diversion of CSF has been the only surgical treatment and no patient underwent deep x-ray therapy. Five patients have had normal intellectual development. In contrast to the majority of previously described periaqueductal and tectal tumors, this group of lesions appeared to be truly benign. The authors suggest that patients presenting with these clinical and radiological features may be managed by CSF diversion, serial examination, and MR imaging.

Adolescent↗
PubMed1991

Neuroimaging and pediatrics.

The emphasis in understanding significant categories of pediatric brain and spinal cord lesions, such as brain neoplasms, white matter diseases, fetal abnormalities and lesions of the pituitary gland, is changing towards a clinical perspective with respect to modern imaging techniques. The initial experience with magnetic resonance imaging (MRI), Doppler sonography, computerized tomography (CT), and high-resolution ultrasound (US) is now being consolidated, compared and contrasted with each other and with the increasing clinical experience, particularly in diseases that are peculiar to childhood.

Central Nervous System Diseases↗
PubMed1989

Computed tomography in intracranial, supratentorial metastases in children.

This study compares the CT characteristics in a consecutive sample of supratentorial metastases (n = 31) with primary tumors of the same location (n = 49) in childhood. Postcontrast CT was performed in all but one of the metastases cases. In all but one of these children the location and type of primary tumor was known at time of occurrence of cerebral metastasis. Primary CNS tumors (n = 12) had a higher incidense of supratentorial metastatic spread than tumor originating elsewhere. Three children had diffuse subarachnoid seeding, while 28 had solid tumors (21 solitary, 7 multiple). The predilection location for the solid metastases was the gray-white matter junction (n = 12). The following CT findings were significantly less frequent in metastases than in primary tumors (P less than 0.05): Midline location, calcification and cyst formation. On the other hand bleeding, pronounced contrast enhancement and location in the gray-white matter junction were more frequent in the metastatic group (P less than 0.05).

Brain Neoplasms↗
PubMed1984

Parameters of infiltration in posterior fossa tumours of childhood using a high resolution CT scanner.

The computed tomographic changes in 23 posterior fossa tumours of childhood scanned on a GE 8800 scanner have been compared with the detailed operative reports in order to evaluate morphological features indicative of infiltration. The study indicated that the cyst wall of a cystic astrocytoma was always easily enucleated and was free from infiltration and that a sharp enhancing edge of a medulloblastoma or centrally necrotic astrocytoma was usually also not the site of infiltration. Other features however were found to be unreliable.

Astrocytoma↗
PubMed1984

Radiological features of the neuroectodermal tumours of childhood.

The radiological features of 10 cases of primitive neuroectodermal tumour (primary cerebral neuroblastoma) are presented. The angiographic and CT appearances were similar to those previously described in the literature. However, not previously documented was evidence on plain skull radiographs and CT scans of thinning and expansion of the overlying vault in 6 of the 10 cases.

Adolescent↗
PubMed1983

Craniotelencephalic dysplasia in sisters: further delineation of a possible syndrome.

We describe two sisters with a complex of anomalies involving the cranium and brain. The changes in the former are consistent with those previously described as craniotelencephalic dysplasia and those in the latter indicate primary developmental abnormalities of the central nervous system including septo-optic dysplasia, absent olfactory nerves, agenesis of the corpus callosum, and lissencephaly. Per se, these cerebral malformations are causally heterogeneous, but their occurrence in association with craniotelencephalic dysplasia suggests that this combination is a distinct, probably autosomal recessive, syndrome.

Brain↗
PubMed1983

Intracranial vascular malformations in children: computed tomographic and angiographic evaluation.

Thirty-nine cases of intracranial vascular malformations in children were reviewed. All patients underwent preoperative computed tomography (CT) and 35 had complete preoperative angiographic work-ups. The CT features of intracranial vascular malformations in children are described. Among the 39 patients, there were 30 parenchymal arteriovenous malformations, four dural arteriovenous malformations, three cavernous angiomas, and two venous angiomas. Combined CT and angiography allowed a highly specific diagnosis in 77% of the cases.

Adolescent↗