Effect of display type and room illuminance in chest radiographs

Tablets as an Option for Telemedicine-Evaluation of Diagnostic Performance and Efficiency in Intracranial Arterial Aneurysm Detection

Purpose: To evaluate a commercially available mobile device for the highly specialized task of detection of intracranial arterial aneurysm in telemedicine. Methods: Six radiologists with three different levels of experience retrospectively interpreted 60 computed tomography (CT) angiographies for the presence of intracranial arterial aneurysm, among them 30 cases with confirmed positive findings. Each radiologist reviewed the angiography datasets twice: once on a dedicated medical-grade workstation and on a commercially available mobile consumer-grade tablet with an interval of 3 months. Diagnostic performance, reading efficiency and subjective scorings including diagnostic confidence were analyzed and compared. Results: Diagnostic performance was comparable on both devices regardless of readers’ experience, and no significant differences in sensitivity (66–87.5%) and specificity (79.4–87%) were found. Results obtained with tablets and medical workstations were also comparable in terms of subjective assessment across all reader groups. Conclusions: There was no significant difference between tablet and workstation readings of angiography datasets for the presence of intracranial arterial aneurysm. Sensitivity, specificity, efficiency and subjective scorings were similar with the two devices for all three reader groups. While medical workstations are 10 times more expensive, tablets allow higher mobility especially for radiologists on call.

Use of ambient lighting during colonoscopy and its effect on adenoma detection rate and eye fatigue: results of a pilot study

Background and study aims  Adenoma detection rate (ADR) appears to decrease as the number of consecutive hours performing procedures increases, and eye strain may be a contributing factor. Ambient light may improve symptoms of eye strain, but its effects have yet to be explored in the field of gastroenterology. We aim to determine if using ambient lighting during screening colonoscopy will maintain ADRs and improve eye strain symptoms compared with low lighting. Methods  At a single center, retrospective data were collected on colonoscopies performed under low lighting and compared to prospective data collected on colonoscopies with ambient lighting. Eye fatigue surveys were completed by gastroenterologists. Satisfaction surveys were completed by physicians and staff. Results  Of 498 low light and 611 ambient light cases, 172 and 220 adenomas were detected, respectively ( P  = 0.611). Under low lighting, the ADR decreased 5.6 % from first to last case of the day ( P  = 0.2658). With ambient lighting, the ADR increased by 2.80 % ( P  = 0.5445). The difference in the overall change in ADR between first and last cases with ambient light versus low light was statistically significant (8.40 % total unit change, P  = 0.01). The average eye strain scores were 8.12 with low light, and 5.63 with ambient light ( P  = 0.3341). Conclusions  Performing screening colonoscopies with ambient light may improve the differential change in ADR that occurs from the beginning to the end of the day. This improvement in ADR may be related to improvement in operator fatigue. The effect of ambient light on eye strain is unclear. Further investigation is warranted on the impact of ambient light on symptoms of eye strain and ADR.

Evaluation of diagnostic accuracy of intracranial aneurysm detection using medical-grade versus commercial consumer-grade displays and different image reconstructions against the background of process optimization for telemedicine

BACKGROUND

Process optimization in computed tomography (CT) and telemedicine.

PURPOSE

To compare image quality and objective diagnostic accuracy of medical-grade and consumer-grade digital displays/computer terminals for detection of intracranial aneurysms.

MATERIAL AND METHODS

Four radiologists with different levels of experience retrospectively read a total of 60 patients including 30 cases of proven therapy-naïve intracranial aneurysm detectable on a medical-grade grayscale calibrated display. They had 5 min per case reading the first 20 datasets using only axial slices, the next 20 patients using axial slices and multiplanar reconstructions (MPRs), and the last 20 patients using axial slices, MPRs, and maximum intensity projections (MIPs). Three months after the first reading session on a medical-grade display, they read all datasets again under the same standardized conditions but on a consumer-grade display. Diagnostic performance, subjective diagnostic confidence, and reading speed were analyzed and compared. Readers rated image quality on a five-point Likert scale.

RESULTS

Diagnostic accuracy did not differ significantly with areas under the curve of 0.717-0.809 for all readers on both display devices. Sensitivity and specificity did not increase significantly when adding MPRs and/or MIPs. Reading speed was similar with both devices. There were no significant differences in subjective image quality scores, and overall inter-reader variability of all subjective parameters correlated positively between the two devices (P <0.001-0.011).

CONCLUSION

Diagnostic accuracy and readers' diagnostic confidence in detecting and ruling out intracranial aneurysm were similar on commercial-grade and medical-grade displays. Additional reconstructions did not increase sensitivity/specificity or reduce the time needed for diagnosis.

Comparing medical grade to commercial grade display in a radiation oncology environment

Electronic displays are used in every modern day medical clinic. They are used to view images that are needed to diagnose, treat, and follow-up on patients with a variety of conditions. The type of electronic display used varies from department to department. Currently, a type of displays called medical grade displays are used to evaluate and diagnose disease and conditions. Alternatively, commercial or entry level professional displays are used for almost everything else. In the field of radiation oncology medical images are often used to plan the treatment course for each patient. These images are always viewed using a commercial grade display. An experiment was completed to examine the role a medical grade display might have in a radiation oncology setting. Our study had certified dosimetrists and radiation oncologists view medical images on both a medical grade and commercial grade display and rank their preference on a scale. The observers assessed the images in different categories (Contrast, resolution, and sharpness) and also commented on their preference. Results indicated that the medical grade display performed better than the commercial grade display in every image quality category.

Is the digital radiographic detection of approximal caries lesions influenced by viewing conditions?

OBJECTIVES

The aim of this study was to assess the influence of different viewing conditions (combinations of computer display, horizontal viewing angle, and ambient lighting) on the detection of approximal caries lesions on digital radiographic images.

STUDY DESIGN

Forty posterior teeth were mounted in a plaster block and radiographed by using a CMOS sensor-based system. Three oral radiologists assessed the radiographic images under different conditions of computer display (iMac 5K 27", Barco MDRC-2124, and Dell P2314H), horizontal viewing angles (90 degrees, 67.5 degrees, and 45 degrees), and ambient lighting (low, medium, and high) and were asked to detect the presence of approximal caries lesions, which were confirmed by means of micro-computed tomography (micro-CT), using a 5-point scale. The area under the receiver operating characteristic curve, sensitivity, and specificity were calculated and compared by analysis of variance testing (α = 0.05). Intra- and interobserver agreements were assessed with the Kappa test.

RESULTS

Computer display, horizontal viewing angle, and ambient lighting did not significantly influence the diagnosis of approximal caries lesions. In general, moderate values of accuracy, low sensitivity, and high specificity were found for all viewing conditions.

CONCLUSIONS

The viewing conditions assessed in this study did not influence the detection of approximal caries lesions on digital radiographic images. Dental practitioners are encouraged to find their most comfortable viewing condition for this diagnostic task.

Influence of interpretation conditions on the subjective differentiation of radiographic contrast of images obtained with a digital intraoral system

OBJECTIVES

The aim of this study was to evaluate interpretation conditions in the subjective in vitro assessment of dental tissue-equivalent radiographic contrast.

STUDY DESIGN

Radiographic images with the density of dental structures were randomized and arranged in 20 sequences with images juxtaposed and separated. Twelve observers interpreted the sequence among the most radiolucent and radiopaque images with 3 displays, 3 horizontal viewing angles, and 3 ambient light conditions. The evaluation time was recorded. The hit percentage was calculated for each evaluation. Three-way analysis of variance with Tukey's test was used to compare the conditions of interpretation. The intraclass correlation coefficient was used to assess agreement (α = 0.05).

RESULTS

No differences in hit percentages were found among the 3 displays or among the juxtaposed and separated images. Increased hit percentages were recorded for images assessed at 90° compared with 45° for all displays and in high ambient light vs intermediate and low light at 90°. Increased evaluation time was recorded for the consumer-grade display under high ambient light and for the separated images.

CONCLUSIONS

The subjective in vitro assessment of dental tissue-equivalent radiographic contrast is not influenced by computer display, which should be viewed at a horizontal viewing angle of 90° and under high ambient light. Longer evaluation times may be expected with consumer-grade displays.

Media messaging in diagnosis of acute CXR pathology: an interobserver study among residents

The objectives of the study were to determine whether diagnostic accuracy and reliability by on-call teams is affected by communicating chest radiograph (CXR) images via instant messaging on smartphones in comparison to viewing on a workstation. 12 residents viewed 100 CXR images each with a 24% positive rate for significant or acute findings sent to their phones via a popular instant messaging application and reported their findings if any. After an interval of 42 days they viewed the original DICOM images on personal computers and again reported their findings. There were no statistically significant differences in accuracy, agreement, sensitivity, specificity, positive predictive value or negative predictive value between desktop workstation viewed images and images sent via the mobile application. Media messaging is a useful adjunct for quick second opinions on radiological images, without significant decay in diagnostic accuracy. If technical, ethical and legal issues are addressed, it could be incorporated into practice as a useful adjunct.

Comparison of medical-grade and calibrated consumer-grade displays for diagnosis of subtle bone fissures

OBJECTIVE

To compare the diagnostic accuracy of medical-grade and calibrated consumer-grade digital displays for the detection of subtle bone fissures.

METHODS

Three experienced radiologists assessed 96 digital radiographs, 40 without and 56 with subtle bone fissures, for the presence or absence of fissures in various bones using one consumer-grade and two medical-grade displays calibrated according to the DICOM-Grayscale Standard Display Function. The reference standard was consensus reading. Subjective image quality was also assessed by the three readers. Statistical analysis was performed using receiver operating characteristic analysis and by calculating the sensitivity, specificity, and Youden's J for each combination of reader and display. Cohen's unweighted kappa was calculated to assess inter-rater agreement. Subjective image quality was compared using the Wilcoxon signed-rank test.

RESULTS

No significant differences were found for the assessment of subjective image quality. Diagnostic performance was similar across all readers and displays, with Youden's J ranging from 0.443 to 0.661. The differences were influenced more by the reader than by the display used for the assessment.

CONCLUSION

No significant differences were found between medical-grade and calibrated consumer-grade displays with regard to their diagnostic performance in assessing subtle bone fissures. Calibrated consumer-grade displays may be sufficient for most radiological examinations.

KEY POINTS

• Diagnostic performance of calibrated consumer-grade displays is comparable to medical-grade displays. • There is no significant difference with regard to subjective image quality. • Use of calibrated consumer-grade displays could cut display costs by 60-80%.