The use of a test phantom in step-shaped forms (test steps) for the clarification of different problem situations in x-ray diagnosis. 1. The use of test steps for the estimation of image quality after modified darkroom technics

Properly exposed radiographs and under- or overexposed ones were processed differently with regard to temperature and time. Using a step wedge for the objective estimation, the alteration of well-exposed radiographs by neglecting time and temperature control was examined. Further information is given about the possibility to improve the quality of wrongly exposed radiographs by manipulation of the processing, and about the quantity of acceptable radiographs received in this way. Stop bath, fixation bath, wash bath and drying were performed regularly. The result showed, that the only chance to get high quality radiographs is by exact and correct working.     

The problems of X-ray image formation in veterinary practice--result of a cyclic study with the use of a test phantom for the determination of image quality

To grasp the problems of producing X-ray pictures in veterinary surgery, a ring trial was carried out. The task of the veterinarians was to produce two radiographs: from a certain body region, together with a test phantom, which allowed the judgement of the image quality immediately. The dates and technique of exposure had to be chosen as usual, one picture had to be developed in the dark room, either manually--the usual way with the normally used chemicals or by automatic developing machine. The other picture was developed under standard conditions in the Institute of Medical Physics. For a third radiograph, already exposed with the correct dose, only development was requested. Therewith the total process of producing an x-ray picture, the exposure dates and -technique and the dark-room procedure should be analyzed. Additionally a protocol was drawn up. All results were treated anonymously. The outcome of the trial obviously showed the problems: blatant tendency to overexposure, in no case underexposure, combined with faults in the dark room--e.g. disregarding the condition of the developer or the probably given necessity of changing the developer and even the importance of controlling time and temperature during developing. No informations were requested about fixation- and stop bath or the method of drying.(ABSTRACT TRUNCATED AT 250 WORDS)     

Enhancing septoria leaf blotch forecasts in winter wheat II: model architecture and validation results

Journal of Plant Diseases and Protection - In precision agriculture, pesticides and other inputs shall be used precisely when (and where) they are needed. European Directive 2009/128/EC calls for...     

The use of a test model in a stepped form (test steps) for the clarification of different problem situations in X-ray diagnosis. 2. The use of test steps for testing the POLAROID-TPX immediate X-ray picture system

The stepwedge, described in part 1 and in other publications, was used for the examination of the POLAROID-Instant Radiographic System. The result showed, that this system is a quite acceptable method for the practitioner. POLAROID-radiographs, in comparison with the classic radiographs, show equal contrast and detail-visibility, but demand a higher radiation dose.     

A simple test phantom in the form of a staircase for running control of the image in veterinary roentgenology

Quality control in veterinary radiology seems to be neglected. For the correct estimation of the radiographic quality, there is no adequate phantom available. Although measurements have shown that the exposure to radiation is far under the admissible limits, the quantity of repeated examination has to be reduced. So it was necessary to create a phantom, which allows the objective judgement of the x-ray photograph taken immediately from the patient. The phantom shows the following characteristics: 1) It is small-sized, so that it can be represented on the radiograph together with the object, but without remarkable enlargement of the beam and additional exposure to radiation. 2) It consists of tissue-similar material, which absorbs and scatters x-rays similar to the body region. According to the fact that the indications for radiographs in veterinary medicine are mostly problems in skeleton regions, this region is represented first of all. 3) Therefore the phantom shows variable thickness, so that it can simulate different skeleton parts. 4) The represented parameters are: 4.1 the different radiographic densities; 4.2 the latitude; 4.3 the radiographic contrast; 4.4 the radiographic detail visibility (film-far, film-close) in the relevant parts of the x-ray picture 5) The phantom is universally applicable. By a way of "calibration" it is multipurpose for certain kinds and sizes of animals.