Biomedical subjects
J A Brunberg
Publications and source records attributed to J A Brunberg.
In vivo MR determination of water diffusion coefficients and diffusion anisotropy: correlation with structural alteration in gliomas of the cerebral hemispheres.
PURPOSE: To determine whether a relationship exists between water diffusion coefficients or diffusion anisotropy and MR-defined regions of normal or abnormal brain parenchyma in patients with cerebral gliomas. METHODS: In 40 patients with cerebral gliomas, diffusion was characterized in a single column of interest using a motion-insensitive spin-echo sequence that was applied sequentially at two gradient strength settings in three orthogonal directions. Apparent diffusion coefficients (ADCs) were derived for the three orthogonal axes at 128 points along the column. An average ADC and an index of diffusion anisotropy (IDA = diffusion coefficientmax-min/diffusionmean) was than calculated for any of nine MR-determined regions of interest within the tumor or adjacent parenchyma. RESULTS: In cerebral edema, mean ADC (all ADCs as 10(-7) cm2/s) was 138 +/- 24 (versus 83 +/- 6 for normal white matter) with mean IDA of 0.26 +/- 0.14 (versus 0.45 +/- 0.17 for normal white matter). Solid enhancing central tumor mean ADC was 131 +/- 25 with mean IDA of 0.15 +/- 0.10. Solid enhancing tumor margin mean ADC was 131 +/- 25, with IDA of 0.25 +/- 0.20. Cyst or necrosis mean ADC was 235 +/- 35 with IDA of 0.07 +/- 0.04. CONCLUSION: In cerebral gliomas ADC and IDA determinations provide information not available from routine MR imaging. ADC and IDA determinations allow distinction between normal white matter, areas of necrosis or cyst formation, regions of edema, and solid enhancing tumor. ADCs can be quickly and reliably characterized within a motion-insensitive column of interest with standard MR hardware.
Postvaricella basal ganglia infarction in children.
Two patients presented with acute neurologic deficits attributable to contralateral basal ganglia infarction 1 to 3 months after episodes of chickenpox. Both presented with hemiparesis with one patient also demonstrating ipsilateral choreoathetosis. In both patients MR revealed unilateral basal ganglia infarction. Cerebral angiography findings in one patient were normal; in the second, there was unilateral narrowing of the common carotid artery and of proximal branches of the anterior and middle cerebral artery.
Ventricular enlargement, neuropsychological status, and premorbid function in schizophrenia.
Ventricular enlargement is one of the most consistently documented neurobiological abnormalities in schizophrenia. The timing of the development of this abnormality in the course of schizophrenic illness and its relationship to neuropsychological dysfunction and premorbid adjustment is, however, unclear. To address these questions, we examined the relationship between ventricle-brain ratio (VBR), premorbid adjustment, and neuropsychological function, in 23 acutely exacerbated chronic schizophrenic inpatients. We observed that larger ventricles were associated with better current neuropsychological test performance, better premorbid cognitive ability, greater cognitive deterioration, better childhood premorbid social function, and greater decline in social function from premorbid levels. These data suggest that at least two developmental processes may operate in the genesis of cognitive and social dysfunction in schizophrenia: (1) childhood onset associated with poor premorbid childhood function, low educational achievement, lower intelligence quotient (IQ) and variably with VBR; and (2) adolescent onset associated with relatively normal childhood social function, higher academic achievement and IQ and increased VBR. Ventricular enlargement may reflect a late developmental or degenerative pathological process in schizophrenia.
Cystic cervical intramedullary ependymoma with previous intracyst hemorrhage. Magnetic resonance imaging at 1.5 T.
A patient with a cystic cervical ependymoma is described. Magnetic resonance imaging identified evidence of previous intratumor hemorrhage, which was confirmed at surgery. The images, operative findings, and pathology are reviewed.
Aggressive papillary middle ear tumors: a report of two cases with review of the literature.
Adenomatous tumors of the middle ear are rare, with only approximately 100 cases reported. A distinct subclass of this tumor demonstrates microscopic papillary architecture and has a propensity to erode the petrous bone and extend intracranially. The term "aggressive papillary middle ear tumor" has recently been proposed to describe this more invasive type of middle ear tumor. Thirty-seven cases of aggressive papillary middle ear tumors have been reported. We present two additional cases and discuss the clinical, radiologic, histologic, and operative features of this locally aggressive neoplasm. The tumor affects adults of both sexes. The clinical prodrome is prolonged. Presenting signs and symptoms most often relate to the involvement of cranial nerves V-VIII. Imaging studies reveal large, enhancing, destructive tumors with a generous vascular supply. Intraoperatively, the tumors are bloody, fibrous, and adherent to surrounding structures. Various surgical approaches in combination or in series may be used. Preoperative embolization may be helpful. The role of adjunctive radiation is unclear. Aggressive papillary middle ear tumors are histologically benign tumors with clinically destructive behavior. However, it appears that aggressive surgical management affords prolonged survival with minimal worsening of cranial nerve deficits.
Experimental intracerebral hemorrhage: relationship between brain edema, blood flow, and blood-brain barrier permeability in rats.
There have been few investigations of brain edema formation after intracerebral hemorrhage (ICH), despite the fact that mass effect and edema are important clinical complications. The present study was designed to investigate the time course for the formation and resolution of brain edema and to determine how changes in cerebral blood flow (CBF) and blood-brain barrier (BBB) permeability are temporally related to edema formation following ICH. Anesthetized adult rats received a sterile injection of 100 microliters of autologous blood into the caudate nucleus. Water and ion contents were measured immediately, at 4 and 12 hours, and daily to Day 7 (10 time points, six rats at each time) after experimental ICH. The water content of the ipsilateral basal ganglia increased progressively (p < 0.002) over the first 24 hours, then remained constant until after Day 5, when the edema began to resolve. Edema was most severe in the tissue immediately surrounding the hemorrhage; however, it was also present in the ipsilateral cortex, the contralateral cortex, and the basal ganglia. Measurements of local CBF (using [14C]-iodoantipyrine) and BBB permeability (using [3H]-alpha-aminoisobutyric acid) were obtained in separate groups of six to eight rats at various time intervals between 1 and 48 hours after ICH. Cerebral blood flow was reduced to 50% of control at 1 hour, returned to control values by 4 hours, but then decreased to less than 50% of control between 24 and 48 hours after ICH. The BBB permeability increased significantly prior to the occurrence of significant edema in the tissue surrounding the clot. However, BBB permeability in the more distant structures remained normal despite the development of edema. These results demonstrate a time course for the formation and resolution of brain edema following ICH similar to that observed during focal ischemia. Brain edema forms in the immediate vicinity of the clot as a result of both BBB disruption and the local generation of osmotically active substances and then spreads to adjacent structures. While local ischemia, due to the mass effect of the hemorrhage, may play a role in producing cytotoxic and vasogenic edema, the release of toxic substances from the clot should also be considered. Since edema is nearly maximal by 24 hours after ICH, therapy directed at reducing edema formation must be instituted within the 1st day.
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Craniopharyngiomas--the utility of contrast medium enhancement for MR imaging at 1.5 T.
To evaluate the efficacy of i.v. contrast medium administration in MR imaging at 1.5 T in patients with craniopharyngiomas, MR studies of 10 men and 6 women with pathologically proven craniopharyngiomas were made. The MR images were obtained as 3- to 5-mm-thick coronal (n = 13) or axial (n = 3) Tl-weighted images (T1WI) prior to and following i.v. Gd-DTPA administration. Proton density- (PD) and T2-weighted images (T2WI) were also obtained. Conspicuity of tumor margins, cystic versus solid components, size, location and effect upon adjacent structures were separately characterized in all imaging sequences. In 6 patients contrast medium-enhanced T1WI. PD and T2WI demonstrated cystic tumor components not seen on unenhanced T1WI. There were significant differences (p < 0.004) on 2-tailed Student's t-test comparing tumor conspicuity on contrast medium-enhanced T1WI with unenhanced T1WI, PD and T2WI. Optimal tumor delineation on MR imaging of patients with craniopharyngiomas justifies the use of i.v. contrast medium.
[15O]H2O positron emission tomography determination of cerebral blood flow during balloon test occlusion of the internal carotid artery.
PURPOSE: To determine the utility of [15O]H2O positron emission tomography (PET) for the quantitative determination of cerebral blood flow in patients undergoing balloon test occlusion of the internal carotid artery. METHODS: Twenty-two [15O]H2O PET cerebral blood flow studies were completed on 20 patients for whom temporary or permanent occlusion of the internal carotid artery was being considered because of skull base tumor or internal carotid artery aneurysm. In each study, cerebral blood flow was determined during temporary balloon internal carotid artery occlusion, and again after deflation and removal of the balloon from the internal carotid artery. RESULTS: Patients were divided into three groups based on clinical and cerebral blood flow response to balloon test occlusion. Studies were classified as group I when associated with no clinical symptomatology and with a cerebral blood flow decrease of less than 10 mL/100 g per minute (16 of 22 patients); as group II when there was no clinical symptomatology and cerebral blood flow fell to 25 to 35 mL/100 g per minute on the occluded side (5 of 22); and as group III when the patient was clinically unable to tolerate test occlusion and had a cerebral blood flow of less than 20 mL/100 g per minute on the occluded side (1 of 22). Neurologic sequelae developed in none of the eight group I patients later undergoing permanent internal carotid artery occlusion. Cerebral infarction developed subsequently in the one group II patient who underwent internal carotid artery occlusion. CONCLUSION: During internal carotid artery balloon test occlusion, [15O] H2O PET determination of cerebral blood flow allows rapid quantitative determination of cerebral blood flow throughout the entire brain, predicting the adequacy of collateral flow after permanent occlusion. All patients were able to tolerate the [15O]H2O PET cerebral blood flow determination, and there were no complications of the procedure.
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