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Biomedical subjects

G Bergstrand

Publications and source records attributed to G Bergstrand.

34 records · Page 2Linked to original sources
PubMed1983

Postural displacements of the brain--on the feasibility of using CT for determination of stereotactic coordinates.

Ten patients were studied with CT. In order to achieve consistent and reproducible CT slices an external helmet fixation system was used. Certain well defined cerebral structures were chosen as anatomical landmarks and their relationship to the skull determined with the patient in supine, lateral and prone positions. No displacements of brain structures could be observed. The results show the feasibility of using the same coordinates for intracranial structures at CT and at operation irrespective of the position of the patient's head at these procedures. Four of these patients were examined after lumbar intrathecal administration of 5 ml metrizamide (200 mgJ/ml). This small amount of positive contrast does not seem to influence on the position for the brain.

Brain↗
PubMed1983

Nasal meningoencephalocele. A clinical problem.

Four cases of nasal meningoencephalocele are reported. They demonstrate the importance of considering the diagnosis of nasal glioma or meningoencephalocele in adults with a nasal polyp of atypical appearance, or in infants with nasal obstruction and unilateral nasal polyp. Misdiagnosed and incorrectly handled patients with nasal meningoencephaloceles may develop serious ascending infections and/or a constant CSF leak. A thorough radiological examination including conventional and computerized tomography of the anterior cranial fossa, isotope cisternography and CT-cisternography is advocated. A multi-disciplinary approach is recommended in the diagnosis and treatment. The surgical procedure includes an anterior fossa craniotomy often in combination with a transnasal approach.

Adult↗
PubMed1982

Positron emission tomography with 68Ga-EDTA in the diagnosis and localization of csf fistulas.

Five patients with cerebrospinal fluid (CSF) rhinorrhea were investigated with computed tomography (CT) and positron emission tomography (PET) to localize the site of a CSF fistula. After intrathecal injection of 10 MBq of 68Ga-EDTA, radioactivity was demonstrated in the basal cisterns. In three cases, the site of the fistula was visualized with PET. It is not always possible to demonstrate a CSF leakage with CT cisternography (CTC) using metrizamide, particularly in cases with minute fistulas or intermittent CSF rhinorrhea. With further experience and improved PET techniques, it may be possible to detect even very small fistulas.

Cerebrospinal Fluid Rhinorrhea↗
PubMed1981

CSF circulation in subjects with the empty sella syndrome.

The etiology to the empty sella syndrome (ESS) is not known. Increased intracranial pressure (ICP) has been suggested to be one of the possible causes. In the present study the CSF circulation was analyzed in 48 subjects with ESS with gamma cisternography, pneumoencephalography (PEG) and computed tomography (CT). In 80% of the subjects the CSF circulation was retarded with convexity block which was combined with widened CSF transport pathways and basal cisterns. These findings were correlated with the clinical signs and symptoms, most of which seemed to be related to the imparied CSF circulation (i.e. impared memory, balance disturbances, cerebellar ataxia, papilledema, hypertension and pituitary disorders). Headache, psychiatric symptoms, visual field defects and obesity, however, were not related to the impaired CSF circulation. It is concluded that impaired CSF dynamics leading to intermittent increase of ICP has a major impact on the development of the ESS and that most of the patients' complaints are related to this disturbance. Thus it is important to obtain information of the CSF dynamics concurrent with the diagnosis of ESS. For this purpose PEG or CT may be used as the first examination. Moreover, the patient should be examined at least every second year for symptoms and signs of progressive impairments of the CSF circulation.

Adolescent↗
PubMed1980

DNA distribution in various parts of malignant gliomas assayed on stereotactic biopsies.

The study concerns the relation between the computerized tomogram, histopathology and DNA distribution in gliomas. The investigation was performed on stereotactic biopsies, which enabled the comparison to be made on a point-to-point basis. No clear-cut relation was found between histopathological grading and DNA distribution. In 1 patient diploid and aneuploid tissue was found in different parts of the tumor. In this case the difference in ploidy was mirrored by differences in histopathological grading and gross morphology as indicated by the CT scan.

Biopsy↗
PubMed1979

Angiographic findings in subdural hematoma correlated with CT attenuation values.

Twenty-eight subdural hematomas in 24 patients were examined by angiography and computed tomography (CT). The angiographic appearance of the hematomas was classified as either crescentic, lentiform, or transitional. The attenuation value of the hematomas was calculated from the CT scans. The mean attenuation of crescentic hematomas (13.8 EMI units--EU: 500 scale) was considerably lower than those of lentiform (21.7 EU) and transitional (19.8 EU) hematomas. The crescentic and transitional hematomas were either subacute or chronic, the chronic crescentic hematomas having an attenuation value at or around serum level. The lentiform hematomas were all more than 24 days old. The relatively high attenuation in chronic lentiform and transitional hematomas was probably caused by rebleeding, and the shape indicates enlargement of the hematomas after membrane formation has occurred. In the chronic, low attenuation crescentic hematomas, no recent bleed and no enlargement had occurred.

Adolescent↗
PubMed1976

Visibility of the intrapericardiac segment of the ascending aorta on conventional lateral chest films.

In a retrospective survey of the lateral chest films of 284 adult patients the intrapericardiac part of the ascending aorta was at least partly discernible in more than half of the cases; those with visible calcifications in the aortic wall were excluded. None of the patients had known heart disease. When the intrapericardiac part of the ascending aorta is visible it can be clinically useful for the localisation of intracardiac calcifications in relation to the aortic orifice (inside or outside), for estimating the sagittal diameter of the left atrium and for evaluating the width and shape of the aortic root.

Adult↗
PubMedDate not supplied

Cardiac gated MR imaging of cerebrospinal fluid flow.

This is a preliminary investigation of the cerebrospinal fluid (CSF) spaces using cardiac gated magnetic resonance imaging. A variation of intensity of the signal from the cerebral aqueduct is demonstrated during the cardiac cycle. The pattern of this variation suggests pulsatile CSF flow. Calculations that have been verified by phantom measurements show that CSF flow rates less than 1 mm/s may be detectable. Magnetic resonance may therefore offer a new method for the demonstration and measurement of CSF flow.

Cerebral Aqueduct↗
PubMedDate not supplied

Computed tomography of the brain in cases with venous vasculitis compared with an age-matched reference group.

Patients with a particular, steroid-sensitive headache and often characteristic pathology at orbital phlebography, have been suggested to suffer from venous vasculitis. Fifty such patients were examined with computed tomography (CT) of the brain. The findings were compared with those of an age-matched reference group selected at random to represent normal subjects. The CT examinations were analyzed with respect to size of lateral ventricles and signs of atrophy. In both groups, there was a significant increase of atrophy with age. There was also a significantly higher degree of atrophy in the patient group as compared with the reference group. The findings indicate that the supposedly underlying venous vasculitis is related to early aging and atrophy of the brain.

Adult↗
PubMedDate not supplied

Orbital phlebography for differentiation between multiple sclerosis and venous vasculitis in subacute blindness.

Thirteen consecutive patients with subacute unilateral loss of vision and periorbital pain but without pathology of the fundus or increased erythrocyte sedimentation rate, were investigated with visual evoked response, electrophoresis of serum and cerebrospinal fluid, and orbital phlebography. Seven of these patients were found to suffer from multiple sclerosis. The remaining 6 were considered to have venous vasculitis. There was a spontaneous recovery from visual impairment in all patients with multiple sclerosis, but not in patients with venous vasculitis. Of the latter patients, only two, who were treated with steroids within the first four days after onset of symptoms, regained vision. It appears that orbital phlebography is the diagnostic procedure of choice for proper management of patients with subacute loss of vision.

Adult↗
PubMedDate not supplied

Comparative double-blind investigation of meglumine metrizoate, metrizamide, and iohexol in carotid angiography.

The new nonionic contrast medium iohexol (Omnipaque) was compared with its predecessor metrizamide (Amipaque) and with the conventional ionic medium meglumine metrizoate (Isopaque Cerebral) in carotid angiography using a double-blind crossover technique. The results indicated that iohexol and metrizamide caused less discomfort than the ionic medium. The circulatory effects of the three media were generally mild, and the diagnostic effectiveness was comparable when the iodine concentration was kept in the range of 280-300 mg I/ml.

Adolescent↗
PubMedDate not supplied

Cerebrospinal fluid circulation: evaluation by single-photon and positron emission tomography.

Gamma camera cisternography after intrathecal administration of 111In-DTPA is a widely used and well established technique for studies of cerebrospinal fluid (CSF) circulation. The radiation dose from 111In, however, is a limiting factor that sometimes seriously affects the image quality and, hence, correct interpretation. This investigation was designed to assess the value of tomographic techniques for studies of CSF flow. Single-photon emission computed tomography (SPECT) was performed on 15 patients by means of the Karolinska Hospital rotating gamma camera system after injection of 111In-DTPA or 99mTc-DTPA. The combination of SPECT and 99mTc-DTPA proved to be a valuable technique. It permits a clear evaluation of the location of the isotope intracranially and its precise relation to the ventricles. Positron emission tomography (PET) applied after intrathecal administration of 68Ga-EDTA demonstrates that small amounts of radioactivity can be registered and that PET is a promising technique for the evaluation of CSF dynamics.

Cerebrospinal Fluid↗
PubMedDate not supplied

Postural displacement of the brain: feasibility of using CT for determination of stereotaxic coordinates.

Ten patients were studied with computed tomography (CT) in an attempt to determine if CT could be used preoperatively to establish stereotaxic coordinates for an operation and to find out more about how postural changes affect the position of the brain. Certain well defined cerebral structures were chosen as anatomic landmarks, and their relation to the skull determined with the patient in the supine, lateral, and prone positions. An external helmet fixation system was used to ensure consistent and reproducible CT slices. No displacement of the brain structures was observed in any of the positions, so it may be assumed that it is feasible to use CT-generated preoperative stereotaxic coordinates for reference during an operation, regardless of the patient's position. Four of the 10 patients were examined after lumbar intrathecal administration of metrizamide (200 mg I/ml). This small amount of positive contrast material did not seem to influence the position of the brain.

Brain↗
PubMedDate not supplied

Computed orbital phlebography of the cavernous sinuses.

Computed orbital phlebography (COP), described as computed tomography with concomitant injection of contrast medium into a frontal vein, was used to evaluate the cavernous sinuses in 19 patients with intrasellar or parasellar lesions and in two normal controls. Bilateral opacification occurred in 12 subjects, eight of whom had pituitary tumors. Unilateral partial obliteration was encountered in four subjects, all of whom had pituitary tumors with marked parasellar extension. In three subjects with parasellar tumors, ipsilateral total obliteration of the cavernous sinus was seen. In one subject with no sign of parasellar tumor, there was no opacification of the cavernous sinuses, a failure attributed to technical factors. In one other subject, the frontal vein puncture was unsuccessful and COP could not be performed.

Cavernous Sinus↗