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

Digital Paper Prints as Replacement for LASER Films: A Study of Intra-Observer Agreement for Wrist Radiographic Findings in Rickets

INTRODUCTION

Replacement of conventional LASER films with digital paper prints as supplement to radiology reports may serve as an economical and environment friendly method. However, it is essential that such a change does not compromise patient's intended diagnostic outcome.

AIM

The aim of this study was to assess the reliability and acceptability of digital paper prints for the radiographic images by the treating physicians and radiologists.

MATERIALS AND METHODS

This observational analytical study was done at a tertiary care hospital of New Delhi, India. A total of 58 consecutively ordered wrist radiographs of paediatric patients (6 months to 12 years of age) for ruling out rickets were retrieved from the PACS (Picture Archiving and Communication System). These 58 radiographs, out of which 21 (36.2%) had radiological evidence of rickets over PACS were printed on two different media i.e., LASER films and glossy photographic paper. An objective scoring for the severity of rickets was done on both LASER films and paper prints by six observers independently. Overall comfort level with paper prints was rated on a 1-5 point Likert scale. Data was analysed using STATA 14.0 (Stata Corp, College Station, TX).

RESULTS

Intra-observer percentage agreement and value of Cohen's kappa for PACS vs. LASER films and PACS vs. paper prints was equal i.e., 98.3% and 0.97, respectively. Intra-observer agreement between LASER films and paper prints for all six observers was excellent, ranging from 0.92 to 1.00; percentage agreement ranging from 94.8% to 100%. Fracture of ulna/radius present in 4 sets of the X-rays was well demonstrated in both LASER films and paper prints. Comfort level with paper prints was rated as 5 out of 5 by all due to no requirement of any special illuminated view box and dark room.

CONCLUSION

This study concludes that the use of paper prints may serve as a reliable alternative to LASER films to communicate the report of wrist radiographs for the treating physicians without any compromise over diagnostic information in cases of rickets.

Can paper replace laser film to communicate the results of wrist radiographs in trauma cases? A reproducibility study of the reading of wrist trauma case radiographs on a PACS workstation, laser film, and paper

The main goal of this study was to determine the reproducibility of the reading of wrist trauma case radiographs using three different media: laser film, a picture archiving and communication systems (PACS) workstation, and paper with an optimized layout. The study was conducted retrospectively in 200 consecutive patients consulting at the emergency department for wrist trauma and who underwent wrist X-ray investigation using a computed radiography system. There were 82 men and 118 women. The mean age was 48.3 years (16-95 years). Our institutional review board does not require patient approval or informed consent for retrospective review of case records. The readings were made by two independent readers who analyzed the 200 patient radiographs consecutively in one session for each type of media: paper, laser film, and on a PACS dual-screen workstation. The inter-reader agreements were substantial or almost perfect, with kappa values of 0.83 (0.76-0.90) for the PACS, 0.83 (0.76-0.90) for film, and 0.80 (0.72-0.87) for paper. The inter-technique agreement was almost perfect in all cases. There is a high interobserver agreement between PACS, laser film, and paper readings for wrist trauma cases. With a layout of one radiograph on each sheet, paper could replace laser films to communicate the results of wrist radiographs in trauma cases for outpatients.

Ink-jet printout of radiographs on transparent film and glossy paper versus monitor display: an ROC analysis

The aim of this study was to compare the depiction ability of small grayscale contrasts in ink-jet printouts of digital radiographs on different print media with CRT monitor. A CCD-based digital cephalometric image of a stepless aluminum wedge containing 50 bur holes of different depth was cut into 100 isometric images. Each image was printed on glossy paper and on transparent film by means of a high-resolution desktop inkjet printer at specific settings. The printed images were viewed under standardized conditions, and the perceptibility of the bur holes was evaluated and compared to the perceptibility on a 17-in CRT monitor. Thirty observers stated their blinded decision on a five-point confidence scale. Areas (Az) under receiver operating characteristics curves were calculated and compared using the pair wise sign tests. Overall agreement was estimated using Cohen's kappa device and observer bias using McNemar's test. Glossy paper prints and monitor display revealed significantly higher (P < 0.001) average Az values (0.83) compared to prints on transparent film (0.79), which was caused by higher sensitivity. Specificity was similar for all modalities. The sensitivity was dependent on the mean gray scale values for the transparent film.

Comparison of paper print and soft copy reading in plain paediatric radiographs

With the introduction of a Picture Archiving and Communication System, Computed (CR) and Digital Radiography (DR), reading digital images takes place from a computer screen. Laser paper print rather than laser film would be a significantly more cost-effective option for hard copy production, but would need to demonstrate acceptable diagnostic quality compared to the reference standard of screen reading. A comparative study of 51 digital paediatric CR radiographs presented in laser paper print and soft copy format to determine the diagnostic value of the paper print when compared to the reference standard of screen reading. Chest radiography had a poor sensitivity of 66.1% while musculoskeletal and abdominal radiography had acceptable sensitivities of 90% and 99%, respectively. Specificity was excellent for the different regions (98.6-99.5%). The paper print format should not be used for diagnostic purposes in paediatric chest radiography, but may still be used for demonstration when accompanied by the radiology rapport obtained from soft copy reading. Further studies would be needed to investigate the use of paper prints in abdominal and musculoskeletal radiography owing to the low number of abdominal radiographs and lack of musculoskeletal case variety in our study.

Image quality of film transparency printer output of digital dental radiographs

OBJECTIVE

The purpose of this study was to evaluate the physical properties of the film transparency output of a printer and its potential use in dental radiography.

STUDY DESIGN

A color printer (Sony UP-D70XR) was used to produce film transparencies of digital radiographs. A physical evaluation for the image quality was conducted including measurements of the image density reproducibility, the dose response function, the root mean square (RMS) granularity and the modulation transfer function (MTF).

RESULTS

The characteristic curve of the hard copy image produced a nonlinear, sigmoid response for pixel value or x-ray absorbed dose. The RMS of the scan parallel direction was greater than that of the scan perpendicular direction in low density areas, but it reversed beyond density 1.3. The MTF of the scan perpendicular direction was superior to that of the scan parallel direction.

CONCLUSION

It was suggested that further examination of the image qualities of this printer is worthwhile.

Assessing the accuracy of caries diagnosis via radiograph

BACKGROUND

The authors conducted this study to determine if proximal caries diagnoses made using bitewing radiographic images printed on photographic paper were comparable with diagnoses made using traditional radiographic film images.

METHODS

The authors digitized 15 posterior bitewing radiographs that contained 74 carious and 127 sound unrestored proximal surfaces and printed them on photographic paper. Fourteen dentists evaluated the radiographs and two printed image formats (4 x 3 centimeters and 8 x 6 cm) for evidence of caries. The diagnostic accuracy and interobserver agreement for caries diagnoses obtained in the two printed image formats were compared with those for radiographic film images.

RESULTS

Overall, the diagnostic accuracy of printed images did not differ significantly from radiographic film images for dentinal caries. However, for caries limited to the enamel surface, a decrease in sensitivity was noted in six of the 14 observers for the smaller print images, while no significant differences in the diagnoses of enamel caries were observed among any of the observers in the enlarged print format.

CONCLUSION

This study provides evidence that printed images can be used to diagnose dental caries reliably.

CLINICAL IMPLICATIONS

The results of this study indicate that the diagnostic information obtained by viewing printed images is equivalent to that obtained by viewing standard radiographs. Size of the printed image also may be important in caries diagnosis and care must be taken to print bitewing radiographic images at a size that optimizes interpretation. Other factors that must be considered are the type of printer, printer resolution, paper quality and type of ink used. With careful consideration of printing parameters, clinicians can be assured of diagnostic quality in printed images.

Accuracy of digital panoramic images displayed on monitor, glossy paper, and film for assessment of mandibular third molars

OBJECTIVE

The aim of this study was to compare the accuracy of 3 modalities of digital panoramic radiographs-monitor-displayed images and printed copies on glossy paper and on blue transparent film-for assessment of position and morphology of mandibular third molars.

STUDY DESIGN

164 third molars were recorded with one of 2 digital panoramic systems (Digora and Orthophos Plus) and assessed by 4 observers on 3 radiographic modalities: monitor display, glossy paper, and transparent film. The assessments were compared with surgeons' findings at the time of the operation ("gold standard").

RESULTS

Overall, the observer variation was larger than the variation between methods. A detailed paired analysis revealed some differences between the modalities for some diagnostic categories, but these were few and inconsistent.

CONCLUSION

Printed images from the Kodak 1200 ink-jet printer on glossy paper and blue transparent film may be as accurate as the original monitor-displayed digital panoramic images from the Digora and Orthophos Plus systems for assessment of position and morphology of mandibular third molars.

Using Receiver Operating Characteristic Methodology to Evaluate the Diagnostic Quality of Radiography on Paper Prints Versus Film

OBJECTIVE

The aim of this study was to compare the diagnostic quality of paper prints with film copies in a sample of observers who were trying to detect small coin lesions on radiographs of a phantom.

MATERIALS AND METHODS

The phantom consisted of 60 high-contrast and 60 low-contrast test objects, half of which had holes in them. Diameter and depth of the holes varied from 0.5 mm to 2 mm. Fifteen radiographs were obtained from different areas of the test objects. Film copies and paper prints were made using high-quality printers. Five observers independently evaluated 1,800 high-contrast and 1,800 low-contrast images. Data were evaluated using the well-established receiver operating characteristic methodology.

RESULTS

The mean area under the curve rated 0.863 for paper prints (0.859 for high contrast and 0.860 for low contrast) and 0.926 for laser films (0.937 for high contrast and 0.913 for low contrast). The difference between the two imaging techniques was statistically significant for both high- and low-contrast lesions (p < 0.05).

CONCLUSION

Detection of small coin lesions on radiographs of a phantom was significantly less sensitive on paper prints than on film. We found paper prints less acceptable for the diagnosis of small-sized lesions.