Displaying publications 41 - 60 of 765 in total

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  1. Nurul Raihan, A.K., Narwani, H., Mohd Effendi, M.G., Chung, W.M.
    Medicine & Health, 2020;15(1):280-287.
    MyJurnal
    Penekanan saraf lateral kutaneus femoral merupakan punca kepada penyakit meralgia parestetika. Gejala penyakit ini ialah kesakitan dan perubahan sensori pada bahagian lateral paha. Namun, gejala penyakit ini seakan menyerupai gejala penyakit lain seperti radikulopati lumbar, penyempitan ruang femoro-acetabular, bursitis trokanterik dan beberapa contoh lain. Meralgia parestetika merupakan diagnosis secara pengecualian setelah penyebab kepada kesakitan pada bahagian lateral paha tidak dapat dibuktikan melalui hasil penyiasatan yang terperinci. Pengetahuan anatomi tentang saraf yang mensarafi bahagian paha adalah amat penting untuk mengenalpasti punca kesakitan yang dialami. Kami ingin melaporkan satu kes yang melibatkan seorang pesakit lelaki berumur 46 tahun, telah didiagnos menghidap kencing manis, darah tinggi, masalah jantung yang telah datang ke Jabatan Kecemasan dan Trauma dengan aduan kesakitan akut pada bahagian lateral paha kanan. Kesakitan yang dialami digambarkan sebagai rasa seperti terbakar, dicucuk dan disertai dengan rasa kebas. Selain itu, terdapat pengurangan sensasi rasa pada bahagian paha yang sakit. Tiada aduan berkaitan sakit pada rangsangan ringan (allodinia) atau sakit yang berlebihan pada rangsangan kuat (hiperalgesia). Bacaan gula darah kapilari ialah 8.4 mmol/l dan keputusan HbA1c ialah 7%. Diagnosis meralgia parestetika telah disahkan setelah semua kemungkinan diagnosis lain tidak dapat dibuktikan melalui pemeriksaan fizikal, ujian makmal dan radiologi (x-ray, ultrasound dan MRI). Keadaan pesakit bertambah baik selepas diberikan rawatan ubat secara oral dan menjalani sesi fisioterapi.

    Matched MeSH terms: Magnetic Resonance Imaging
  2. Ismail UN, Azlan CA, Khairullah S, Azman RR, Omar NF, Md Shah MN, et al.
    J Magn Reson Imaging, 2021 01;53(1):190-198.
    PMID: 33237616 DOI: 10.1002/jmri.27294
    BACKGROUND: β-thalassemia is a genetic disease that causes abnormal production of red blood cells (ineffective erythropoiesis, IE). IE is a condition known to change bone marrow composition.

    PURPOSE: To evaluate the effect of IE on the marrow fat content and fat unsaturation levels in the proximal femur using 1 H-MRS.

    STUDY TYPE: Prospective.

    SUBJECTS: Twenty-three subjects were included in this study, seven control and 16 β-thalassemia subjects.

    FIELD STRENGTH/SEQUENCE: 3.0T; stimulated echo acquisition Mode (STEAM); magnetic resonance spectroscopy (MRS) sequence.

    ASSESSMENT: Multiecho MRS scans were performed in four regions of the proximal left femur of each subject, that is, diaphysis, femoral neck, femoral head, and greater trochanter. The examined regions were grouped into red (diaphysis and femoral neck) and yellow marrow regions (femoral head and greater trochanter).

    STATISTICAL TESTS: The Jonckheere-Terpstra test was used to evaluate the impact of increasing disease severity on bone marrow fat fraction (BMFF), marrow conversion index, and fat unsaturation index (UI). Pairwise comparison analysis was performed when a significant trend (P 

    Matched MeSH terms: Magnetic Resonance Imaging
  3. Inoue M, Isa ILM, Orita S, Suzuki-Narita M, Inage K, Shiga Y, et al.
    Spine (Phila Pa 1976), 2021 Aug 01;46(15):E810-E816.
    PMID: 34228691 DOI: 10.1097/BRS.0000000000003921
    STUDY DESIGN: An in vivo model to study the effect of an injectable hyaluronic acid (HA) hydrogel following puncture-induced lumbar disc injury in rabbits.

    OBJECTIVES: The aim of this study was to determine the efficacy of an injectable HA hydrogel to maintain disc height and tissue hydration, promote structural repair, and attenuate inflammation and innervation in the lumbar discs.

    SUMMARY OF BACKGROUND DATA: Previously, we have demonstrated that HA hydrogel alleviated inflammation, innervation, and pain to promote disc repair. Nevertheless, the effect of an injectable HA hydrogel in the lumbar disc in a weight-bearing animal model was not performed.

    METHODS: We have adopted a surgically puncture-induced disc injury at lumbar levels in a rabbit model. The discs were grouped into sham, puncture with water injection, and puncture with HA hydrogel injection. Postoperatively, we measured changes in disc height using x-ray. We used magnetic resonance imaging to assess disc degeneration on tissue hydration after euthanasia. Post-mortem, we determined histological changes, innervation (PGP9.5) and inflammation (interleukin [IL]-6, IL-1β, and tumor necrosis factor [TNF]-α) in the discs.

    RESULTS: We have demonstrated a significant reduction of disc height and T2/T1ρ mapping with histological evidence of degenerative discs, increase of innervation and inflammation in puncture-induced disc injury over time. In the HA hydrogel group, disc height was increased at weeks four and eight. A slight increase of T2 mapping, but significantly in T1ρ mapping, was observed in the HA hydrogel group at week 8. We observed homogenous NP distribution and organised AF lamellae at week eight and a slight reduced innervation score in the treatment group. HA hydrogel significantly downregulated IL-6 expression at day 1. This, however, was only slightly reduced for IL-1β and TNF-α.

    CONCLUSION: An injectable HA hydrogel had the protective effects in suppressing the loss of disc height, promoting tissue hydration for structural repair, and attenuating inflammation and innervation to prevent further disc degeneration.Level of Evidence: N/A.

    Matched MeSH terms: Magnetic Resonance Imaging
  4. Al-Hiyali MI, Yahya N, Faye I, Hussein AF
    Sensors (Basel), 2021 Aug 04;21(16).
    PMID: 34450699 DOI: 10.3390/s21165256
    The functional connectivity (FC) patterns of resting-state functional magnetic resonance imaging (rs-fMRI) play an essential role in the development of autism spectrum disorders (ASD) classification models. There are available methods in literature that have used FC patterns as inputs for binary classification models, but the results barely reach an accuracy of 80%. Additionally, the generalizability across multiple sites of the models has not been investigated. Due to the lack of ASD subtypes identification model, the multi-class classification is proposed in the present study. This study aims to develop automated identification of autism spectrum disorder (ASD) subtypes using convolutional neural networks (CNN) using dynamic FC as its inputs. The rs-fMRI dataset used in this study consists of 144 individuals from 8 independent sites, labeled based on three ASD subtypes, namely autistic disorder (ASD), Asperger's disorder (APD), and pervasive developmental disorder not otherwise specified (PDD-NOS). The blood-oxygen-level-dependent (BOLD) signals from 116 brain nodes of automated anatomical labeling (AAL) atlas are used, where the top-ranked node is determined based on one-way analysis of variance (ANOVA) of the power spectral density (PSD) values. Based on the statistical analysis of the PSD values of 3-level ASD and normal control (NC), putamen_R is obtained as the top-ranked node and used for the wavelet coherence computation. With good resolution in time and frequency domain, scalograms of wavelet coherence between the top-ranked node and the rest of the nodes are used as dynamic FC feature input to the convolutional neural networks (CNN). The dynamic FC patterns of wavelet coherence scalogram represent phase synchronization between the pairs of BOLD signals. Classification algorithms are developed using CNN and the wavelet coherence scalograms for binary and multi-class identification were trained and tested using cross-validation and leave-one-out techniques. Results of binary classification (ASD vs. NC) and multi-class classification (ASD vs. APD vs. PDD-NOS vs. NC) yielded, respectively, 89.8% accuracy and 82.1% macro-average accuracy, respectively. Findings from this study have illustrated the good potential of wavelet coherence technique in representing dynamic FC between brain nodes and open possibilities for its application in computer aided diagnosis of other neuropsychiatric disorders, such as depression or schizophrenia.
    Matched MeSH terms: Magnetic Resonance Imaging
  5. Ahmad, N. Z., Aini Ismafairus, A. H., Khairiah, A. H., Wan Ahmad Kamil, W. A., Mazlyfarina, M., Hanani, A. M.
    MyJurnal
    Introduction: This multiple-subject fMRI study continue to further investigate brain activation within and effective connectivity between the significantly (p
    Matched MeSH terms: Magnetic Resonance Imaging
  6. Ahmad Nazlim Yusoff, Mohd Harith Hashim, Mohd Mahadir Ayob, Iskandar Kassim
    MyJurnal
    Kajian garis pangkal pengimejan resonans magnet kefungsian (fMRI) telah dijalankan di Jabatan Radiologi, Hospital Universiti Kebangsaan Malaysia ke atas seorang subjek lelaki sihat berumur 25 tahun menggunakan sistem pengimejan resonans magnet (MRI) 1.5 T. Kajian ini menggunakan gerakan jari tangan kanan dan kiri untuk merangsang aktiviti neuron di dalam korteks serebrum. Subjek diarahkan supaya menekan jari-jari pada ibu jari secara bergilir-gilir semasa imbasan kefungsian dilakukan. Paradigma 5 kitar aktifrehat digunakan dengan setiap kitar masing-masing mengandungi 20 siri pengukuran. Keputusan menunjukkan bahawa rantau otak yang aktif akibat gerakan jari adalah girus presentral merangkumi kawasan motor primer. Pengaktifan otak adalah secara kontralateral terhadap gerakan jari tangan kanan dan kiri. Keamatan isyarat keadaan aktif didapati lebih tinggi daripada keamatan isyarat keadaan rehat. Analisis yang dilakukan ke atas beberapa rantau pengaktifan yang diminati (ROI) pada beberapa hirisan menunjukkan perbezaan yang bererti (p < 0.05) antara keamatan keadaan aktif dan rehat untuk nilai ambang statistik (Z) = 1.0 dan 1.5. Perbezaan purata antara kedua-dua purata keamatan isyarat keadaan aktif dan rehat pada manamana hirisan untuk kedua-dua nilai Z menunjukkan magnitud pengaktifan yang lebih tinggi pada hemisfera kanan otak iaitu apabila subjek menggerakkan tangan kirinya. Bilangan voksel yang aktif juga didapati lebih tinggi pada hemisfera kanan berbanding pada hemisfera kiri otak. Keputusan ini menyokong fakta bahawa bagi subjek yang tidak kidal, kawasan pengaktifan motor pada hemisfera kanan otak semasa gerakan jari tangan kiri mengalami rangsangan hemodinamik yang lebih tinggi berbanding dengan hemisfera kiri otak semasa gerakan jari tangan kanan. Fenomena rangsangan hemodinamik yang diperhatikan dalam kajian ini dibincangkan berdasarkan kepada kebergantungan kontras isyarat kepada aras oksigen darah (BOLD).
    Matched MeSH terms: Magnetic Resonance Imaging
  7. Ahmad Nazlim Yusoff, Mohd Harith Hashim, Mohd Mahadir Ayob, Iskandar Kassim
    MyJurnal
    Kajian garis pangkal pengimejan resonans magnet kefungsian (fMRI) telah dijalankan ke atas 2 orang subjek lelaki sihat (kidal dan tidak kidal) masing-masing berumur 22 dan 25 tahun. Imbasan fMRI dijalankan menggunakan sistem pengimejan resonans magnet (MRI) 1.5 T di Jabatan Radiologi, Hospital Universiti Kebangsaan Malaysia. Kajian ini menggunakan gerakanjari tangan kanan dan kiri untuk merangsang aktiviti neuron di dalam korteks serebrum. Paradigma 5 kitar aktifIrehat digunakan dengan setiap kitar mengandungi satu blok aktif dan satu blok rehat yang masing-masing mengandungi 10 siri pengukuran. Imej fMRI dianalisis menggunakan pekej perisian MatLab dan pemetaan statistik berparameter 2 (sPM2). Proses pendaftaran jasad tegar menggunakan penjelmaan afin 6 parameter dilakukan ke atas kesemua imej kefungsian berwajaran T2*. Keputusan menunjukkan bahawa pergerakan subjek adalah minimum sama ada dalam arah translasi (< 1 mm) atau putaran (< 1 ). Kesemua imej dinormalkan melalui proses peledingan tak linear menggunakan penjelmaan afin 12 parameter dan didapati sepadan dengan pencontoh yang telahpun mematuhi ruang anatomi piawai. Walau bagaimanapun, bentuk, resolusi dan kontras imej kefungsian telah berubah sedikit berbanding dengan imej asal. Pelicinan imej menggunakan kernel Gaussian isotropik 6 mm menyebabkan data imej lebih bersifat parametrik dengan kehilangan yang ketara dalam resolusi dan kontras. Pengasingan struktur yang dilakukan ke atas imej berwajaran T1 mengklaskan tisu otak kepadajirim kelabu, jirim putih dan bendalir serebrospina. Pasca pemprosesan ruang bagi imej kefungsian dan struktur menjadikan data imej bersifat parametrik dengan taburan jenis Gaussian dan sedia untuk dianalisis menggunakan model linear am dan teori medan rawak Gaussian.
    Matched MeSH terms: Magnetic Resonance Imaging
  8. Ee, G.C.L., Jong, V.Y.M., Sukari, M.A., Rahmani, M., Kua, A.S.M.
    MyJurnal
    The roots of Calophyllum inophyllum (Guttiferae), furnished six xanthones which are brasilixanthone (1), 1,3,5-trihydroxy-2- methoxy xanthone (2), caloxanthone A (3), pyranojacareubin (4), caloxanthone B (5) and tovopyrifolin (6), Structural elucidations of these compounds, were achieved through 1D and 2D NMR andMS techniques. In this paper, the isolation and structural elucidation data for these xanthones are reported.
    Matched MeSH terms: Magnetic Resonance Imaging
  9. Ahmad Nazlim Yusoff
    MyJurnal
    Kajian pengimejan resonans magnet kefungsian (fMRI) subjek tunggal ini menyelidiki kesan daya dan laju tepikan ke atas sifat pengaktifan korteks berkaitan motor semasa tepikan jari rentak sendiri secara bilateral. Subjek melakukan empat cara tepikan jari rentak sendiri iaitu sentuh-perlahan (SP), sentuh-laju (SL), tekan-perlahan (TP) dan tekan-laju (TL) dalam satu imbasan fMRI. Model linear am (GLM) digunakan dalam penjanaan pengaktifan otak. Pentaakulan statistik kemudiannya dibuat mengenai pengaktifan otak menggunakan teori medan rawak (RFT) Gaussian pada aras keertian diperbetulkan (α = 0.05), dengan andaian tiada pengaktifan berlaku. Keputusan mendapati otak mengkoordinasi tepikan jari bilateral rentak sendiri dengan penglibatan korteks berkaitan motor iaitu girus presentral (PCG) bilateral, serebelum bilateral dan juga kawasan motor tambahan (SMA). Peningkatan daya tepikan menonjolkan pengaktifan yang bererti (p < 0.05 diperbetulkan) pada PCG bilateral (Kawasan Brodmann (BA) 6) sejajar dengan fungsinya dalam mencetus tindakan motor seperti mengawal daya tepikan. Peningkatan laju tepikan pula menyebabkan peningkatan pengaktifan otak secara bererti (p < 0.05 diperbetulkan) hanya pada korteks kesatuan somatoderia iaitu pada lobus parietal superior (SPL) kanan atau BA7 kanan. Ini mencadangkan bahawa SPL memainkan peranan penting dalam mengkoordinasi pergerakan berkemahiran terancang.


    Matched MeSH terms: Magnetic Resonance Imaging
  10. Hamzah Ahmad, Nur Aqilah Othman
    MyJurnal
    This paper deals with the analysis of different Fuzzy membership type performance for Extended Kalman Filter (EKF) based mobile robot navigation. EKF is known to be incompetent in non-Gaussian noise condition and therefore the technique alone is not sufficient to provide solution. Motivated by this shortcoming, a Fuzzy based EKF is proposed in this paper. Three membership types are considered which includes the triangular, trapezoidal and Gaussian membership types to determine the best estimation results for mobile robot and landmarks locations. Minimal rule design and configuration are also other aspects being considered for analysis purposes. The simulation results suggest that the Gaussian memberships surpassed other membership type in providing the best solution in mobile robot navigation.
    Matched MeSH terms: Magnetic Resonance Imaging
  11. Nurwahidah, M., Wan, E.Z.W.A.R., Shaharuddin, C.S.
    MyJurnal
    This paper presents the application of active contours region-based method of image segmentation to Computed Tomography (CT) images. Previous researchers applied this region based method on Magnetic Resonance Image (MRI), in vivo images and synthetic images which contain intensity inhomogeneities. In this paper, a different modality known as Computed Tomography (CT) scan was applied. CT scan also produces images containing intensity inhomogeneity, and it is predicted that this method provide good segmentation results. The main objective of applying this method is to check its applicability on CT images. The segmentation process begins by finding the area of interest (black region). Results from this experiment are then used in estimating time of death. Experimental results show that this method has successfully segmented the black region when some parameters changed, provided that the regions are closed to each other. If the black regions are located far from each other, then this method will only segment certain areas.
    Matched MeSH terms: Magnetic Resonance Imaging
  12. Shahid Anwar, Mohamad Fadli Zolkipli, Julius Odili, Mushtaq Ali, Zakira Inayat, Jasni Mohamad Zain
    MyJurnal
    Android devices have gained a lot of attention in the last few decades due to several reasons including ease of use, effectiveness, availability and games, among others. To take advantage of Android devices, mobile users have begun installing an increasingly substantial number of Android applications on their devices. Rapid growth in many Android devices and applications has led to security and privacy issues. It has, for instance, opened the way for malicious applications to be installed on the Android devices while downloading different applications for different purposes. This has caused malicious applications to execute illegal operations on the devices that result in malfunction outputs. Android botnets are one of these malfunctions. This paper presents Android botnets in various aspects including their security, architecture, infection vectors and techniques. This paper also evaluates Android botnets by categorising them according to behaviour. Furthermore, it investigates the Android botnets with respect to Android device threats. Finally, we investigate different Android botnet detection techniques in depth with respect to the existing solutions deployed to mitigate Android botnets.
    Matched MeSH terms: Magnetic Resonance Imaging
  13. Ahmad Nazlim Yusoff, Hanani Abdul Manan, Siti Zamratol-Mai Sarah Mukari
    Sains Malaysiana, 2015;44:1339-1350.
    Proses penuaan seringkali dikaitkan dengan kemerosotan sistem kognitif. Kemerosotan tersebut bermula seawal usia dua puluhan dan berterusan secara linear. Walau bagaimanapun, kesan penuaan ke atas ciri kehubungan antara kawasan otak masih belum difahami. Dalam kajian ini, pengimejan resonans magnet kefungsian (fMRI) digunakan untuk mengkaji kesan penuaan ke atas kehubungan otak yang terhasil daripada tugasan mengulang secara terbalik (BRT). Subjek normal dalam empat kumpulan umur iaitu 20-29 tahun (n=14), 30-39 tahun (n=14), 40-49 tahun (n=10) dan 50-65 tahun (n=14) mengambil bahagian dalam kajian ini. Stimulus BRT terdiri daripada satu siri lima perkataan yang diberi secara auditori. Pemetaan statistik berparameter (SPM) dan pemodelan sebab dan akibat dinamik (DCM) digunakan untuk menentukan pengaktifan dan kehubungan otak. Sebanyak 200 model kehubungan intrahemisfera dan 150 interhemisfera dibina bagi menguji kewujudan gandingan antara girus temporal superior (STG), girus Heschl (HG), talamus (TH) dan girus presentral (PCG) kesemua subjek. Keputusan DCM menunjukkan subjek keempat-empat kumpulan umur menggunakan kehubungan intrahemisfera yang sama semasa tugasan BRT. Kehubungan interhemisfera pula didapati berubah menjadi semakin kompleks apabila usia meningkat. Perubahan tersebut didapati bermula pada usia 40 tahun. Keputusan ini menyokong penemuan terdahulu bahawa penuaan menyebabkan perubahan pada sistem neuron otak seterusnya mempengaruhi pemprosesan kognitif.
    Matched MeSH terms: Magnetic Resonance Imaging
  14. Darfizzi Derawi, Jumat Salimon
    Sains Malaysiana, 2016;45:817-823.
    Sebatian hidroksi-eter-POo
    (80% hasil) disintesis melalui pembukaan gelang oksirana minyak sawit olein terepoksida
    (EPOo
    ) secara alkoholisis. Hasil optimum pembukaan gelang oksirana (99.2%) dicapai dengan menggunakan asid
    sulfurik 3% v/bt pada suhu tindak balas yang tinggi (80o
    C) selama 30 minit masa tindak balas. Spektrum resonan
    magnetik nukleus-proton (1
    H-NMR) hidroksi-eter-POo
    telah menunjukkan kehadiran puncak proton pada karbon eter
    (3.2, 3.5 ppm) dan proton pada kumpulan hidroksil (4.8 ppm). Spektrum resonan magnetik nukleus-karbon (13C-NMR)
    hidroksi-eter-POo
    telah menunjukkan kehadiran puncak karbon yang terikat dengan kumpulan hidroksil (75 ppm) dan
    karbon pada karbonil kumpulan eter (72 ppm). Kelikatan kinematik hidroksi-eter-POo
    adalah 234.4 cSt (40o
    C) dan 28.1
    cSt (100o
    C) dengan indeks kelikatan 156.
    Matched MeSH terms: Magnetic Resonance Imaging
  15. A.N. Yusoff
    Sains Malaysiana, 2013;42:765-771.
    Kajian pengimejan resonans magnet kefungsian (fMRI) subjek tunggal ini menyelidiki interaksi psikofisiologi (PPI) antara girus presentral (PCG) dan lobus parietal superior (SPL) kanan semasa tepikan jari rentak sendiri secara bilateral. Model kehubungan efektif antara PCG dan SPL kanan dibina menggunakan analisis PPI dengan mengambil daya dan laju tepikan sebagai faktor uji kaji. Keputusan menunjukkan bahawa peningkatan daya dan laju tepikan masing-masing mengaktifkan PCG bilateral dan SPL kanan secara bererti (p<0.05). PCG dan SPL kanan didapati saling berhubungan semasa tepikan jari dilakukan dengan daya dan laju tepikan sebagai faktor uji kaji yang mempengaruhi kehubungan efektif antara mereka. Kajian ini telah mendedahkan maklumat asas berguna untuk kajian fMRI pada masa depan ke atas koordinasi motor dan boleh digunakan untuk mengkaji ketaktertiban otak misalnya strok.
    Matched MeSH terms: Magnetic Resonance Imaging
  16. Muhammad Jefri Mohd Yusof, Nur Aidasyakirah Mohd Tahir, Fazira Firdaus, Siti Fairus M. Yusoff
    Sains Malaysiana, 2018;47:2055-2061.
    Getah asli cecair (LNR) dihasilkan daripada proses penyahpolimeran getah asli yang menghasilkan rantaian polimer
    lebih pendek dan berat molekular kurang daripada 105
    . Namun, LNR masih mempamerkan tahap degradasi dan ketahanan
    termal yang rendah seperti getah asli, disebabkan oleh kehadiran ikatan karbon ganda dua pada rantaian polimer.
    Dalam kajian ini, penurunan diimida menggunakan pengoksidaan hidrazin hidrat dengan hidrogen peroksida dijalankan
    untuk menghidrogenkan unit tidak tepu LNR. LNR terhidrogen (HLNR) dicirikan menggunakan spektrometer infra-merah
    (FTIR) dan spektrometer resonans magnetik nuklear (NMR). Pengoptimuman parameter tindak balas dilakukan dengan
    memanipulasi parameter masa dan suhu tindak balas berdasarkan kaedah rangsangan permukaan (RSM) dengan
    5-aras-2-faktor reka bentuk komposit putaran tengah (CCRD). Satu model kuadratik yang signifikan telah dihasilkan
    untuk menghubungkan dua parameter tersebut dengan nilai R2 adalah 0.9986, menunjukkan bahawa model yang terhasil
    adalah sangat sepadan dengan data uji kaji. Keputusan kajian menunjukkan bahawa peratus penghidrogenan boleh
    ditingkatkan sehingga 91.2%. Seterusnya, berdasarkan RSM, parameter yang optimum bagi penurunan diimida LNR ini
    didapati pada suhu 55.9o
    C selama 6.7 jam, menghasilkan 80.2% HLNR. Kajian ini telah menunjukkan reka bentuk uji kaji
    secara statistik yang novel bagi menghidrogenkan LNR. Pelbagai variasi peratus penghidrogenan produk HLNR dalam
    kajian ini menyumbang kepada lebih banyak aplikasi produk yang memerlukan peratusan ketepuan unit yang tertentu.
    Matched MeSH terms: Magnetic Resonance Imaging
  17. Hanani Abdul Manan, Ahmad Nazlim Yusoff, Siti Zamratol-Mai Sarah Mukari
    Sains Malaysiana, 2018;47:1843-1852.
    Proses penuaan seringkali dikaitkan dengan kemerosotan pada sistem kognitif. Kemerosotan kognitif bermula seawal
    usia dua puluhan dan berterusan secara linear. Selain itu, kemerosotan kognitif juga menjadi lebih nyata dengan
    kehadiran hingar latar. Walau bagaimanapun, kesan penuaan ke atas mekanisme pemprosesan persepsi pertuturan
    menggunakan tugasan mengulang secara terus (FRT) dalam senyap dan hingar belum difahami dengan jelas. Dalam
    kajian ini, pengimejan resonans magnet kefungsian (fMRI) digunakan untuk membandingkan kesan penuaan ke atas
    kehubungan efektif otak yang terhasil daripada tugasan FRT ke atas subjek normal dengan empat kumpulan umur yang
    berlainan iaitu 20 - 29 tahun (n = 15), 30 - 39 tahun (n = 15), 40 - 49 tahun (n = 10) dan 50 - 65 tahun (n = 14). Satu siri
    lima perkataan yang diselang-seli dalam keadaan hingar dengan senyap diberikan secara auditori. Pemetaan statistik
    berparameter (SPM8) dan pemodelan dinamik penyebab (DCM10) digunakan untuk menentukan kehubungan efektif otak.
    Kawasan yang terlibat dalam pembinaan model kehubungan efektif otak adalah STG, HG dan PCG. Model optimum yang
    dipilih dalam kajian ini adalah model yang menunjukkan keseimbangan antara ketepatan dan kesukaran. Keputusan
    fMRI kehubungan efektif menunjukkan bahawa komunikasi antara intrahemisfera tidak berubah dengan menggunakan
    tugasan FRT ini apabila seseorang semakin berusia, tetapi komunikasi antara interhemisfera menjadi semakin kompleks.
    Matched MeSH terms: Magnetic Resonance Imaging
  18. Subramaniam S, Johan S, Hayati F, Ng CY, Azizan N, Chuah JA, et al.
    BMC Surg, 2020 Jun 11;20(1):130.
    PMID: 32527309 DOI: 10.1186/s12893-020-00787-8
    BACKGROUND: Sialolipoma is a rare tumour which may arise from both major and minor salivary glands and has recently been described as a variant of salivary gland lipomatous lesions.

    CASE PRESENTATION: We report a 54-year-old male who presented with a 7-year history of large right anterior neck swelling. He was clinically euthyroid and had no compressive or infiltrative symptoms. He sought medical attention due to the discomfort exerted by the weight of the mass and was keen for excision. The swelling appeared like a goitre but physical examination proved otherwise. Imaging was suggestive of a benign tumour arising from the right parapharyngeal fossa. The mass was surgically excised and was noted to be adherent to part of the submandibular gland. Histopathological examination revealed a new variant of benign adipocytic tumour of salivary gland or sialolipoma arising from the submandibular gland. Besides being the largest sialolipoma to be reported, there are also no reports of giant submandibular sialolipomas masquerading as a huge goitre in appearance.

    CONCLUSION: Submandibular sialolipomas can present in really large sizes and appear as a giant goitre. It is important to differentiate between benign lipomas from liposarcomas and tailor the management accordingly. Surgical enucleation is the preferred choice of treatment for these benign tumours with low recurrence rates.

    Matched MeSH terms: Magnetic Resonance Imaging
  19. Dewey RS, Hall DA, Plack CJ, Francis ST
    Magn Reson Med, 2021 11;86(5):2577-2588.
    PMID: 34196020 DOI: 10.1002/mrm.28902
    PURPOSE: Detecting sound-related activity using functional MRI requires the auditory stimulus to be more salient than the intense background scanner acoustic noise. Various strategies can reduce the impact of scanner acoustic noise, including "sparse" temporal sampling with single/clustered acquisitions providing intervals without any background scanner acoustic noise, or active noise cancelation (ANC) during "continuous" temporal sampling, which generates an acoustic signal that adds destructively to the scanner acoustic noise, substantially reducing the acoustic energy at the participant's eardrum. Furthermore, multiband functional MRI allows multiple slices to be collected simultaneously, thereby reducing scanner acoustic noise in a given sampling period.

    METHODS: Isotropic multiband functional MRI (1.5 mm) with sparse sampling (effective TR = 9000 ms, acquisition duration = 1962 ms) and continuous sampling (TR = 2000 ms) with ANC were compared in 15 normally hearing participants. A sustained broadband noise stimulus was presented to drive activation of both sustained and transient auditory responses within subcortical and cortical auditory regions.

    RESULTS: Robust broadband noise-related activity was detected throughout the auditory pathways. Continuous sampling with ANC was found to give a statistically significant advantage over sparse sampling for the detection of the transient (onset) stimulus responses, particularly in the auditory cortex (P < .001) and inferior colliculus (P < .001), whereas gains provided by sparse over continuous ANC for detecting offset and sustained responses were marginal (p ~ 0.05 in superior olivary complex, inferior colliculus, medial geniculate body, and auditory cortex).

    CONCLUSIONS: Sparse and continuous ANC multiband functional MRI protocols provide differing advantages for observing the transient (onset and offset) and sustained stimulus responses.

    Matched MeSH terms: Magnetic Resonance Imaging
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