ORCID Profile
0000-0002-5357-4193
Current Organisation
Universiti Putra Malaysia
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Publisher: MDPI AG
Date: 30-08-2021
DOI: 10.3390/DIAGNOSTICS11091573
Abstract: Hepatocellular carcinoma (HCC) is considered as a complex liver disease and ranked as the eighth-highest mortality rate with a prevalence of 2.4% in Malaysia. Magnetic resonance imaging (MRI) has been acknowledged for its advantages, a gold technique for diagnosing HCC, and yet the false-negative diagnosis from the examinations is inevitable. In this study, 30 MR images from patients diagnosed with HCC is used to evaluate the robustness of semi-automatic segmentation using the flood fill algorithm for quantitative features extraction. The relevant features were extracted from the segmented MR images of HCC. Four types of features extraction were used for this study, which are tumour intensity, shape feature, textural feature and wavelet feature. A total of 662 radiomic features were extracted from manual and semi-automatic segmentation and compared using intra-class relation coefficient (ICC). Radiomic features extracted using semi-automatic segmentation utilized flood filling algorithm from 3D-slicer had significantly higher reproducibility (average ICC = 0.952 ± 0.009, p 0.05) compared with features extracted from manual segmentation (average ICC = 0.897 ± 0.011, p 0.05). Moreover, features extracted from semi-automatic segmentation were more robust compared to manual segmentation. This study shows that semi-automatic segmentation from 3D-Slicer is a better alternative to the manual segmentation, as they can produce more robust and reproducible radiomic features.
Publisher: Elsevier BV
Date: 12-2019
Publisher: MDPI AG
Date: 30-09-2022
DOI: 10.3390/HEALTHCARE10101917
Abstract: A set of national diagnostic reference levels (DRLs) was established in Malaysia for a range of breast thicknesses in 2013, but no updates for full-field digital mammography (FFDM) and digital breast tomosynthesis (DBT). Due to the increasing number of DBTs used and concern over radiation exposure, this study aimed to explore and establish local diagnostic reference levels for FFDM and DBT in Malaysia health facilities at different compressed breast thickness (CBT) ranges. The CBT, kilovoltage peak (kVp), Entrance surface dose (ESD), and average glandular dose (AGD) were retrospectively extracted from the mammography Digital Imaging and Communications in Medicine (DICOM) header. The 75th and 95th percentile values were obtained for the AGD distribution of each mammography projection for three sets of CBT range. The difference in AGD values between FFDM and DBT at three CBT ranges was determined. The DRLs for FFDM were 1.13 mGy, 1.52 mGy, and 2.87 mGy, while DBT were 1.18 mGy, 1.88 mGy, and 2.78 mGy at CBT ranges of 20–39 mm, 40–59 mm, and 60–99 mm, respectively. The AGD of DBT was significantly higher than FFDM for both mammographic views (p 0.005). All three CBT groups showed a significant difference in AGD values for FFDM and DBT (p 0.005). The local DRLs from this study were lower than the national DRLs, with the AGD of FFDM significantly lower than DBT.
Publisher: MDPI AG
Date: 27-01-2021
DOI: 10.3390/APP11031172
Abstract: This study aimed to introduce an alternative, inexpensive, and straightforward polymer with specific mechanical and dielectric properties suitable for the fabrication of a clinical-grade kidney phantom. Two polymer-based phantom materials, polydimethylsiloxane (PDMS) and silicone elastomer (SE), were investigated for their capability to meet the requirements. The concentration ratios of base to curing agent (B/C) were 9.5/1.5, 19/3, 10/1, 20/2, 10.5/0.5, and 21/1 for PDMS and 4.5/5.5, 10/12, 5/5, 11/11, 5.5/4.5, and 12/10 for SE. All s les were mixed, degassed, and poured into Petri dishes and small beakers. The polymer was cured under room temperature for 2 h and then demolded from the hard mold. The air bubbles produced were removed using a vacuum desiccator for 30 min. All s les underwent mechanical testing (tensile strength and elastic modulus), and their dielectric properties were measured using a dielectric probe kit equipped with 85071E materials measurement software. The radiation attenuation properties were also measured using PhyX-Zetra for PDMS phantoms with the chemical formula C2H6OSi. Small changes in base and cross-linker play an essential role in modifying the elastic modulus and tensile strength. The effective atomic number of PDMS showed a similar pattern with human kidney tissue at the intermediate energy level of 1.50 × 10−1 to 1 MeV. Therefore, PDMS can potentially be used to mimic the human kidney in terms of tensile strength, flexibility, the acceptable real part of the complex dielectric constant ε′r, and conductivity, which allows it to be used as a stable kidney phantom for medical imaging purposes.
Publisher: IOP Publishing
Date: 03-2020
DOI: 10.1088/1742-6596/1497/1/012032
Abstract: Radiotherapy plays an important role in cancer treatment however, the incidence of radio-resistance remains become major challenges in cancer treatment. The presence of epithelial-mesenchymal transition (EMT) has become a clinical hallmark for cancer to relapse after radiation treatment. The aim of this study was to investigate the morphological changes and cell survival of EMT6 cell line post–gamma ray irradiation. The irradiation of EMT6 cells was conducted with two approaches, first, EMT6 cells were treated with single dose of gamma-ray ranging low to high dose of gamma-ray (0-16 Gy) and second, EMT6 cells were exposed to fractionated gamma-ray irradiation (2 Gy per cycle) where cells that survive the initial irradiation were further irradiated with 2 Gy dose. Results showed that there were morphological changes in treated cell compared to sham-control cells in both irradiation approaches which include loss of glandular pattern, vacuolated cell plasma, pleomorphic nuclei and enlarged size. For survival fraction, the survival fractions were reduced with increasing dose compared to the sham-control in single dose reaction while for the fractionated irradiation, survival fractions were reduced until 3 rd cycles and increased in 4 th cycles and maintained until 6 cycles which showed resistance of EMT6. In conclusion, radiation therapy causes cell morphological changes and fractionation of gamma-ray irradiation lead to resistance EMT6 after 4 cycles.
Publisher: MDPI AG
Date: 28-01-2022
Abstract: Medical imaging phantoms are considered critical in mimicking the properties of human tissue for calibration, training, surgical planning, and simulation purposes. Hence, the stability and accuracy of the imaging phantom play a significant role in diagnostic imaging. This study aimed to evaluate the influence of hydrogen silicone (HS) and water (H2O) on the compression strength, radiation attenuation properties, and computed tomography (CT) number of the blended Polydimethylsiloxane (PDMS) s les, and to verify the best material to simulate kidney tissue. Four s les with different compositions were studied, including s les S1, S2, S3, and S4, which consisted of PDMS 100%, HS/PDMS 20:80, H2O/PDMS 20:80, and HS/H2O/PDMS 20:40:40, respectively. The stability of the s les was assessed using compression testing, and the attenuation properties of s le S2 were evaluated. The effective atomic number of S2 showed a similar pattern to the human kidney tissue at 1.50 × 10−1 to 1 MeV. With the use of a 120 kVp X-ray beam, the CT number quantified for S2, as well measured 40 HU, and had the highest contrast-to-noise ratio (CNR) value. Therefore, the S2 s le formulation exhibited the potential to mimic the human kidney, as it has a similar dynamic and is higher in terms of stability as a medical phantom.
Publisher: IOP Publishing
Date: 06-2019
DOI: 10.1088/1742-6596/1248/1/012012
Abstract: The aim of this study is to evaluate effective dose received by participants from Lung Cancer Screening program in Institut Kanser Negara (IKN), Putrajaya. This retrospective study was performed between April 2016 - December 2016 where all scanning acquisition protocols and dose information from forty (40) participants were recorded and investigated. The screening process involves two types of imaging technique, the Dual Energy Subtraction (DES) Chest Xray and Low-Dose Computed Tomography (LDCT) imaging technique. Participant’s effective dose (ED) from DES and MSCT were analysed by using PCXMC (Version 2.0, Finland) and CT-EXPO (Version 2.3, Germany) software, respectively. It was observed that the mean ( ± SD) value for DES (at 60 kV), DES (at 120 kV) and MSCT examinations were 0.006 ± 0.005 mSv, 0.018 ± 0.005 mSv and 1.558 ± 0.129 mSv, respectively. In a whole, the total cumulative ED values for participants were ranged from 1.376 mSv to 1.986 mSv. It was summarized that both optimized techniques were useful for screening needs and the ED value from this study were lower when compared to other established reference.
Location: Malaysia
No related grants have been discovered for Muhammad Karim.