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H K Beyer

Publications and source records attributed to H K Beyer.

At least 19 recordsLinked to original sources
PubMed1990

[Initial experience with the use of oral gadolinium-DTPA in nuclear magnetic resonance tomography of the pelvis].

The use of an oral contrast medium has so far not become a matter of routine in MR of the abdomen. In the present study the use of orally applied gadolinium-DTPA was examined in respect of tumorous diseases in the minor pelvis. 18 patients with tumours in the minor pelvis were examined before and after oral administration of gadolinium-DTPA (Gd-DTPA). 10 ml/kg body weight of a gadolinium DTPA solution were applied in a concentration of 1.0 mmol/l. T1-weighted and T2-weighted sequences were carried out before application and T1-weighted sequences after application. Oral application gadolinium-DTPA resulted in enhancing the signals of the filled intestinal portions. In 54% of the cases the sequences showed a sharper delineation between tumour and intestine. In 19% the delineation between pathological tissue and intestine on contrast examination was as well defined as in T2-weighted contrast images; in 27% of the cases oral administration of gadolinium-DTPA did not yield any additional information. No significant side effects were seen.

Administration, Oral↗
PubMed1990

Magnetic resonance imaging and computer tomography of acute spinal cord trauma.

Spinal cord lesions are not detectable on roentgenograms and computed tomography (CT) scans. Magnetic resonance images (MRIs) are able to make soft-tissue lesions visible. Interpretations of MRIs, CT scans, and roentgenograms were compared in 25 patients and three postmortem specimens with spinal cord injuries. In 14 patients and one specimen with normal roentgenograms and CT scans, the MRI demonstrated ten soft-tissue injuries as minimal displacement of the vertebral bodies or as a high signal intensity in the disc space, indicating a hematoma. Seven of the ten patients demonstrating soft-tissue injuries also had an intramedullary lesion, while in five of the 15 patients with normal CT scans, only a medullary lesion was present on MRI. In 11 patients and two postmortem specimens, fractures were seen on roentgenograms and CT scans. In these patients, the CT was superior to the MRI in detecting small bony fragments, but the medullary lesions were visible only on the MRIs. An intramedullary low signal intensity corresponded to macroscopically visible hemorrhages in the three postmortem specimens. The MRI provided important information in patients with neurologic deficits. No obvious pathologic changes were evident on the roentgenograms and CT scans. The MRI also demonstrated intramedullary and extramedullary soft-tissue lesions and was useful in establishing a diagnosis and in choosing appropriate therapy. CT, on the other hand, was superior in detecting small bony fragments and fracture lines.

Acute Disease↗
PubMed1989

Comparative assays of the chemotoxicity of iodinated radiographic contrast media based on impairment of fibrin antithrombin activity.

Radiographic iodized contrast media impair the antithrombin effect of the fibrin clot. The extent of the impairment correlates with dosage and lipophilicity. Normally, 90% of the thrombin activity of 2.3 IU/ml are inactivated by a fibrin clot generated by 2 mg/ml fibrinogen. The effect is due to contrast media-induced protein denaturation with subsequent impairment of thrombin binding to the fibrin clot. Two hepatogenic, two ionic, nephrotopic, and four nonionic contrast media were assayed by this test system at different concentrations. Clear-cut differences were found between the three main groups. Smaller, yet statistically significant, differences could be established between ioglicate and diatrizoate and between iosimide, iopromide or iohexol and iotrolan. No differences were found between iotroxate and iodoxamate. The results are in concordance with the partition coefficients (water/n-butanol) of these contrast media. The assay sensitivity is suitable as a screening system of the chemotoxicity of contrast media. It is easily performed, inexpensive, and assays the clinically important contrast media interaction with fibrinogen.

Blood Coagulation↗
PubMed1989

[The present status of the radiologic diagnosis of acute pulmonary failure].

Acute pulmonary failure is a very serious cause of respiratory failure and can occur in association with a multitude of disease. Radiological diagnosis occupies a central position in intensive-care monitoring. X-ray film of the thorax is performed not only for detecting any complications, but mainly for noninvasive and semiquantitative determination of the extravascular pulmonary fluid and hence of the fluid balance, although it is imperative to take into account any influence that associated disease and therapy measures. Other methods such as MR or methods of nuclear medicine have not acquired substantial importance in respect of diagnosing and monitoring acute pulmonary failure.

Acute Disease↗
PubMed1989

[Possibilities of phosphorus 31 spectroscopy in assessing the therapeutic effects on cellular energy metabolism of the myocardium].

We present a general review of the literature concerning the role of the 31 P spectroscopy in studying the metabolic effects of drugs like verapamil, chlorpromazin, propranolol, acebutolol, 2-mercaptopropionylglycine, insulin, 2-deoxyglucose, cardioplegic solutions, as well as perfluorocarbon solutions on the energy status of the ischemic myocardium. Using 31 P spectroscopy several important results have been found concerning the changes of the concentration of the high energy phosphates and of the intracellular pH during myocardial ischemia. It is now possible to gain interesting insights into the metabolic effects of different drugs. By using these drugs, changes in the high energy phosphates, as PCr and ATP were attenuated during the myocardial ischemia. A better recovery of the PCr and ATP contents during reperfusion was noted. The myocardial pH changes during ischemia are attenuated compared to controls. A good correlation between the preservation of the high energy phosphates and myocardial pH and the recovery of the ventricular function was described. An in vivo documentation of the mitochondrial oxidative phosphorylation is now possible. A short overview is presented about the phosphorylation potential and its prognostic value for various cardiac diseases. The 31 P spectroscopy successfully shifted the research interest towards biochemical processes at the cellular level in the diagnosis and therapy monitoring. It extends our knowledge on the pathophysiology of the myocardium.

Acebutolol↗
PubMed1989

[Magnetic resonance tomography studies with contrast media in post-discotomy syndrome].

The syndrome encompassing failed back-surgery is a relatively uniform combination of complaints caused by a variety of pathological changes in the lumbar spine, alone or in various combinations. The MRI's capability of detecting these factors is described. MRI can detect recurrent disc herniations and separate them from intradural and/or extradural scar formation. With further experience, MRI might also be able to assess instability of the lumbar spine motion segments. MRI is not very helpful in detecting neural lesions or facette syndromes. For this kind of pathology, advances in diagnosis will depend on the further improvement of neuro- and electrophysiological tests. The same applies to the diagnosis of cases of spinal stenosis. The size of the spinal canal can be measured by MRI as well as by other modalities. These results just point out the risk of disease - not the disease itself.

Discitis↗
PubMed1989

[The value of magnetic resonance tomography using gadolinium-DTPA in the diagnosis of the post-lumbar disk surgery syndrome].

Our results have shown that MR tomography - especially if gadolinium-DTPA is used as a contrast medium - is an excellent method to differentiate between the various possible causes of the post-discotomy syndrome. In particular, it is definitely possible to differentiate between a relapsed hernia of an intervertebral disc and a postoperative development of cicatricial tissue which is practically inevitable. This differentiation is of vital importance to the clinician, because a second operation should be performed only in case of a relapse, whereas cicatricial tissue is best left alone, because no matter how carefully the operation is performed with preparation of the neural structures, even more extensive cicatricial plates are bound to develop. Instability of the vertebral column in the operated disc segment, or other causes of complaints, can be identified via MR equally well if not better than by other means. Hence, the method should be the method of choice in postdiscotomy syndrome, since it facilitates the difficult choice between conservative therapy and reoperation.

Contrast Media↗
PubMed1988

[31-P-spectroscopy as a method for studying biochemical changes in skin tumors: exemplified by malignant melanoma and squamous cell carcinoma].

We report on the basic principles concerning in vivo P-31 MR spectroscopy and give a short review of the corresponding studies on skin tumors described in the literature. Malignant melanoma and squamous cell carcinoma are both characterized by high concentrations of phosphomonoester and phosphodiester. By means of the P-31 spectroscopy technique, we are able to detect changes regarding the tumor metabolism as a response to chemotherapy, irradiation, or biological immune modifiers (e.g. interferon).

Carcinoma, Squamous Cell↗
PubMed1988

[Spin-echo sequences and rapid image sequences in a comparison of spinal diseases].

Rapid image sequences of the spine were compared with proton and T2-weighted spin-echo sequences in 30 patients concerning their diagnostic value and image contrast. The rapid series was carried out with an angle of rotation of 30%, TR of 21 and TE of 12 msec., the spin-echo sequences with a TR/TE of 2,000/20/80 msec. The quality and contrast of the rapid series was markedly inferior to the spin-echo sequences; this was particularly marked for demonstrating disc and bone degeneration. At present, the routine use of rapid sequences cannot be recommended as a substitute for spine-echo examinations.

Humans↗
PubMed1988

[Importance of contrast medium administration in determining the age of traumatic renal hemorrhage by NMR tomography--experimental results].

In eleven Han-Wistar rats, experimental renal haematomas were produced and scanned by magnetic resonance tomography at two hours to 21 days. Bleeding during the first three or four days showed prolongation of T1 and T2 relaxation times. On subsequent days there was shortening of the T1 and T2 times. Gadolinium DTPA produced a marked effect in the second to fourth day following the trauma, if the examination was carried out 90 to 120 minutes after the administration of contrast medium. Gadolinium can be used in determining the age and clarifying the differential diagnosis of an bleeding if there is clinical support.

Animals↗
PubMed1988

[Specific detection of various stages of Osler's disease of the brain using high field magnetic resonance tomography (1.5 Tesla)].

MR is a sensitive noninvasive examination method for diagnosing parenchymatous cryptic arteriovenous malformations and sequels of cerebral haemorrhage. In a patient with recurring nosebleed and brain stem syndrome eleven so-called cryptic arteriovenous malformations or their haemorrhage sequels were diagnosed via magnetic resonance tomography. Basing on these specific findings, nosebleeding, and a positive family anamnesis, the findings could be classified as belonging to manifestations of Osler's disease (hereditary haemorrhagic telangiectasia). This rare disease is characterised by a triad of signs: telangiectasias, recurring bleeding, and heredity. In this article the specific MR image is compared with the CT pattern and the results are discussed against the background of literature on Osler's disease which is also known as Rendu-Osler-Weber disease.

Adult↗