Displaying publications 201 - 220 of 1046 in total

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  1. Sulieman A, Mahmoud MZ, Serhan O, Alonazi B, Alkhorayef M, Alzimami K, et al.
    Appl Radiat Isot, 2018 Nov;141:261-265.
    PMID: 30054177 DOI: 10.1016/j.apradiso.2018.07.011
    Patient effective doses and the associated radiation risks arising from particular computed tomography (CT) imaging procedures are assessed. The objectives of this research are to measure radiation doses for patients and to quantify the radiogenic risks from CT brain and chest procedures. Patient data were collected from five calibrated CT modality machines in Saudi Arabia. The results are from a study of a total of 60 patients examined during CT procedures using the calibrated CT units. For CT brain and chest, the mean patient effective doses were 1.9 mSv (with a range of 0.6-2.5 mSv) and 7.4 mSv (with a range of 0.5-34.8 mSv) respectively. The radiogenic risk to patients ranged from between 10-5 and 10-4 per procedure. With 65% of the CT procedure cases diagnosed as normal, this prompts re-evaluation of the referral criteria. The establishment of diagnostic reference levels (DRL) and implementation of radiation dose optimisation measures would further help reduce doses to optimal values.
    Matched MeSH terms: Tomography, X-Ray Computed
  2. Amin,O., Nik Azlan, N.M., Afliza, A.B.
    Medicine & Health, 2017;12(1):127-130.
    MyJurnal
    Altered mental status in the setting of polytrauma poses a challenge to the emergency team managing the patient. The tendency to miss positive findings in these circumstances increases several folds due to multiple factors such as depressed mental status/intoxication, presence of distracting injuries and concurrent life-threatening injuries that require more urgent attention. In view of this, NEXUS (National Emergency X-Radiography Utilization Study) criteria of clearing the cervical spine was adopted and used worldwide. Consensus on clearance of the other parts of spine is still lacking. This case reports highlights the findings in a 18-yrs-old male who presented with altered mental status, facial pain and abrasion, following a motor vehicle accident. Facial bone fracture was diagnosed and he was discharged. Three days later, he came with severe epigastric pain. Tenderness on palpation was noted at the spine and Computed Tomography (CT) scan was done. Multiple thoracic vertebra fractures were seen. As a conclusion, thorough primary and secondary survey should be done in patients who have regained full consciousness prior to discharge in order to avoid overlooking other serious injuries.
    Keywords: altered, CT scan, fracture, mental status, thoracic vertebra
    Matched MeSH terms: Tomography, X-Ray Computed
  3. Moghbel M, Mashohor S, Mahmud R, Saripan MI
    EXCLI J, 2016;15:406-23.
    PMID: 27540353 DOI: 10.17179/excli2016-402
    Segmentation of liver tumors from Computed Tomography (CT) and tumor burden analysis play an important role in the choice of therapeutic strategies for liver diseases and treatment monitoring. In this paper, a new segmentation method for liver tumors from contrast-enhanced CT imaging is proposed. As manual segmentation of tumors for liver treatment planning is both labor intensive and time-consuming, a highly accurate automatic tumor segmentation is desired. The proposed framework is fully automatic requiring no user interaction. The proposed segmentation evaluated on real-world clinical data from patients is based on a hybrid method integrating cuckoo optimization and fuzzy c-means algorithm with random walkers algorithm. The accuracy of the proposed method was validated using a clinical liver dataset containing one of the highest numbers of tumors utilized for liver tumor segmentation containing 127 tumors in total with further validation of the results by a consultant radiologist. The proposed method was able to achieve one of the highest accuracies reported in the literature for liver tumor segmentation compared to other segmentation methods with a mean overlap error of 22.78 % and dice similarity coefficient of 0.75 in 3Dircadb dataset and a mean overlap error of 15.61 % and dice similarity coefficient of 0.81 in MIDAS dataset. The proposed method was able to outperform most other tumor segmentation methods reported in the literature while representing an overlap error improvement of 6 % compared to one of the best performing automatic methods in the literature. The proposed framework was able to provide consistently accurate results considering the number of tumors and the variations in tumor contrast enhancements and tumor appearances while the tumor burden was estimated with a mean error of 0.84 % in 3Dircadb dataset.
    Matched MeSH terms: Tomography, X-Ray Computed
  4. Teoh KH, Balraj S, Navarasi SR
    Med J Malaysia, 2017 02;72(1):68-70.
    PMID: 28255147 MyJurnal
    Intrapancreatic accessory spleen (IPAS) is a benign anomaly of splenic embryology and a rare cause of pancreatic pseudotumour. Here, we report a case of a 70-year-old Malay lady whose IPAS was discovered incidentally during her surveillance computed tomography for her underlying left lower lung fibrosis. Radiologically, the lesion mimicked a neuroendocrine pancreatic tumour and was only diagnosed pathologically as IPAS after surgery. In conclusion, recognising IPAS as a differential for enhancing pancreatic mass allows us to exhaust all non-invasive diagnostic means to diagnose this benign lesion. It will allow the patient to avoid unnecessary surgery and its accompanying complications.
    Matched MeSH terms: Tomography, X-Ray Computed
  5. Hwong WY, Bots ML, Selvarajah S, Kappelle LJ, Abdul Aziz Z, Sidek NN, et al.
    PLoS One, 2016;11(10):e0165330.
    PMID: 27768752 DOI: 10.1371/journal.pone.0165330
    A shortage of computed tomographic (CT) machines in low and middle income countries often results in delayed CT imaging for patients suspected of a stroke. Yet, time constraint is one of the most important aspects for patients with an ischemic stroke to benefit from thrombolytic therapy. We set out to assess whether application of the Siriraj Stroke Score is able to assist physicians in prioritizing patients with a high probability of having an ischemic stroke for urgent CT imaging.
    Matched MeSH terms: Tomography, X-Ray Computed
  6. Rahim RA, Thiam CK, Rahiman MH
    Sensors (Basel), 2008 Mar 27;8(4):2082-2103.
    PMID: 27879811
    The use of a personal computer together with a Data Acquisition System (DAQ) as the processing tool in optical tomography systems has been the norm ever since the beginning of process tomography. However, advancements in silicon fabrication technology allow nowadays the fabrication of powerful Digital Signal Processors (DSP) at a reasonable cost. This allows this technology to be used in an optical tomography system since data acquisition and processing can be performed within the DSP. Thus, the dependency on a personal computer and a DAQ to sample and process the external signals can be reduced or even eliminated. The DSP system was customized to control the data acquisition process of 16x16 optical sensor array, arranged in parallel beam projection. The data collected was used to reconstruct the cross sectional image of the pipeline conveyor. For image display purposes, the reconstructed image was sent to a personal computer via serial communication. This allows the use of a laptop to display the tomogram image besides performing any other offline analysis.
    Matched MeSH terms: Tomography, X-Ray Computed
  7. Mohammad Hanafiah, Mohd Farhan Hamdan, Azura Mohamed Mukhari Shahizon, Wong, Sau Wei, Yoganathan Kanaheswari
    Neurology Asia, 2018;23(2):179-184.
    MyJurnal
    Granulomatous amoebic encephalitis caused by Acanthamoeba is a rare entity mainly affecting
    immunocompromised patients. We reported a case of Acanthamoeba encephalitis of a 1-year-old
    immunocompetent child and described the CT and MRI findings of the brain, while reviewing the
    relevant literatures. The imaging findings of Acanthamoeba meningoencepalitis in immunocompetent
    patients are non-specific and pose a diagnostic challenge.
    Matched MeSH terms: Tomography, X-Ray Computed
  8. Ong, Wu Zhuan, Jamalia Rahmat, Ramasamy, Sunder, Amir Samsudin
    MyJurnal
    Retinoblastoma is a rare intraocular malignant tumour more commonly seen in children below five years of age. We presented a rare case of retinoblastoma in an older child. A nine-year-old girl noticed that she had loss of vision OS following a fall at home. Her vision was 6/6 OD and only light perception OS. Examination of the left eye revealed an extensive exudative retinal detachment. Her right eye examination was unremarkable. CT scan showed a left eye intraocular mass with calcification. EUA revealed a mixed endophytic and exophytic mass with extensive exudative retinal detachment. Family members consented to left eye enucleation and histopathological report confirmed the diagnosis of retinoblastoma. Post enucleation, patient is doing well with a prosthetic eye. In conclusion, any unexplained visual loss in children regardless of age warrants a full ophthalmological examination as the possibility of retinoblastoma cannot be ruled out.
    Matched MeSH terms: Tomography, X-Ray Computed
  9. Ch'ng LS, Tazuddin EEM, Young B, Ali AFM
    BJR Case Rep, 2016;2(2):20150306.
    PMID: 30363592 DOI: 10.1259/bjrcr.20150306
    Radiofrequency ablation (RFA) of a hepatic tumour is an established treatment option with an acceptable complication rate. Formation of a pseudoaneurysm after RFA of liver metastasis is an uncommon complication. We report the case of a 69-year-old female patient developing a hepatic pseudoaneurysm after RFA of liver metastasis. On a follow-up CT scan 6 weeks later, there was spontaneous resolution of the pseudoaneurysm. Hepatic pseudoaneurysms are usually treated owing to the risk of rupture. Invasive procedures or conservative management of an asymptomatic hepatic pseudoaneurysm is still the subject of debate. The spontaneous resolution of a hepatic pseudoaneurysm in our patient suggests that an asymptomatic pseudoaneurysm maybe observed for resolution instead of being treated at presentation.
    Matched MeSH terms: Tomography, X-Ray Computed
  10. Zhang T, Zhou Y, Su G, Shi D, Gopinath SCB, Lakshmipriya T, et al.
    J Anal Methods Chem, 2019;2019:5872347.
    PMID: 31662948 DOI: 10.1155/2019/5872347
    Hydrocephalus is widely known as "hydrocephaly" or "water in the brain," a building up of abnormal cerebrospinal fluid in the brain ventricles. Due to this abnormality, the size of the head becomes larger and increases the pressure in the skull. This pressure compresses the brain and causes damage to the brain. Identification by imaging techniques on the hydrocephalus is mandatory to treat the disease. Various methods and equipment have been used to image the hydrocephalus. Among them, computerized tomography (CT) scan and nuclear magnetic resonance (NMR) are the most considered methods and gives accurate result of imaging. Apart from imaging, cerebrospinal fluid-based biomarkers are also used to identify the condition of hydrocephalus. This review is discussed on "hydrocephalus" and its imaging captured by CT scan and NMR to support the biomarker analysis.
    Matched MeSH terms: Tomography, X-Ray Computed
  11. Siew PF, Wan Yusmawati Wan Yusoff, Azman Jalar
    Sains Malaysiana, 2014;43:827-832.
    The physical properties and structural stability of the Quad Flat No-Leads (QFN) package with different gamma radiation doses have been investigated. The packages were irradiated with Co-60 gamma radiation with varying doses of 5 Gy, 50 Gy, 500 Gy, 5 kGy and 50 kGy with operating dose of 2.54 kGylh at room temperature. The infinite focus microscope (IFM) was used to measure the dimensional change and slantinglwarpage behaviour, while the 3D CT Scan X-ray machine was used to determine the occurrence of deflection on a wire in package due to exposure. It is believed that radiation effect on ceramic filler in the epoxy mold compound (EMC) plays an important role to induce the defects and resulted in swelling of the package. The slantinglwarpage behaviour is believed to be caused by the swelling behaviour of ceramic filler and further induced structural stability. The induced stress on the EMC structural after the dimensional change and slantinglwarpage failure leads to the occurrence of wire sweep. The finding suggests that defect production in swelled ceramic filler leads to the occurrence of dimensional and structure instability.
    Matched MeSH terms: Tomography, X-Ray Computed
  12. Smith K
    Biomed Imaging Interv J, 2012 Jan;8(1):e2.
    PMID: 22970058 DOI: 10.2349/biij.8.1.e2
    A 69 year-old man presented with an incidental finding on radiograph of a lesion in the left upper lobe. CT indicated it was likely to be a neoplasm and CT-guided FNA was requested. The lesion was located medial to the scapula so a creative approach was utilised to gain access to the lesion. This study discusses the approach used and why it reduced patient risk compared to a more conventional procedure. The sample was positive for neoplasm and there were no complications arising from the procedure.
    Matched MeSH terms: Tomography, X-Ray Computed
  13. Amin MFM, Zakaria WMW, Yahya N
    Skeletal Radiol, 2021 Dec;50(12):2525-2535.
    PMID: 34021364 DOI: 10.1007/s00256-021-03801-z
    OBJECTIVES: CT examination can potentially be utilised for early detection of bone density changes with no additional procedure and radiation dose. We hypothesise that the Hounsfield unit (HU) measured from CT images is correlated to the t-scores derived from dual energy X-ray absorptiometry (DXA) in multiple anatomic regions.

    MATERIALS & METHODS: Data were obtained retrospectively from all patients who underwent both CT examinations - brain (frontal bone), thorax (T7), abdomen (L3), spine (T7 & L3) or pelvis (left hip) - and DXA between 2014 and 2018 in our centre. To ensure comparability, the period between CT and DXA studies must not exceed one year. Correlations between HU values and t-scores were calculated using Pearson's correlation. Receiver operating characteristic (ROC) curves were generated, and the area under the curve (AUC) was used to determine threshold HU values for predicting osteoporosis.

    RESULTS: The inclusion criteria were met by 1043 CT examinations (136 head, 537 thorax, 159 lumbar and 151 left hip). The left hip consistently provided the most robust correlations (r = 0.664-0.708, p  0.05.

    CONCLUSION: HU values derived from the hip, T7 and L3 provided a good to moderate correlation to t-scores with a good prediction for osteoporosis. The suggested optimal thresholds may be used in clinical settings after external validations are performed.

    Matched MeSH terms: Tomography, X-Ray Computed
  14. Yap LPP, Wong JHD, Muhammad Gowdh NF, Ng WL, Chung E, Eturajulu RC, et al.
    J Med Imaging Radiat Sci, 2021 06;52(2):257-264.
    PMID: 33531272 DOI: 10.1016/j.jmir.2021.01.003
    INTRODUCTION: Fixed volume (FV) contrast media administration during CT examination is the standard practice in most healthcare institutions. We aim to validate a customised weight-based volume (WBV) method and compare it to the conventional FV methods, introduced in a regional setting.

    METHODS: 220 patients underwent CT of the chest, abdomen and pelvis (CAP) using a standard FV protocol, and subsequently, a customised 1.0 mL/kg WBV protocol within one year. Both image sets were assessed for contrast enhancement using CT attenuation at selected regions-of-interest (ROIs). The visual image quality was evaluated by three radiologists using a 4-point Likert scale. Quantitative CT attenuation was correlated with the visual quality assessment to determine the HU's enhancement indicative of the image quality grades. Contrast media usage was calculated to estimate cost-savings from both protocols.

    RESULTS: Mean patient age was 61 ± 14 years, and weight was 56.1 ± 8.7 kg. FV protocol produced higher contrast enhancement than WBV, p 

    Matched MeSH terms: Tomography, X-Ray Computed
  15. Liman ARUA, Tuang GJ, Mansor M
    Ear Nose Throat J, 2021 Dec;100(10_suppl):1004S-1005S.
    PMID: 32525702 DOI: 10.1177/0145561320927828
    Matched MeSH terms: Tomography, X-Ray Computed
  16. Vu H, Khanh Tuong TT, Hoang Lan N, Quoc Thang T, Bilgin K, Hoa T, et al.
    Clin Ter, 2022 11 15;173(6):565-571.
    PMID: 36373456 DOI: 10.7417/CT.2022.2483
    Background: Various non-invasive methods have been studied for assessing the severity of fatty liver disease and coronary atherosclero-sis. However, the correlation between hepatic steatosis and coronary atherosclerosis has not been fully studied, either globally or specifically in Vietnam. This study investigated the association between nonalcoholic fatty liver disease (NAFLD) and coronary atherosclerosis using coronary computed tomography angiography (CCTA).

    Methods: An analytical cross-sectional study was performed, including 223 patients treated by the Cardiology Department, the Emergency Interventional Cardiology Departments, and the Internal Cardiology Clinic of Thong Nhat Hospital.

    Results: In our cohort of 223 patients, the NAFLD was detected in 66% of the population, the mean coronary artery stenosis (CAS) was 44.54% ± 20.23%, and the mean coronary artery calcium score (CACS) was 3569.05 ± 425.99, as assessed using the Agatston method. The proportion of patients with significant atherosclerotic plaque (CAS 50%) >was 32%, whereas the remaining 68% had insignificant stenosis. Among our study population, 16% had no coronary artery calcification, 38% had mild calcification, and 46% had moderate to severe calcification. In the group of NAFLD patients, 33.3% had significant atherosclerotic plaque, which was not significantly different from the rate in individuals without NAFLD (p = 0.51). Mild coronary artery calcification was detected in 37.4% of NAFLD patients, and moderate to severe calcification was detected in 48.3% (p = 0.45).

    Conclusions: NAFLD was not found to be strongly associated with coronary atherosclerosis in this study. More studies with larger sample sizes remain necessary to verify whether any correlation exists.

    Matched MeSH terms: Tomography, X-Ray Computed
  17. Shaik Amir NS, Kang LZ, Mukari SA, Sahathevan R, Chellappan K
    Healthc Technol Lett, 2020 Feb;7(1):1-6.
    PMID: 32190334 DOI: 10.1049/htl.2018.5003
    A critical step in detection of primary intracerebral haemorrhage (ICH) is an accurate assessment of computed tomography (CT) brain images. The correct diagnosis relies on imaging modality and quality of acquired images. The authors present an enhancement algorithm which can improve the clarity of edges on CT images. About 40 samples of CT brain images with final diagnosis of primary ICH were obtained from the UKM Medical Centre in Digital Imaging and Communication in Medicine format. The images resized from 512 × 512 to 256 × 256 pixel resolution to reduce processing time. This Letter comprises of two main sections; the first is denoising using Wiener filter, non-local means and wavelet; the second section focuses on image enhancement using a modified unsharp masking (UM) algorithm to improve the visualisation of ICH. The combined approach of Wiener filter and modified UM algorithm outperforms other combinations with average values of mean square error, peak signal-to-noise ratio, variance and structural similarity index of 2.89, 31.72, 0.12 and 0.98, respectively. The reliability of proposed algorithm was evaluated by three blinded assessors which achieved a median score of 65%. This approach provides reliable validation for the proposed algorithm which has potential in improving image analysis.
    Matched MeSH terms: Tomography, X-Ray Computed
  18. Lee CK, Chan CYW, Gani SMA, Kwan MK
    Eur Spine J, 2017 11;26(11):2951-2960.
    PMID: 28819799 DOI: 10.1007/s00586-017-5266-5
    PURPOSE: This study aimed at studying the accuracy and safety of extra-pedicular screw insertion for dysplastic pedicles in AIS comparing cannulated screw system versus conventional screw system.

    METHODS: 104 AIS patients with 1524 pedicle screws were evaluated using CT scan. 302 screws were inserted in dysplastic pedicles using fluoroscopic guidance technique. 155 screws were inserted using a cannulated system (Group 1), whereas 147 screws were inserted using standard screws (Group 2). The pedicle perforations were assessed using a classification by Rao et al.; G0: no violation; G1: <2 mm perforation; G2: 2-4 mm perforation; and G3: >4 mm perforation). For anterior perforations, the pedicle perforations were assessed using a modified grading system (Grade 0: no violation, Grade 1: less than 4 mm perforation; Grade 2: 4 mm to 6 mm perforation; and Grade 3: more than 6 mm perforation).

    RESULTS: The perforation rate in Group 1 was 4.5% and in Group 2 was 15.6% (p = 0.001). Most of the perforations were anterior perforations (53.3%). The anterior perforation rate in Group 1 was 1.9% compared to 8.8% in Group 2 (p = 0.009). Group 1 has a medial perforation rate of 1.3% compared to Group 2, 6.1% (p = 0.031). The rate of critical pedicle perforation in Group 1 was 2.6% and in Group 2 was 6.8% (p = 0.102). In Group 1, there were no critical medial perforation but there was one G2 lateral perforation, one G2 superior perforation and two G3 anterior perforations. In Group 2, there were three G2 medial perforations, one G2 lateral perforation, one G2 anterior perforation and five G3 anterior perforations.

    CONCLUSION: Usage of cannulated screw system significantly increases the accuracy of pedicle screw insertion in dysplastic pedicles in AIS.

    Matched MeSH terms: Tomography, X-Ray Computed
  19. Mohammad N, Wan Ghazali WS
    IDCases, 2017;10:4-6.
    PMID: 28791214 DOI: 10.1016/j.idcr.2017.07.008
    Cavitary lung lesions of various etiologies may be encountered in patients with respiratory symptoms associated with fever. Non-malignant cavitary lesions may mimic malignant lung lesions on most of radiographic modalities including chest radiographs or thoracic computed tomography (CT). Primary lung malignancy can be detected in as high as one-fifths of CT thorax as cavitary lesions and the remaining aetiologies may be due to bacterial, parasitic, and invasive fungal infections, as well as Granulomatosis with polyangiitis (GPA), sarcoidosis, septic thrombo-embolism, and lung metastasis from extra-pulmonary primaries. We report an interesting case of melioidosis infection complicated with pulmonary embolism, both of which can lead to cavitary lung lesions and subsequently cause a clinical conundrum.
    Matched MeSH terms: Tomography, X-Ray Computed
  20. Chan CYW, Kwan MK
    Asian Spine J, 2017 Dec;11(6):998-1007.
    PMID: 29279757 DOI: 10.4184/asj.2017.11.6.998
    To review existing publications on the safety of pedicle screw insertions in adolescent idiopathic scoliosis (AIS). Despite having increased risk for neurological and visceral injuries, the use of pedicle screws have led to increased correction rates in scoliosis surgery. A review was performed on topics pertinent to pedicle screw insertion in AIS, which included pedicle morphometry in AIS, structures at risk during pedicle screw insertion, and accuracy and safety of various pedicle screw insertion techniques. The importance of computer navigation and future research regarding pedicle screw placement in AIS were also briefly reviewed. Many authors have reported abnormal pedicle anatomy in AIS. Injury to the neural structures was highest over the apical region, whereas aortic injury was the highest at T5 and T10. In the proximal thoracic spine, the esophagus could be injured even with screws as short as 25 mm. Overall pedicle perforation rates for perforations >0 and >2 mm (assessed by computed tomography) ranged from 6.4% to 65.0% and 3.7% to 29.9%, respectively. The critical pedicle perforation (>2 mm excluding lateral thoracic) and anterior perforation (>0 mm) rates was reported to range from 1.5% to 14.5% and 0.0% to 16.1%, respectively. Pedicle perforation rates were lower with the use of computer navigation. The incidence of neurological adverse events after scoliosis surgery was 0.06%-1.9%. Aortic injury has only been observed in case reports. According to the available literature, pedicle screw insertion in AIS is considered safe with low rates of clinical adverse events. Moreover, the use of navigation technology has been shown to reduce pedicle perforation rates.
    Matched MeSH terms: Tomography, X-Ray Computed
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