e-Derma - a Novel Wireless Dermatoscopy System.

Cutaneous Melanoma (CM) is a malignant tumour, and is one of the most rapidly growing cancers. Discovering a melanoma in the early stages of the disease is extremely difficult and, as such, only an invasive disease stage can be identified easily with the naked eye. Dermatoscopy is a diagnostic method intended to maximise early detection of CM performed by the dermatoscopy system. To address the limitations of existing systems a novel, wireless digital dermatoscopy system is presented for providing high-resolution images. It integrates a wire-free camera operation and offers a safe transfer of captured images to the computer. The working process of available dermatoscopy systems was studied, which are the most commonly used in everyday dermatology practice. Some findings, like operability, image quality, scalability, user-friendliness, and safeness, were used for the development of an e-Derma dermatoscopy system. An assessment method was performed by a group of dermatoscopy trained dermatologists to evaluate the quality of the testing images. Finally, a laboratory evaluation of images in regard to different parameters like sharpness, colour representation and illumination was performed with the side-by-side comparison of images of available dermatoscopy systems. e-Derma is a novel dermatoscopy system, which eliminates some limitations of existing systems and provides high-quality images. A novel low-budget highly capable dermatoscopy system is presented. The integrated wireless image transfer technology eliminates the movement limitations of a therapist. The image resolution is not limited by the integrated camera; it is easily upgradable with a wide range of on market alternative or improved camera models.

Using light sensitometry to evaluate mammography film performance.

The performance of commercially available light sensitometers was compared with two other methods of x-ray sensitometry to determine whether commercially available sensitometers are viable for evaluating clinical performance of mammography film. X-ray sensitometry was performed using mammography screens that were modified to accommodate a graded optical step tablet (screen sensitometry). Finally, a means for performing intensity-scale x-ray sensitometry was configured (inverse-square sensitometry). Clinical mammography x-ray exposure conditions were used and film processing quality was closely monitored during the study. Statistical results for chi-square probabilities on the resulting contrast curves yielded good agreement for most of the configurations investigated. Comparison of film gradient versus optical density curves showed good agreement for maximum contrast values and the corresponding optical density for maximum contrast for three of the four screen-film combinations used when comparing light sensitometry to screen sensitometry. A similar comparison of light sensitometers to inverse-square sensitometry showed good agreement for maximum contrast, but less agreement for the corresponding optical density of maximum contrast. Based on these results, the authors concluded that commercially available sensitometers could be used to estimate clinical film performance for the screen-film systems tested. In particular they can be used to determine the range of optical densities that provide optimal film contrast.

Radiographic trends of dental offices and dental schools.

BACKGROUND: A survey of private practice facilities in the United States that perform dental radiography was conducted in 1993 and repeated in dental schools in 1995-1996. METHODS: Both surveys were conducted as part of the Nationwide Evaluation of X-ray Trends, or NEXT, survey program. A representative sample of dental facilities from each participating state were surveyed, and data on patient radiation exposure, radiographic technique, film-image quality, film-processing quality and darkroom fog were collected. RESULTS: The authors found that dental schools use E-speed film more frequently than do private practice facilities. The use of E-speed film and better film processing by dental schools resulted in lower patient radiation exposures without sacrificing image quality. The authors also found that dental school darkrooms had lower ambient fog levels than did those of private practice facilities. CONCLUSIONS: The distribution for the 1993 NEXT survey facilities was greater than that observed for dental schools for radiation exposure, film-processing quality and darkroom fog. Dental schools, in general, had better film quality and lower radiation exposures than did private practice facilities. PRACTICE IMPLICATIONS: Facilities need to emphasize better quality processing and the use of E-speed film to reduce patient exposure and improve image quality.

Mammography in the 1990s: the United States and Canada.

PURPOSE: To evaluate trends in mammography quality before and after the implementation of the Mammography Quality Standards Act (MQSA) of 1992 and to compare technical data collected in the United States with corresponding data obtained from the first survey of mammography facilities conducted in 1994-1995 in Canada. MATERIALS AND METHODS: Data from MQSA inspections conducted in 1995-1997 were analyzed and compared with survey data on U.S. mammography facilities acquired before the MQSA. Technical indicators of mammography quality such as radiation dose phantom image score, film processing, and darkroom fog were analyzed. RESULTS: In the United States, phantom image scores, along with other technical measures of performance such as film processing, darkroom fog, and x-ray beam quality, have improved continuously since 1985. The U.S. mean glandular dose has increased to 1.6 mGy compared with the Canadian dose of 1.1 mGy. The mean total phantom image score with artifact subtraction was 11.1 in Canada in 1994-1995 and 11.8 in the U.S. in 1997. CONCLUSION: Mammography quality is better today than it has been at any other time in the United States. With the exception of radiation dose. Canadian technical measures of performance are comparable to measures before MQSA in the United States.

Patient dosimetry activities in the United States: the nationwide evaluation of X-ray trends (NEXT) and tissue dose handbooks.

In the United States the Food and Drug Administration (FDA) in collaboration with the Conference of Radiation Control Program Directors (CRCPD) and state and local government agencies surveys clinical facilities about X-ray system air kerma and ancillary data related to patient dosimetry for a variety of diagnostic X-ray examinations. The survey program is known as the Nationwide Evaluation of X-ray Trends (NEXT). The survey utilizes reference patient-equivalent phantoms in the collection of comprehensive technical information. With knowledge of the skin-entrance air kerma, specific tissue doses can be calculated. An overview of NEXT and previously published FDA tissue dose handbooks for diagnostic X-ray examinations is presented.

Nationwide survey of fluoroscopy: radiation dose and image quality.

PURPOSE: To determine the average abdominal entrance air kerma, low-contrast sensitivity, and spatial resolution in upper gastrointestinal tract fluoroscopy in the United States. MATERIALS AND METHODS: A random sample of fluoroscopic facilities was selected to be surveyed for the Nationwide Evaluation of X-ray Trends program. Measurements were performed by using a newly developed fluoroscopic phantom. The surveys were conducted by state radiation control personnel. RESULTS: Average air kerma rates 1 cm above the tabletop, free in air, were 43 mGy/min (n = 340). The rate increased to 64 mGy/min when a 1.6-mm-thick copper filter, which simulated the use of barium contrast medium, was added to increase attenuation. The average entrance air kerma, free in air, for radiographs was 3.4 mGy, and an average of 12 radiographs were obtained per examination. Of 352 facilities surveyed, 306 (87%) were able to resolve wire mesh with 20 or more lines per inch. Of 339 facilities for which percentage contrast could be calculated, 192 (57%) had minimum percentage contrast values of 4% or more. CONCLUSION: Spatial resolution for fluoroscopy is adequate for most of the facilities surveyed, but a substantial proportion of facilities could not visualize low-contrast test objects, which strongly suggests image quality problems.