Biomedical subjects
Publications and source records attributed to G Zöllner.
Brain complications from chronic alcoholism (Wernicke encephalopathy, central pontine myelinolysis, Marchiafava-Bignami disease, Korsakoff's syndrome, hepatic encephalopathy, cerebellar atrophy, hemorrhagic and ischemic brain lesions) may be diagnosed by MR imaging.
We present four cases of cerebral cavernous angioma that developed after radiatherapy for brain tumor in three cases and for cavernous angioma in one case. The time interval between irradiation and the detection of the cavernous angioma varied from three to nine years and the doses from 24 to 60 Grays. Brain hemorrhage appeared in two cases. Explanation for the formation of cavernous malformations is unclear but is probably related to proliferation and dilatation of the vascular endothelium with formation of capillary telangiectasis with evolution to cavernous angiomas. The pediatric brain appears particularly vulnerable to radiation injury. The risk of hemorrhage appears higher than with spontaneous cavernous malformations.
Patients with epidermoid cyst of the fourth ventricle usually present with headaches and/or disequilibrium. These cysts are characterized by a focal lesion that is nearly isodense to CSF at CT and nearly isointense to CSF on T1W and T2W MR images. MRI using FLAIR and diffusion weighted images as well as 3D CISS acquisitions is useful to better characterize the lesions and their relation with the vermis, foramen magnum and CP angle cisterns. DWI images are useful for postsurgical evaluation of residual tumor. Extension of the cyst into the CP angle cisterns usually precludes complete surgical resection.
Wernicke encephalopathy (Wernicke-Korsakoff encephalopathy) is related to thiamine deficiency. We report the MRI findings in four patients with visualization of bilateral and symmetrical hyperintense foci on T2W and FLAIR images involving the periaqueductal gray matter, the mamillary bodies and around the third ventricle. Diffusion weighted images obtained in two patients demonstrated mild hypersignal in the same areas. Contrast enhancement within the mamillary bodies was noted in one patient. Follow-up MRI obtained in three patients showed rapid regression of signal abnormalities without correlation with good clinical outcome.
We describe the computed tomographic and magnetic resonance imaging findings in two cases of intrasellar arachnoid cysts. The diagnosis of intrasellar arachnoid cyst with suprasellar extension should be evoked in case of a cyst-like formation whose density and signal appear to be identical to those of the cerebrospinal fluid even if contrast uptake is evidenced in the cyst wall. Contrast uptake can be related to compression of the pituitary stalk and normal pituitary displacement. Suspected intrasellar arachnoid cyst modifies the surgical approach which must be made via a subfrontal route. We discuss the differential diagnosis with other intrasellar cystic formations such as necrosed tumor, abscesses, Rathke pouch cysts, cystic craniopharyngiomas, epidermoid cysts and parasite cysts.
We report a case of arteriovenous fistula due to spontaneous rupture of an aortic aneurysm into the inferior vena cava. This is a rare complication of atheromatous aneurysm, often difficult to diagnose as the clinical presentation may be obscure. Although aortography is the reference diagnostic investigation, spiral CT acquisition with 3D and 2D reformation allowed visualization of the arteriovenous communication and provided an accurate diagnosis.
Eight infants with systemic-pulmonary Blalock-Taussig shunts were evaluated by spin-echo ECG-gated MRI. Contrary to Echocardiography, MRI using coronal oblique projections successfully visualized all palliative shunts entirely in one single plane (including one carried out on a right aberrant subclavian artery). MRI allowed assessment of size, course and patency of the shunt, including pulmonary and subclavian insertion. The proximal portion of the pulmonary and subclavian arteries were also visualized. We conclude that MRI with axial scans completed by coronal oblique planes is a promising, non invasive method for imaging the anatomical features of Blalock-Taussig shunts.
The problems are discussed that are encountered in diagnosing instability of the middle and lower cervical spine on the basis of conventional radiographs. Two aspects are considered: 11 elementary radiological signs are presented; the corresponding radiological syndromes, their clinical presentations, and the roentgenographic signs are discussed. Both aspects are illustrated by means of appropriate radiographs.
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The main purpose of noninvasive high-resolution B-mode sonography of the extracranial carotid artery is to detect clinically relevant arteriosclerotic lesions. That is the reason why reproducible parameters are needed for the description of normal and pathological echo patterns of the vascular lumen and the vascular wall. From an experimental evaluation of 100 carotid specimens examined with a high resolution real time scanner a list of definitions for sonomorphologic parameters is derived. These parameters refer to the clinical importance of luminal and intramural changes. Because of its high sensitivity for even minimal arteriosclerotic lesions, B-mode sonography is a useful method for clinical and epidemiological studies of extracranial carotid disease.
Free urine adrenaline, noradrenaline, (additional free plasma catecholamines in the physicians), and blood lactate were determined in 11 ambulance men and 5 physicians to assess stress during medical service. Stress was evaluated employing a stress index, based on difficulties in driving, traffic, severity of injuries or illness. Emergency cases with seriously injured subjects or reanimation were judged to have a 4-fold higher stress index than routine cases where strong physiological or psychological stress was absent. Urine catecholamines and stress indices were estimated in 3-h intervals. The calculations were based on the stress induced catecholamine concentrations minus the basal excretion during the same 3-h interval. Urine adrenaline and noradrenaline in ambulance men and physicians correlated directly with the stress index, as well as the plasma catecholamines of the physicians. Lactate levels showed similar behaviour and a descriptive direct correlation with the plasma catecholamines. Urine adrenaline increased more--dependent on the stress index--than urine noradrenaline. This over-proportional adrenaline response may be an indicator for the additional psychological stress in emergency cases. Therefore physicians showed--based on the same stress index--a tendency to higher urine adrenaline excretion and blood lactate levels than the ambulance men, which might be the consequence of the overall responsibility of the physicians. Because of the observed catecholamine responses during medical service, coronary insufficiency or hypertension might be contra-indications for participation in the medical service; regular clinical investigations including ergometric tests are advisable.
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