Purpose. Methods and materials

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1 Comparison of consumer grade, tablet and 6MP-displays: observer performance in detection of anatomical and pathological structures in panoramic radiographs Poster No.: B-1190 Congress: ECR 2015 Type: Scientific Paper Authors: S. Kallio-Pulkkinen 1, M. Haapea 1, E. Liukkonen 1, S. Huumonen 2, Keywords: DOI: O. Tervonen 1, M. T. Nieminen 1 ; 1 Oulu/FI, 2 Turku/FI Computer applications, Head and neck, Conventional radiography, Observer performance, Infection, Cysts /ecr2015/B-1190 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 12

2 Purpose To compare observer performance in detecting anatomical structures and pathology in panoramic radiographs using a consumer grade display (CG) and tablet (3 rd generation ipad) under suboptimal, with reference to 6 MegaPixels display (6MP) under dim-lighting conditions. Methods and materials Thirty panoramic radiographs were selected by standard criteria, i.e., the structures to be evaluated had to be clearly visible. An oral and maxillofacial radiologist who did not participate in the evaluation selected retrospectively images taken during a three-month period. All images were subjected to routine quality standards and exposure, and/or position errors were not allowed (e.g. head position in the image layer had to be correct), and movement artefacts were not allowed. Ambient light level was approx.16 lx. Ambient light was measured from the surface of the display in the direction of the viewer using a luminance meter (RaySafe Xi; Unfors; Billdal; Sweden). The selection was made using the 6MP display (Fig 1). The images were taken as part of patient treatment at the Department of Diagnostic Radiology, Oulu University Hospital. All radiographs were taken with the Orthopantomograph OP200 D (Instrumentarium Corp., Tuusula, Finland) by experienced radiographers. The parameters used were 66 kv, 9.9 ma. The acquired digital raw data were sent to the Picture Archiving and Communication System server (PACS). All images were stored as Digital Imaging and Communications in Medicine (DICOM) format file. The digital archives system used was the neapacs (Neagen Oy, Finland), the case selection system, i.e., the Radiology Information System (RIS) used was nearis (Neagen Oy, Finland) and ESKO patient data system (Oulu University Hospital, Finland). The viewer used was an HTML4/5 nealink (Neagen Oy, Finland). A standard PC (Lifebook S-761 VPro, Fujitsu, Japan, integrated graphic card: Esprimo C5731E) was connected to the consumer grade displays. A power computer (Fujitsu Celsius R570, Fujitsu, Japan, graphic card: Barco 5200) was connected to the 6MP displays. Two sets of three identical displays were used for convenience and to save interpretation time. Technical specifications of each display are given in Table I (Fig 1). Before the study, constant luminance was adjusted on the consumer grade displays, tablet, and 6MP displays using a luminance meter (RaySafe Xi; Unfors; Billdal; Sweden). The detailed Page 2 of 12

3 specifications are given in Table I (Fig 1). The tablet was fixed on the table before adjusting the luminance. The panoramic images were observed independently by two observers, one an oral and maxillofacial radiologist with eight years of interpreting experience (observer 1) and the other a resident in oral and maxillofacial radiology with two years of interpreting experience (observer 2). Altogether seven structures were evaluated from the left side of the jaw: the dentinoenamel junction from the first lower molar, the possible presence of dentinal caries and periapical inflammatory lesions (widening of the periapical periodontal space twice from normal or radiolucent lesion) from the first upper and lower permanent molars, and the visibility of the cortical border of the floor and possible pathological lesions in maxillary sinus, such as thickening of mucous membrane, fluid-level, or cysts (Fig. 2, A, B). A fivepoint scaling system was used: 1 = definitely not a finding, 2 = probably not a finding, 3 = unable to evaluate, 4 = probably a finding, and 5 = definitely a finding. Both anatomical structures and pathology were chosen because they provided low- and high-contrast details. Before the evaluation, the observers were given a one-hour training on how to use the viewing programs. The observers evaluated 30 radiographs in two evaluation session during which they were allowed to adjust the brightness, contrast and magnification of the images through a mouse control. Each observer evaluated 30 radiographs from three displays. The consumer grade display and the tablet were evaluated during the first evaluation and the 6MP display during the second evaluation with three weeks' delay between the evaluation sessions. The displays in each session were randomized between observers 1 and 2. The observation was performed under standardized conditions. The radiographs were displayed in random order at each evaluation to minimize the memory effect. Evaluation time of one minute per one image was allowed during which all seven different anatomical structures and pathological lesions were assessed. The consensus between the two observers that was made within each diagnostic item for thirty panoramic radiographs six months after initial viewing was considered as reference. This assessment was made using the 6MP display under ambient light of approx.16 lx (Fig 1). Intraobserver agreement was determined by observer 1 by re-evaluating 15 panoramic radiographs six months after initial viewing. This evaluation was made under ambient light of approx. 16 lx using the 6MP display (Fig. 1). Statistical Methods Page 3 of 12

4 Agreement between both observers and consensus was calculated as proportion of concordant ratings (i.e., exactly the same). Rating of dentino-enamel junction was dichotomized as visible or unable to evaluate. In order to evaluate the reliability of the ratings Cohen's kappa (k) was calculated for dentino-enamel junction and linearly weighted kappa (k w ) for dentinal caries and presence of periapical lesions from upper and lower molars, and pathological lesions from maxillary sinus. A commonly cited scale used when interpreting kappa statistic is as follows: < 0, poor (less than chance); , slight; , fair; , moderate; , substantial; and , almost perfect agreement. Independent samples chi-square test was used to compare overall differences between the three displays and separately between tablet and 6MP display. The linear association test was used to evaluate the linearity of agreement between the displays in observing pathological lesions. P-value of 0.05 was considered as statistically significant. Intra-observer reliability was analyzed by calculating the proportion of concordant ratings and weighted kappa. IBM SPSS Statistics 21 (IBM Corporation) was used to conduct the statistical analyses. Images for this section: Page 4 of 12

5 Fig. 1: The table has already published, "Kallio-Pulkkinen et al (2014) Comparison of consumer grade, tablet and 6MP-displays: Observer performance in detection of anatomical and pathological structures in panoramic radiographs. Oral Surg Oral Med Oral Pathol Oral Radiol 118: ". Page 5 of 12

6 Fig. 2: The figure has already published, "Kallio-Pulkkinen et al (2014) Comparison of consumer grade, tablet and 6MP-displays: Observer performance in detection of anatomical and pathological structures in panoramic radiographs. Oral Surg Oral Med Oral Pathol Oral Radiol 118: ". Page 6 of 12

7 Results The border of the left maxillary sinus was visible on all displays for both observers. Results on the visibility of dentino-enamel junction are shown in Table II (Fig 3). Observer 1 performed reasonably well with the consumer grade display and tablet (k = 0.54 and k = 0.63, respectively) whereas with the 6MP display the agreement was lower (k = 0.19). Observer 2 performed better with the 6MP display than the consumer grade display or tablet. The proportion of concordant findings between observer 1 and consensus did not differ statistically significantly between different displays (Fig 4). However, agreement measured by k w was lower with tablet than with consumer grade or 6MP displays in dentinal caries in upper and lower molars, and highest with tablet as compared to consumer grade or 6MP displays in periapical lesions in upper molar. For pathological lesions in maxillary sinus the agreement increased significantly from consumer grade to 6MP display (P=0.020 in linear association test). The proportion of concordant findings between observer 2 and consensus was higher with 6MP display than consumer grade display or tablet in dentinal caries in upper and lower molars (P=0.027 and P=0.042, respectively), and periapical lesions in upper molar (P=0.005). In pathological lesions in maxillary sinus the agreement was low with all displays. Observer performance was also compared between tablet and 6MP display (Fig. 4). For observer 1, detection of dentino-enamel junction (Fig. 3) and periapical lesions in upper molar was not significantly different between tablet and 6MP displays. Observer 2 performed significantly worse on tablet as compared to 6MP display in detection of dentinal caries in lower molar (p = 0.014) and periapical lesions in upper molar (P = 0.012). Observer 2 performed non-significantly worse by tablet as compared to 6MP in all structures. The intra-observer reliability was moderate at the dentino-enamel junction, almost perfect in upper and substantial in lower dentin caries, fair in upper and substantial in lower periapical lesions, and moderate in pathological lesions in left maxillary sinus (Fig. 5). Images for this section: Page 7 of 12

8 Fig. 3: The table has already published, "Kallio-Pulkkinen et al (2014) Comparison of consumer grade, tablet and 6MP-displays: Observer performance in detection of anatomical and pathological structures in panoramic radiographs. Oral Surg Oral Med Oral Pathol Oral Radiol 118: ". Page 8 of 12

9 Fig. 4: The table has already published, "Kallio-Pulkkinen et al (2014) Comparison of consumer grade, tablet and 6MP-displays: Observer performance in detection of anatomical and pathological structures in panoramic radiographs. Oral Surg Oral Med Oral Pathol Oral Radiol 118: ". Page 9 of 12

10 Fig. 5: The table has already published, "Kallio-Pulkkinen et al (2014) Comparison of consumer grade, tablet and 6MP-displays: Observer performance in detection of anatomical and pathological structures in panoramic radiographs. Oral Surg Oral Med Oral Pathol Oral Radiol 118: ". Page 10 of 12

11 Conclusion A dentist who is an early phases of training to interpret panoramic images may be more dependent on a high-quality medical display usen under optimal viewing conditions to detect both anatomical structures and pathological lesions in panoramic radiographs while an experienced dentist can achieve high diagnostic standards using suboptimal diagnostic technology. Personal information Soili Kallio-Pulkkinen Oral radiologist Department of Diagnostic Radiology Oulu University Hospital Medical Research Center Oulu, Oulu University Hospital and University of Oulu P.O.Box 50 Fin Oulu University Hospital References 1.American Association of Physicists in Medicine Task Group 18. Assessment of display performance for medical imaging systems. Published April Accessed February 7, Institute of Physics and Engineering in Medicine: Recommended standards for the routine performance testing of diagnostic X-ray imaging systems. IPEM Report No. 91.York, IPEM, Page 11 of 12

12 3.Swedish Standards Institute. Light and lighting-lighting of work places-part 1: indoor work places. Stockholm, Sweden: Swed St Ins7semi; Kim TY, Choi JW, Lee SS, Huh KH, Yi WJ, Heo MS et al. Effect of LCD display type and observer experience on diagnostic performance in soft-copy interpretations of the maxillary sinus on panoramic radiographs. Imaging Sci Dent 2011;41: U.S. Food and Drug Administration. Press release: FDA clears first diagnostic radiology applications for mobile devices. Available at: (accessed February 7, 2013). 6.Samei E, Ranger NT, Delong DM. A comparative contrast-detail study of five medical displays. Med Phys 2008;35: Hellen-Halme K, Nilsson M, Petersson A. Effect of displays on approximal caries detection in digital radiographs-standard versus precalibrated DICOM Part 14 displays: an in vitro study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;107: Hellén-Halme K, Nilsson M, Petersson A. Effect of ambient light and display brightness and contrast settings on the detection of approximal caries in digital radiographs. An in vitro study. Dentomaxillofac Radiol 2008;37: Mc Laughlin P, Neill SO, Fanning N, Mc Garrigle AM, Connor OJ, Wyse G et al. Emergency CT brain: preliminary interpretation with a tablet device: image quality and diagnostic performance of the Apple ipad. Emerg Radiol 2012;19: Yoshimura K, Nihashi T, Ikeda M, Ando Y, Kawai H, Kawakami K et al. Comparison of liquid crystal display monitors calibrated with gray-scale standard display function and with # 2.2 and ipad: Observer performance in detection of cerebral infraction on brain CT. Am J Roentgenol 2013;200: Shintaku WH, Scarbecz M, Venturin JS. Evaluation of interproximal caries using the Tablet 2 and a liquid crystal display display. Oral Surg Oral Med Oral Pathol Oral Radiol 2012;113:e40-e44. Page 12 of 12