Displaying publications 221 - 240 of 255 in total

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  1. Fulltext Modified global and modified linear contrast stretching algorithms: new colour contrast enhancement techniques for microscopic analysis of malaria slide images
    Abdul-Nasir AS, Mashor MY, Mohamed Z
    Comput Math Methods Med, 2012;2012:637360.
    PMID: 23082089 DOI: 10.1155/2012/637360
    Malaria is one of the serious global health problem, causing widespread sufferings and deaths in various parts of the world. With the large number of cases diagnosed over the year, early detection and accurate diagnosis which facilitates prompt treatment is an essential requirement to control malaria. For centuries now, manual microscopic examination of blood slide remains the gold standard for malaria diagnosis. However, low contrast of the malaria and variable smears quality are some factors that may influence the accuracy of interpretation by microbiologists. In order to reduce this problem, this paper aims to investigate the performance of the proposed contrast enhancement techniques namely, modified global and modified linear contrast stretching as well as the conventional global and linear contrast stretching that have been applied on malaria images of P. vivax species. The results show that the proposed modified global and modified linear contrast stretching techniques have successfully increased the contrast of the parasites and the infected red blood cells compared to the conventional global and linear contrast stretching. Hence, the resultant images would become useful to microbiologists for identification of various stages and species of malaria.
    Matched MeSH terms: Image Processing, Computer-Assisted
  2. 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: Image Processing, Computer-Assisted
  3. Scattering noise estimation of range-gated imaging system in turbid condition
    Tan C, Seet G, Sluzek A, Wang X, Yuen CT, Fam CY, et al.
    Opt Express, 2010 Sep 27;18(20):21147-54.
    PMID: 20941011 DOI: 10.1364/OE.18.021147
    The range-gated imaging systems are reliable underwater imaging system with the capability to minimize backscattering effect from turbid media. The tail-gating technique has been developed to fine tune the signal to backscattering ratio and hence improve the gated image quality. However, the tail-gating technique has limited image quality enhancement in high turbidity levels. In this paper, we developed a numerical model of range-gated underwater imaging system for near target in turbid medium. The simulation results matched the experimental work favorably. Further investigation using this numerical model shows that the multiple scattering components of the backscattering noise dominate for propagation length larger than 4.2 Attenuation Length (AL). This has limited the enhancement of tail-gating technique in high turbidity conditions.
    Matched MeSH terms: Image Processing, Computer-Assisted
  4. Tooth size discrepancies in an orthodontic population
    Othman S, Harradine N
    Angle Orthod, 2007 Jul;77(4):668-74.
    PMID: 17605478
    To explore how many millimeters of tooth size discrepancy (TSD) are clinically significant, to determine what percentage of a representative orthodontic population has such a tooth size discrepancy, and to determine the ability of simple visual inspection to detect such a discrepancy.
    Matched MeSH terms: Image Processing, Computer-Assisted
  5. Dental arch shape and size in Malay schoolchildren with Class II malocclusion
    Banabilh SM, Rajion ZA, Samsudin R, Singh GD
    Aust Orthod J, 2006 Nov;22(2):99-103.
    PMID: 17203572
    To quantify and localise differences in Class I and Class II dental arches in Malay schoolchildren.
    Matched MeSH terms: Image Processing, Computer-Assisted
  6. Continuous separation of colloidal particles using dielectrophoresis
    Yunus NA, Nili H, Green NG
    Electrophoresis, 2013 Apr;34(7):969-78.
    PMID: 23436439 DOI: 10.1002/elps.201200466
    Dielectrophoresis is the movement of particles in nonuniform electric fields and has been of interest for application to manipulation and separation at and below the microscale. This technique has the advantages of being noninvasive, nondestructive, and noncontact, with the movement of particle achieved by means of electric fields generated by miniaturized electrodes and microfluidic systems. Although the majority of applications have been above the microscale, there is increasing interest in application to colloidal particles around a micron and smaller. This paper begins with a review of colloidal and nanoscale dielectrophoresis with specific attention paid to separation applications. An innovative design of integrated microelectrode array and its application to flow-through, continuous separation of colloidal particles is then presented. The details of the angled chevron microelectrode array and the test microfluidic system are then discussed. The variation in device operation with applied signal voltage is presented and discussed in terms of separation efficiency, demonstrating 99.9% separation of a mixture of colloidal latex spheres.
    Matched MeSH terms: Image Processing, Computer-Assisted
  7. Use of non-invasive phase contrast magnetic resonance imaging for estimation of atrial septal defect size and morphology: a comparison with transesophageal echo
    Piaw CS, Kiam OT, Rapaee A, Khoon LC, Bang LH, Ling CW, et al.
    Cardiovasc Intervent Radiol, 2006 Mar-Apr;29(2):230-4.
    PMID: 16252078
    Transesophageal echocardiography (TEE) is a trusted method of sizing atrial septal defect (ASD) prior to percutaneous closure but is invasive, uncomfortable, and may carry a small risk of morbidity and mortality. Magnetic resonance imaging (MRI) may be useful non-invasive alternative in such patients who refuse or are unable to tolerate TEE and may provide additional information on the shape of the A0SD.
    Matched MeSH terms: Image Processing, Computer-Assisted
  8. Decoding of visual information from human brain activity: A review of fMRI and EEG studies
    Zafar R, Malik AS, Kamel N, Dass SC, Abdullah JM, Reza F, et al.
    J Integr Neurosci, 2015 Jun;14(2):155-68.
    PMID: 25939499 DOI: 10.1142/S0219635215500089
    Brain is the command center for the body and contains a lot of information which can be extracted by using different non-invasive techniques. Electroencephalography (EEG), Magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) are the most common neuroimaging techniques to elicit brain behavior. By using these techniques different activity patterns can be measured within the brain to decode the content of mental processes especially the visual and auditory content. This paper discusses the models and imaging techniques used in visual decoding to investigate the different conditions of brain along with recent advancements in brain decoding. This paper concludes that it's not possible to extract all the information from the brain, however careful experimentation, interpretation and powerful statistical tools can be used with the neuroimaging techniques for better results.
    Matched MeSH terms: Image Processing, Computer-Assisted
  9. Fulltext Brain death: rapid evaluation using computerized radionuclide cerebral flow study
    Paramsothy M, Ong GSY, Wong BH, Loh TG, Delilkan AE
    Med J Malaysia, 1986 Sep;41(3):189-97.
    PMID: 2823083
    Demonstration of arrested intracerebral blood flow is the ultimate evidence of brain death. Computerized radionuclide cerebral flow study was done on 18 patients diagnosed clinically as brain dead. Correlation was made with clinical neurophysiological and EEG findings. The criteria for diagnosis of arrested intracerebral perfusion using radionuclide flow study were: non-visualization of blood flow activity in the intracranial arteries during the arterial phase, diffused cerebral activity during the capillary phase and non-filling of venous sinuses during the venous phase; visualization of typical 'hot nasal' activity; the time activity curve over the cerebral hemispheres lacks a bolus effect and instead shows a delayed gradual rise of activity. These features are pathognomonic of brain tamponade.
    Arrested intracranial circulation was seen in 16 patients (ten had electrocerebral silence; one had extremely abnormal EEG with small voltage activity and five had no EEG done). In the remaining two patients, some cerebral blood flow was demonstrated (one had no definite cerebral activity and the other had diffused EEG activity).
    Radionuclide cerebral flow study is a very sensitive, accurate, safe, simple, rapid and non-invasive modality in confirming brain death and is especially useful in patients on "brain-protection" regime, in hypothermia or in certain metabolic states where diagnosis based on clinical and EEG criteria is difficult. EEG need not be a required procedure once brain death is established by the demonstration of arrested intracranial circulation.
    Matched MeSH terms: Image Processing, Computer-Assisted
  10. Cross-sectional morphology and minimum canal wall widths in C-shaped roots of mandibular molars
    Chai WL, Thong YL
    J Endod, 2004 Jul;30(7):509-12.
    PMID: 15220648
    The cross-sectional canal morphology and minimum widths of buccal and lingual canal walls were studied in 20 mandibular molars with C-shaped roots and canal orifices. The roots were mounted in clear resin blocks and sectioned transversely at 1-mm intervals. A total of 154 cross-sections were evaluated with an image analyzer. Twelve different longitudinal canal configurations were identified. The most prevalent were types 1-2 and 1-2-1 with each type occurring in four roots. Evaluation of the cross-sectional morphology showed that the configurations were complete "C" (27%), incomplete C (64%), and non-C (9%). The mean value for the minimum width of the lingual canal wall was 0.58 +/- 0.21 mm and the buccal wall was 0.96 +/- 0.26 mm. This suggests that there is a higher risk of root perforation at the thinner lingual walls of C-shaped canals during shaping and post canal preparation procedures. Both buccal and lingual canal walls were frequently narrower at mesial locations.
    Matched MeSH terms: Image Processing, Computer-Assisted
  11. Probing the characteristics and biofunctional effects of disease-affected cells and drug response via machine learning applications
    Mudali D, Jeevanandam J, Danquah MK
    Crit Rev Biotechnol, 2020 Nov;40(7):951-977.
    PMID: 32633615 DOI: 10.1080/07388551.2020.1789062
    Drug-induced transformations in disease characteristics at the cellular and molecular level offers the opportunity to predict and evaluate the efficacy of pharmaceutical ingredients whilst enabling the optimal design of new and improved drugs with enhanced pharmacokinetics and pharmacodynamics. Machine learning is a promising in-silico tool used to simulate cells with specific disease properties and to determine their response toward drug uptake. Differences in the properties of normal and infected cells, including biophysical, biochemical and physiological characteristics, plays a key role in developing fundamental cellular probing platforms for machine learning applications. Cellular features can be extracted periodically from both the drug treated, infected, and normal cells via image segmentations in order to probe dynamic differences in cell behavior. Cellular segmentation can be evaluated to reflect the levels of drug effect on a distinct cell or group of cells via probability scoring. This article provides an account for the use of machine learning methods to probe differences in the biophysical, biochemical and physiological characteristics of infected cells in response to pharmacokinetics uptake of drug ingredients for application in cancer, diabetes and neurodegenerative disease therapies.
    Matched MeSH terms: Image Processing, Computer-Assisted
  12. The Heritability of Palatal Rugae Morphology Among Siblings*, †
    Chong JA, Syed Mohamed AMF, Marizan Nor M, Pau A
    J Forensic Sci, 2020 Nov;65(6):2000-2007.
    PMID: 32692413 DOI: 10.1111/1556-4029.14507
    Although there is clinical applicability of the palatal rugae as an identification tool in forensic odontology, controversy exists whether the palatal rugae patterns are stable or variable. The greater the genetic component, the higher the probability that palatal rugae patterns are stable. The aim of this study was to compare the palatal rugae morphology between full siblings and the proportion of variability due to genetic component. This cross-sectional study was conducted on digital models of 162 siblings aged 15-30 years old. The palatal rugae patterns were assessed with Thomas and Kotze (1983) classification using Geomagic Studio software (3D Systems, Rock Hill, SC). The palatal rugae morphology between siblings showed significantly similar characteristics for total number of left rugae (p = 0.001), left primary rugae (p = 0.017), secondary rugae for right (p = 0.024) and left sides (p = 0.001), right straight rugae (p = 0.010), and right convergent rugae (p = 0.005) accounting for at least 6.25%-12.8% of the variability due to heredity. Despite the similarities found, the palatal rugae patterns showed significant differences between siblings of at least 46.9% (p = 0.001). Zero heritability was found in 9 of the 14 rugae patterns. Meanwhile, total number of rugae, primary, backward, and convergent rugae showed moderate heritability (h2  > 0.3) and total number of secondary rugae showed high heritability (h2  > 0.6). In conclusion, despite the individuality characteristics, an appreciable hereditary component is observed with significant similarities found between sibling pairs and the palatal rugae patterns were both environmentally and genetically influenced.
    Matched MeSH terms: Image Processing, Computer-Assisted
  13. Fulltext Protein expression in sera of patients with amoebic liver abscess (ALA): potential use of haptoglobin as a surrogate disease marker
    Othman N, Zainudin NS, Mohamed Z, Yahya MM, Leow VM, Noordin R
    Trop Biomed, 2013 Jun;30(2):257-66.
    PMID: 23959491 MyJurnal
    The protein profile of serum samples from patients with amoebic liver abscess (ALA) was compared to those of normal individuals to determine their expression levels and to identify potential surrogate disease markers. Serum samples were resolved by two dimensional electrophoresis (2-DE) followed by image analysis. The up and down-regulated protein spots were excised from the gels and analysed by MS/MS. The concentration of three clusters of proteins i.e. haptoglobin (HP), α1-antitrypsin (AAT) and transferrin in serum samples of ALA patients and healthy controls were compared using competitive ELISA. In addition, serum concentrations of HP and transferrin in samples of patients with ALA and pyogenic liver abscess (PLA) were also compared. The results of the protein 2-DE expression analysis showed that HP cluster, AAT cluster, one spot each from unknown spots no. 1 and 2 were significantly up-regulated and transferrin cluster was significantly down-regulated in ALA patients' sera (p<0.05). The MS/MS analysis identified the unknown protein spot no.1 as human transcript and haptoglobin and spot no. 2 as albumin. Competitive ELISA which compared concentrations of selected proteins in sera of ALA and healthy controls verified the up-regulated expression (p<0.05) of HP and the down-regulated expression (p<0.01) of transferrin in the former, while there was no significant difference in AAT expression (p> 0.05). However, when ALA and PLA samples were compared, competitive ELISA showed significant increased concentration of HP (p<0.05) while transferrin levels were not different. In conclusion, this study showed that HP is a potential surrogate disease marker for ALA.
    Matched MeSH terms: Image Processing, Computer-Assisted
  14. A study of decoding human brain activities from simultaneous data of EEG and fMRI using MVPA
    Zafar R, Kamel N, Naufal M, Malik AS, Dass SC, Ahmad RF, et al.
    Australas Phys Eng Sci Med, 2018 Sep;41(3):633-645.
    PMID: 29948968 DOI: 10.1007/s13246-018-0656-5
    Neuroscientists have investigated the functionality of the brain in detail and achieved remarkable results but this area still need further research. Functional magnetic resonance imaging (fMRI) is considered as the most reliable and accurate technique to decode the human brain activity, on the other hand electroencephalography (EEG) is a portable and low cost solution in brain research. The purpose of this study is to find whether EEG can be used to decode the brain activity patterns like fMRI. In fMRI, data from a very specific brain region is enough to decode the brain activity patterns due to the quality of data. On the other hand, EEG can measure the rapid changes in neuronal activity patterns due to its higher temporal resolution i.e., in msec. These rapid changes mostly occur in different brain regions. In this study, multivariate pattern analysis (MVPA) is used both for EEG and fMRI data analysis and the information is extracted from distributed activation patterns of the brain. The significant information among different classes is extracted using two sample t test in both data sets. Finally, the classification analysis is done using the support vector machine. A fair comparison of both data sets is done using the same analysis techniques, moreover simultaneously collected data of EEG and fMRI is used for this comparison. The final analysis is done with the data of eight participants; the average result of all conditions are found which is 65.7% for EEG data set and 64.1% for fMRI data set. It concludes that EEG is capable of doing brain decoding with the data from multiple brain regions. In other words, decoding accuracy with EEG MVPA is as good as fMRI MVPA and is above chance level.
    Matched MeSH terms: Image Processing, Computer-Assisted
  15. Segmentation of left ventricle in late gadolinium enhanced MRI through 2D-4D registration for infarct localization in 3D patient-specific left ventricular model
    Leong CO, Lim E, Tan LK, Abdul Aziz YF, Sridhar GS, Socrates D, et al.
    Magn Reson Med, 2019 02;81(2):1385-1398.
    PMID: 30230606 DOI: 10.1002/mrm.27486
    PURPOSE: To evaluate a 2D-4D registration-cum-segmentation framework for the delineation of left ventricle (LV) in late gadolinium enhanced (LGE) MRI and for the localization of infarcts in patient-specific 3D LV models.

    METHODS: A 3-step framework was proposed, consisting of: (1) 3D LV model reconstruction from motion-corrected 4D cine-MRI; (2) Registration of 2D LGE-MRI with 4D cine-MRI; (3) LV contour extraction from the intersection of LGE slices with the LV model. The framework was evaluated against cardiac MRI data from 27 patients scanned within 6 months after acute myocardial infarction. We compared the use of local Pearson's correlation (LPC) and normalized mutual information (NMI) as similarity measures for the registration. The use of 2 and 6 long-axis (LA) cine-MRI scans was also compared. The accuracy of the framework was evaluated using manual segmentation, and the interobserver variability of the scar volume derived from the segmented LV was determined using Bland-Altman analysis.

    RESULTS: LPC outperformed NMI as a similarity measure for the proposed framework using 6 LA scans, with Hausdorrf distance (HD) of 1.19 ± 0.53 mm versus 1.51 ± 2.01 mm (endocardial) and 1.21 ± 0.48 mm versus 1.46 ± 1.78 mm (epicardial), respectively. Segmentation using 2 LA scans was comparable to 6 LA scans with a HD of 1.23 ± 0.70 mm (endocardial) and 1.25 ± 0.74 mm (epicardial). The framework yielded a lower interobserver variability in scar volumes compared with manual segmentation.

    CONCLUSION: The framework showed high accuracy and robustness in delineating LV in LGE-MRI and allowed for bidirectional mapping of information between LGE- and cine-MRI scans, crucial in personalized model studies for treatment planning.

    Matched MeSH terms: Image Processing, Computer-Assisted
  16. Facial dimensions of Malay children with repaired unilateral cleft lip and palate: a three dimensional analysis
    Zreaqat M, Hassan R, Halim AS
    Int J Oral Maxillofac Surg, 2012 Jun;41(6):783-8.
    PMID: 22424709 DOI: 10.1016/j.ijom.2012.02.003
    This comparative cross-sectional study assessed the facial surface dimensions of a group of Malay children with unilateral cleft lip and palate (UCLP) and compared them with a control group. 30 Malay children with UCLP aged 8-10 years and 30 unaffected age-matched children were voluntarily recruited from the Orthodontic Specialist Clinic in Hospital Universiti Sains Malaysia (HUSM). For the cleft group, lip and palate were repaired and assessment was performed prior to alveolar bone grafting and orthodontic treatment. The investigation was carried out using 3D digital stereophotogrammetry. 23 variables and two ratios were compared three-dimensionally between both groups. Statistically significant dimensional differences (P<0.05) were found between the UCLP Malay group and the control group mainly in the nasolabial region. These include increased alar base and alar base root width, shorter upper lip length, and increased nose base/mouth width ratio in the UCLP group. There were significant differences between the facial surface morphology of UCLP Malay children and control subjects. Particular surgical procedures performed during primary surgeries may contribute to these differences and negatively affect the surgical outcome.
    Matched MeSH terms: Image Processing, Computer-Assisted/methods
  17. Fulltext Multiple adaptive neuro-fuzzy inference system with automatic features extraction algorithm for cervical cancer recognition
    Al-batah MS, Isa NA, Klaib MF, Al-Betar MA
    Comput Math Methods Med, 2014;2014:181245.
    PMID: 24707316 DOI: 10.1155/2014/181245
    To date, cancer of uterine cervix is still a leading cause of cancer-related deaths in women worldwide. The current methods (i.e., Pap smear and liquid-based cytology (LBC)) to screen for cervical cancer are time-consuming and dependent on the skill of the cytopathologist and thus are rather subjective. Therefore, this paper presents an intelligent computer vision system to assist pathologists in overcoming these problems and, consequently, produce more accurate results. The developed system consists of two stages. In the first stage, the automatic features extraction (AFE) algorithm is performed. In the second stage, a neuro-fuzzy model called multiple adaptive neuro-fuzzy inference system (MANFIS) is proposed for recognition process. The MANFIS contains a set of ANFIS models which are arranged in parallel combination to produce a model with multi-input-multioutput structure. The system is capable of classifying cervical cell image into three groups, namely, normal, low-grade squamous intraepithelial lesion (LSIL) and high-grade squamous intraepithelial lesion (HSIL). The experimental results prove the capability of the AFE algorithm to be as effective as the manual extraction by human experts, while the proposed MANFIS produces a good classification performance with 94.2% accuracy.
    Matched MeSH terms: Image Processing, Computer-Assisted
  18. Improved biliary detection and diagnosis through intelligent machine analysis
    Logeswaran R
    Comput Methods Programs Biomed, 2012 Sep;107(3):404-12.
    PMID: 21194781 DOI: 10.1016/j.cmpb.2010.12.002
    This paper reports on work undertaken to improve automated detection of bile ducts in magnetic resonance cholangiopancreatography (MRCP) images, with the objective of conducting preliminary classification of the images for diagnosis. The proposed I-BDeDIMA (Improved Biliary Detection and Diagnosis through Intelligent Machine Analysis) scheme is a multi-stage framework consisting of successive phases of image normalization, denoising, structure identification, object labeling, feature selection and disease classification. A combination of multiresolution wavelet, dynamic intensity thresholding, segment-based region growing, region elimination, statistical analysis and neural networks, is used in this framework to achieve good structure detection and preliminary diagnosis. Tests conducted on over 200 clinical images with known diagnosis have shown promising results of over 90% accuracy. The scheme outperforms related work in the literature, making it a viable framework for computer-aided diagnosis of biliary diseases.
    Matched MeSH terms: Image Processing, Computer-Assisted
  19. Minimally invasive image-guided removal of retrobulbar intraconal foreign body
    Vairavan N, Tajunisah I, Subrayan V, Waran V
    Orbit, 2009;28(6):442-3.
    PMID: 19929682 DOI: 10.3109/01676830903103365
    Surgical approaches are becoming increasingly minimally invasive, without compromising either safety or ease. Penetrating ocular foreign bodies has traditionally been approached either by intraocular or supraorbital access. We successfully attempted a minimally invasive approach to remove a retrobulbar foreign body under computer-assisted image guidance in a 19-year-old man involved in an industrial mishap.
    Matched MeSH terms: Image Processing, Computer-Assisted
  20. An Asian community's perspective on facial profile attractiveness
    Soh J, Chew MT, Wong HB
    Community Dent Oral Epidemiol, 2007 Feb;35(1):18-24.
    PMID: 17244134
    To assess the facial profile preferences of laypersons in an Asian community and the influence of age, ethnic and gender on profile selection.
    Matched MeSH terms: Image Processing, Computer-Assisted
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