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Biomedical subjects

K Manegold

Publications and source records attributed to K Manegold.

8 recordsLinked to original sources

[Variation in X-ray dose quantity using an amorphous selenium based flat-panel detector -- a study on the dose reduction rate up to the limit of diagnostical utilization].

PURPOSE: To evaluate the diagnostic quality and minimum required dose to obtain acceptable images for diagnostic purposes in the field of musculoskeletal radiology. MATERIALS AND METHODS: A critical comparison of the image quality produced by a novel flat panel detector and the conventional screen/film system using a contrast-detail phantom was performed in phase I. Images from both systems were obtained with the same dose and displayed with similar contrast and density. In phase II images of significant anatomical structures in cadaver extremities obtained using the digital detector system and the standard film/screen system were critically evaluated. After a successive reduction in the X-ray dose for 84 patients in phase III, eight independent radiologists compared the image quality of the screen/film system to that of the novel flat panel detector. RESULTS: Phases I and II revealed a difference in the image quality achieved by the standard screen/film system and the digital detector system to the advantage of the digital detector system. In 77 of 84 patients (91.7 %), phase III showed equal image quality after a 50 % reduction in the X-ray dose. In 3 cases (3.6 %) the image quality and the level of contrast were better. No unified statement could be made for 4 patients (4.7 %). CONCLUSION: Digital imaging of skeletal disorders using the novel flat panel detector makes it possible to reduce the X-ray dose by 50 % with equal or even better image quality.

Adult↗

131-Metaiodobenzylguanedine therapy of neuroblastoma in childhood. One year of therapeutic experience.

Eleven children with neuroblastoma refractory to conventional therapy or relapse of neuroblastoma were treated with 131-metaiodobenzylguanedine (MIBG). The therapeutic results and the side effects were evaluated. In one patient with disseminated bone marrow involvement complete remission was obtained. Partial remission was observed in six patients and stable disease in another. Three patients did not respond to MIBG, in two of them the tumours did not accumulate a sufficient MIBG dose. Clinical and laboratory examinations revealed an excellent tolerance of MIBG in all patients. First attempts to continue cytostasis after MIBG therapy were made. MIBG has a good therapeutic efficacy is sufficiently incorporated into the tumour cell.

3-Iodobenzylguanidine↗

[Radiation burden in heart catheter studies--significance of measures for reducing scatter radiation].

During diagnostic and, more particularly, therapeutic intervention, such as transluminal coronary angioplasty, the operator may be exposed to a considerable degree of scatter radiation. In our study, we measured the level of radiation exposure of the head, unprotected knees and lower legs. A flexible lead screen, attached to the catheterization table (0.5 mm Pb) reduced scatter radiation of the lower legs by 95%. In addition, scatter radiation exposure of the head decreased by 54% by covering the patient with a rubber leaden blanket (0.25 mm Pb). Finally, the use of these supplementary yet simple measures did not hinder or interfere with the examination procedure in any way.

Cardiac Catheterization↗

[Endoscopic intraductal radiotherapy of high bile-duct carcinoma].

A new method for palliative intraductal radiotherapy of high malignant bile duct occlusion was used in three patients. It consists of insertion of a 4 cm x 0,6 mm iridium-192 wire into the stenosis caused by the tumour. It uses a modified nasobiliary probe which is guided endoscopically retrograde transpapillary. A radiation output of 0.85 Gy/min (85 rd/min) and a requested therapeutic dosage of 60 Gy (6000 rd) at a distance of 0.5 cm lead to in situ position of the wire for about 70 hours. During that time bile flow is effected via the nasobiliary probe. The advantage over previously described methods (percutaneous transhepatic, surgical after installation of U-drainage) lies in a smaller complication rate and improved follow-up treatment as change of the endoprosthesis or repeat irradiation is not associated with renewed tissue trauma.

Adenocarcinoma↗