Displaying publications 21 - 40 of 1491 in total

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  1. Abdul Rahim R, Leong LC, Chan KS, Rahiman MH, Pang JF
    ISA Trans, 2008 Jan;47(1):3-14.
    PMID: 17709106
    This paper presents the implementing multiple fan beam projection technique using optical fibre sensors for a tomography system. From the dynamic experiment of solid/gas flow using plastic beads in a gravity flow rig, the designed optical fibre sensors are reliable in measuring the mass flow rate below 40% of flow. Another important matter that has been discussed is the image processing rate or IPR. Generally, the applied image reconstruction algorithms, the construction of the sensor and also the designed software are considered to be reliable and suitable to perform real-time image reconstruction and mass flow rate measurements.
    Matched MeSH terms: Tomography/instrumentation*
  2. Abdul Rahim R, Pang JF, Chan KS, Leong LC, Sulaiman S, Abdul Manaf MS
    ISA Trans, 2007 Apr;46(2):131-45.
    PMID: 17367791
    The data distribution system of this project is divided into two types, which are a Two-PC Image Reconstruction System and a Two-PC Velocity Measurement System. Each data distribution system is investigated to see whether the results' refreshing rate of the corresponding measurement can be greater than the rate obtained by using a single computer in the same measurement system for each application. Each system has its own flow control protocol for controlling how data is distributed within the system in order to speed up the data processing time. This can be done if two PCs work in parallel. The challenge of this project is to define the data flow process and critical timing during data packaging, transferring and extracting in between PCs. If a single computer is used as a data processing unit, a longer time is needed to produce a measurement result. This insufficient real-time result will cause problems in a feedback control process when applying the system in industrial plants. To increase the refreshing rate of the measurement result, an investigation on a data distribution system is performed to replace the existing data processing unit.
    Matched MeSH terms: Tomography, Optical/methods*
  3. Abdul Rahim, R., Pang, J.F., Chan, K.S., Leong, L.C., Fazalul Rahiman, M.H.
    ASM Science Journal, 2007;1(1):27-36.
    MyJurnal
    In this study, real-time imaging was monitored for flowing solid particles when various baffles were created to block certain areas of the pipe. The generated flow regimes were full-flow, three-quarter-flow, half-flow and quarter-flow. A vertical pneumatic conveyor was designed to hold a 85 mm inner diameter pipeline. The four projection optical tomography systems used, applied the parallel beam projection approach and use infrared light sources so that the sensor was free of noise from the surrounding visible light source. The two orthogonal and two rectilinear projections were axial, but ideally they should have been in the same layer. The sensor readings could be related to the varying light intensity effects of the dropping particles and were used to provide cross-sectional distribution information for the conveyor. By using computer programming, the information was reconstructed to produce coloured images and concentration was obtained by reference to a colour code. The results obtained from this study showed how imaged flow followed the artificial flow regime. This study could benefit industrial production lines in maintaining the desired flow rates.
    Matched MeSH terms: Tomography, X-Ray Computed; Tomography, Optical
  4. Abdul Rahman MR, Yaman MN, Dimon MZ, Zabir AF, Min JO, Hamid HA
    Ann Thorac Surg, 2011 Aug;92(2):714-5.
    PMID: 21801925 DOI: 10.1016/j.athoracsur.2011.02.028
    We present a 35-year-old man with a preoperative diagnosis of a right lower lobe cystic mass. Misled by a radiological suggestion of an intraparenchymal lesion, he had a thoracotomy and right lower lobectomy. An intraoperative finding of a pedunculated cyst arising from the parietal pleural with subsequent histopathology confirmation of a benign bronchogenic cyst, however, would have made a less invasive surgical excision more appropriate.
    Matched MeSH terms: Tomography, X-Ray Computed
  5. Abdul Rashid AM, Md Noh MSF
    BMC Neurol, 2018 May 29;18(1):76.
    PMID: 29843624 DOI: 10.1186/s12883-018-1079-3
    BACKGROUND: Dyke-Davidoff-Masson syndrome is a rare condition of unknown frequency resulting from brain injury due to a multitude of causes; especially in early life. Characteristics include cerebral hemiatrophy/hypoplasia, contralateral hemiparesis, seizures, and compensatory osseous hypertrophy.

    CASE PRESENTATION: We present a case of a 13-year-old girl who initially presented with headaches, followed by episodic complex-partial seizures; which was controlled via medication. She also had right sided hemiparesis. Computed tomography (CT) showed evidence of left parieto-temporal infarct with cerebral atrophy. Complementary magnetic resonance imaging (MRI) did not reveal additional information. Workup for young stroke was negative. Upon further evaluation by Neuroradiology, features suggesting Dyke-Davidoff-Masson syndrome were confirmed. Patient has been under Neurology follow up since.

    CONCLUSIONS: Due to its rarity, Dyke-Davidoff-Masson syndrome may easily be missed by the majority of treating clinicians. Knowledge of its features on imaging enables timely and accurate diagnosis - allowing appropriate management.

    Matched MeSH terms: Tomography, X-Ray Computed
  6. Abdul Rashid S, Ab Hamid S, Mohamad Saini S, Muridan R
    Biomed Imaging Interv J, 2012 Apr;8(2):e11.
    PMID: 22970067 MyJurnal DOI: 10.2349/biij.8.2.e11
    Diagnosing acute appendicitis in children can be difficult due to atypical presenting symptoms. While there are reported cases of acute appendicitis or appendiceal masses causing unilateral hydronephrosis, bilateral hydronephrosis as a complication of appendiceal mass is very rare. We report a case of a child who presented with cardinal symptomatology associated with the urogenital tract. Ultrasound (US) investigation showed a pelvic mass causing bilateral hydronephrosis. An initial diagnosis of a pelvic teratoma was made based on the US and computed tomography (CT) scan findings. The final diagnosis of an appendiceal mass causing bilateral hydronephrosis was established intraoperatively.
    Matched MeSH terms: Tomography, X-Ray Computed
  7. Abdul Rashid SN, Mohamad Saini SB, Abdul Hamid S, Muhammad SJ, Mahmud R, Thali MJ, et al.
    Br J Radiol, 2014 Apr;87(1036):20130472.
    PMID: 24472728 DOI: 10.1259/bjr.20130472
    The purpose of this study was to retrospectively evaluate the sensitivity, specificity and accuracy of identifying methamphetamine (MA) internal payloads in "drug mules" by plain abdominal digital radiography (DR).
    Matched MeSH terms: Tomography, X-Ray Computed/methods
  8. Abdul Satar H, Yaakub A, Md Shukri N, Ahmad Tajudin LS
    Cureus, 2021 Apr 09;13(4):e14392.
    PMID: 33981511 DOI: 10.7759/cureus.14392
    Paediatric orbital cellulitis is a potential sight- and life-threatening condition. It is a serious infection in children that can result in significant complications, including blindness, cavernous sinus thrombosis, cerebral venous sinus thrombosis, meningitis, subdural empyema, and brain abscess. Of the patients with orbital cellulitis, 17% died from meningitis, and 20% of the survivors had permanent loss of vision. Therefore, the potential for sight- and life-threatening complications makes prompt diagnosis and early treatment very important. We report here a case of a two-year-old girl who presented with a three-day history of left periorbital swelling, preceded by left upper perioral swelling that extended upward to the left cheek and left lower lid and was associated with low-grade fever. The patient had been admitted and was treated as having left preseptal with facial cellulitis; the patient was started on intravenous amoxicillin/clavulanic acid (200 mg three times per day dose), and chloramphenicol ointment was applied to the periorbital area. On day 3, the condition worsened, and dental examination showed multiple dental caries, upper gum swelling and abscess, and mobility of teeth 61 and 62 (two baby teeth). Contrast-enhanced computed tomography (CECT) of the orbit, paranasal, and brain showed a left periosteal abscess collection extending to the inferomedial region of the orbit. Examination and tooth extraction were performed under general anesthesia. The intraoperative results showed the presence of a left upper gum abscess, which was possibly the primary source of infection. Clinical improvement was observed postoperatively. Orbital cellulitis can be a complication of a dental abscess. This case emphasizes the importance of primary tooth care in children. A lack of care can result in fatal complications.
    Matched MeSH terms: Tomography
  9. Abdul-Rahman NA, Azman RR, Kumar G
    Saudi Med J, 2016 May;37(5):584-6.
    PMID: 27146625 DOI: 10.15537/smj.2016.5.15042
    Matched MeSH terms: Tomography, X-Ray Computed
  10. Abdulkareem KH, Mostafa SA, Al-Qudsy ZN, Mohammed MA, Al-Waisy AS, Kadry S, et al.
    J Healthc Eng, 2022;2022:5329014.
    PMID: 35368962 DOI: 10.1155/2022/5329014
    Coronavirus disease 2019 (COVID-19) is a novel disease that affects healthcare on a global scale and cannot be ignored because of its high fatality rate. Computed tomography (CT) images are presently being employed to assist doctors in detecting COVID-19 in its early stages. In several scenarios, a combination of epidemiological criteria (contact during the incubation period), the existence of clinical symptoms, laboratory tests (nucleic acid amplification tests), and clinical imaging-based tests are used to diagnose COVID-19. This method can miss patients and cause more complications. Deep learning is one of the techniques that has been proven to be prominent and reliable in several diagnostic domains involving medical imaging. This study utilizes a convolutional neural network (CNN), stacked autoencoder, and deep neural network to develop a COVID-19 diagnostic system. In this system, classification undergoes some modification before applying the three CT image techniques to determine normal and COVID-19 cases. A large-scale and challenging CT image dataset was used in the training process of the employed deep learning model and reporting their final performance. Experimental outcomes show that the highest accuracy rate was achieved using the CNN model with an accuracy of 88.30%, a sensitivity of 87.65%, and a specificity of 87.97%. Furthermore, the proposed system has outperformed the current existing state-of-the-art models in detecting the COVID-19 virus using CT images.
    Matched MeSH terms: Tomography, X-Ray Computed/methods
  11. Abdullah A, Abdul Rahman R, Aziz S, Abu Bakar S, AbAziz AA
    Med J Malaysia, 2013;68(1):76-8.
    PMID: 23466775 MyJurnal
    Nasal obstruction in neonates is a potentially fatal condition because neonates are obligatory nasal breathers. Bilateral choanal atresia is therefore a neonatal emergency. Several approaches for corrections of choanal atresia are available including the helium laser: YAG. A 5-year-old Chinese girl born with bilateral choanal atresia, had birth asphyxia that required intubation. She underwent multiple surgeries for correction of choanal atresia at other hospitals but failed to improve. She was referred to Universiti Kebangsaan Malaysia Medical Center (UKMMC) after presenting with intermittent respiratory distress and cyanosis following an upper respiratory tract infection. A repeat computed tomography (CT) scan done preoperatively showed complete bony stenosis over the left choana and finding was confirmed by examination under general anesthesia. She underwent endoscopic transnasal removal of left bony atretic plate. There was no intra or postoperative complications. During follow up 10 years later, the airway on both sides remains patent.
    Matched MeSH terms: Tomography, X-Ray Computed
  12. Abdullah A, Mahmud MR, Maimunah A, Zulfiqar MA, Saim L, Mazlan R
    Ann Acad Med Singap, 2003 Jul;32(4):442-5.
    PMID: 12968546
    INTRODUCTION: Accurate preoperative imaging of the temporal bone in patients receiving cochlear implants is important. High resolution computed tomography (HRCT) and magnetic resonance (MR) imaging are the 2 preoperative imaging modalities that provide critical information on abnormalities of the otic capsule, pneumatisation of the mastoid, middle ear abnormalities, cochlear ducts patency and presence of cochlear nerve.

    MATERIALS AND METHODS: The HRCT and MR imaging in 46 cochlear implant patients in our department were reviewed.

    RESULTS: Majority of our patients [34 patients (73.9%)] showed normal HRCT of the temporal bone; 5 (10.9%) patients had labyrinthitis ossificans, 2 (4.3%) had Mondini's abnormality and 2 (4.3%) had middle ear effusion. One patient each had high jugular bulb, hypoplasia of the internal auditory canal and single cochlear cavity, respectively.

    CONCLUSION: The above findings contribute significantly to our surgical decisions regarding candidacy for surgery, side selection and surgical technique in cochlear implantation.

    Matched MeSH terms: Tomography, X-Ray Computed/methods*
  13. Abdullah AC, Adnan JS, Rahman NA, Palur R
    Malays J Med Sci, 2017 Mar;24(1):104-112.
    PMID: 28381933 DOI: 10.21315/mjms2017.24.1.11
    INTRODUCTION: Computed tomography (CT) is the preferred diagnostic toolkit for head and brain imaging of head injury. A recent development is the invention of a portable CT scanner that can be beneficial from a clinical point of view.

    AIM: To compare the quality of CT brain images produced by a fixed CT scanner and a portable CT scanner (CereTom).

    METHODS: This work was a single-centre retrospective study of CT brain images from 112 neurosurgical patients. Hounsfield units (HUs) of the images from CereTom were measured for air, water and bone. Three assessors independently evaluated the images from the fixed CT scanner and CereTom. Streak artefacts, visualisation of lesions and grey-white matter differentiation were evaluated at three different levels (centrum semiovale, basal ganglia and middle cerebellar peduncles). Each evaluation was scored 1 (poor), 2 (average) or 3 (good) and summed up to form an ordinal reading of 3 to 9.

    RESULTS: HUs for air, water and bone from CereTom were within the recommended value by the American College of Radiology (ACR). Streak artefact evaluation scores for the fixed CT scanner was 8.54 versus 7.46 (Z = -5.67) for CereTom at the centrum semiovale, 8.38 (SD = 1.12) versus 7.32 (SD = 1.63) at the basal ganglia and 8.21 (SD = 1.30) versus 6.97 (SD = 2.77) at the middle cerebellar peduncles. Grey-white matter differentiation showed scores of 8.27 (SD = 1.04) versus 7.21 (SD = 1.41) at the centrum semiovale, 8.26 (SD = 1.07) versus 7.00 (SD = 1.47) at the basal ganglia and 8.38 (SD = 1.11) versus 6.74 (SD = 1.55) at the middle cerebellar peduncles. Visualisation of lesions showed scores of 8.86 versus 8.21 (Z = -4.24) at the centrum semiovale, 8.93 versus 8.18 (Z = -5.32) at the basal ganglia and 8.79 versus 8.06 (Z = -4.93) at the middle cerebellar peduncles. All results were significant with P-value < 0.01.

    CONCLUSIONS: Results of the study showed a significant difference in image quality produced by the fixed CT scanner and CereTom, with the latter being more inferior than the former. However, HUs of the images produced by CereTom do fulfil the recommendation of the ACR.

    Matched MeSH terms: Tomography, X-Ray Computed; Tomography Scanners, X-Ray Computed
  14. Abdullah AH, Todo M, Nakashima Y
    Med Eng Phys, 2017 06;44:8-15.
    PMID: 28373012 DOI: 10.1016/j.medengphy.2017.03.006
    Femoral bone fracture is one of the main causes for the failure of hip arthroplasties (HA). Being subjected to abrupt and high impact forces in daily activities may lead to complex loading configuration such as bending and sideway falls. The objective of this study is to predict the risk of femoral bone fractures in total hip arthroplasty (THA) and resurfacing hip arthroplasty (RHA). A computed tomography (CT) based on finite element analysis was conducted to demonstrate damage formation in a three dimensional model of HAs. The inhomogeneous model of femoral bone was constructed from a 79 year old female patient with hip osteoarthritis complication. Two different femoral components were modeled with titanium alloy and cobalt chromium and inserted into the femoral bones to present THA and RHA models respectively. The analysis included six configurations, which exhibited various loading and boundary conditions, including axial compression, torsion, lateral bending, stance and two types of falling configurations. The applied hip loadings were normalized to body weight (BW) and accumulated from 1 BW to 3 BW. Predictions of damage formation in the femoral models were discussed as the resulting tensile failure as well as the compressive yielding and failure elements. The results indicate that loading directions can forecast the pattern and location of fractures at varying magnitudes of loading. Lateral bending configuration experienced the highest damage formation in both THA and RHA models. Femoral neck and trochanteric regions were in a common location in the RHA model in most configurations, while the predicted fracture locations in THA differed as per the Vancouver classification.
    Matched MeSH terms: Tomography, X-Ray Computed*
  15. Abdullah B, Vengathajalam S, Md Daud MK, Wan Mohammad Z, Hamizan A, Husain S
    J Asthma Allergy, 2020;13:523-531.
    PMID: 33149624 DOI: 10.2147/JAA.S275536
    Purpose: The allergic phenotype of chronic rhinosinusitis (CRS) and central compartment atopic disease (CCAD) have been described. The CCAD is a radiological phenotype in patients with CRS that presents as a central mucosal disease due to allergy. The subset of patients having chronic rhinosinusitis with nasal polyps (CRSwNP) has not been well characterized. We aim to describe the clinical and radiological characterizations of patients presenting with the allergic phenotype of CRSwNP.

    Patients and Methods: A cross-sectional study at a tertiary hospital was performed. Adult patients diagnosed with CRSwNP who had both allergology and radiological assessments were enrolled. The symptoms of allergic rhinitis, Lund-Kennedy (LK) endoscopic scoring, Lund-Mackay (LM) computed tomography scan of paranasal sinuses (CTPNS) scoring, CCAD features, skin prick test (SPT) and level of specific IgE were assessed. All the patients underwent SPT for house dust mites.

    Results: A total of 38 patients were enrolled. Symptoms, endoscopic and CTPNS scores were higher in the allergy and CCAD groups compared to the nonallergy and nonCCAD groups. The symptom of "need to blow nose" was statistically significant in allergy vs nonallergy (p=0.01) and CCAD vs nonCCAD (p=0.02). There were significant differences in the endoscopic scores in both allergy and CCAD (allergy vs nonallergy, p=0.01; CCAD vs nonCCAD, p=0.03), and CT scores in both allergy and CCAD (allergy vs nonallergy, p=0.02; CCAD vs nonCCAD, p=0.02). All patients with CCAD have worse scoring than nonCCAD (LK score, p=0.03; LM score, p=0.02). Patients with allergy have more polypoidal involvement of the middle turbinates (left middle turbinate, p=0.141; right middle turbinate, p=0.074) and CCAD (left middle turbinate, p=0.017; right middle turbinate, p=0.009) than nonallergy and nonCCAD patients.

    Conclusion: Allergic phenotype of CRSwNP has a worse clinical and radiological disease burden. Optimal treatment of allergy is essential for a better outcome.

    Matched MeSH terms: Tomography; Tomography, X-Ray Computed
  16. Abdullah B, Lim EH, Mohamad H, Husain S, Aziz ME, Snidvongs K, et al.
    Surg Radiol Anat, 2019 May;41(5):543-550.
    PMID: 30542929 DOI: 10.1007/s00276-018-2157-3
    PURPOSE: The variations of the anterior ethmoidal artery (AEA) in different populations should be recognized by surgeons to prevent unwarranted complications during surgery. The aim of this study was to assess the anatomical variations of AEA in Asian population.

    METHODS: A cross-sectional study of 252 AEA identified by computed tomography (CT) of the paranasal sinuses. The multiplanar CT images were acquired from SOMATOM® Definition AS+ and reconstructed to axial, coronal and sagittal view at 1 mm slice thickness.

    RESULTS: 42.5% of AEA was within skull base (grade I), 20.2% at skull base (grade II) and 37.3% coursed freely below skull base (grade III). The prevalence of supraorbital ethmoid cell (SOEC) and suprabullar cell (SBC) was 29.8% and 48.0%. The position of AEA at skull base has significant association with SOEC (p 

    Matched MeSH terms: Tomography, X-Ray Computed
  17. Abdullah BJ, Yeong CH, Goh KL, Yoong BK, Ho GF, Yim CC, et al.
    Eur Radiol, 2015 Jan;25(1):246-57.
    PMID: 25189152 DOI: 10.1007/s00330-014-3391-7
    OBJECTIVE: This study aimed to assess the technical success, radiation dose, safety and performance level of liver thermal ablation using a computed tomography (CT)-guided robotic positioning system.

    METHODS: Radiofrequency and microwave ablation of liver tumours were performed on 20 patients (40 lesions) with the assistance of a CT-guided robotic positioning system. The accuracy of probe placement, number of readjustments and total radiation dose to each patient were recorded. The performance level was evaluated on a five-point scale (5-1: excellent-poor). The radiation doses were compared against 30 patients with 48 lesions (control) treated without robotic assistance.

    RESULTS: Thermal ablation was successfully completed in 20 patients with 40 lesions and confirmed on multiphasic contrast-enhanced CT. No procedure related complications were noted in this study. The average number of needle readjustment was 0.8 ± 0.8. The total CT dose (DLP) for the entire robotic assisted thermal ablation was 1382 ± 536 mGy.cm, while the CT fluoroscopic dose (DLP) per lesion was 352 ± 228 mGy.cm. There was no statistically significant (p > 0.05) dose reduction found between the robotic-assisted versus the conventional method.

    CONCLUSION: This study revealed that robotic-assisted planning and needle placement appears to be safe, with high accuracy and a comparable radiation dose to patients.

    KEY POINTS: • Clinical experience on liver thermal ablation using CT-guided robotic system is reported. • The technical success, radiation dose, safety and performance level were assessed. • Thermal ablations were successfully performed, with an average performance score of 4.4/5.0. • Robotic-assisted ablation can potentially increase capabilities of less skilled interventional radiologists. • Cost-effectiveness needs to be proven in further studies.

    Matched MeSH terms: Tomography, X-Ray Computed
  18. Abdullah BJ, Yeong CH, Goh KL, Yoong BK, Ho GF, Yim CC, et al.
    Eur Radiol, 2014 Jan;24(1):79-85.
    PMID: 23928933 DOI: 10.1007/s00330-013-2979-7
    OBJECTIVE: Computed tomography (CT)-compatible robots, both commercial and research-based, have been developed with the intention of increasing the accuracy of needle placement and potentially improving the outcomes of therapies in addition to reducing clinical staff and patient exposure to radiation during CT fluoroscopy. In the case of highly inaccessible lesions that require multiple plane angulations, robotically assisted needles may improve biopsy access and targeted drug delivery therapy by avoidance of the straight line path of normal linear needles.

    METHODS: We report our preliminary experience of performing radiofrequency ablation of the liver using a robotic-assisted CT guidance system on 11 patients (17 lesions).

    RESULTS/CONCLUSION: Robotic-assisted planning and needle placement appears to have high accuracy, is technically easier than the non-robotic-assisted procedure, and involves a significantly lower radiation dose to both patient and support staff.

    KEY POINTS: • An early experience of robotic-assisted radiofrequency ablation is reported • Robotic-assisted RFA improves accuracy of hepatic lesion targeting • Robotic-assisted RFA makes the procedure technically easier with significant lower radiation dose.

    Matched MeSH terms: Tomography, X-Ray Computed
  19. Abdullah BJ, Liam CK, Kaur H, Mathew KM
    Br J Radiol, 1997 Oct;70(838):1063-5.
    PMID: 9404213
    Lipoma of the parapharyngeal space is very rare, only three cases having been reported in the literature. A parapharyngeal space lipoma causing obstructive sleep apnoea has not been reported before. A 60-year-old man presented at the ear, nose and throat (ENT) clinic with a history of loud snoring associated with sleep apnoea secondary to a right parapharyngeal space lipoma. The causes of sleep apnoea and the radiological features of a parapharyngeal space lipoma are discussed.
    Study site: ENT clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
    Matched MeSH terms: Tomography, X-Ray Computed
  20. Abdullah D, Eziana Hussein F, Abd Ghani H
    Iran Endod J, 2017;12(2):257-260.
    PMID: 28512497 DOI: 10.22037/iej.2017.50
    This case report describes the endodontic treatment of an idiopathic perforated internal root resorption. A 24-year-old male Malay patient presented with internal root resorption of two of his anterior teeth. The medical history was non-contributory and he had no history of traumatic injury or orthodontic treatment. Cone-beam computed tomography (CBCT) determined the nature, location and severity of the resorptive lesion. Non-surgical root canal treatment of tooth #22 and combined non-surgical and surgical approach for tooth #11 were carried out using mineral trioxide aggregate (MTA) as the filling material. The clinical and radiographic examination three years after completion of treatment revealed evidences of periapical healing. The appropriate diagnosis and the treatment of internal root resorption allowed good healing of these lesions and maintained the tooth in function for as long as possible.
    Matched MeSH terms: Cone-Beam Computed Tomography
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