An evaluation of line quality in photocopied signatures

Qualified forensic document examiners from Canada, USA, Great Britain and Australia participated in this study. They were sent one photocopied signature, together with a set of original known standards to evaluate the line quality of the photocopied signature and compare these characteristics with the standards. They were asked to assess the photocopies for the presence of tremor, hesitation, pen lifts, patching, blunt initial or terminal strokes, and abrupt changes in direction. The authors compared the assessments with the corresponding original signatures. It was possible to determine which line quality characteristics were the most difficult to detect, which indicia of simulation were concealed and what anomalies were introduced by the photocopying process. Results indicated that line quality characteristics can be identified in average quality photocopies. Furthermore, accurate judgements can be made regarding similarities and differences in line quality when comparing a photocopied signature with original known standards. In a few instances, ink line morphology was problematic when striation patterns and ink gooping were misinterpreted as pen lifts, hesitation and patching on the photocopies.

Reproduction of radiologic images on plain paper

Skyrocketing health care costs and pressures from managed care have combined to promote cost-cutting strategies in radiology and radiation oncology departments. A study was conducted to evaluate the use of a high-resolution laser printer for printing plain-paper images as substitutes for both original and duplicate radiologic film images. A variety of radiologic images were used to evaluate the image reproduction capabilities of the printer in terms of linearity, detail, and contrast. In many cases, printed images had a quality comparable to that of the original images. Six computed tomographic (CT) scans and six radiation therapy simulator radiographs were compared with printed reproductions by each of seven board-certified radiation oncologists, who rated the reproductions as acceptable for documentation, acceptable for diagnostic purposes (CT scans only), or unacceptable. Ninety-five percent of printed CT images and 90% of printed simulation images were rated acceptable for documentation. The quality of printed images of radiation therapy port films was not quantitatively measured but was improved by adjusting image contrast and brightness and using various image enhancement techniques. The use of printed images is less expensive than that of processed film and eliminates the environmental, time, storage, and delivery problems associated with film. Technologic advances in imaging, networking, and printing have made possible the inexpensive duplication of medical images.

Computer-printer denture microlabeling system

This procedure is easy to use and is cost-effective because it uses equipment that exist in any office or institution. The material used, transparency film for use with plain paper copier, is less expensive than either photographic slide film or normal slide films. Moreover, the transparency sheet can be used again for photocopying until the sheet is fully used up. There is no added cost of development of film, or is it necessary to wait for the whole roll of film to be used before the label can be retrieved and used. The background of the label is clear and only the black images of the characters of the label can be clearly seen. The effect of the transparency film, photocopy ink, and adhesive glue is not known. But no adverse effects have been noted. Microlabels have advantages over conventional labels with characters in font size 8 to 12, because more information, such as the full name of the patient, sex, country of origin, and national identification number can be incorporated. With more detailed information, quick identification of a deceased person can be made. Microlabels with a clear background will have minimal esthetic impact on the patient. The disadvantages of the technique is that it may not withstand a fire. In situations where the deceased body is badly burned, the denture and its identification strip may be burned, too. However, this risk can be minimized by placing the strip in the most posterior part of the denture-palatal in the maxillary denture and distal lingual in the mandibular denture. For testing of durability, dentures with the labels were placed in water for up to 4 months. The labels showed no sign of fading or deterioration.

[Choice of electron equipment for x-ray diagnostic digital scanning system]

The paper deals with the choice of electron equipment for X-ray diagnostic devices with digital image processing which are intended for population-based mass prophylactic examinations of lung. Guidelines for the optimization of the package of electron devices for processing and storing of data and for obtaining hard copies of X-ray films.

Manual and computer-aided space analysis: a comparative study

Recently, computers have been used to measure key landmarks from photocopies of upper and lower study models to increase simplicity, accuracy, and informatics. This is a comparative study to evaluate the accuracy and reliability of computer-aided space analysis. Data were collected from a series of randomly selected study models. All subjects had Angle Class I molar relationships with minor malocclusions such as crowding, rotations, or diastemas. Two investigators independently measured teeth on models with a Vernier gauge that had sharpened caliper tips. Intraexaminer and interexaminer reliability was determined at 0.2 mm. All teeth, to and including the first molars, were measured. Two photocopies of each set of models were made on a photostat machine (Xerox, Japan) and were coded. A template with a ruler was used, to allow the investigator to compensate for any reduction or enlargement error during the photocopying process. The mesiodistal sizes were measured with a digitizer, and results were processed by using a dedicated computer program. Evaluations were done in a double-blind manner. The nonparametric Wilcoxon signed rank test for paired observations to compare median differences between measurements was used. Intraexaminer digitized measurements were almost identical and differed (p < 0.0001) for only one measurement. However, interexaminer manual and digitized measurements differed significantly (p < 0.001) for 20 of the 24 teeth. Nineteen of these digitized tooth measurements were smaller. The mean arch length measurements differed by 4.7 mm (p < 0.0001) in the maxilla and by 3.1 mm (p < 0.0001) in the mandible. The difference between the manual and digitized analyses may be due to the photocopying process. The inability to accurately measure a three-dimensional study cast that has been duplicated in two dimensions, convex structure of teeth, curve of Spee, tooth inclination, and tooth position may play a role. The computer-aided measuring system is reliable, but accurate mesiodistal measurements cannot be made from photocopies of dental models. Manual measurements that use a calibrated gauge produce the most accurate, reliable, and reproducible results.

Polaroid photography as an alternative method of recording clinical material in plastic surgery

Polaroid photography has been used as a method for assessing and recording certain plastic surgery cases. It has the advantage of being easily and immediately available. Photocopies, in black and white or in colour, can be obtained and can be enlarged. Either the originals or photocopies can be sent to clinicians for rapid appraisal or for their own records. This technique is useful whether silhouette or contrast changes are important, and it allows immediate presentation to the patient for discussion and illustration. Several clinical pre- and post-operative examples demonstrating these facts are given in photographic form. The possible advantages of using Polaroid cameras, which rival the quality and cost of conventional photography, are raised.

Value of intraoperative image intensifier prints in trauma surgery

We have studied the use of image intensification in a trauma theatre over a period of 6 months with particular reference to the acquisition of intraoperative image intensifier thermal prints instead of formal radiographs. The quality of the prints and the savings generated have been assessed. During the study period, 476 patients underwent orthopaedic trauma procedures. The image intensifier was used for intraoperative screening in 280 patients. In 278 of these a thermal print was obtained. This was used, instead of formal check radiographs, to plan further management in 210 patients (75%). In 68 patients, the printout was insufficient in its coverage of the operated area, and a check radiograph was also obtained. In no case did the clarity of the thermal image hinder accurate interpretation. We believe that thermal images are a useful substitute for formal postoperative radiographs in many trauma cases, and that, with notable exceptions, their use could decrease costs, reduce patient discomfort and radiation dose and spare overloaded radiology services.

Maintaining confidentiality: health care's ongoing dilemma

Confidentiality of patient information is an ethical obligation of health care professionals. The exercise of confidentiality is not a simple process; it is dynamic rather than static and must be upgraded with changes in technology. This article discusses some of the common issues that arise in maintaining confidentiality in the health care environment, including spoken and written breaches of confidentiality, use of the computer, confidentiality as an ethical rather than legal obligation, and the use of programs in health care institutions to maintain confidentiality.

The gray-scale ink-jet printer: value in making hard copies of digital images

Referring physicians often are supplied with copies of images to illustrate a report of the findings of a radiologic study or so that the radiologist can retain the original images. The increasing costs of production, film, and recovery of chemicals have enhanced the requirement for a clean, low-cost dry printing process. An ink-jet gray-scale paper printer (Unitone, Scitex Medical Systems, Bedford, MA) can print high-quality (300 dots per inch [dpi]) images with an effective 10-bit gray scale range by using the Hertz continuous ink-jet method [1-3], which does not require the use of a darkroom or hazardous chemicals. Several types of media (matte paper, glossy paper, transparency film) with a printing area of 26.9 x 43.7 cm (10.6 x 17.4 inches) may be used. The consumables are approximately 50-70% less expensive than the cost of silver halide film, providing a cost advantage over film for referral and archival copies. The results of an initial evaluation of the ink-jet printer at our institution are reported here.

Development of a digital duplication system for portable chest radiographs

To provide high-quality duplicate chest images for the intensive care units, we have developed a digital duplication system in which film digitization is performed in conjunction with nonlinear density correction, contrast adjustment, and unsharp mask filtering. This system provides consistent image densities over a wide exposure range and enhancement of structures in the mediastinum and upper abdominal areas, improving visibility of catheters and tubes. The image quality is often superior to that of the original radiograph and is more consistent from day to day. Repeat rates for portable chest radiographs have been reduced by more than a factor of two since implementation of digitization in December 1991, and the number of repeat examinations caused by exposure errors have been substantially reduced.

Evaluation of the image quality of ink-jet printed paper copies of digital chest radiographs as compared with film: a receiver operating characteristic study

Paper copies of digital radiographs printed with the continuous ink-jet technique have proved to be of a high enough quality for demonstration purposes. We present a study on the image quality of ink-jet printed paper copies of digital chest radiographs, based on receiver operating characteristic (ROC) analysis. Eighty-three digital radiographs of a chest phantom with simulated tumors in the mediastinum and right lung, derived from a computed radiography (CR) system were presented in two series of hard copies as ink-jet printed paper copies and as laser recorded film. The images, with a matrix of 1,760 x 2,140 pixels, were printed with a spatial resolution of 10 pixels/mm in the CR film recorder as well as in the ink-jet printer. On film, every image was recorded in two versions, one optimized for the mediastinum and one for the lungs. On paper, only one image was printed; this constituted an effort to optimize both the mediastinum and the lungs. The ink-jet printed images, printed on a matt coated paper, were viewed as on-sight images with reflected light. The examinations were reviewed by six radiologists, and ROC curves were constructed. No significant difference was found between the performance of film and that of ink-jet paper prints. Because the cost for a paper copy is only a tenth of that of film, remarkable cost reductions can be achieved by using the ink jet technique instead. Our results show that further quality studies of ink-jet printed images are worthwhile.

[Use of color photocopying machine in the reproduction of images in surgery]

Diagnostic imaging is becoming more and more important and effective in modern medicine. The author describes a quick, inexpensive and simple technique suitable for reproducing immediately colour images of surgical specimens (recovered from the operating room) by means of a colour photocopying machine. Untrained people too are able to run this method that allows the production of well defined images helpful for a closer and more careful real time communication between the surgeon and the pathologist. This document can also be part of the patient's record, and it's useful for the discussion with other physicians involved in diagnostic or therapeutic procedures. The method saves the specimen from every injury and allows its investigation by the pathologist.

ELF magnetic field exposures in an office environment

Potential exposures to extremely low frequency (ELF) magnetic fields were investigated in response to worker concerns about an apparent increased spontaneous abortion risk in a payroll office environment. Concern in this office centered on the use of video display terminals (VDTs), which have been investigated as a potential cause of adverse reproductive outcomes among women. In this investigation, magnetic field sources were evaluated using a hand-held survey meter. Emdex datalogging dosimeters were also used to determine full shift personal exposures for 15 women working in the payroll area. On average, the exposures of workers to ELF magnetic fields in the payroll office area ranged from 1.0 to 6.5 mG with a mean of 3.2 +/- 1.5 mG. The results of this study indicate that many sources of ELF magnetic fields, including printers, photocopiers, and the electrical distribution system, can contribute to a worker's exposure in an office environment.