Angiographic resolution of a neonatal intracranial cavernous hemangioma coincident with steroid therapy. Case report.
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Blood Platelet Disorders↗
Biomedical subjects
M Gado
Publications and source records attributed to M Gado.
Anterior cervical discectomy without interbody bone graft.
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Bone Transplantation↗
The carotid angiogram in suprasellar masses.
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Adenoma↗
Clinico-radiological study of collateral circulation after internal carotid and middle cerebral occlusion.
The intracranial collateral channels apart from the circle of Willis have been studied angiographically in 34 patients with internal carotid artery occlusion and 19 with occlusion of the middle cerebral artery. These collaterals are present in a high percentage of cases within a week of the ictus and are more common when the stroke has developed slowly. Their presence in occlusion of the middle cerebral artery seems to offer some protection against infarction but in internal carotid artery occlusion they are less important than the circle of Willis and when present suggest inadequacy of this structure.
Adult↗
The moyamoya syndrome associated with irradiation of an optic glioma in children: report of two cases and review of the literature.
We report two cases of the moyamoya syndrome which became clinically apparent after irradiation of an optic glioma during childhood. A summary of 14 cases of this syndrome following irradiation of intracranial tumors is also presented. Nine of these cases were optic gliomas; five were found in children with neurofibromatosis, another disorder that has a strong association with the moyamoya syndrome. The effectiveness of irradiation of optic gliomas in childhood is not definitely established. The possibility of inducing serious vascular disease is a further reason for caution when considering irradiating these tumors.
Arterial Occlusive Diseases↗
Interactive segmentation of cerebral gray matter, white matter, and CSF: photographic and MR images.
Digital photography of postmortem brain slices was compared with magnetic resonance imaging (MRI) for morphological analysis of human brain atrophy. In this study, we used two human brains obtained at autopsy: a cognitively defined nondemented control (70-yr-old male) and a demented Alzheimer's disease (AD) subject (82-yr-old female). For each of two brains, interactive manual image segmentation was performed by two observers on two image sets: (a) four coronal T1-weighted MR images (5 mm slices); and (b) four digitized photographic images from comparable rostrocaudal levels. Microcomputer image analysis software was used to measure the areas of three segmented cerebral compartments--gray matter (GM), white matter (WM) and CSF--for both image types. Resegmentation error was defined as the absolute difference between the areas derived from two segmentation trials divided by the value from trial 1 and multiplied by 100. This yielded the percent difference between the area measurements from the two trials. We found intra-observer agreement was better (error rates 1-18%) than inter-observer agreement (3-70%) with best agreement for WM and least for CSF, the smallest object class. MRI overestimated GM area relative to digitized photographs in the control but not the AD brain. The results define limitations of manual image segmentations and comparison of MRI with pathologic section photographic images.
Aged↗
Utilization characteristics of a superconductive MR system undergoing initial clinical trial.
The authors describe their initial 7 month experience with magnetic resonance (MR) imaging using a superconductive MR system. Factors affecting system utilization were scheduled and unscheduled downtime, specific system characteristics, and physician experience with the new technology. Technical improvements that reduced the duty cycle and radiologist experience in tailoring examinations have improved patient throughput by reducing the average patient study time by approximately 40% during the 7 month survey. These considerations have important economic consequences for patients and operators of MR equipment.
Adolescent↗
Neurodegenerative diseases of childhood: MR and CT evaluation.
To evaluate the diagnostic utility of MR and CT in neurodegenerative diseases of childhood, we examined 63 children (MR in 44, CT in 53) carrying diagnoses of Leigh disease (14 patients), various metabolic diseases (13 patients), leukodystrophies (13 patients), other specific degenerative diseases (10 patients), and unclassified neurodegenerative disorders (13 children). Magnetic resonance yielded positive findings in 86% and CT in 81%. Lesion extent and conspicuity were consistently greater with MR. The high frequency of abnormalities detected on MR, and to a lesser extent on CT, helps distinguish children with neurodegenerative diseases from those with nonprogressive idiopathic movement disorders. The most common abnormalities included signal alterations (MR) or decreased attenuation (CT) of the basal ganglia and cerebral white matter, as well as local or generalized brain atrophy. Although considerable overlap was present, the findings showed four general patterns that may assist in tentative classification of patients with nonspecific clinical and laboratory findings.
Adolescent↗
Pre- and postcontrast MR studies in tuberous sclerosis.
The MR findings in eight patients with intracranial manifestations of tuberous sclerosis are reported. There were subependymal lesions in seven patients and peripheral lesions (i.e., cortical and subcortical) in all patients. All lesions were supratentorial. We emphasize two findings that have not been previously stressed. The signal intensity patterns of the subependymal lesions varied from patient to patient, but in all patients receiving intravenous contrast medium, the majority of these lesions enhanced. Although this finding may signify early breakdown of the blood-brain barrier with potential for lesion growth, the high frequency of enhancement challenges earlier concepts of equating this phenomenon with existence of actively growing giant cell astrocytomas. The peripheral lesions were more numerous than subependymal lesions. These lesions were nearly always hyperintense in the proton density weighted and T2-weighted images. Most notable is the fact that, in half of the lesions, signal intensity was also elevated in the T1-weighted image, an observation that has not been emphasized in previous reports. Although not pathologically confirmed this signal pattern may represent early stages of calcification within these lesions. Finally, unlike subependymal lesions, none of the peripheral lesions showed contrast enhancement.
Adolescent↗
Measure of regional cerebral blood volume in vivo by means of excited fluorescent x-radiation, and factors affecting this parameter.
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Animals↗
Glomus jugulare and vagale.
The therapeutic results in 72 patients with glomus jugulare and nine with glomus vagale have indicated a surgical cure rate of 80% in the former and 100% in the latter. Radiotherapy demonstrated a 65% tumor response rate and a 25% cure rate histologically and clinically. Embolization with Gelfoam beads in seven patients resulted in diminished tumor size and arterial circulation from the external carotid system. However, in all cases the tumor persisted. Embolization diminished intraoperative bleeding. Nevertheless, the use of embolization as a palliative modality demonstrated significant symptomatic relief in aged, debilitated patients and in all patients with large inoperable glomus jugulare tumors.
Adolescent↗
High-intensity basal ganglia lesions on T1-weighted MR images in neurofibromatosis.
Basal ganglia lesions, characterized on MR by increased signal intensity on T1-weighted images, were observed in seven patients with documented neurofibromatosis. These lesions most often involved the globus pallidus and internal capsules in a bilateral and symmetric fashion, and extended across the anterior commissure resulting in a "dumbbell" configuration. Smaller and less prominent foci of increased signal also were present on corresponding T2-weighted images. These lesions did not exhibit mass effect, edema, or enhancement with gadolinium-DTPA. They were not visible on CT (performed in two patients) and demonstrated no progression during a 2-year interval in three patients. Their signal characteristics and morphology suggest that they represent heterotopias containing Schwann cells and/or melanin deposits. Migrational abnormalities of these neural crest derivatives are known to occur in neurofibromatosis, and the presence of such heterotopias has been documented pathologically in patients with this disorder. While recent reports discuss foci of increased signal intensity on T2-weighted MR images in patients with neurofibromatosis, signal abnormalities on T1-weighted images have not yet been described. When lesions characterized by similar signal as well as morphologic characteristics are encountered on MR, the diagnosis of neurofibromatosis should be considered.
Adolescent↗
Water content and water structure in CT and MR signal changes: possible influence in detection of early stroke.
Recent work by the authors and others has shown that MR imaging is more sensitive than CT in the detection of acute stroke. To separate the effects of water content and water structure on MR signal intensity, we undertook two sets of experiments that used simple model systems: gelatin gels with increasing water content and hardened hens' eggs. CT and MR were performed on both systems. On CT there was a direct linear relationship between CT attenuation (Hounsfield units) and the specific gravity of the gelatin gels, and an inverse relationship with water content. There was only a minimal change in the specific gravity of egg samples with hardening and, as expected on CT, no change in linear attenuation accompanying hardening. On MR there was a linear relationship between water content in gelatin gels and spin-lattice (T1) relaxation time (r = .92, p less than .01) and spin-spin (T2) relaxation time (r = .91, p less than .05). However, these changes were insufficient to explain the changes of signal intensity that occur in the brain with infarction. The simple cellular system with hens' eggs demonstrated that shortening of T1 and T2 accompanied egg hardening with minimal change in water content; the shift of water from bulk water to a bound or structured form was probably the basis of this phenomenon. We found that water structure and not merely water content is a significant mechanism underlying relaxation time changes and signal intensity changes in acute stroke.
Animals↗
Brain atrophy in dementia judged by CT scan ranking.
In order to further investigate the relationships of brain atrophy, age, and dementia, computed tomographic (CT) scans on two groups of subjects aged 65-80 years were rank-ordered according to ventricular and sulcal size. Each group contained subjects with mild senile dementia of the Alzheimer type (SDAT) and matched controls. In both experiments there was a strong correlation between these rank orders, ventricular size, and the clinical dementia rating. There was also a weaker but significant correlation between rank ordering and sulcal size. This suggests that brain atrophy in excess of that normal for age alone occurs in early SDAT.
Aged↗
Lateral disk herniation into the lumbar intervertebral foramen: differential diagnosis.
Lateral disk herniation into the intervertebral foramen if not recognized may result in a negative surgical exploration. The condition is readily recognized by computed tomography (CT), which demonstrates a soft-tissue mass in the intervertebral foramen, focal protrusion of the posterolateral margin of the disk into the foramen, absence of dural sac deformity, and occasionally the presence of calcium or gas in the intervertebral foramen. The differential diagnosis includes metastatic neoplasm, primary neoplasm, and conjoined root sheath anomaly. Features that enable CT differentiation of these conditions from lateral disk herniation are described. Myelography is useful in the identification of a conjoined root sheath.
Diagnosis, Differential↗
Aging, dementia, and brain atrophy: a longitudinal computed tomographic study.
Studies involving linear measurements of ventricular size and a volumetric measurement of the cerebrospinal fluid (CSF) space were performed on elderly subjects with mild dementia of the Alzheimer type and on age-matched controls. Forty-five subjects were studied twice at a 1 year interval; linear ventricular measurements showed not only a greater degree but a more rapid evolution of brain atrophy in individuals with mild dementia as compared with controls. An additional 12 normal subjects were studied twice over a 1 year period with volumetric estimates of the CSF space, which demonstrated development of significant brain atrophy within 1 year, while linear measurements on the same scans showed no significant change. The volumetric method is regarded as a more sensitive indicator of brain volume and is potentially useful in further studies in dementia.
Aged↗