Papers by Noor Diyana Osman
Journal of Radiation Research and Applied Sciences, 2020
Bookmarks Related papers MentionsView impact
Radiography, May 1, 2023
Bookmarks Related papers MentionsView impact
Journal of Physics: Conference Series, 2020
Cone-beam computed tomography (CBCT) technique has been widely used in dental imaging as it offer... more Cone-beam computed tomography (CBCT) technique has been widely used in dental imaging as it offers different image views such as panoramic, cephalometric, tomographic, and three dimensions (3D). This study aimed to assess image distortion due to beam misalignment for CBCT system using phantom study. A ball phantom was scanned with default exposure setting for standard panoramic imaging (68 kV, 8 mA and patient size of M) using Planmeca ProMax CBCT unit. Three different measurements were performed on the phantom images such as distance measurement between the centre of the middle ball and rear middle ball, distance measured from the centre of middle ball to tenth ball (left and right), and measurement of both vertical and horizontal distance of any four balls. From the findings, most of measured distance between middle ball and rear middle ball were below the acceptable level, but two measurements exceeded the reference value by 6% and 75%. Similar with the measured distances of the ...
Bookmarks Related papers MentionsView impact
Radiation Physics and Chemistry, 2020
Bookmarks Related papers MentionsView impact
Applied Radiation and Isotopes, 2019
Bookmarks Related papers MentionsView impact
NOVEMBER ISSUE
Introduction: Metal artifacts can degrade the image quality of computed tomography (CT) images wh... more Introduction: Metal artifacts can degrade the image quality of computed tomography (CT) images which lead to errors in diagnosis. This study aims to evaluate the performance of Laplace interpolation (LI) method for metal artifacts reduction (MAR) in CT images in comparison with cubic spline (CS) interpolation. Methods: In this study, the proposed MAR algorithm was developed using MATLAB platform. Firstly, the virtual sinogram was acquired from CT image using Radon transform function. Then, dual-adaptive thresholding detected and segmented the metal part within the CT sinogram. Performance of the two interpolation methods to replace the missing part of segmented sinogram were evaluated. The interpolated sinogram was reconstructed, prior to image fusion to obtain the final corrected image. The qualitative and quantitative evaluations were performed on the corrected CT images (both phantom and clinical images) to evaluate the effectiveness of the proposed MAR technique. Results: From t...
Bookmarks Related papers MentionsView impact
Journal of Radiotherapy in Practice
Background: Intensity-modulated radiation therapy (IMRT) treatment delivery requires pre-treatmen... more Background: Intensity-modulated radiation therapy (IMRT) treatment delivery requires pre-treatment patient-specific quality assurance (QA) for the dosimetry verification due to its complex multileaf-collimator movement. The prostate target close position between the bladder and rectum requires a tight margin during planning, and mistreatment would have a huge impact on the patient. A commercially available QA tool consists of a homogeneous medium and does not represent an exact photon interaction on the tumour and also on the nearby healthy organ. Objective: A heterogeneous male pelvis phantom was developed and investigated the efficiency of the treatment planning system (TPS) calculation on the off-axis region. Methods: Polymethyl methacrylate was used for the phantom housing, and the material closed to the bladder, rectum and prostate density was chosen to construct the organ models. The phantom was scanned and validated by the computed tomography number and density. An IMRT treat...
Bookmarks Related papers MentionsView impact
Asian Journal of Medicine and Biomedicine
Diagnostic reference range (DRR) were introduced to help manage image quality as well as patient ... more Diagnostic reference range (DRR) were introduced to help manage image quality as well as patient dose by providing minimum estimated dose that covers 25–75% range of dose distribution. The International Commission on Radiological Protection (ICRP) (2017) recommended 75th percentile as upper boundary and 25th percentile as lower boundary of DRR [1]. Dose below the lower range should compromised accurate interpretation of the image and dose above the upper range may be in excess and need to be reviewed. Meanwhile, Diagnostic Reference Levels (DRLs) also recommended by ICRP as a guidance to identify any uncommon high dose delivered by computed tomography (CT) scanner. DRLs are established at 75th percentile of dose distribution and should be implemented at international, regional, or local level for dose management. This study aims to establish a local DRR based on five most common clinical indications for adult head CT scanning at Department of Radiology, Hospital Universiti Sains M...
Bookmarks Related papers MentionsView impact
Asian Journal of Medicine and Biomedicine
The concept of diagnostic reference range (DRR) is introduced to address the balance between a pa... more The concept of diagnostic reference range (DRR) is introduced to address the balance between a patient’s risk (radiation dose) and benefit (image quality necessary for an accurate diagnosis). R provides a minimum estimated dose that covers 25–75% range of dose distribution. The International Commission on Radiological Protection, ICRP (2017) recommended the 75th percentile as the upper d 25th percentile as the lower limit of DRR [1]. Dose below the lower range should compromise accurate interpretation of the image and dose above the upper range may be in excess and need to be reviewed. Meanwhile, Diagnostic Reference Levels (DRLs) are set at the 75th percentile of dose distribution and recommended by ICRP as a guidance to identify any unusual computed tomography (CT) procedures that consistently exceed the established DRLs. The aim of this study was to establish the local DRR for CT scanning based on clinical indications associated to thorax, abdomen, and pelvic regions in adult pat...
Bookmarks Related papers MentionsView impact
Asian Journal of Medicine and Biomedicine
The determination of size specific dose estimation (SSDE) has been proposed for accurate CT dose ... more The determination of size specific dose estimation (SSDE) has been proposed for accurate CT dose assessment. The SSDE introduction has prompted numerous manufacturers and researchers to develop various methodologies that have progressed from manual to automated methods in SSDE determination. Few studies reported on truncation effects with respect to specific size and SSDE determination and CT manufacturers are yet to incorporate truncation correction in their system [1,2]. This study aimed to evaluate the effects of truncation artifacts on the measurement of effective diameter (Deff) and SSDE in CT imaging. A phantom study was performed using CTDI phantom of different diameters, 22 and 32 cm with Siemens SOMATOM Definition AS+ CT scanner. Phantom images of different truncation percentage (TP) of 5%, 10%, 15%, and 20% were simulated and acquired. The Deff and SSDE were determined based on the displayed CTDIvol, and the AAPM correction factor table was used to calculate the SSDE accu...
Bookmarks Related papers MentionsView impact
Radiation Protection Dosimetry
Clinical challenges in pediatrics dose estimation by the displayed computed tomography (CT) dose ... more Clinical challenges in pediatrics dose estimation by the displayed computed tomography (CT) dose indices may lead to inaccuracy, and thus size-specific dose estimate (SSDE) is introduced for better-personalized dose estimation. This study aims to estimate pediatric dose adapted to specific size. This retrospective study involved pediatric population aged 0–12 y. SSDE was derived from scanner reported volume CT dose index (CTDIvol), based on individual effective diameter (Deff) with corresponding size correction factors. The correlations of Deff with other associated factors such as age, exposure setting, CTDIvol and SSDE were also studied. The average Deff of Malaysian pediatric was smaller than reference phantom size (confidence interval, CI = 0.28, mean = 14.79) and (CI = 0.51, mean = 16.33) for head and abdomen, respectively. These have led to underestimation of pediatric dose as SSDE was higher than displayed CTDIvol. The percentage differences were statistically significant (p ...
Bookmarks Related papers MentionsView impact
Computed Tomography (CT) images serve many benefit in radiology as well as radiotherapy treatment... more Computed Tomography (CT) images serve many benefit in radiology as well as radiotherapy treatment. Unfortunately the metal type inhomogeneities such as metal amalgam results a metal streak artifact in the images and thus raise errors in treatment planning system (TPS) [1,2]. In radiotherapy errors of radiation delivery can cause various side effects to patient. For this reason a metal artifact reduction (MAR) algorithm was developed in MATLAB platform to give a satisfaction in image quality and thus to TPS
Bookmarks Related papers MentionsView impact
3rd International Conference on Radiation Safety & Security in Healthcare Services, 2018
Patient exposure from digital dental radiography has increased rapidly and contributes to one of ... more Patient exposure from digital dental radiography has increased rapidly and contributes to one of the major sources for radiation doses received in diagnostic radiology. Therefore, assessment on patient dose is crucially important for dose optimisation and justification. However, there are currently no national diagnostic reference level (NDRL) has been established in Malaysia for dental radiography. This study was aimed to evaluate the patient doses received from digital dental radiography which includes orthopantomogram (OPG), cone beam computed tomography (CBCT), and cephalometric examinations at Advanced Medical and Dental Institute (AMDI), Malaysia and serves as preliminary work in establishment of local DRL. The data of dose-area product (DAP) values for all dental examinations performed were gathered started from May 2015 until March 2017. For comparative study, the third quartiles for each examination were determined and compared with the international DRL. A total of 684 cases, consisting of OPG (67%), CBCT (6%), and cephalometric examinations (27%) performed during that period. The DAP values were ranged between 47.4 and 363.2 mGy cm2 for OPG, 392.4 and 1254.4 mGy cm2 for CBCT, and 17.4 and 33.3 mGy cm2 for cephalometric procedure. From the results, it showed that patient dose mainly depends on image acquisition protocol. Patient dose assessment is significant for radiation protection management in clinical practice.
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
SSRN Electronic Journal, 2021
Bookmarks Related papers MentionsView impact
The assessment of post-operative spine using computed tomography (CT) imaging is so challenging i... more The assessment of post-operative spine using computed tomography (CT) imaging is so challenging in the presence of metal artifacts induced by spinal implants. Metal artifacts can severely affect the quality of CT images, and mislead the diagnosis interpretation. The artifacts are due to the beam hardening, photon starvation effect, and inappropriate correction algorithm during image reconstruction. Knowledge on factors affecting the artifacts is crucially important to minimize these artifacts. The main aim of this study is to develop a novel technique for suppression of metal artifacts and this study generally consists three main parts. The first part is the development of a simple phantom useful for metal streaking analysis performed in the second part of this work. A customized phantom was constructed with tissue equivalent materials and various metal inserts to simulate the streaking artifacts similar to the clinical findings in post-operative spine imaging. In this work, a thoro...
Bookmarks Related papers MentionsView impact
Bookmarks Related papers MentionsView impact
Journal of Medical Physics, 2015
Bookmarks Related papers MentionsView impact
Radiation Protection Dosimetry, 2019
The aim of this study was to propose local diagnostic reference levels (LDRLs) for the most commo... more The aim of this study was to propose local diagnostic reference levels (LDRLs) for the most common computed tomography (CT) examinations (including contrast and non-contrast scan phase) performed at Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia (USM), Malaysia. A retrospective CT dose survey of 1488 subjects from January 2015 until December 2018 was performed at AMDI USM, Malaysia. The proposed DRLs were established at 50th and 75th percentile of dose distribution for all dose metrics (CT dose index [CTDI]; CTDIvol, CTDIw and dose–length product). The proposed LDRLs were compared with national DRLs and other established DRLs. The 10 most common CT examinations at AMDI were thorax–abdomen–pelvis (TAP) CT (46%), followed by pelvis CT (17%), abdomen–pelvis CT (10%), brain/head CT (9%) and other CT protocols. The local DRLs were established using the third quartile values of dose distribution and were categorized based on CT region protocols. Most of the propos...
Bookmarks Related papers MentionsView impact
CT assessment of postoperative spine is challenging in the presence of metal streak artifacts tha... more CT assessment of postoperative spine is challenging in the presence of metal streak artifacts that could deteriorate the quality of CT images. In this paper, we studied the influence of different acquisition parameters on the magnitude of metal streaking. A water-bath phantom was constructed with metal insertion similar with postoperative spine assessment. The phantom was scanned with different acquisition settings and acquired data were reconstructed using various reconstruction settings. Standardized ROIs were defined within streaking region for image analysis. The result shows increased kVp and mAs enhanced SNR values by reducing image noise. Sharper kernel enhanced image quality compared to smooth kernel, but produced more noise in the images with higher CT fluctuation. The noise between both kernels were significantly different (P <0.05) with increment of noise in the bone kernel images (mean difference = 54.78). The technical settings should be selected appropriately to att...
Bookmarks Related papers MentionsView impact
Uploads
Papers by Noor Diyana Osman