Image quality assessment

Quality assessment is an integral stage in the processing and analysis of digital images in various automated systems. With the increase in the number and variety of devices that allow receiving data in various digital formats, as well as the expansion of human activities in which information technology (IT) is used, the need to assess the quality of the data obtained is growing. As well as the bar grows for the requirements for their quality.The article describes the factors that deteriorate the quality of digital images, areas of application of image quality assessment functions, a method for normalizing proximity measures, classes of digital images and their possible distortions, image databases available on the Internet for conducting experiments on assessing image quality with visual assessments of experts.

Comparison of non-subjective relative fungal biomass measurements to quantify the Leptosphaeria maculans—Brassica napus interaction

Background Blackleg disease, caused by the fungal pathogen Leptosphaeria maculans, is a serious threat to canola (Brassica napus) production worldwide. Quantitative resistance to this disease is a highly desirable trait but is difficult to precisely phenotype. Visual scores can be subjective and are prone to assessor bias. Methods to assess variation in quantitative resistance more accurately were developed based on quantifying in planta fungal biomass, including the Wheat Germ Agglutinin Chitin Assay (WAC), qPCR and ddPCR assays. Results Disease assays were conducted by inoculating a range of canola cultivars with L. maculans isolates in glasshouse experiments and assessing fungal biomass in cotyledons, petioles and stem tissue harvested at different timepoints post-inoculation. PCR and WAC assay results were well correlated, repeatable across experiments and host tissues, and able to differentiate fungal biomass in different host-isolate treatments. In addition, the ddPCR assay was shown to differentiate between L. maculans isolates. Conclusions The ddPCR assay is more sensitive in detecting pathogens and more adaptable to high-throughput methods by using robotic systems than the WAC assay. Overall, these methods proved accurate and non-subjective, providing alternatives to visual assessments to quantify the L. maculans-B. napus interaction in all plant tissues throughout the progression of the disease in seedlings and mature plants and have potential for fine-scale blackleg resistance phenotyping in canola.

PSI-3 An assessment of the barrier function of canine skin after repeated decontamination

Working canines are often deployed to environments with unknown chemical and biological contaminants. Deployed canines may operate in highly contaminated disaster sites for lengthy periods of time requiring daily decontamination efforts. The skin provides a barrier by retaining moisture and preventing entry by contaminants and pathogens. However, few data exist on the impact of repeated decontamination to the canine skin. The objective of this study was to identify changes in dermal health during and after a 14-day serial decontamination program. Labrador retrievers (n = 8) were decontaminated daily using a dish detergent solution (1:8, detergent:water). Skin measurements were collected weekly for pH, trans-epidermal water loss (TEWL), sebum, and moisture. Additionally, visual assessments were recorded for skin health, coat condition, and dander scores (back and body). Statistical tests were conducted with SAS (version 9.4) with measurements analyzed using a PROC GLM Two Way ANOVA and visual assessments analyzed using PROC FREQ Chi Square test. Significance was set at 5% for all tests. Repeated decontamination significantly increased TEWL (P < 0.0001) through day 16. Sebum content was also impacted by repeated daily decontamination efforts (P = 0.0387). Sebum decreased initially before steadily rising. In contrast, moisture content (P = 0.3842) and pH (P = 0.7462), were unaffected by repeated decontamination. Interestingly, dander scores assessed on the back were worsened by repeated decontamination (P = 0.0222) but dander scores assessed across the whole body were unaffected (P = 0.1804). Coat shine was unaffected by decontamination (P = 0.1156) similar to coat softness (P = 0.3418). Overall coat condition remained unchanged as a result of repeated decontamination efforts (P = 0.9466). These data reveal that daily decontamination impacts dermal function, potentially risks for canines working in contaminated areas. Future work should include investigations into methods for decontamination to mitigate these risks.

Visual outcomes of cataract surgery: An observational study of ten years from a tertiary eye care hospital in Pakistan

Objectives: To observe and analyze the visual outcomes of cataract surgery of ten years at a tertiary eye care hospital, Karachi. Methods: An observational study with retrospective data search was conducted in Al Ibrahim Eye Hospital (AIEH), Karachi. Data of all adults (above 16 years) who underwent cataract surgery from 2010-2019 was retrieved from HIMS. Presence of opacity in the lens was labelled as cataract. Surgery was advised when patient’s BCVA was found to be 6/18. Visual assessments of the patients were done on day 01, one week and six weeks postoperatively. Postoperatively, 6/6 – 6/12 was considered as good, 6/18 as mild visual impairment, < 6/18 to 6/60 as moderate visual impairment and < 6/60 as severe visual impairment. Results: A total of 1,027,840 patients visited AIEH with different eye diseases. Among 1027840 individuals, cataract was identified in 88443 (8.6%). Surgery was advised to 58371 and performed in 38616. Records of operated cases (38616) were retrieved. Mean age of patients was 54.96±14.22 years. There were 20578 (53.29%) males and 18038 (46.71%) females who underwent surgery . At the end of sixth week, 3561 (18.4%), patients were found to have “good vision”, 12242 (63.43%) had mild visual impairment, 2676 (13.86%) had moderate visual impairment and 822 (4.26%) had severe visual impairment. Corneal Complications was the commonest cause (33.56%) at sixth week. Conclusions: The institution achieved WHO recommended criteria of “good visual outcome” (6/6 to 6/18) of 81.83% which is near to recommended ≥ 90% and severe visual impairment of 4.26%. doi: https://doi.org/10.12669/pjms.37.7.4428 How to cite this:Ahsan S, Memon MS, Bukhari S, Mahmood T, Fahim MF, Haseeb U, et al. Visual outcomes of cataract surgery: An observational study of ten years from a tertiary eye care hospital in Pakistan. Pak J Med Sci. 2021;37(7):---------. doi: https://doi.org/10.12669/pjms.37.7.4428 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Benefits of Using Fluorescence Induced Theragnosis in Fixed Orthodontic Therapy: Status, Technology and Future Trends

Dental biofilm is often found to be the source of bacteria that releases toxins, peptides, lipopolysaccharides as well as organic acids, which lead to gingival inflammation and tooth caries. Further, the persistent plaque may result in the continued destruction of the surrounding soft and hard tissues. During fixed orthodontic therapy, arch-wires, brackets, and elastic modules have been shown to be sites of significant plaque accumulation, making it difficult for a patient to maintain proper oral hygiene. The problem most dentists face is that they cannot visualize this biofilm completely to be able to carry out efficient plaque removal. Visual assessment is, to date, the most common method for plaque visualization, and various indexes have been demonstrated to be sufficient for quantification of the amount of plaque present. However, the problem is that visual assessments are inconsistent, operator dependent and often subjective, which can lead to inconsistency in results. Fluorescence is one such method that can be explored for its use in effective plaque identification and removal. Literature has it that dentists and patients find it particularly useful for monitoring oral hygiene status during treatment. Fluorescence has the capability of offering clinical orthodontists and researchers a new method of detection of demineralization during orthodontic treatment, furthermore, for efficient removal of orthodontic adhesive cements, fluorescent light may be used in conjunction with high-speed burs to deliver fast, less time consuming, and safer results. The benefit of direct visual treatment using fluorescence enhanced theragnosis is that the patient receives controlled and guided therapy. It has multiple benefits, such as early diagnosis of caries, biofilm identification, and even helps to achieve improved treatment outcomes by better resin selection for esthetic procedures.

Multi-level dilated residual network for biomedical image segmentation

We propose a novel multi-level dilated residual neural network, an extension of the classical U-Net architecture, for biomedical image segmentation. U-Net is the most popular deep neural architecture for biomedical image segmentation, however, despite being state-of-the-art, the model has a few limitations. In this study, we suggest replacing convolutional blocks of the classical U-Net with multi-level dilated residual blocks, resulting in enhanced learning capability. We also propose to incorporate a non-linear multi-level residual blocks into skip connections to reduce the semantic gap and to restore the information lost when concatenating features from encoder to decoder units. We evaluate the proposed approach on five publicly available biomedical datasets with different imaging modalities, including electron microscopy, magnetic resonance imaging, histopathology, and dermoscopy, each with its own segmentation challenges. The proposed approach consistently outperforms the classical U-Net by 2%, 3%, 6%, 8%, and 14% relative improvements in dice coefficient, respectively for magnetic resonance imaging, dermoscopy, histopathology, cell nuclei microscopy, and electron microscopy modalities. The visual assessments of the segmentation results further show that the proposed approach is robust against outliers and preserves better continuity in boundaries compared to the classical U-Net and its variant, MultiResUNet.

How much do standard area diagrams improve accuracy of visual estimates of plant disease severity? A systematic review and meta-analysis

Plant disease severity is commonly estimated visually without or with the aid of standard area diagram sets (SADs). It is generally believed that the use of SADs leads to less biased (more accurate) and thus more precise estimates, but the degree of improvement has not been characterized in a systematic manner. We built on a previous review and screened 153 SAD studies published from 1990 to 2021. A systematic review resulted in a selection of 72 studies that reported three linear regression statistics for individual raters, which are indicative of the two components of bias (intercept = constant bias; slope = systematic bias) and precision (Pearson's correlation coefficient, r), to perform a meta-analysis of these accuracy components. The meta-analytic model determined an overall gain of 0.07 (r increased from 0.88 to 0.95) in precision. Globally, there was a reduction of 2.65 units in the intercept, from 3.41 to 0.76, indicating a reduction in the constant bias. Slope was least affected and was reduced slightly from 1.09 to 0.966, indicating marginally less systematic bias when using SADs. A multiple correspondence analysis suggested an association of less accurate, unaided estimates with diseases that produce numerous lesions and for which maximum severities of 50% are rarely attained. On the other hand, more accurate estimates were observed with diseases that cause only a few lesions and those diseases where the lesions coalesce and occupy more than 50% of the specimen surface. This was most pronounced for specimen types other than leaves. By quantitatively exploring how characteristics of the pathosystem and how SADs affect precision and constant and systematic biases, we affirm the value of SADs for reducing bias and imprecision of visual assessments. We have also identified situations where SADs have greater or lesser effects as an assessment aid.

Dowsing for Bone

Locating clandestine graves is often a significant challenge for law enforcement and other investigators. A number of search techniques can be employed including visual assessments, canines, geophysical techniques, and imaging, often depending on the location/terrain, case information, and available resources. Dowsing is believed by some to be a reliable method for locating underground items of interest including water, oil, ore, and even graves; others, however, consider the practice to be controversial or even pseudoscience. Here we assess the ability of dowsing rods (wielded by previously inexperienced dowsers) to locate buried bones using a controlled blind test. Assemblages of bones were buried in three of nine holes. A control group of participants was asked to identify which holes they believed to contain bones by visual inspection, and a test group was asked to identify which holes they believed to contain bones using dowsing rods. Results indicate that neither method had a significant relationship with the true location of the bones (Matthew’s Correlation Coefficient –0.19 for the control group and 0.00 for the test group), and that there was no significant difference between the two groups (p = 0.36). In this study, dowsing was not found to be a reliable method of detecting buried bones. Some practitioners continue to advocate dowsing or other scientifically questionable search methods, even charging investigators or families substantial fees for these services. It is therefore important that such techniques are well-understood and rigorously tested, and that investigators seek and employ methods that are appropriate and valid.