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Biomedical subjects

J Rieger

Publications and source records attributed to J Rieger.

At least 73 records · Page 4Linked to original sources
PubMed1994

[The use of new turbo spin-echo pulse sequences with and without fat suppression in the diagnosis and staging of prostatic carcinoma].

MR studies using turbo spin-echo pulse sequences (TSE) were performed on 27 patients with histologically confirmed prostate cancer. A prospective study was conducted in 15 patients who underwent radical prostatectomy. Turbo SE pulse sequences generate strongly T2-weighted images of excellent quality with reduction of measurement time by a factor of 4-6. A comparison with standard T2-weighted spin-echo pulse sequences indicated an objective improvement in the contrast of pathological structures (p < 0.001). With respect to differentiation of stages T2 and T3 (TNM) during pathohistological correlation, sensitivity of 80%, specificity of 40% and an accuracy rate of 67% were obtained. Sensitivity of 71% and specificity of 75% were obtained when decoding cases of infiltration into the seminal vesicles, with an accuracy rate of 73%.

Adipose Tissue↗
PubMed1994

[Cerebral aneurysms: their 3-dimensional imaging with spiral CT].

In this study, the possibility of non-invasive, three-dimensional demonstration of aneurysms of the basal cerebral arteries by means of spiral CT was investigated. The first step was to obtain exact definition of optimal examination parameters. Angio CTs at appropriate levels were performed on 10 subjects and time/density curves of the arterial and venous phases obtained in order to optimise the beginning of the arterial spiral CT series. The second step in this investigation was to examine 7 patients; in 6 of these basal aneurysms had been demonstrated by DSA. By means of multiplanar three-dimensional reconstruction from the data of the spiral CT it was possible to demonstrate 7 aneurysms with a diameter between 5 and 18 mm. Their position and relationship to the bony skull was also shown.

Adult↗
PubMed1994

[Cerebral arteriovenous angiomas: 3-dimensional demonstration by spiral CT].

In 20 patients with known or suspected supratentorial arteriovenous malformations, an attempt was made to see how far CT angiography with 3-dimensional reconstructions is able to make a diagnosis and to differentiate the various components of the angioma. Spiral CT was performed following an intravenous bolus injection of 60-80 ml of iodine containing contrast medium. In all patients the diagnosis was confirmed by intra-arterial DSA of the vertebral vessels. In 13 patients, av malformations could be diagnosed following multiplanar 3-D reconstructions which agreed with the findings on DSA. The large supplying vessels, the nidus and the large draining veins could be defined with certainty. In 6 patients follow-up examination after embolisation was performed. The results could be demonstrated in three dimensions and the success of treatment could be documented unequivocally. CT angiography with 3-D reconstruction is able to supply important information in the majority of intracranial av malformations, both during initial investigation and following treatment.

Adolescent↗
PubMed1994

[Diphtheria immunity in the German population].

In the years 1991-1993 the diphtheria antitoxin titres of the blood serum of 2404 persons living in germany was determined by means of the ELISA test. Its aim was to to get an idea of the population's protection given by vaccination against diphtheria. It became evident that the average protection given by vaccination against diphtheria was on the decrease as people grew older. Thus only 3.8% of the 2-5-year olds did not have any protection given by vaccination (antitoxin titre < 0.01 IU/ml). The same was true for approximately 25% of the examined persons who were older than 30. Less than 10% of these persons had a thorough protection given by vaccination/(antitoxin titre > 0.1 IU/ml). In the age group of the 51-60-year olds better immunological protection than expected was found, which could be ascribed to the fact that there was a natural immunigation during the last wide-spread diphtheria epidemic in germany in the 'forties. Another aspect of this result could be a better motivation for-diphtheria vaccination in this age group. Furthermore, it was noticed that the average diphtheria antitoxin titres of women in all age groups were below those of men. In view of the great percentage of the adult population which is not sufficiently protected against diphtheria, it appears necessary to provide for more information of this population group to stimulate and motivate them to care for better protection by vaccination.

Adolescent↗
PubMed1992

Weight consideration in the use of cerrobend beam blocks.

The technique of using customized field blocking to protect sensitive normal tissue during megavoltage radiation treatment is common practice in modern radiation therapy. The introduction of CT-based treatment planning has revolutionized customized field shaping. We carried out a prospective evaluation of 54 cerrobend blocks during a one-month time period. The goals of this study were to analyze the specific block patterns and correlate these with field size, block weight, and field setup. Factors contributing to excessively large and heavy cerrobend blocks defined as > or = 20 lbs. were identified. Twenty-two percent of blocks were found to be excessively large and one-third of these were a consequence of planning decisions. A review of these situations suggests that alternative methods would have avoided the excessive weight. Concerns have been raised regarding the safety of large and heavy cerrobend blocks. These blocks were therefore analyzed in terms of tray sag and tray break-point. Our data suggest that within this clinical range of block weight, neither tray sag nor tray break-point are of significant concern.

Humans↗
PubMed1989

[Value of skull identification as evidence using a superimposed video image technic with reference to individual craniometric differences in the human skull].

The possibility of using the video superimposition technique for the identification of a skull by comparing it with photographs of missing persons is based on the fact that the human skull, unlike any other part of the human skeleton, shows unmistakable individual characteristics. In order to obtain a quantification, the individuality of human skulls is defined in terms of craniometric data and their probability distribution. First calculations based on the coordinates of some important encephalometric points of 52 European skulls suggest that there are individual aspects comparable to those of fingerprints. Under certain conditions, the video superimposition technique can establish very strong evidence for the identity of an unknown skull, provided that it is applied correctly and carefully.

Cephalometry↗
PubMed1986

Quincke's edema in a dialysis patient after administration of acrylic bone cement: possible role of ethylene oxide allergy.

A 33-year-old female dialysis patient suffered from osteomyelitis and luxation of the dens axis with cervical myelopathy. In the past she had had three attacks of anaphylaxis after treatment with dialyzers that had been sterilized with ethylene oxide. IgE-type antibodies directed against human serum albumin-ethylene oxide complexes could be demonstrated in the patient's serum by radioallergosorbent techniques. Immediately after an operation in which acrylic bone cement (Palacos-R) sterilized with ethylene oxide was implanted for stabilization of the cervical spine, the patient developed massive edema of the larynx, pharynx, and tongue, suggesting Quincke's edema. It is concluded that ethylene oxide present in acrylic bone cement may induce acute allergic reactions in sensitized patients. Dialysis patients may be at special risk, since the incidence of ethylene oxide allergy in this patient population is about 10%.

Adult↗
PubMed1985

[Use of low molecular-weight heparin in hemodialysis patients].

Low-molecular-weight (LMW) heparin has been compared to standard unfractionated (UF) heparin in a total of 49 patients on hemodialysis and hemofiltration in order to determine the necessary therapeutic dose and its effect on the coagulation system. A LMW heparin dose corresponding to 50% of the normal UF heparin dose was found to produce similar plasma heparin levels (anti-FXa-U/ml) in particular on minimal heparinization. At higher doses, UF heparin produced a more marked increase in plasma-heparin than did LMW heparin. Highly significant differences were found between UF and LMW heparin in their effects on PTT and thrombin time. Partial thromboplastin time (PTT) increased under UF heparin by an average of 120 s whereas LMW heparin only produced an increase of 5-7 s. Thrombin time was increased by 250-280 s under UF heparin and by 5-8 s under LMW heparin. With this LMW heparin dose of 50% of the UF heparin dose, no thrombosis of the extracorporal system occurred and no macroscopic detectable thrombotic material was found in the dialyzers or filters. No significant differences were observed between the effects of UF and LMW heparin on Factor VIII activity and fibrin monomers, so that a difference in coagulation activation between the two heparins can be excluded. Furthermore, there were no changes in thromboplastin time according to Quick, fibrinogen, antithrombin III, plasminogen, and a2-antiplasmin.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood↗