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  1. Fulltext Reproducibility and Repeatability of Coronary Computed Tomography Angiography (CCTA) Image Segmentation in Detecting Atherosclerosis: A Radiomics Study
    Yunus MM, Sabarudin A, Karim MKA, Nohuddin PNE, Zainal IA, Shamsul MSM, et al.
    Diagnostics (Basel), 2022 Aug 19;12(8).
    PMID: 36010355 DOI: 10.3390/diagnostics12082007
    Atherosclerosis is known as the leading factor in heart disease with the highest mortality rate among the Malaysian population. Usually, the gold standard for diagnosing atherosclerosis is by using the coronary computed tomography angiography (CCTA) technique to look for plaque within the coronary artery. However, qualitative diagnosis for noncalcified atherosclerosis is vulnerable to false-positive diagnoses, as well as inconsistent reporting between observers. In this study, we assess the reproducibility and repeatability of segmenting atherosclerotic lesions manually and semiautomatically in CCTA images to identify the most appropriate CCTA image segmentation method for radiomics analysis to quantitatively extract the atherosclerotic lesion. Thirty (30) CCTA images were taken retrospectively from the radiology image database of Hospital Canselor Tuanku Muhriz (HCTM), Kuala Lumpur, Malaysia. We extract 11,700 radiomics features which include the first-order, second-order and shape features from 180 times of image segmentation. The interest vessels were segmentized manually and semiautomatically using LIFEx (Version 7.0.15, Institut Curie, Orsay, France) software by two independent radiology experts, focusing on three main coronary blood vessels. As a result, manual segmentation with a soft-tissuewindowing setting yielded higher repeatability as compared to semiautomatic segmentation with a significant intraclass correlation coefficient (intra-CC) 0.961 for thefirst-order and shape features; intra-CC of 0.924 for thesecond-order features with p < 0.001. Meanwhile, the semiautomatic segmentation has higher reproducibility as compared to manual segmentation with significant interclass correlation coefficient (inter-CC) of 0.920 (first-order features) and a good interclass correlation coefficient of 0.839 for the second-order features with p < 0.001. The first-order, shape order and second-order features for both manual and semiautomatic segmentation have an excellent percentage of reproducibility and repeatability (intra-CC > 0.9). In conclusion, semi-automated segmentation is recommended for inter-observer study while manual segmentation with soft tissue-windowing can be used for single observer study.
  2. Potential diverse applications of diffusion-derived vessel density (DDVD) pixel-by-pixel mapping
    Yao DQ, Zheng CJ, Deng YY, Lu BL, Lu T, Hu GW, et al.
    Quant Imaging Med Surg, 2024 Mar 15;14(3):2136-2145.
    PMID: 38545048 DOI: 10.21037/qims-24-164
  3. Fulltext Underestimation of liver hemangioma perfusion fraction by standard intravoxel incoherent motion diffusion magnetic resonance imaging
    Wáng YXJ, Sabarudin A
    Quant Imaging Med Surg, 2024 Feb 01;14(2):2128-2135.
    PMID: 38415141 DOI: 10.21037/qims-23-1651
  4. Fulltext Implications of Web of Science journal impact factor for scientific output evaluation in 16 institutions and investigators' opinion
    Wáng YX, Arora R, Choi Y, Chung HW, Egorov VI, Frahm J, et al.
    Quant Imaging Med Surg, 2014 Dec;4(6):453-61.
    PMID: 25525577 DOI: 10.3978/j.issn.2223-4292.2014.11.16
    Journal based metrics is known not to be ideal for the measurement of the quality of individual researcher's scientific output. In the current report 16 contributors from Hong Kong SAR, India, Korea, Taiwan, Russia, Germany, Japan, Turkey, Belgium, France, Italy, UK, The Netherlands, Malaysia, and USA are invited. The following six questions were asked: (I) is Web of Sciences journal impact factor (IF) and Institute for Scientific Information (ISI) citation the main academic output performance evaluation tool in your institution? and your country? (II) How does Google citation count in your institution? and your country? (III) If paper is published in a non-SCI journal but it is included in PubMed and searchable by Google scholar, how it is valued when compared with a paper published in a journal with an IF? (IV) Do you value to publish a piece of your work in a non-SCI journal as much as a paper published in a journal with an IF? (V) What is your personal view on the metric measurement of scientific output? (VI) Overall, do you think Web of Sciences journal IF is beneficial, or actually it is doing more harm? The results show that IF and ISI citation is heavily affecting the academic life in most of the institutions. Google citation and evaluation, while is being used and convenient and speedy, has not gain wide 'official' recognition as a tool for scientific output evaluation.
  5. Effectiveness of Post-Mortem Computed Tomography (PMCT) In Comparison with Conventional Autopsy: A Systematic Review
    Uthandi D, Sabarudin A, Mohd Z, Rahman MAA, Karim MKA
    Curr Med Imaging Rev, 2019 Aug 21.
    PMID: 32407281 DOI: 10.2174/1573405615666190821115426
    BACKGROUND: With the advancement of technology, Computed Tomography (CT) scan imaging could be used to gain deeper insight into the cause of death.

    AIM: The purpose of this study is to perform a systematic review of the efficacy of Post-Mortem Computed Tomography (PMCT) scan compared with conventional autopsies gleaned from literature published in English between the year 2009 and 2016.

    METHODOLOGY: A literature search was conducted in three databases, namely PubMed, MEDLINE, and Scopus. A total of 387 articles were retrieved, but only 21 studies were accepted after meeting the review criteria. Data, such as the number of victims, the number of radiologists and forensic pathologists involved, causes of death, and additional and missed diagnoses in PMCT scans were tabulated and analysed by two independent reviewers.

    RESULTS: Compared with the conventional autopsy, the accuracy of PMCT scans in detecting injuries and causes of death was observed to range between 20% and 80%. The analysis also showed that PMCT had more advantages in detecting fractures, fluid in airways, gas in internal organs, major hemorrhages, fatty liver, stones, and bullet fragments. Despite its benefits, PMCT also could miss certain important lesion in a certain region such as cardiovascular injuries and minor vascular injuries.

    CONCLUSIONS: This systematic review suggests that PMCT can replace most of the conventional autopsy in specific cases and is also a good complementary tool in most cases.

  6. Radiation dose associated with cerebral CT angiography and CT perfusion: an experimental phantom study
    Sabarudin A, Yusof MZ, Mohamad M, Sun Z
    Radiat Prot Dosimetry, 2014 Dec;162(3):316-21.
    PMID: 24255172 DOI: 10.1093/rpd/nct280
    A study on the radiation dose associated with cerebral CT angiography (CTA) and CT perfusion (CTP) was conducted on an anthropomorphic phantom with the aim of estimating the effective dose (E) and entrance skin dose (ESD) in the eyes and thyroid gland during different CTA and CTP protocols. The E was calculated to be 0.61 and 0.28 mSv in CTA with 100 and 80 kV(p), respectively. In contrast, CTP resulted in an estimated E of 2.74 and 2.07 mSv corresponding to 40 and 30 s protocols, respectively. The eyes received a higher ESD than the thyroid gland in all of these protocols. The results of this study indicate that combining both CTA and CTP procedures are not recommended in the stroke evaluation due to high radiation dose. Application of modified techniques in CTA (80 kV(p)) and CTP (30 s) is highly recommended in clinical practice for further radiation dose reduction.
  7. Fulltext Coronary CT angiography: Dose reduction strategies
    Sabarudin A, Sun Z
    World J Cardiol, 2013 Dec 26;5(12):465-72.
    PMID: 24392191 DOI: 10.4330/wjc.v5.i12.465
    With the introduction of 64- and post-64 slice computed tomography (CT) technology, coronary CT angiography has been increasingly used as a less invasive modality for the diagnosis of coronary artery disease. Despite its high diagnostic value and promising results compared to invasive coronary angiography, coronary CT angiography is associated with high radiation dose, leading to potential risk of radiation-induced cancer. A variety of dose-reduction strategies have been reported recently to reduce radiation dose with effective outcomes having been achieved. This article presents an overview of the various methods currently used for radiation dose reduction.
  8. Fulltext Radiation dose measurements in coronary CT angiography
    Sabarudin A, Sun Z
    World J Cardiol, 2013 Dec 26;5(12):459-64.
    PMID: 24392190 DOI: 10.4330/wjc.v5.i12.459
    Coronary computed tomography (CT) angiography is associated with high radiation dose and this has raised serious concerns in the literature. Awareness of various parameters for dose estimates and measurements of coronary CT angiography plays an important role in increasing our understanding of the radiation exposure to patients, thus, contributing to the implementation of dose-saving strategies. This article provides an overview of the radiation dose quantity and its measurement during coronary CT angiography procedures.
  9. Fulltext Beta-blocker administration protocol for prospectively ECG-triggered coronary CT angiography
    Sabarudin A, Sun Z
    World J Cardiol, 2013 Dec 26;5(12):453-8.
    PMID: 24392189 DOI: 10.4330/wjc.v5.i12.453
    The aim of this article is to discuss the protocol of beta-blockers that is commonly used for prospectively ECG-triggered coronary computed tomography angiography (CCTA). It is essential to ensure a low and regular heart rate in patients undergoing prospectively ECG-triggered CCTA for optimal visualization of coronary arteries. Although early generations of computed tomographyscanners are not applicable to be tailored according to patients' heart rate, a low and regular heart rate is possible to be achieved by the administration of medications according to the beta-blocker protocol. Beta-blocker can be safely administered to reduce patients' heart rate for CCTA examination if patients are screened for certain contraindications.
  10. Fulltext Coronary CT angiography: Diagnostic value and clinical challenges
    Sabarudin A, Sun Z
    World J Cardiol, 2013 Dec 26;5(12):473-83.
    PMID: 24392192 DOI: 10.4330/wjc.v5.i12.473
    Coronary computed tomography (CT) angiography has been increasingly used in the diagnosis of coronary artery disease due to improved spatial and temporal resolution with high diagnostic value being reported when compared to invasive coronary angiography. Diagnostic performance of coronary CT angiography has been significantly improved with the technological developments in multislice CT scanners from the early generation of 4-slice CT to the latest 320- slice CT scanners. Despite the promising diagnostic value, coronary CT angiography is still limited in some areas, such as inferior temporal resolution, motion-related artifacts and high false positive results due to severe calcification. The aim of this review is to present an overview of the technical developments of multislice CT and diagnostic value of coronary CT angiography in coronary artery disease based on different generations of multislice CT scanners. Prognostic value of coronary CT angiography in coronary artery disease is also discussed, while limitations and challenges of coronary CT angiography are highlighted.
  11. Radiation dose in coronary CT angiography associated with prospective ECG-triggering technique: comparisons with different CT generations
    Sabarudin A, Sun Z, Ng KH
    Radiat Prot Dosimetry, 2013;154(3):301-7.
    PMID: 22972797 DOI: 10.1093/rpd/ncs243
    A retrospective analysis was performed in patients undergoing prospective ECG-triggered coronary computed tomography (CT) angiography (CCTA) with the single-source 64-slice CT (SSCT), dual-source 64-slice CT (DSCT), dual-source 128-slice CT and 320-slice CT with the aim of comparing the radiation dose associated with different CT generations. A total of 164 patients undergoing prospective ECG-triggered CCTA with different types of CT scanners were studied with the mean effective doses estimated at 6.8 ± 3.2, 4.2 ± 1.9, 4.1±0.6 and 3.8 ± 1.4 mSv corresponding to the 128-slice DSCT, 64-slice DSCT, 64-slice SSCT and 320-slice CT scanners. In this study a positive relationship was found between the effective dose and the body mass index (BMI). A low radiation dose is achieved in prospective ECG-triggered CCTA, regardless of the CT scanner generation. BMI is identified as the major factor that has a direct impact on the effective dose associated with prospective ECG-triggered CCTA.
  12. Dual-source CT coronary angiography: effectiveness of radiation dose reduction with lower tube voltage
    Sabarudin A, Md Yusof AK, Tay MF, Ng KH, Sun Z
    Radiat Prot Dosimetry, 2013;153(4):441-7.
    PMID: 22807493 DOI: 10.1093/rpd/ncs127
    This study was conducted to investigate the effectiveness of dose-saving protocols in dual-source computed tomography (CT) coronary angiography compared with invasive coronary angiography (ICA). On 50 patients who underwent coronary CT angiography was performed dual-source CT (DSCT) and compared with ICA procedures. Entrance skin dose (ESD), which was measured at the thyroid gland, and effective dose (E) were assessed for both imaging modalities. The mean ESD measured at the thyroid gland was the highest at 120 kVp, followed by the 100 kVp DSCT and the ICA protocols with 4.0±1.8, 2.7±1.0 and 1.1±1.2 mGy, respectively. The mean E was estimated to be 10.3±2.1, 6.2±2.3 and 5.3±3.4 mSv corresponding to the 120-kVp, 100-kVp DSCT and ICA protocols, respectively. The application of 100 kVp in DSCT coronary angiography is feasible only in patients with a low body mass index of <25 kg m(-2), which leads to a significant dose reduction with the radiation dose being equivalent to that of ICA.
  13. Coronary CT angiography with single-source and dual-source CT: comparison of image quality and radiation dose between prospective ECG-triggered and retrospective ECG-gated protocols
    Sabarudin A, Sun Z, Yusof AK
    Int J Cardiol, 2013 Sep 30;168(2):746-53.
    PMID: 23098849 DOI: 10.1016/j.ijcard.2012.09.217
    This study is conducted to investigate and compare image quality and radiation dose between prospective ECG-triggered and retrospective ECG-gated coronary CT angiography (CCTA) with the use of single-source CT (SSCT) and dual-source CT (DSCT).
  14. Fulltext Cerebral CT angiography and CT perfusion in acute stroke detection: a systematic review of diagnostic value
    Sabarudin A, Subramaniam C, Sun Z
    Quant Imaging Med Surg, 2014 Aug;4(4):282-90.
    PMID: 25202664 DOI: 10.3978/j.issn.2223-4292.2014.07.10
    The purpose of this study was to analyse the diagnostic value of cerebral CT angiography (CTA) and CT perfusion (CTP) examinations in the detection of acute stroke based on a systematic review of the current literature. The review was conducted based on searching of seven databases for articles published between 1993 and 2013. Diagnostic value in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy was analysed from 21 articles which were found to meet selection criteria. The mean sensitivity, specificity, PPV, NPV and accuracy for CTA were significantly higher than those for CTP with 83.2% (95% CI: 57.9-100.0%), 95.0% (95% CI: 74.4-100%), 84.1% (95% CI: 50.0-100%), 97.1 (95% CI: 94.0-100%) and 94.0% (95% CI: 83.0-99.0) versus 69.9% (95% CI: 20.0-97.0%), 87.4 (95% CI: 61.0-100.0%), 76.4% (95% CI: 48.0-95.4%), 78.2% (95% CI: 55.8-93.9%) and 89.8% (95% CI: 75.7-97.1%), respectively. This analysis shows that CTA has high diagnostic value in detecting high degree of cerebral arterial stenosis (>70%) whereas CTP provides high specificity in the detection of ischemia and infarct tissue of brain.
  15. Fulltext Image quality assessment in panoramic dental radiography: a comparative study between conventional and digital systems
    Sabarudin A, Tiau YJ
    Quant Imaging Med Surg, 2013 Feb;3(1):43-8.
    PMID: 23483085 DOI: 10.3978/j.issn.2223-4292.2013.02.07
    This study is designed to compare and evaluate the diagnostic image quality of dental panoramic radiography between conventional and digital systems. Fifty-four panoramic images were collected and divided into three groups consisting of conventional, digital with and without post processing image. Each image was printed out and scored subjectively by two experienced dentists who were blinded to the exposure parameters and system protocols. The evaluation covers of anatomical coverage and structures, density and image contrast. The overall image quality score revealed that digital panoramic with post-processing scored the highest of 3.45±0.19, followed by digital panoramic system without post-processing and conventional panoramic system with corresponding scores of 3.33±0.33 and 2.06±0.40. In conclusion, images produced by digital panoramic system are better in diagnostic image quality than that from conventional panoramic system. Digital post-processing visualization can improve diagnostic quality significantly in terms of radiographic density and contrast.
  16. Radiation dose reduction in thoracic and abdomen-pelvic CT using tube current modulation: a phantom study
    Sabarudin A, Mustafa Z, Nassir KM, Hamid HA, Sun Z
    J Appl Clin Med Phys, 2015 Jan;16(1):319-328.
    PMID: 28297258 DOI: 10.1120/jacmp.v16i1.5135
    This phantom study was designed to compare the radiation dose in thoracic and abdomen-pelvic CT scans with and without use of tube current modulation (TCM). Effective dose (ED) and size-specific dose estimation (SSDE) were calculated with the absorbed doses measured at selective radiosensitive organs using a thermoluminescence dosimeter-100 (TLD-100). When compared to protocols without TCM, the ED and SSDE were reduced significantly with use of TCM for both the thoracic and abdomen-pelvic CT. With use of TCM, the ED was 6.50±0.29 mSv for thoracic and 6.01±0.20 mSv for the abdomen-pelvic CT protocols. However without use of TCM, the ED was 20.07±0.24 mSv and 17.30±0.41 mSv for the thoracic and abdomen-pelvic CT protocols, respectively. The corresponding SSDE was 10.18±0.48 mGy and 11.96±0.27 mGy for the thoracic and abdomen-pelvic CT protocols with TCM, and 31.56±0.43 mGy and 33.23±0.05 mGy for thoracic and abdomen-pelvic CT protocols without TCM, respectively. The highest absorbed dose was measured at the breast with 8.58±0.12 mGy in the TCM protocols and 51.52±14.72 mGy in the protocols without TCM during thoracic CT. In the abdomen-pelvic CT, the absorbed dose was highest at the skin with 9.30±1.28 mGy and 29.99±2.23 mGy in protocols with and without use of TCM, respectively. In conclusion, the TCM technique results in significant dose reduction; thus it is to be highly recommended in routine thoracic and abdomen-pelvic CT. PACS numbers: 87.57.Q-, 87.57.qp, 87.53.Bn.
  17. Fulltext A comparison study of radiation effective dose in ECG-Gated Coronary CT Angiography and calcium scoring examinations performed with a dual-source CT scanner
    Sabarudin A, Siong TW, Chin AW, Hoong NK, Karim MKA
    Sci Rep, 2019 03 13;9(1):4374.
    PMID: 30867480 DOI: 10.1038/s41598-019-40758-5
    In this report we have evaluated radiation effective dose received by patients during ECG-gated CCTA examinations based on gender, heart rate, tube voltage protocol and body mass index (BMI). A total of 1,824 patients were retrospectively recruited (1,139 men and 685 women) and they were divided into Group 1 (CCTA with calcium scoring), Group 2 (CCTA without calcium scoring) and Group 3 (only calcium scoring), where the association between gender, heart rate, tube voltage protocol and body mass index (BMI) were analysed. Examinations were performed using a retrospective ECG-gated CCTA protocol and the effective doses were calculated from the dose length product with a conversion coefficient of 0.026 mSv.mGy-1cm-1. No significant differences were observed in the mean effective dose between gender in all groups. The mean estimated dose was significantly higher when the heart rate was lower in Group 1 (p 
  18. Fulltext Effectiveness of an educational module in improving knowledge, awareness and perception among pregnant women regarding the safe use of prenatal ultrasound
    Ravintaran T, Go KX, Che Isa IN, Mohd Norsuddin N, Sabarudin A, Mohamed Sharif N, et al.
    Heliyon, 2023 Jan;9(1):e12773.
    PMID: 36685374 DOI: 10.1016/j.heliyon.2022.e12773
    BACKGROUND: Lack of public understanding, perception and awareness of the biological effects of prenatal ultrasound has led to the non-medical use of ultrasound. An educational programme is required to enlighten pregnant women and the public regarding prenatal ultrasound safety.

    OBJECTIVE: To evaluate the effectiveness of educational modules (video and brochure) in improving knowledge, awareness and perception (KAP) among pregnant women regarding prenatal ultrasound safety.

    METHODS: This is a quasi-experimental study with a pre-and post-test design. This study recruited 51 pregnant women as respondents from the Obstetrics and Gynaecology clinic (O&G) of Hospital Canselor Tuanku Muhriz (HCTM). The first phase of the study was conducted by distributing a set of closed-ended questionnaires with multiple choice and Likert scale answers to assess the KAP of pregnant women regarding the safe use of prenatal ultrasound, followed by educational modules where the respondents were allocated into three groups (17 watched a video, 17 received brochure and 17 received combined media). After the intervention, the respondents' KAP were assessed using the same questionnaire.

    RESULTS: The Wilcoxon signed rank test showed that educational modules like video, brochure and combined media had a statistically significant increase in post-test scores over the pre-test scores (video: mean rank = 9.00, p  0.05). The Kruskal Wallis test indicated that educational video was more effective in improving the KAP of pregnant women than the brochure and combined media (mean rank = 34.62, p 

  19. A comparative study of radiation doses between phantom and patients via CT angiography of the intra-/extra-cranial, pulmonary, and abdominal/pelvic arteries
    Karim MKA, Sabarudin A, Muhammad NA, Ng KH
    Radiol Phys Technol, 2019 Dec;12(4):374-381.
    PMID: 31468370 DOI: 10.1007/s12194-019-00532-8
    This study aimed to evaluate effective dose and size-specific dose estimate (SSDE) of computed tomography angiography (CTA) examination using an anthropomorphic phantom. We included three CTA examination protocols to evaluate the intra- and extra-cranial arteries, pulmonary artery (CTPA), and abdominal vessels. Patient SSDEs were measured retrospectively to estimate patient dose, relative to the bodyweight of the patient and volume CT dose index (CTDIvol). Our findings revealed that the highest dose was absorbed by the left lobe of the thyroid gland during intra-/extra-cranial CTA and CTPA, that is, 14.11 ± 0.24 mGy and 16.20 ± 3.95 mGy, respectively. However, the highest absorbed dose in abdominal/pelvic CTA was the gonads (8.98 ± 0.30 mGy), while other radiosensitive organs in intra- and extra-cranial CTA, CTPA, and abdominal/pelvic CTA did not demonstrate significant differences between organs/structures with p value 0.88, 0.11, and 0.54, respectively. The estimated effective dose in intra-/extra-cranial CTA was lower in patients (0.80 ± 0.60 mSv) than in the phantom (0.83 mSv), but it was the opposite for CTPA, with the effective dose being higher in patients (7.54 ± 3.09 mSv) than in the phantom (6.68 mSv). Similar to the effective dose, only CTPA SSDEs were significantly higher in men than in women (19.74 ± 4.79 mGy versus 7.9 mGy). Effective dose and SSDE are clinically relevant parameters that can help estimate a more accurate patient dose based on a patient's size.
  20. Fulltext Association of Radiation Doses and Cancer Risks from CT Pulmonary Angiography Examinations in Relation to Body Diameter
    Harun HH, Abdul Karim MK, Abbas Z, Abdul Rahman MA, Sabarudin A, Ng KH
    Diagnostics (Basel), 2020 Sep 09;10(9).
    PMID: 32917029 DOI: 10.3390/diagnostics10090681
    In this study, we aimed to estimate the probability of cancer risk induced by CT pulmonary angiography (CTPA) examinations concerning effective body diameter. One hundred patients who underwent CTPA examinations were recruited as subjects from a single institution in Kuala Lumpur. Subjects were categorized based on their effective diameter size, where 19-25, 25-28, and >28 cm categorized as Groups 1, 2, and 3, respectively. The mean value of the body diameter of the subjects was 26.82 ± 3.12 cm, with no significant differences found between male and female subjects. The risk of cancer in breast, lung, and liver organs was 0.009%, 0.007%, and 0.005% respectively. The volume-weighted CT dose index (CTDIvol) was underestimated, whereas the size-specific dose estimates (SSDEs) provided a more accurate description of the radiation dose and the risk of cancer. CTPA examinations are considered safe but it is essential to implement a protocol optimized following the As Low as Reasonably Achievable (ALARA) principle.
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