Robust watermarking for magnetic resonance images with automatic region of interest detection

Medical image watermarking requires special considerations compared to ordinary watermarking methods. The first issue is the detection of an important area of the image called the Region of Interest (ROI) prior to starting the watermarking process. Most existing ROI detection procedures use manual-based methods, while in automated methods the robustness against intentional or unintentional attacks has not been considered extensively. The second issue is the robustness of the embedded watermark against different attacks. A common drawback of existing watermarking methods is their weakness against salt and pepper noise. The research carried out in this thesis addresses these issues of having automatic ROI detection for magnetic resonance images that are robust against attacks particularly the salt and pepper noise and designing a new watermarking method that can withstand high density salt and pepper noise. In the ROI detection part, combinations of several algorithms such as morphological reconstruction, adaptive thresholding and labelling are utilized. The noise-filtering algorithm and window size correction block are then introduced for further enhancement. The performance of the proposed ROI detection is evaluated by computing the Comparative Accuracy (CA). In the watermarking part, a combination of spatial method, channel coding and noise filtering schemes are used to increase the robustness against salt and pepper noise. The quality of watermarked image is evaluated using Peak Signal-to-Noise Ratio (PSNR) and Structural Similarity Index (SSIM), and the accuracy of the extracted watermark is assessed in terms of Bit Error Rate (BER). Based on experiments, the CA under eight different attacks (speckle noise, average filter, median filter, Wiener filter, Gaussian filter, sharpening filter, motion, and salt and pepper noise) is between 97.8% and 100%. The CA under different densities of salt and pepper noise (10%-90%) is in the range of 75.13% to 98.99%. In the watermarking part, the performance of the proposed method under different densities of salt and pepper noise measured by total PSNR, ROI PSNR, total SSIM and ROI SSIM has improved in the ranges of 3.48-23.03 (dB), 3.5-23.05 (dB), 0-0.4620 and 0-0.5335 to 21.75-42.08 (dB), 20.55-40.83 (dB), 0.5775-0.8874 and 0.4104-0.9742 respectively. In addition, the BER is reduced to the range of 0.02% to 41.7%. To conclude, the proposed method has managed to significantly improve the performance of existing medical image watermarking methods

Individual and External Catalysts and Barriers of Biking: A Community Based Study in a Metropolis

Biking has proven health, environmental and traffic benefits. To prevail biking at community infrastructures and "BicycleSharing Systems (BSS)" have been developed, but their effectiveness is dependent on people's attitudes and perceptions.We aim to investigate attitudes of people toward biking and related infrastructures with regard to demographic factors inMashhad, Iran-a metropolis with unsuccessful BSS. The present work was conducted as a cross-sectional study at Mashhad,Iran, in 2015. In a multistage sampling, adult inhabitants were selected and data about their perceptions of benefits andbarriers of biking were collected through a researcher-designed questionnaire. Of 437 study participants with a mean(±SD) age of 29.9 (±11.3) years, 250 (57.3%) were female. Only 3 (0.7%) of respondents used bikes. Positive attitudeswere significantly associated with gender, marital status and occupation of participants. Car ownership was accompaniedby higher perceptions of "tiredness of biking"(p=0.02), its "low safety" (p=0.02) and "time wasting" (p=0.01). According tothe results, cultural interventions are needed for biking promotion regardless of their socioeconomic status. Educationalprograms at academic settings are also valuable. Safety, convenience, and affordability of different groups of populations(like elderly and deprived people) should be regarded during designing and constructing biking infrastructures and settingparticipation rules

A heuristic automatic and robust ROI detection method for medical image warermarking

This paper presents an automatic region of interest (ROI) segmentation method for application of watermarking in medical images. The advantage of using this scheme is that the proposed method is robust against different attacks such as median, Wiener, Gaussian, and sharpening filters. In other words, this technique can produce the same result for the ROI before and after these attacks. The proposed algorithm consists of three main parts; suggesting an automatic ROI detection system, evaluating the robustness of the proposed system against numerous attacks, and finally recommending an enhancement part to increase the strength of the composed system against different attacks. Results obtained from the proposed method demonstrated the promising performance of the method

Outcome-Based Validity and Reliability Assessment of Raters Regarding the Admission Triage Level in the Emergency Department: a Cross-Sectional Study

Introduction: Emergency department (ED) is usually the first line of healthcare supply to patients in non-urgent to critical situations and, if necessary, provides hospital admission. A dynamic system to evaluate patients and allocate priorities is necessary. Such a structure that facilitates patients’ flow in the ED is termed triage. Objective: This study was conducted to investigate the validity and reliability of implementation of Emergency Severity Index (ESI) system version 4 by triage nurses in an overcrowded referral hospital with more than 80000 patient admissions per year and an average emergency department occupancy rate of more than 80%. Method: This prospective cross-sectional study was conducted in a tertiary care teaching hospital and trauma center with an emergency medicine residency program. Seven participating expert nurses were asked to assess the ESI level of patients in 30 written scenarios twice within a three-week interval to evaluate the inter-rater and intra-rater reliability. Patients were randomly selected to participate in the study, and the triage level assigned by the nurses was compared with that by the emergency physicians. Finally, based on the patients’ charts, an expert panel evaluated the validity of the triage level. Results: During the study period, 527 patients with mean age of 54 ± 7 years, including 253 (48%) women and 274 (52%) men, were assessed by seven trained triage nurses. The degree of retrograde agreement between the collaborated expert panel’s evaluation and the actual triage scales by the nurses and physicians for all 5 levels was excellent, with the Cohen’s weighted kappa being 0.966 (CI 0.985–0.946, p < 0.001) and 0.813 (CI 0.856–0.769, p<0.001), respectively. The intra-rater reliability was 0.94 (p < 0.0001), and the inter-rater reliability for all the nurses was in perfect agreement with the test result (Cohen’s weighted kappa were as follows: 0.919, 0.956, 0.911, 0.955, 0.860, 0.956, and 0.868; p < 0.001). Conclusion: The study findings showed that there was perfect reliability and, overall, almost perfect validity for the triage performed by the studied nurses

Outcome-Based Validity and Reliability Assessment of Raters Regarding the Admission Triage Level in the Emergency Department: a Cross-Sectional Study

Introduction: Emergency department (ED) is usually the first line of healthcare supply to patients in non-urgent to critical situations and, if necessary, provides hospital admission. A dynamic system to evaluate patients and allocate priorities is necessary. Such a structure that facilitates patients’ flow in the ED is termed triage. Objective: This study was conducted to investigate the validity and reliability of implementation of Emergency Severity Index (ESI) system version 4 by triage nurses in an overcrowded referral hospital with more than 80000 patient admissions per year and an average emergency department occupancy rate of more than 80%. Method: This prospective cross-sectional study was conducted in a tertiary care teaching hospital and trauma center with an emergency medicine residency program. Seven participating expert nurses were asked to assess the ESI level of patients in 30 written scenarios twice within a three-week interval to evaluate the inter-rater and intra-rater reliability. Patients were randomly selected to participate in the study, and the triage level assigned by the nurses was compared with that by the emergency physicians. Finally, based on the patients’ charts, an expert panel evaluated the validity of the triage level. Results: During the study period, 527 patients with mean age of 54 ± 7 years, including 253 (48%) women and 274 (52%) men, were assessed by seven trained triage nurses. The degree of retrograde agreement between the collaborated expert panel’s evaluation and the actual triage scales by the nurses and physicians for all 5 levels was excellent, with the Cohen’s weighted kappa being 0.966 (CI 0.985–0.946, p < 0.001) and 0.813 (CI 0.856–0.769, p<0.001), respectively. The intra-rater reliability was 0.94 (p < 0.0001), and the inter-rater reliability for all the nurses was in perfect agreement with the test result (Cohen’s weighted kappa were as follows: 0.919, 0.956, 0.911, 0.955, 0.860, 0.956, and 0.868; p < 0.001). Conclusion: The study findings showed that there was perfect reliability and, overall, almost perfect validity for the triage performed by the studied nurses

Educational Evaluation of Medical Student in Health Centers Using Portfolios: A Pilot Study

Background & Objective: The desire for portfolio application, as a suitable method for evaluation of clinical students, has recently expanded. This study investigated the implementation of portfolio in the evaluation of medical students. Methods: In the current study, medical students in their educational rotations in health centers in Mashhad, Iran, in 2011 were evaluated by using portfolio. The scores of medical students' performance and health centers supervisors' evaluation of them were assessed during 10 months and compared with scores from a similar period in the past. Data were analyzed using t-test and SPSS software. Results: Portfolios were completed by all medical students during their rotation in health centers and and evaluation of student was done based on portfolio scoring. Mean performance scores of medical students and health center supervisors' evaluation of them had increased compared of them by portfolio evaluation had increased compared with traditional students' evaluation method in similar past period. Conclusion: Using portfolios for evaluation of medical students' performance in community educational fields is proposed as a performance-based approach. Key Words: Portfolio, Evaluation, Medical students, Health center

Acupressure has not an analgesic effect in patients with renal colic: a randomized controlled trial

BACKGROUND Easing renal colic (RC) pain is of the most important issues in the emergency departments. This study was conducted to investigate the analgesic effects of intravenous paracetamol in comparison to acupressure and intramuscular diclofenac in patients with RC. METHODS This randomized clinical trial was conducted on 96 eligible patients with RC, visiting the Emergency Department of Imam Reza Hospital of Mashhad, Iran. The participants were selected by consecutive non-random sampling method, and were randomized in three groups, each comprising of 32 participants. The first and second groups received 75 mg intramuscular diclofenac and lg intravenous paracetamol, respectively. In the third group, three acupressure points were manually stimulated for six minutes. The pain score was measured by Visual Analog Scale for pain at baseline and after 10, 30, and 60 minutes. Collected information analyses by SPSS version 20 and interpreted using descriptive statistics (frequency, percentage) and inferential statistics (chi-square test). RESULTS The mean age was 31.60 +/- 7.42 years (range:18-50). The two methods (diclofenac and paracetamol groups) were significantly better in pain reduction compared to acupressure after 10 minutes (p<0.001). Ninety four percent of participants in diclofenac group, 87% of paracetamol group and none of acupressure group were completely satisfied with their treatment method (p<0.001). CONCLUSION This study demonstrated that acupressure did not effectively reduces renal colic pain. It seems that contrary to acupressure, intravenous paracetamol is a safe and effective analgesic medicine for patients with RC.Mashhad University of Medical SciencesOpen access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

The Psychological Effects of Exercise on Perceived Stress in Athlete Staff: Presenting a Theoretical Model

Background: The study is intended to examine a model of direct and indirect effects (through mediating role of self-assessment latent variable containing self-efficacy and self-esteem components) of sports mental toughness construct (including the components of confidence, consistency and control) on perceived stress of athlete employees. Method: The research design of study was correlational and its approach was structural equations. The population were all athlete employees at National Iranian Gas Company (NIGC) 400 of whom were selected with simple random method. The applied instruments were reliable and valid. Data analysis was performed using macro program of Preacher and Hayes in SPSS-19 software and also using AMOS-20 software. Results: The results indicated that the direct path of the proposed model should be eliminated and after eliminating this path, the model’s fitness parameters were optimized. Conclusion: According to the data of this research it can be concluded that one of the mechanisms of sport’s impact on perceived stress of employees is that first, it influences the three aspects of sports mental toughness and then, a mixture of these variables’ effects improve this employees’ perceived stress through increasing the self- assessment construct of them (and its components)

The Psychological Effects of Exercise on Perceived Stress in Athlete Staff: Presenting a Theoretical Model

Background: The study is intended to examine a model of direct and indirect effects (through mediating role of self-assessment latent variable containing self-efficacy and self-esteem components) of sports mental toughness construct (including the components of confidence, consistency and control) on perceived stress of athlete employees. Method: The research design of study was correlational and its approach was structural equations. The population were all athlete employees at National Iranian Gas Company (NIGC) 400 of whom were selected with simple random method. The applied instruments were reliable and valid. Data analysis was performed using macro program of Preacher and Hayes in SPSS-19 software and also using AMOS-20 software. Results: The results indicated that the direct path of the proposed model should be eliminated and after eliminating this path, the model’s fitness parameters were optimized. Conclusion: According to the data of this research it can be concluded that one of the mechanisms of sport’s impact on perceived stress of employees is that first, it influences the three aspects of sports mental toughness and then, a mixture of these variables’ effects improve this employees’ perceived stress through increasing the self- assessment construct of them (and its components)