Displaying publications 1 - 20 of 165 in total

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  1. Saif AF, Prabuwono AS, Mahayuddin ZR
    PLoS One, 2015;10(6):e0126212.
    PMID: 26030818 DOI: 10.1371/journal.pone.0126212
    Fast and computationally less complex feature extraction for moving object detection using aerial images from unmanned aerial vehicles (UAVs) remains as an elusive goal in the field of computer vision research. The types of features used in current studies concerning moving object detection are typically chosen based on improving detection rate rather than on providing fast and computationally less complex feature extraction methods. Because moving object detection using aerial images from UAVs involves motion as seen from a certain altitude, effective and fast feature extraction is a vital issue for optimum detection performance. This research proposes a two-layer bucket approach based on a new feature extraction algorithm referred to as the moment-based feature extraction algorithm (MFEA). Because a moment represents the coherent intensity of pixels and motion estimation is a motion pixel intensity measurement, this research used this relation to develop the proposed algorithm. The experimental results reveal the successful performance of the proposed MFEA algorithm and the proposed methodology.
    Matched MeSH terms: Imaging, Three-Dimensional*
  2. Hariri F, Zainudin NAA, Anuar AMS, Ibrahim N, Abdullah NA, Aziz IA, et al.
    J Craniofac Surg, 2020 11 7;32(1):355-359.
    PMID: 33156163 DOI: 10.1097/SCS.0000000000006981
    BACKGROUND: In syndromic craniosynostosis (SC), unlike persistent corneal irritation due to severe exophthalmos and increased intracranial pressure, optic canal (OC) stenosis has been scarcely reported to cause visual impairment. This study aimed to validate the OC volumetric and surface area measurement among SC patients.

    METHODS: Sixteen computed tomography scan of SC patients (8 months-6 years old) were imported to Materialise Interactive Medical Image Control System (MIMICS) and Materialise 3-matics software. Three-dimensional (3D) OC models were fabricated, and linear measurements were obtained. Mathematical formulas were used for calculation of OC volume and surface area from the 3D model. The same measurements were obtained from the software and used as ground truth. Data normality was investigated before statistical analyses were performed. Wilcoxon test was used to validate differences of OC volume and surface area between 3D model and software.

    RESULTS: The mean values for OC surface area for 3D model and MIMICS software were 103.19 mm2 and 31.27 mm2, respectively, whereas the mean for OC volume for 3D model and MIMICS software were 184.37 mm2 and 147.07 mm2, respectively. Significant difference was found between OC volume (P = 0.0681) and surface area (P = 0.0002) between 3D model and software.

    CONCLUSION: Optic canal in SC is not a perfect conical frustum thus making 3D model measurement and mathematical formula for surface area and volume estimation not ideal. Computer software remains the best modality to gauge dimensional parameter and is useful to elucidates the relationship of OC and eye function as well as aiding intervention in SC patients.

    Matched MeSH terms: Imaging, Three-Dimensional*
  3. Rajion, Z.A.
    MyJurnal
    Imaging is a keystone for the understanding and delivery of craniofacial health care and recent developments have led to many diverse technologies and approaches. This paper reviews new developments in three-dimensional imaging, as well as three-dimensional facial image acquisition. Visualization and convergence of the data from these technologies are also described for construction of patient-specific models.
    Matched MeSH terms: Imaging, Three-Dimensional
  4. Ali A, Logeswaran R
    J Digit Imaging, 2007 Dec;20(4):352-66.
    PMID: 17372781
    This article proposes a set-up for a 3-dimensional ultrasound system using visual probe localization on the conventional 2-dimensional ultrasound machines readily available in most hospitals. A calibrated digital camera is used for probe-tracking (localization) purposes, whereas ultrasound probe calibration is implemented using a purpose-built phantom. The calibration steps and results are detailed here. The overall system is proven effective in clinical trials through scanning of human organs. Results obtained show successful, accurate 3-dimensional representations using this simple cost-effective set-up.
    Matched MeSH terms: Imaging, Three-Dimensional/economics*; Imaging, Three-Dimensional/instrumentation
  5. Chan VS, Mohamed F, Yusoff YA, Dewi DEO, Anuar A, Shamsudin MA, et al.
    Med Biol Eng Comput, 2020 May;58(5):889-902.
    PMID: 31599379 DOI: 10.1007/s11517-019-02044-4
    Position tracking has been widely used in medical applications, especially in 3D ultrasound imaging, where it has transformed the 2D slice limitation into 3D volume with bigger clinical impacts. As a game controller can also produce position tracking information, it has the potential to act as a low-cost and portable position tracker for ultrasound probes. This paper aims to investigate the feasibility of a game controller to perform as a position tracker and to design its implementation in 3D ultrasound imaging. The study consists of data acquisition and 3D ultrasound reconstruction for visualization. The data acquisition is accomplished by capturing the 2D ultrasound frame and its relative positional and orientation data by using an ultrasound probe and game controller respectively. These data are further reconstructed to produce 3D ultrasound volume for visualization. Our experiments include game controller position tracker testing and 3D ultrasound reconstruction on baby phantom. The results have confirmed that the game controller performance was closely aligned with that of in a robot arm. Also, the 3D ultrasound reconstruction implementation has revealed promising outcomes. With these features, the function of the currently available ultrasound probes can be prospectively improved using a game controller position tracker effectively. Graphical Abstract.
    Matched MeSH terms: Imaging, Three-Dimensional/instrumentation*; Imaging, Three-Dimensional/methods*
  6. Gandhamal A, Talbar S, Gajre S, Razak R, Hani AFM, Kumar D
    Comput Biol Med, 2017 Sep 01;88:110-125.
    PMID: 28711767 DOI: 10.1016/j.compbiomed.2017.07.008
    Knee osteoarthritis (OA) progression can be monitored by measuring changes in the subchondral bone structure such as area and shape from MR images as an imaging biomarker. However, measurements of these minute changes are highly dependent on the accurate segmentation of bone tissue from MR images and it is challenging task due to the complex tissue structure and inadequate image contrast/brightness. In this paper, a fully automated method for segmenting subchondral bone from knee MR images is proposed. Here, the contrast of knee MR images is enhanced using a gray-level S-curve transformation followed by automatic seed point detection using a three-dimensional multi-edge overlapping technique. Successively, bone regions are initially extracted using distance-regularized level-set evolution followed by identification and correction of leakages along the bone boundary regions using a boundary displacement technique. The performance of the developed technique is evaluated against ground truths by measuring sensitivity, specificity, dice similarity coefficient (DSC), average surface distance (AvgD) and root mean square surface distance (RMSD). An average sensitivity (91.14%), specificity (99.12%) and DSC (90.28%) with 95% confidence interval (CI) in the range 89.74-92.54%, 98.93-99.31% and 88.68-91.88% respectively is achieved for the femur bone segmentation in 8 datasets. For tibia bone, average sensitivity (90.69%), specificity (99.65%) and DSC (91.35%) with 95% CI in the range 88.59-92.79%, 99.50-99.80% and 88.68-91.88% respectively is achieved. AvgD and RMSD values for femur are 1.43 ± 0.23 (mm) and 2.10 ± 0.35 (mm) respectively while for tibia, the values are 0.95 ± 0.28 (mm) and 1.30 ± 0.42 (mm) respectively that demonstrates acceptable error between proposed method and ground truths. In conclusion, results obtained in this work demonstrate substantially significant performance with consistency and robustness that led the proposed method to be applicable for large scale and longitudinal knee OA studies in clinical settings.
    Matched MeSH terms: Imaging, Three-Dimensional/methods*
  7. Ahmed N, Halim MSB, Ghani ZA, Khan ZA, Abbasi MS, Jamayet NB, et al.
    Biomed Res Int, 2021;2021:6674400.
    PMID: 33969123 DOI: 10.1155/2021/6674400
    The objective of this paper was to evaluate the existence of golden percentage in natural maxillary anterior teeth with the aid of 3D digital dental models and 2D photographs. And to propose regional values of golden percentage for restoration of maxillary anterior teeth. For this purpose, one hundred and ninety dentate subjects with sound maxillary anterior teeth were selected. Standardized frontal images were captured with DSLR, and the apparent width of maxillary anterior teeth was measured utilizing a software on a personal laptop computer. Once the dimensions were recorded, the calculations were made according to the golden percentage theory (GPT). The data were analyzed by independent and paired T-test. The level of significance was set at p < 0.05. The golden percentage values were not found in this study. The values obtained were 16%, 15%, 20%, 20%, 15%, and 16% moving from the right canine to the left canine teeth. There was no significant gender difference in the golden percentage values. Thus, golden percentage should not be used solely for the correction of anterior teeth or for determining dental attractiveness. Emphasis should be given to a range of dental proportion on regional basis.
    Matched MeSH terms: Imaging, Three-Dimensional*
  8. Ali A, Logeswaran R
    Comput Biol Med, 2007 Aug;37(8):1141-7.
    PMID: 17126314
    The 3D ultrasound systems produce much better reproductions than 2D ultrasound, but their prohibitively high cost deprives many less affluent organization this benefit. This paper proposes using the conventional 2D ultrasound equipment readily available in most hospitals, along with a single conventional digital camera, to construct 3D ultrasound images. The proposed system applies computer vision to extract position information of the ultrasound probe while the scanning takes place. The probe, calibrated in order to calculate the offset of the ultrasound scan from the position of the marker attached to it, is used to scan a number of geometrical objects. Using the proposed system, the 3D volumes of the objects were successfully reconstructed. The system was tested in clinical situations where human body parts were scanned. The results presented, and confirmed by medical staff, are very encouraging for cost-effective implementation of computer-aided 3D ultrasound using a simple setup with 2D ultrasound equipment and a conventional digital camera.
    Matched MeSH terms: Imaging, Three-Dimensional/economics; Imaging, Three-Dimensional/instrumentation*; Imaging, Three-Dimensional/statistics & numerical data
  9. Versiani MA, Ahmed HM, Sousa-Neto MD, De-Deus G, Dummer PM
    Braz Dent J, 2016 Sep-Oct;27(5):589-591.
    PMID: 27982239 DOI: 10.1590/0103-6440201601106
    The relationship of the main foramen to the anatomic root apex has been the subject of several studies. Although they are anatomically close, they rarely coincide, and their distance can vary according to age or tooth type, ranging from 0.2 to 3.0 mm. The aim of this short communication was to evaluate the distance between the main foramen of independent middle mesial canals (MMCs) and the anatomical mesial root apex of mandibular first molars using the micro-computed tomography. Twenty-five mandibular first molars with MMCs were scanned (resolution of 9.9 µm), and the distance from its main foramen to the anatomical apex was evaluated. Overall, the distance ranged from 0.2 to 2.4 mm; however, in 3 specimens the distance was greater than 3 mm. This report demonstrates that the exit of the main foramen of the MMC varies considerably and could approach a substantial distance from the anatomical apex greater than previously reported in the literature.
    Matched MeSH terms: Imaging, Three-Dimensional
  10. Al-Khatib, Ali Rajih
    MyJurnal
    The surface facial imagings have many applications in medical fields. The recent past has seen great advances in three dimensional imaging which include laser scanning or stereophotogrammetry. Here, we reviewed various systems with reference to image acquisition, advantages and disadvantages. Examples of important clinical application with reference to the human face are also discussed. Finally, a 3D imaging system at Universiti Sains Malaysia (USM) is described.
    Matched MeSH terms: Imaging, Three-Dimensional
  11. Mohamed Najib Salleh, Halim Mad Lazim, Hendrik Lamsali
    Movement Health & Exercise, 2018;7(1):179-187.
    MyJurnal
    Body measurement is the first process that must be encountered before any
    custom-made compression garment can be designed. The current practice of
    obtaining the measurement is by traditional methods using tools like
    measuring tape. However, this method is considered to be time-consuming
    and usually not accurate. The most popular solution to the problem is by using
    non-contact measurement. The development of the 3D whole body scanner
    has made non-contact body measurement become a reality due to its capacity
    to capture a vast amount of information. However, the cost to buy the whole
    body scanner is quite expensive. Moreover, their sizes are also bulky which
    make them less portable. Thus, a handheld body scanner provides a solution
    to the problem. Despite that, current handheld scanner only provide image
    and visualization aspect, but not the measurement aspect. This paper reports
    the development of a method to acquire body data from a 3D handheld
    scanner. In this new method, the point cloud of a body part was collected
    using the handheld scanner. Then, the data was transformed into point
    coordinates. Several processes were developed to filter the number of points
    to allow for faster processing time and increasing the measurement accuracy.
    In the first process, only points at specific height/layers are selected. In the
    second process, the remaining points are rearranged according to their height
    and angle. In the last process, the number of points is further reduced. In this
    process, the number of points per layer is limited to 72 points. Results show
    that the method can be used to determine body measurement.
    Matched MeSH terms: Imaging, Three-Dimensional
  12. Chua SY, Guo N, Tan CS, Wang X
    Sensors (Basel), 2017 Sep 05;17(9).
    PMID: 28872589 DOI: 10.3390/s17092031
    Accuracy is an important measure of system performance and remains a challenge in 3D range gated reconstruction despite the advancement in laser and sensor technology. The weighted average model that is commonly used for range estimation is heavily influenced by the intensity variation due to various factors. Accuracy improvement in term of range estimation is therefore important to fully optimise the system performance. In this paper, a 3D range gated reconstruction model is derived based on the operating principles of range gated imaging and time slicing reconstruction, fundamental of radiant energy, Laser Detection And Ranging (LADAR), and Bidirectional Reflection Distribution Function (BRDF). Accordingly, a new range estimation model is proposed to alleviate the effects induced by distance, target reflection, and range distortion. From the experimental results, the proposed model outperforms the conventional weighted average model to improve the range estimation for better 3D reconstruction. The outcome demonstrated is of interest to various laser ranging applications and can be a reference for future works.
    Matched MeSH terms: Imaging, Three-Dimensional
  13. Zheng S, Rahmat RWO, Khalid F, Nasharuddin NA
    PeerJ Comput Sci, 2019;5:e236.
    PMID: 33816889 DOI: 10.7717/peerj-cs.236
    As the technology for 3D photography has developed rapidly in recent years, an enormous amount of 3D images has been produced, one of the directions of research for which is face recognition. Improving the accuracy of a number of data is crucial in 3D face recognition problems. Traditional machine learning methods can be used to recognize 3D faces, but the face recognition rate has declined rapidly with the increasing number of 3D images. As a result, classifying large amounts of 3D image data is time-consuming, expensive, and inefficient. The deep learning methods have become the focus of attention in the 3D face recognition research. In our experiment, the end-to-end face recognition system based on 3D face texture is proposed, combining the geometric invariants, histogram of oriented gradients and the fine-tuned residual neural networks. The research shows that when the performance is evaluated by the FRGC-v2 dataset, as the fine-tuned ResNet deep neural network layers are increased, the best Top-1 accuracy is up to 98.26% and the Top-2 accuracy is 99.40%. The framework proposed costs less iterations than traditional methods. The analysis suggests that a large number of 3D face data by the proposed recognition framework could significantly improve recognition decisions in realistic 3D face scenarios.
    Matched MeSH terms: Imaging, Three-Dimensional
  14. Yasir SF, Jani J, Mukri M
    Data Brief, 2019 Jun;24:103821.
    PMID: 30976635 DOI: 10.1016/j.dib.2019.103821
    This data illustration the similarity and accuracy of two subsurface profile analysis software which is RES2DINV and VOXLER. Electrical resistivity imaging methods was conducted as a geophysical technique to get subsurface profile were borehole had previously been made in the same locations. The General Department of Geoscience (JMG) conducted the drilling of the borehole in three locations which is Kampung Bangkahulu, Gemas, Kampung Semerbok, Rembau and Felda Bukit Rokan Utara. The 2D resistivity image from RES2DINV and the 3D image from VOXLER was highly matching the subsurface profile compared with borehole data log. The depth of the resistivity was 76.8, 87.2 and 39.4 respectively for the sites. This two software gave more clearly interpreted result for investigate the sub ground and geological formations.
    Matched MeSH terms: Imaging, Three-Dimensional
  15. Teo BG, Dhillon SK
    BMC Bioinformatics, 2019 Dec 24;20(Suppl 19):658.
    PMID: 31870297 DOI: 10.1186/s12859-019-3210-x
    BACKGROUND: Studying structural and functional morphology of small organisms such as monogenean, is difficult due to the lack of visualization in three dimensions. One possible way to resolve this visualization issue is to create digital 3D models which may aid researchers in studying morphology and function of the monogenean. However, the development of 3D models is a tedious procedure as one will have to repeat an entire complicated modelling process for every new target 3D shape using a comprehensive 3D modelling software. This study was designed to develop an alternative 3D modelling approach to build 3D models of monogenean anchors, which can be used to understand these morphological structures in three dimensions. This alternative 3D modelling approach is aimed to avoid repeating the tedious modelling procedure for every single target 3D model from scratch.

    RESULT: An automated 3D modeling pipeline empowered by an Artificial Neural Network (ANN) was developed. This automated 3D modelling pipeline enables automated deformation of a generic 3D model of monogenean anchor into another target 3D anchor. The 3D modelling pipeline empowered by ANN has managed to automate the generation of the 8 target 3D models (representing 8 species: Dactylogyrus primaries, Pellucidhaptor merus, Dactylogyrus falcatus, Dactylogyrus vastator, Dactylogyrus pterocleidus, Dactylogyrus falciunguis, Chauhanellus auriculatum and Chauhanellus caelatus) of monogenean anchor from the respective 2D illustrations input without repeating the tedious modelling procedure.

    CONCLUSIONS: Despite some constraints and limitation, the automated 3D modelling pipeline developed in this study has demonstrated a working idea of application of machine learning approach in a 3D modelling work. This study has not only developed an automated 3D modelling pipeline but also has demonstrated a cross-disciplinary research design that integrates machine learning into a specific domain of study such as 3D modelling of the biological structures.

    Matched MeSH terms: Imaging, Three-Dimensional
  16. Al-Surmi A, Wirza R, Mahmod R, Khalid F, Dimon MZ
    J Cardiothorac Surg, 2014;9:161.
    PMID: 25274253 DOI: 10.1186/s13019-014-0161-1
    The identification and segmentation of inhomogeneous image regions is one of the most challenging issues nowadays. The surface vessels of the human heart are important for the surgeons to locate the region where to perform the surgery and to avoid surgical injuries. In addition, such identification, segmentation, and visualisation helps novice surgeons in the training phase of cardiac surgery.
    Matched MeSH terms: Imaging, Three-Dimensional*
  17. Bakhshipour Z, Huat BB, Ibrahim S, Asadi A, Kura NU
    ScientificWorldJournal, 2013;2013:629476.
    PMID: 24501583 DOI: 10.1155/2013/629476
    This work describes the application of the electrical resistivity (ER) method to delineating subsurface structures and cavities in Kuala Lumpur Limestone within the Batu Cave area of Selangor Darul Ehsan, Malaysia. In all, 17 ER profiles were measured by using a Wenner electrode configuration with 2 m spacing. The field survey was accompanied by laboratory work, which involves taking resistivity measurements of rock, soil, and water samples taken from the field to obtain the formation factor. The relationship between resistivity and the formation factor and porosity for all the samples was established. The porosity values were plotted and contoured. A 2-dimensional and 3-dimensional representation of the subsurface topography of the area was prepared through use of commercial computer software. The results show the presence of cavities and sinkholes in some parts of the study area. This work could help engineers and environmental managers by providing the information necessary to produce a sustainable management plan in order to prevent catastrophic collapses of structures and other related geohazard problems.
    Matched MeSH terms: Imaging, Three-Dimensional/methods*
  18. Teo BG, Dhillon SK, Lim LH
    PLoS One, 2013;8(10):e77650.
    PMID: 24204903 DOI: 10.1371/journal.pone.0077650
    In this paper, a digital 3D model which allows for visualisation in three dimensions and interactive manipulation is explored as a tool to help us understand the structural morphology and elucidate the functions of morphological structures of fragile microorganisms which defy live studies. We developed a deformable generic 3D model of haptoral anchor of dactylogyridean monogeneans that can subsequently be deformed into different desired anchor shapes by using direct manipulation deformation technique. We used point primitives to construct the rectangular building blocks to develop our deformable 3D model. Point primitives are manually marked on a 2D illustration of an anchor on a Cartesian graph paper and a set of Cartesian coordinates for each point primitive is manually extracted from the graph paper. A Python script is then written in Blender to construct 3D rectangular building blocks based on the Cartesian coordinates. The rectangular building blocks are stacked on top or by the side of each other following their respective Cartesian coordinates of point primitive. More point primitives are added at the sites in the 3D model where more structural variations are likely to occur, in order to generate complex anchor structures. We used Catmull-Clark subdivision surface modifier to smoothen the surface and edge of the generic 3D model to obtain a smoother and more natural 3D shape and antialiasing option to reduce the jagged edges of the 3D model. This deformable generic 3D model can be deformed into different desired 3D anchor shapes through direct manipulation deformation technique by aligning the vertices (pilot points) of the newly developed deformable generic 3D model onto the 2D illustrations of the desired shapes and moving the vertices until the desire 3D shapes are formed. In this generic 3D model all the vertices present are deployed for displacement during deformation.
    Matched MeSH terms: Imaging, Three-Dimensional/methods*
  19. Logeswaran R, Eswaran C
    J Med Syst, 2006 Apr;30(2):133-8.
    PMID: 16705998
    Many medical examinations involve acquisition of a large series of slice images for 3D reconstruction of the organ of interest. With the paperless hospital concept and telemedicine, there is very heavy utilization of limited electronic storage and transmission bandwidth. This paper proposes model-based compression to reduce the load on such resources, as well as aid diagnosis through the 3D reconstruction of the structures of interest, for images acquired by various modalities, such as MRI, Ultrasound, CT, PET etc. and stored in the DICOM file format. An example implementation for the biliary track in MRCP images is illustrated in the paper. Significant compression gains may be derived from the proposed method, and a suitable mixture of the models and raw images would enhance the patient medical history archives as the models may be stored in the DICOM file format used in most medical archiving systems.
    Matched MeSH terms: Imaging, Three-Dimensional*
  20. Dietz HP, Severino M, Kamisan Atan I, Shek KL, Guzman Rojas R
    Ultrasound Obstet Gynecol, 2016 Aug;48(2):239-42.
    PMID: 26289617 DOI: 10.1002/uog.15728
    OBJECTIVES: The levator hiatus is the largest potential hernial portal in the human body. Excessive distensibility is associated with female pelvic organ prolapse (POP). Distension occurs not just laterally but also caudally, resulting in perineal descent and hiatal deformation or 'warping'. The aim of this study was to quantify the warping effect in symptomatic women, to validate the depth of the rendered volume used for the 'simplified method' of measuring hiatal dimensions and to determine predictors for the degree of warping.

    METHODS: This was a retrospective study utilizing records of patients referred to a tertiary urogynecological service between November 2012 and March 2013. Patients underwent a standardized interview, clinical assessment using the POP quantification system of the International Continence Society and four-dimensional translabial ultrasound. The craniocaudal difference in the location of minimal distances in mid-sagittal and coronal planes was determined by offline analysis of ultrasound volumes, and provided a numerical measure of warping. We tested potential predictors, such as demographic factors, signs and symptoms of prolapse, levator avulsion and levator distensibility, for an association with warping.

    RESULTS: Full datasets were available for 190 women. The mean craniocaudal difference in location of minimal distances in mid-sagittal and coronal planes was -1.26 mm (range, -6.7 to 4.6 mm; P 

    Matched MeSH terms: Imaging, Three-Dimensional/methods*
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