Green-sensitive Film Research Articles

Comparison of X-ray films in term of kVp, mA, exposure time and distance using Radiographic Chest Phantom as a radiation quality

Chest X-rays are one of the most commonly performed procedures for diagnosing conditions affecting the chest and its contents. It's also represents the change of actual human body to compare the image produced by using different parameters. And comparing the image characteristics of a particular x-ray system with different techniques. The aim of this experiment is to obtain the best quality radiograph by evaluating the optimum parameters such as kVp, mA, exposure time, and distance associated with the film characteristic and to find the difference in optical density (OD) of air stepwedge with different thicknesses. The comparison of the image produced in terms of exposure assessment was made by using the Toshiba KXO 50R X-ray Machine. The RMI Radiographic Chest Phantom, Model 170B, was used as the subject matter in this experiment. Radiographic film KONICA MG-SR PLUS, which is green-sensitive film, was used and inserted into a cassette. It was placed right below the RMI Radiographic Chest Phantom, Model 170B and then was exposed by using different kVp, which were 60, 70, and 80 kVp with 2, 2.5, 3.2, and 4 mAs for each kVp. The source-to-image distance, which was 183 cm, was kept constant in this study. The film was then processed by using an automatic processor in the darkroom. From the observations, 80 kVp with 2 mAs provides a better image quality as compared to others, and the optical density (OD) of air stepwedge increases with increasing thickness.

A quality control programme for medical X-ray films in India

Medical X-ray films are continued to be the major image receptors in diagnostic radiology in India. About 9×10⁶ m² of medical X-ray films are used per annum for diagnostic imaging in India, and its magnitude may further increase as the number of diagnostic X-ray units is increasing rapidly. A national quality control programme was initiated for testing the medical X-ray films of various suppliers/manufacturers so that optimum quality film can only be used in diagnostic radiography examinations. X-ray laboratory of Radiological Physics and Advisory Division, Bhabha Atomic Research Centre was recognised as national film testing laboratory. A dedicated test phantom was fabricated as per the prescription of International Organization for Standardization (ISO 9236-I, 1996), simulating the attenuation and scatter properties of chest of an average patient for periodic X-ray sensitometric evaluations of the medical X-ray films. The basic fog, speed, latitude, maximum optical density, uniformity and artefacts of all the films tested so far were found well within the requirements specified in the national standards. The average gradient for a few blue and green sensitive films were found less than the specified value. Suppliers/manufacturers of such films were advised to improve the performance quality of their films.

Hochkontrastauflösung von Film-Folien-Systemen in der Zahn-, Mund- und Kieferheilkunde

The aim was to determine differences in high-contrast resolution of film-screen systems used in dental panoramic and cephalometric radiography by calculating the modulation transfer function (MTF). The radiographs used to determine the MTF should be taken by the same x-ray units as those used for patient radiographs. The MTF was determined using a lead grid and according to DIN 6867-2 for 11 film-screen systems (speed 250, speed class 200 and 400) used in dental radiographic diagnostics. The optical density was measured using a microdensitometer developed by PTB. With 10% of the modulation transfer factor, newly developed film-screen systems (speed class 200 and 400) demonstrated a resolution of 4.9 to 6 line pairs per mm (panoramic radiography). In cephalometric radiography a film-screen system (speed class 400 and green-sensitive film) had a resolution of 4.2 line pairs per mm and surpassed two film-screen systems (speed class 400, resolution of 3 line pairs per mm, blue-sensitive films). The relevance of this study is underlined by the diagnostic reference doses defined in the German X-ray Ordinance (RöV) which are also intended for dentistry. Film-screen systems (speed 250, speed class 200) previously used in dental panoramic and cephalometric radiography can be replaced by newly developed film-screen systems (speed class 400). In dental radiography dose reductions are possible with film-screen systems (speed class 400) without impairing diagnostic accuracy. The introduction of newly developed film-screen systems (speed class 400) requires lower milliampere-seconds and therefore an adjustment of the x-ray units to lower milliampere settings.

Recommendations on the Use of X-Ray Film in Domestic Medical Practice

A broad range of X-ray films is available on the Russian medical market. It includes the best films of foreign manufacture supplied together with special intensifying screens, automatic equipment for photochemical processing providing optimal modes of X-ray film development, and photochemical reagents. However, in domestic practice X-ray films of foreign manufacture are usually used in combination with intensifying screens of domestic manufacture and are processed using domestic processing equipment and reagents. X-Ray films are often overexposed and the time of development is selected incorrectly. Thus, the problem of optimal use of X-ray films of foreign manufacture is very important. The goal of this work was to suggest recommendations for manual processing of X-ray films of foreign manufacture using reagents of domestic manufacture. Consideration is restricted to blue-sensitive films, because green-sensitive films are still not widely used in domestic practice. The main characteristics of X-ray films determining the quality of images are considered below. Methods for measurement of these parameters are considered in detail in [1].

Evaluation of XD/A Plus and ST8G films for cephalometric radiography with Grenex G8 and BH-III screens

Objectives. Sensitometric properties, clinical image quality, and patient dose requirements are important considerations when selecting film for cephalometrics. Two recently released films, XD/A Plus and ST 8G green sensitive films, were studied. Methods. The films were each combined with Grenex G8 (Fuji Medical) green-fluorescing matched and BH-III (Kasei Optonix) blue-fluorescing mismatched intensifying screens. The density response and resolution for each screen-film combination were evaluated by use of the characteristic curve and modulation transfer function. The kilovoltage settings providing clinically acceptable images were assessed individually by 12 observers. Clinically acceptable images for each combination were also compared, and the skin entrance doses in the temporomandibular joint region were determined. Results. The average contrast at the most effective density range was found to be slightly higher for the BH-III group than for the G8 group. The modulation transfer function for the BH-III group was inferior to that for the G8 screens. There were no significant differences in diagnostically acceptable image quality among the four combinations; nevertheless the BH-III screen group required two to three times more exposure than the G8 screen group. Conclusions. XD/A Plus and ST8G films provide acceptable image detail for cephalometrics. To minimize the patient dose they should be used with green-emitting screens.

A rare earth screen‐film system for dental panoramic radiography

Abstract— The use of rare earth intensifying screens and green sensitive film can contribute substantially to radiation reduction in dental panoramic tomography without loss of image quality. Reduced radiation output means a shorter cooling period for the X‐ray tube between exposures. Thus the equipment can be used more efficiently and it can also be expected that the tube life will be increased.

New intensifying screens in clinical radiology. II. Examinations in clinical practice

A clinically applicable procedure for testing new intensifying rare earth screens, as well as the special Siemens' screen is described. The results are related to universal screens. The film-screen combination alpha 4XD (gadolinium oxysulphide with normal, green sensitive film) results in a reduction of radiation dose to half with detail comparable with universal screens. The Siemens' special screen has similar advantages. Screens with a higher intensification factor and reduction of the mAs to one sixth results in loss of detail. This does not necessarily reduce their clinical use if they are used for appropriate purposes. The results of this clinically orientated technique agreed well with physically objective methods using lead grids. The advantages of the new screens are discussed in terms of their practical application.

Letter: Evaluation of a new screen/film combination.

Evans et al. (1975) have investigated the Trimax system of rare-earth screens and green-sensitive films by measuring relative sensitivities, γ values and “contrast transfer functions”. Their main conclusion is that “The Trimax system offers the possibility of reducing exposures for the majority of diagnostic X-ray examinations by factors of about 4 without a reduction in the quality of the image” (my italics).