Lanex Regular Screens Research Articles

Ceramic scintillator-coupled linear array PIN photodiode for X-ray scanner

In order to design the full system of dual-energy X-ray scanner, each component of the system has been fabricated and tested. The high-energy X-ray detector modules used a ceramic scintillator of Eu 3+-doped (Gd,Y) 2O 3, manufactured using Glycine Nitrate Process (GNP). This was coupled to a 16-channel linear array PIN-type photodiode. The low-energy module was a commercially available Lanex Regular screen that was also coupled to a 16-channel linear array PIN-type photodiode. The 16-channel linear array PIN-type photodiode of 1.5 mm×3.2 mm was fabricated in the process of Electronics and Telecommunications Research Institute (ETRI). With a data acquisition system, signal-to-noise ratio was measured at low X-ray energy and low photon flux to evaluate each scintillator-coupled detector module. Through the experiment results and analysis, we inspected each component of the system as a dual-energy single-exposure X-ray scanner.

Image layer characteristics of the PC 1000 (mark II)

The objective of this study was to investigate empirically the image layer characteristics of the PC 1000 Mark II. Radiographs were taken of a lead resolution grid positioned at 1 mm increments along angular intervals of the projected x-ray beam. The receptor was T-Mat G film combined with Lanex Regular Screens. The path of the effective rotation center was determined using a film positioned horizontally at right angles to the slit beam. The vertical magnification factor, horizontal magnification and Distortion Index, corrected for the position of the tomographic layer, were calculated using a reference object placed at various resolution limits of the image layer. The beam projection angle was compared to the average dental arch shape and proximal contact angle.

Film-screen systems: Sensitometric comparison of Kodak Ektavision system to Kodak T-Mat/RA system

Background. In 1995, Eastman Kodak Company (Rochester, N.Y.) marketed the Ektavision Extraoral Imaging Film and Screen System. It produced high-resolution images by keeping the light emitted by intensifying screens from “punching through” one emulsion layer on the film to another. Objectives. The objectives of the experiment were (1) to compare the sensitometric properties of the Ektavision system to its predecessor, the T-Mat/RA system and (2) to determine whether films and screens of the Ektavision and the T-Mat/RA systems could be interchanged without clinically changing the sensitometric properties. Ektavision and Lanex Regular intensifying screens were used in combination with Ektavision, T-Mat G/RA, T-Mat L/RA, and T-Mat H/RA films. Results. The results showed that the Ektavision film was slightly slower than the T-Mat G/RA film no matter what type of screen was used. The type of screen used had little effect on inherent contrast or exposure latitude. The Ektavision film had approximately similar inherent contrast as the T-Mat G/RA film but less than that of the T-Mat H/RA film; its latitude was less than that of the T-Mat L/RA film. The manufacturer does not recommend combining T-Mat/RA film with Ektavision screens or Lanex Regular screens with Ektavision film because of a possible reduction in image resolution. But this mismatch did not clinically affect inherent contrast and exposure latitude; however, film speed was slightly affected. Conclusions. The Ektavision system is the result of advanced technology that produces images of high resolution. The high-resolution Ektavision film is slightly slower than the T-Mat G/RA film but is equivalent to it in its contrast and latitude. Therefore when changing from the combination of T-Mat/RA film plus Lanex Regular screens to that of Ektavision film plus Ektavision screens, a slight increase in x-radiation exposure should be made.

Observer performance comparison of digital radiograph systems for stereotactic breast needle biopsy

Two digital radiograph systems for stereotactic mammography, one using a lens to couple a Lanex Regular screen to a back-illuminated charge-coupled device (CCD) and one using a fiber-optic taper to couple a Min-R Regular-type screen to a front-illuminated CCD, were evaluated with respect to observer performance. A contrast-detail phantom was imaged in a variety of equivalent exposure conditions on both systems. Six observers viewed images on a video monitor and recorded which objects were detected. Performance (percent correct detections) with the lens-coupled system using the Lanex Regular screen was significantly higher than with the fiber-optic-coupled system using the Min-R Regular-type screen. Differences in absorption efficiencies of phosphors used, as well as differences in design of the two cameras, can explain differences in observer detection performance.

Visualization of basal pleural space and lung with advanced multiple beam equalization radiography (AMBER)

During clinical use of AMBER (Advanced Multiple Beam Equalization Radiography) it was frequently felt that the basal lung and pleural space were better appreciated than with standard chest radiography. We aimed to quantify the amount of additional relevant anatomy seen in this part region and to review the normal radiographic anatomy. Four hundred patients without known chest disease were evaluated. Two groups of 200 patients (50% female) were studied with either AMBER or standard chest radiography (140 kVp, 180 cm FFD, Kodak Tmat G film, Lanex regular screen; for both techniques). Visualization of the pleural sinuses (in percent of the transverse thoracic diameter) and the basal pulmonary vessels (4-point scale) was evaluated by a panel of 3 radiologists. The shape of the sinus was traced if sufficiently visible and subjectively evaluated. A significantly ( P<0.05 larger segment of the dorsal (41 ± 34%) and ventral (14 ± 15%) sinuses was seen with the AMBER technique than with the standard technique (16 ± 21% and 9 ± 11%, respectively). Vessel visibility was also significantly ( P<0.001) better with AMBER (3.2 ± 0.6) than with the standard technique (1.9 ± 0.6). The dorsal sinus showed alternatively a curved or pointed configuration.

A comparison of two different T-grain films in rare-earth screens with a standard film–screen combination for intravenous pyelography and bone examinations

T-grain film is claimed to give significantly improved image quality, allowing the use of faster screens without loss of quality and thus reducing radiation dose. We tested this claim for two systems. In each case comparison was made with our usual screen-film combination, Agfa Curix RP1 film with Kodak Xomatic Regular screens (a nominally 200 speed system). The systems tested were Kodak TMatG in Kodak Lanex Medium screens (300 speed) and Agfa STG in Kodak Lanex Regular screens (400 speed). The Agfa STG-Lanex Regular system performed less well than the standard system for intravenous pyelograms (IVPs), bones and soft-tissue detail. Its speed advantage was not apparent below 70 kV. The Kodak TMatG-Lanex Medium system was better than the standard system for IVPs but not as good for bones. It gave virtually no speed advantage below 90 kV. Kodak T-grain film in a medium-speed, rare-earth screen was found to be better than the standard system for IVPs. Agfa T-grain film in a fast rare-earth screen was unsatisfactory for IVPs. Neither combination was as good as the standard system for bones.

Reduction of radiation dose in radiologic examination of patients with scoliosis.

In an attempt to reduce the radiation dose during the examination of scoliotic patients, several screen-film combinations have been compared with a conventional system used at present. Kodak's Lanex Regular screen with Kodak Ortho H film enables the dose to be reduced eight times without significant deterioration of the image quality. The dose to the mammary glands can be reduced further by a factor of five if posterior--anterior instead of anterior--posterior projection is used.