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Inter-observer Variability Analysis of Automatic Lung Delineation in Normal and Disease Patients

Saba L, Than JC, Noor NM, Rijal OM, Kassim RM, Yunus A, et al.

J Med Syst, 2016 Jun;40(6):142.
PMID: 27114353 DOI: 10.1007/s10916-016-0504-7

Human interaction has become almost mandatory for an automated medical system wishing to be accepted by clinical regulatory agencies such as Food and Drug Administration. Since this interaction causes variability in the gathered data, the inter-observer and intra-observer variability must be analyzed in order to validate the accuracy of the system. This study focuses on the variability from different observers that interact with an automated lung delineation system that relies on human interaction in the form of delineation of the lung borders. The database consists of High Resolution Computed Tomography (HRCT): 15 normal and 81 diseased patients' images taken retrospectively at five levels per patient. Three observers manually delineated the lungs borders independently and using software called ImgTracer™ (AtheroPoint™, Roseville, CA, USA) to delineate the lung boundaries in all five levels of 3-D lung volume. The three observers consisted of Observer-1: lesser experienced novice tracer who is a resident in radiology under the guidance of radiologist, whereas Observer-2 and Observer-3 are lung image scientists trained by lung radiologist and biomedical imaging scientist and experts. The inter-observer variability can be shown by comparing each observer's tracings to the automated delineation and also by comparing each manual tracing of the observers with one another. The normality of the tracings was tested using D'Agostino-Pearson test and all observers tracings showed a normal P-value higher than 0.05. The analysis of variance (ANOVA) test between three observers and automated showed a P-value higher than 0.89 and 0.81 for the right lung (RL) and left lung (LL), respectively. The performance of the automated system was evaluated using Dice Similarity Coefficient (DSC), Jaccard Index (JI) and Hausdorff (HD) Distance measures. Although, Observer-1 has lesser experience compared to Obsever-2 and Obsever-3, the Observer Deterioration Factor (ODF) shows that Observer-1 has less than 10% difference compared to the other two, which is under acceptable range as per our analysis. To compare between observers, this study used regression plots, Bland-Altman plots, two tailed T-test, Mann-Whiney, Chi-Squared tests which showed the following P-values for RL and LL: (i) Observer-1 and Observer-3 were: 0.55, 0.48, 0.29 for RL and 0.55, 0.59, 0.29 for LL; (ii) Observer-1 and Observer-2 were: 0.57, 0.50, 0.29 for RL and 0.54, 0.59, 0.29 for LL; (iii) Observer-2 and Observer-3 were: 0.98, 0.99, 0.29 for RL and 0.99, 0.99, 0.29 for LL. Further, CC and R-squared coefficients were computed between observers which came out to be 0.9 for RL and LL. All three observers however manage to show the feature that diseased lungs are smaller than normal lungs in terms of area.

Matched MeSH terms: Observer Variation*
Computerized segmentation and measurement of chronic wound images

Ahmad Fauzi MF, Khansa I, Catignani K, Gordillo G, Sen CK, Gurcan MN

Comput Biol Med, 2015 May;60:74-85.
PMID: 25756704 DOI: 10.1016/j.compbiomed.2015.02.015

An estimated 6.5 million patients in the United States are affected by chronic wounds, with more than US$25 billion and countless hours spent annually for all aspects of chronic wound care. There is a need for an intelligent software tool to analyze wound images, characterize wound tissue composition, measure wound size, and monitor changes in wound in between visits. Performed manually, this process is very time-consuming and subject to intra- and inter-reader variability. In this work, our objective is to develop methods to segment, measure and characterize clinically presented chronic wounds from photographic images. The first step of our method is to generate a Red-Yellow-Black-White (RYKW) probability map, which then guides the segmentation process using either optimal thresholding or region growing. The red, yellow and black probability maps are designed to handle the granulation, slough and eschar tissues, respectively; while the white probability map is to detect the white label card for measurement calibration purposes. The innovative aspects of this work include defining a four-dimensional probability map specific to wound characteristics, a computationally efficient method to segment wound images utilizing the probability map, and auto-calibration of wound measurements using the content of the image. These methods were applied to 80 wound images, captured in a clinical setting at the Ohio State University Comprehensive Wound Center, with the ground truth independently generated by the consensus of at least two clinicians. While the mean inter-reader agreement between the readers varied between 67.4% and 84.3%, the computer achieved an average accuracy of 75.1%.

Matched MeSH terms: Observer Variation
Clinical evaluation of the anterior translation of glenohumeral joint using ultrasonography: an intra- and inter-rater reliability study

Joseph LH, Hussain RI, Pirunsan U, Naicker AS, Htwe O, Paungmali A

Acta Orthop Traumatol Turc, 2014;48(2):169-74.
PMID: 24747625 DOI: 10.3944/AOTT.2014.3184

The aim of this study was to investigate the intra- and inter-rater reliability of ultrasonography (US) to measure anterior translation of the humeral head (ATHH) among healthy subjects and patients with sacroiliac joint dysfunction.

Matched MeSH terms: Observer Variation
Reliability and validity of television food advertising questionnaire in Malaysia

Zalma AR, Safiah MY, Ajau D, Khairil Anuar MI

Health Promot Int, 2015 Sep;30(3):523-30.
PMID: 24150531 DOI: 10.1093/heapro/dat072

Interventions to counter the influence of television food advertising amongst children are important. Thus, reliable and valid instrument to assess its effect is needed. The objective of this study was to determine the reliability and validity of such a questionnaire. The questionnaire was administered twice on 32 primary schoolchildren aged 10-11 years in Selangor, Malaysia. The interval between the first and second administration was 2 weeks. Test-retest method was used to examine the reliability of the questionnaire. Intra-rater reliability was determined by kappa coefficient and internal consistency by Cronbach's alpha coefficient. Construct validity was evaluated using factor analysis. The test-retest correlation showed moderate-to-high reliability for all scores (r = 0.40*, p = 0.02 to r = 0.95**, p = 0.00), with one exception, consumption of fast foods (r = 0.24, p = 0.20). Kappa coefficient showed acceptable-to-strong intra-rater reliability (K = 0.40-0.92), except for two items under knowledge on television food advertising (K = 0.26 and K = 0.21) and one item under preference for healthier foods (K = 0.33). Cronbach's alpha coefficient indicated acceptable internal consistency for all scores (0.45-0.60). After deleting two items under Consumption of Commonly Advertised Food, the items showed moderate-to-high loading (0.52, 0.84, 0.42 and 0.42) with the Scree plot showing that there was only one factor. The Kaiser-Meyer-Olkin was 0.60, showing that the sample was adequate for factor analysis. The questionnaire on television food advertising is reliable and valid to assess the effect of media literacy education on television food advertising on schoolchildren.

Matched MeSH terms: Observer Variation
Odontometric sex variation in Malaysians with application to sex prediction

Khamis MF, Taylor JA, Malik SN, Townsend GC

Forensic Sci Int, 2014 Jan;234:183.e1-7.
PMID: 24128748 DOI: 10.1016/j.forsciint.2013.09.019

Information about the sex of individuals is important for human identification. This study was conducted to quantify classification rates of sex prediction models for Malaysians using odontometric profiles. Mesiodistal (MD) and buccolingual (BL) crown dimensions of the permanent dentition were studied in 400 young adult Malaysians, giving a total of 28 tooth size variables. The sample consisted of three major ethnic groups, the Malays, Chinese and Tamils, since the aim was to assess sex dimorphism in Malaysians as a whole. Results showed that the mesiodistal diameter of the lower canine was the most sexually dimorphic dimension in Malaysian Malays and Tamils. Univariate analyses showed that the magnitude and pattern of sex dimorphism varies between these three ethnic groups, with Malaysian Chinese and Tamils being more dimorphic than the Malaysian Malays. Stepwise discriminant functions were generated bearing in mind their application in practical forensic situations. The range of classification rates was from 70.2% to 78.5% for the composite Malaysian group, and 83.8%, 77.9%, 72.4% for Malaysian Chinese, Malays and Tamils, respectively. The 'Area Under the Receiver Operating Characteristic Curve statistics' indicated good classification rates for three prediction models obtained using a combination of all tooth size variables, mandibular teeth, and mesiodistal dimensions in the composite Malaysian group, and for all tooth size variables in each ethnic group. The present study provides strong support for the value of odontometry as an adjunct scientific method for sex prediction in human identification.

Matched MeSH terms: Observer Variation
Validity and reliability of tooth size and dental arch measurements: a stereo photogrammetric study

Al-Khatib AR, Rajion ZA, Masudi SM, Hassan R, Townsend GC

Aust Orthod J, 2012 May;28(1):22-9.
PMID: 22866590

The development of three-dimensional computer imaging has many applications in dentistry, including the analysis of dental casts.

Matched MeSH terms: Observer Variation
Fulltext Evaluation of the accuracy of the Omron HEM-907 blood pressure device

Gurpreet K, Tee GH, Karuthan C

Med J Malaysia, 2008 Aug;63(3):239-43.
PMID: 19248698 MyJurnal

A study was undertaken to assess the accuracy of the Omron HEM-907 blood pressure measuring device for use in community studies. A modified version of the British Hypertension Society (BHS) and American Association for the Advancement Medical Instrumentation (AAMI) protocol for measuring the accuracy of a blood pressure measuring device was used. A total of 104 subjects were recruited from two clinics. Observer-observer agreement for readings within the 5 mmHg was good; 80.8% and 84.6% of systolic blood pressure (SBP) and diastolic blood pressure (DBP) agreement respectively. Of the two, the better observer-device agreement readings within the 5 mmHg were 66.4% and 50.0% for SBP and DBP respectively, giving an overall grade B. The mean differences and standard deviation of the differences were within < or =5 mmHg with a standard deviation (SD) of < or =8 mmHg. The Omron HEM-907 satisfied both the AAMI and BHS protocols for accuracy for a non-invasive blood pressure monitoring device using single observer readings.
Study site: Klinik Kesihatan Shah Alam, Selangor; Hypertension clinic, Hospital Kuala Lumpur, Malaysia
Device: Standard device: mercury sphygmomanometer (brand?); test device: oscillometric automated electronic BP monitor (Omron HEM-907).

Matched MeSH terms: Observer Variation
Perception of pharmacy students in Malaysia on the use of objective structured clinical examinations to evaluate competence

Awaisu A, Mohamed MH, Al-Efan QA

Am J Pharm Educ, 2007 Dec 15;71(6):118.
PMID: 19503702

OBJECTIVES: To assess bachelor of pharmacy students' overall perception and acceptance of an objective structured clinical examination (OSCE), a new method of clinical competence assessment in pharmacy undergraduate curriculum at our Faculty, and to explore its strengths and weaknesses through feedback.
METHODS: A cross-sectional survey was conducted via a validated 49-item questionnaire, administered immediately after all students completed the examination. The questionnaire comprised of questions to evaluate the content and structure of the examination, perception of OSCE validity and reliability, and rating of OSCE in relation to other assessment methods. Open-ended follow-up questions were included to generate qualitative data.
RESULTS: Over 80% of the students found the OSCE to be helpful in highlighting areas of weaknesses in their clinical competencies. Seventy-eight percent agreed that it was comprehensive and 66% believed it was fair. About 46% felt that the 15 minutes allocated per station was inadequate. Most importantly, about half of the students raised concerns that personality, ethnicity, and/or gender, as well as interpatient and inter-assessor variability were potential sources of bias that could affect their scores. However, an overwhelming proportion of the students (90%) agreed that the OSCE provided a useful and practical learning experience.
CONCLUSIONS: Students' perceptions and acceptance of the new method of assessment were positive. The survey further highlighted for future refinement the strengths and weaknesses associated with the development and implementation of an OSCE in the International Islamic University Malaysia's pharmacy curriculum.

Matched MeSH terms: Observer Variation
Fulltext Discordant identification of pediatric severe sepsis by research and clinical definitions in the SPROUT international point prevalence study

Weiss SL, Fitzgerald JC, Maffei FA, Kane JM, Rodriguez-Nunez A, Hsing DD, et al.

Crit Care, 2015;19:325.
PMID: 26373923 DOI: 10.1186/s13054-015-1055-x

Consensus criteria for pediatric severe sepsis have standardized enrollment for research studies. However, the extent to which critically ill children identified by consensus criteria reflect physician diagnosis of severe sepsis, which underlies external validity for pediatric sepsis research, is not known. We sought to determine the agreement between physician diagnosis and consensus criteria to identify pediatric patients with severe sepsis across a network of international pediatric intensive care units (PICUs).

Matched MeSH terms: Observer Variation
Echocardiographic agreement in the diagnostic evaluation for infective endocarditis

Lauridsen TK, Selton-Suty C, Tong S, Afonso L, Cecchi E, Park L, et al.

Int J Cardiovasc Imaging, 2016 Jul;32(7):1041-51.
PMID: 27100526 DOI: 10.1007/s10554-016-0873-5

Echocardiography is essential for the diagnosis and management of infective endocarditis (IE). However, the reproducibility for the echocardiographic assessment of variables relevant to IE is unknown. Objectives of this study were: (1) To define the reproducibility for IE echocardiographic variables and (2) to describe a methodology for assessing quality in an observational cohort containing site-interpreted data. IE reproducibility was assessed on a subset of echocardiograms from subjects enrolled in the International Collaboration on Endocarditis registry. Specific echocardiographic case report forms were used. Intra-observer agreement was assessed from six site readers on ten randomly selected echocardiograms. Inter-observer agreement between sites and an echocardiography core laboratory was assessed on a separate random sample of 110 echocardiograms. Agreement was determined using intraclass correlation (ICC), coverage probability (CP), and limits of agreement for continuous variables and kappa statistics (κweighted) and CP for categorical variables. Intra-observer agreement for LVEF was excellent [ICC = 0.93 ± 0.1 and all pairwise differences for LVEF (CP) were within 10 %]. For IE categorical echocardiographic variables, intra-observer agreement was best for aortic abscess (κweighted = 1.0, CP = 1.0 for all readers). Highest inter-observer agreement for IE categorical echocardiographic variables was obtained for vegetation location (κweighted = 0.95; 95 % CI 0.92-0.99) and lowest agreement was found for vegetation mobility (κweighted = 0.69; 95 % CI 0.62-0.86). Moderate to excellent intra- and inter-observer agreement is observed for echocardiographic variables in the diagnostic assessment of IE. A pragmatic approach for determining echocardiographic data reproducibility in a large, multicentre, site interpreted observational cohort is feasible.

Matched MeSH terms: Observer Variation
Proptosis--Correlation and Agreement between Hertel Exophthalmometry and Computed Tomography

Ramli N, Kala S, Samsudin A, Rahmat K, Abidin ZZ

Orbit, 2015;34(5):257-62.
PMID: 26186249 DOI: 10.3109/01676830.2015.1057291

To determine the correlation and agreement between Hertel exophthalmometry and computed tomography (CT) of the orbits in measuring proptosis.

Matched MeSH terms: Observer Variation
The cusp of Carabelli in Malaysians

Rusmah M

Odontostomatol Trop, 1992 Mar;15(1):13-5.
PMID: 1287605

The maxillary casts of 320 Malaysian children were examined for the occurrence of the Carabelli trait on the maxillary first permanent molars. The total trait frequency was observed to be 52.2 per cent. Statistical analysis showed no sex dimorphism in the occurrence of the trait. Bilateral occurrence with a tendency towards concordance of expression between sides was also observed.

Matched MeSH terms: Observer Variation
A comparative study of X-ray pelvimetry and CT pelvimetry

Raman S, Samuel D, Suresh K

Aust N Z J Obstet Gynaecol, 1991 Aug;31(3):217-20.
PMID: 1804081

In this study 24 patients who had conventional erect lateral X-ray pelvimetry had a CT pelvimetry done after delivery to complete the pelvimetry views. The erect lateral pelvimetry was read independently by a Consultant Radiologist, Consultant Obstetrician and a Medical Officer training in Obstetrics and Gynaecology. Using CT pelvimetry as the 'gold standard' (as the error of measurement was known with the machine used) the 3 readings were compared. There was no statistical difference in the values suggesting that X-ray pelvimetry is comparable to CT pelvimetry. However CT pelvimetry is preferred, if available, because of the lower dose of radiation involved, more comfort for the patient and shorter time in performing the procedure. Measurements done are easily read directly from the CT console.

Matched MeSH terms: Observer Variation
Fulltext Telemedicine via Smart Glasses in Critical Care of the Neurosurgical Patient-COVID-19 Pandemic Preparedness and Response in Neurosurgery

Munusamy T, Karuppiah R, Bahuri NFA, Sockalingam S, Cham CY, Waran V

World Neurosurg, 2021 01;145:e53-e60.
PMID: 32956888 DOI: 10.1016/j.wneu.2020.09.076

OBJECTIVE: The coronavirus disease 2019 pandemic poses major risks to health care workers in neurocritical care. Recommendations are in place to limit medical personnel attending to the neurosurgical patient as a protective measure and to conserve personal protective equipment. However, the complexity of the neurosurgical patient proves to be a challenge and an opportunity for innovation. The goal of our study was to determine if telemedicine delivered through smart glasses was feasible and effective in an alternative method of conducting ward round on neurocritical care patients during the pandemic.
METHODS: A random pair of neurosurgery resident and specialist conducted consecutive virtual and physical ward rounds on neurocritical patients. A virtual ward round was first conducted remotely by a specialist who received real-time audiovisual information from a resident wearing smart glasses integrated with telemedicine. Subsequently, a physical ward round was performed together by the resident and specialist on the same patient. The management plans of both ward rounds were compared, and the intrarater reliability was measured. On study completion a qualitative survey was performed.
RESULTS: Ten paired ward rounds were performed on 103 neurocritical care patients with excellent overall intrarater reliability. Nine out of 10 showed good to excellent internal consistency, and 1 showed acceptable internal consistency. Qualitative analysis indicated wide user acceptance and high satisfaction rate with the alternative method.
CONCLUSIONS: Virtual ward rounds using telemedicine via smart glasses on neurosurgical patients in critical care were feasible, effective, and widely accepted as an alternative to physical ward rounds during the coronavirus disease 2019 pandemic.

Matched MeSH terms: Observer Variation
Rating the quality of the family environment in different cultures

Rey JM, Peng R, Morales-Blanquez C, Widyawati I, Peralta V, Walter G

J Am Acad Child Adolesc Psychiatry, 2000 Sep;39(9):1168-74.
PMID: 10986814 DOI: 10.1097/00004583-200009000-00017

OBJECTIVE:
To examine the extent to which clinicians from different cultures agree when rating the quality of a child's family environment and the effect of country, language, and training factors on these ratings.

METHOD:
Eighty-seven health professionals from Malaysia, Spain, Australia, Indonesia, the United States, Denmark, and Singapore rated 7 case vignettes using the Global Family Environment Scale. Half (54%) were psychiatrists. One quarter (26%) performed the ratings after attending a training session, the rest (n = 64, 74%) after reading a training manual.

RESULTS:
Overall, interrater agreement (intraclass r) was 0.84 (95% confidence interval: 0.68-0.96). There were no significant differences in agreement according to country, language, training, or professional group, although there were country differences in the ratings given to 2 vignettes. The majority of raters found the description of the anchor points (86%), training manual (95%), and case vignettes (97%) clear.

CONCLUSIONS:
Clinicians from different cultures seem to be able to make global ratings of the quality of the family environment that are reliable and consistent when using case vignettes. This can be achieved with little training. Global ratings of the quality of the family environment may be a useful tool in mental health research and clinical work.

Matched MeSH terms: Observer Variation
Objective assessment of psoriasis erythema for PASI scoring

Ahmad Fadzil MH, Ihtatho D, Affandi AM, Hussein SH

Annu Int Conf IEEE Eng Med Biol Soc, 2008;2008:4070-3.
PMID: 19163606 DOI: 10.1109/IEMBS.2008.4650103

Skin colour is vital information in dermatological diagnosis. It reflects pathological condition beneath the skin and commonly being used to indicate the extent of a disease. Psoriasis is a skin disease which is indicated by the appearance of red plaques. Although there is no cure for psoriasis, there are many treatment modalities to help control the disease. To evaluate treatment efficacy, PASI (Psoriasis Area and Severity Index) which is the current gold standard method is used to determine severity of psoriasis lesion. Erythema (redness) is one parameter in PASI. Commonly, the erythema is assessed visually, thus leading to subjective and inconsistent result. In this work, we proposed an objective assessment of psoriasis erythema for PASI scoring. The colour of psoriasis lesion is analyzed by DeltaL, Deltahue, and Deltachroma of CIELAB colour space. References of lesion with different scores are obtained from the selected lesions by two dermatologists. Results based on 38 lesions from 22 patients with various level of skin pigmentation show that PASI erythema score can be determined objectively and consistent with dermatology scoring.

Matched MeSH terms: Observer Variation
Above or below 14 years? An orthopantomographic study based on chronological course of eruption of mandibular premolars and second molars in a sample of south Indian children

Thomas LA, Thomas LR, Balla SB, Gopalaiah H, Kanaparthi A, Sai Sravanthi G, et al.

Leg Med (Tokyo), 2021 Feb;48:101814.
PMID: 33246253 DOI: 10.1016/j.legalmed.2020.101814

In the context of dental age assessment, two significant factors can be studied; tooth mineralisation and tooth emergence. Little is known about the role of a second molar eruption in forensic age estimation. This paper aims to contribute to forensic age estimation using an age threshold of 14 years, studying the eruption stages of permanent mandibular premolars and second molars. Totally 640 orthopantomograms (OPGs) of south Indian children, aged between 10 and 18 years, were evaluated using Olze et al. staging of tooth eruption stages (A-D). Spearman's rho correlation showed a strong, positive, and statistically significant correlation between the chronological age and the eruption stages of both sexes' teeth. Accuracy, sensitivity, specificity, likelihood ratios, and post-test probability values were calculated for all tested teeth. The best performance to discriminate individuals above or below 14 years showed stage D in second molars. The sensitivity varied between 89% and 94% and specificity between 75% and 84%, respectively. Receiver operating characteristic curve analysis revealed high diagnostic performance for stage D, with area under the ROC curve (AUC) values of 84% and 85% for tooth 37 and 85% and 83% for tooth 47 in males and females, respectively. In conclusion, it is possible to predict age over 14 years in south Indian children using tooth emergence stages from OPGs with a relatively high interobserver agreement and good diagnostic accuracy. However, there are some limitations and, therefore, must be used in conjunction with other methods.

Matched MeSH terms: Observer Variation
The interrater and test-retest reliability of the Home Falls and Accidents Screening Tool (HOME FAST) in Malaysia: Using raters with a range of professional backgrounds

Romli MH, Mackenzie L, Lovarini M, Tan MP, Clemson L

J Eval Clin Pract, 2017 Jun;23(3):662-669.
PMID: 28105771 DOI: 10.1111/jep.12697

RATIONALE, AIMS AND OBJECTIVES: Falls can be a devastating issue for older people living in the community, including those living in Malaysia. Health professionals and community members have a responsibility to ensure that older people have a safe home environment to reduce the risk of falls. Using a standardised screening tool is beneficial to intervene early with this group. The Home Falls and Accidents Screening Tool (HOME FAST) should be considered for this purpose; however, its use in Malaysia has not been studied. Therefore, the aim of this study was to evaluate the interrater and test-retest reliability of the HOME FAST with multiple professionals in the Malaysian context.
METHODS: A cross-sectional design was used to evaluate interrater reliability where the HOME FAST was used simultaneously in the homes of older people by 2 raters and a prospective design was used to evaluate test-retest reliability with a separate group of older people at different times in their homes. Both studies took place in an urban area of Kuala Lumpur.
RESULTS: Professionals from 9 professional backgrounds participated as raters in this study, and a group of 51 community older people were recruited for the interrater reliability study and another group of 30 for the test-retest reliability study. The overall agreement was moderate for interrater reliability and good for test-retest reliability. The HOME FAST was consistently rated by different professionals, and no bias was found among the multiple raters.
CONCLUSION: The HOME FAST can be used with confidence by a variety of professionals across different settings. The HOME FAST can become a universal tool to screen for home hazards related to falls.

Matched MeSH terms: Observer Variation
Investigation of random walks knee cartilage segmentation model using inter-observer reproducibility: Data from the osteoarthritis initiative

Hong-Seng G, Sayuti KA, Karim AH

Biomed Mater Eng, 2017;28(2):75-85.
PMID: 28372262 DOI: 10.3233/BME-171658

BACKGROUND: Existing knee cartilage segmentation methods have reported several technical drawbacks. In essence, graph cuts remains highly susceptible to image noise despite extended research interest; active shape model is often constraint by the selection of training data while shortest path have demonstrated shortcut problem in the presence of weak boundary, which is a common problem in medical images.
OBJECTIVES: The aims of this study is to investigate the capability of random walks as knee cartilage segmentation method.
METHODS: Experts would scribble on knee cartilage image to initialize random walks segmentation. Then, reproducibility of the method is assessed against manual segmentation by using Dice Similarity Index. The evaluation consists of normal cartilage and diseased cartilage sections which is divided into whole and single cartilage categories.
RESULTS: A total of 15 normal images and 10 osteoarthritic images were included. The results showed that random walks method has demonstrated high reproducibility in both normal cartilage (observer 1: 0.83±0.028 and observer 2: 0.82±0.026) and osteoarthritic cartilage (observer 1: 0.80±0.069 and observer 2: 0.83±0.029). Besides, results from both experts were found to be consistent with each other, suggesting the inter-observer variation is insignificant (Normal: P=0.21; Diseased: P=0.15).
CONCLUSION: The proposed segmentation model has overcame technical problems reported by existing semi-automated techniques and demonstrated highly reproducible and consistent results against manual segmentation method.

Matched MeSH terms: Observer Variation
Modified-BRISQUE as no reference image quality assessment for structural MR images

Chow LS, Rajagopal H

Magn Reson Imaging, 2017 11;43:74-87.
PMID: 28716679 DOI: 10.1016/j.mri.2017.07.016

An effective and practical Image Quality Assessment (IQA) model is needed to assess the image quality produced from any new hardware or software in MRI. A highly competitive No Reference - IQA (NR - IQA) model called Blind/Referenceless Image Spatial Quality Evaluator (BRISQUE) initially designed for natural images were modified to evaluate structural MR images. The BRISQUE model measures the image quality by using the locally normalized luminance coefficients, which were used to calculate the image features. The modified-BRISQUE model trained a new regression model using MR image features and Difference Mean Opinion Score (DMOS) from 775 MR images. Two types of benchmarks: objective and subjective assessments were used as performance evaluators for both original and modified-BRISQUE models. There was a high correlation between the modified-BRISQUE with both benchmarks, and they were higher than those for the original BRISQUE. There was a significant percentage improvement in their correlation values. The modified-BRISQUE was statistically better than the original BRISQUE. The modified-BRISQUE model can accurately measure the image quality of MR images. It is a practical NR-IQA model for MR images without using reference images.

Matched MeSH terms: Observer Variation

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