Othman I Alomair

Dr. Othman I Alomair

Radiological Sciences, King Saud University/ College of Applied Medical Sciences, Riyadh, Ar Riyāḑ, Saudi Arabia
orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 June 2015 in PLOS ONE
Verified
Journal Article
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OAOthman I Alomair
Othman I Alomair
IBIan M Brereton
Ian M Brereton
Maree Therese SmithMaree Therese Smith
Maree Therese Smith
GGGraham Galloway
Graham Galloway
NKNyoman D. Kurniawan
Nyoman D. Kurniawan
Magnetic Resonance Imaging (MRI) of the rodent brain at ultra-high magnetic fields (> 9.4 Tesla) offers a higher signal-to-noise ratio that can be exploited to reduce image acquisition time or provide higher spatial resolution. However, significant challenges are presented due to a combination of longer T1 and shorter T2/T2* relaxation times and increased sensitivity to magnetic susceptibility resulting in severe local-field inhomogeneity artefacts from air pockets and bone/brain interfaces. The Stejskal-Tanner spin echo diffusion-weighted imaging (DWI) sequence is often used in high-field rodent brain MRI due to its immunity to these artefacts. To accurately determine diffusion-tensor or fibre-orientation distribution, high angular resolution diffusion imaging (HARDI) with strong diffusion weighting (b >3000 s/mm2) and at least 30 diffusion-encoding directions are required. However, this results in long image acquisition times unsuitable for live animal imaging. In this study, we describe the optimization of HARDI acquisition parameters at 16.4T using a Stejskal-Tanner sequence with echo-planar imaging (EPI) readout. EPI segmentation and partial Fourier encoding acceleration were applied to reduce the echo time (TE), thereby minimizing signal decay and distortion artefacts while maintaining a reasonably short acquisition time. The final HARDI acquisition protocol was achieved with the following parameters: 4 shot EPI, b = 3000 s/mm2, 64 diffusion-encoding directions, 125×150 μm2 in-plane resolution, 0.6 mm slice thickness, and 2h acquisition time. This protocol was used to image a cohort of adult C57BL/6 male mice, whereby the quality of the acquired data was assessed and diffusion tensor imaging (DTI) derived parameters were measured. High-quality images with high spatial and angular resolution, low distortion and low variability in DTI-derived parameters were obtained, indicating that EPI-DWI is feasible at 16.4T to study animal models of white matter (WM) diseases.

1 January 2021 in Radiation Physics and Chemistry
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Journal Article
Closed access
MAM. Alkhorayef
M. Alkhorayef
HAH.I. Al-Mohammed
H.I. Al-Mohammed
FMFareed H. Mayhoub
Fareed H. Mayhoub
ASAbdelmoneim Sulieman
Abdelmoneim Sulieman
HSHassan Salah
Hassan Salah
DBD.A. Bradley
D.A. Bradley

1 February 2021 in Applied Radiation and Isotopes
Verified
Journal Article
Closed access
MAMohammed Alkhorayef
Mohammed Alkhorayef
ASA. Sulieman
A. Sulieman
KAKhalid Alzahrani
Khalid Alzahrani
Mohamed M AbuzaidMohamed M Abuzaid
Mohamed M Abuzaid
OAOthman I Alomair
Othman I Alomair
DBDavid A. Bradley
David A. Bradley

28 March 2025 in Biomedicines
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MAMohammed S Alshuhri
Mohammed S Alshuhri
HAHaitham F. Al-Mubarak
Haitham F. Al-Mubarak
AQAbdulrahman Qaisi
Abdulrahman Qaisi
AAAhmad Abdulrahman Alhulail
Ahmad Abdulrahman Alhulail
AAAbdullah ALMansour
Abdullah ALMansour
FAFatmah Jamal Alablani
Fatmah Jamal Alablani
Background/Objectives: Glioblastoma (GBM) is an aggressive and lethal primary brain tumor with a poor prognosis, with a 5-year survival rate of approximately 5%. Despite advances in oncologic treatments, including surgery, radiotherapy, and chemotherapy, survival outcomes have remained stagnant, largely due to the failure of conventional therapies to address the tumor’s inherent heterogeneity. Radiomics, a rapidly emerging field, provides an opportunity to extract features from MRI scans, offering new insights into tumor biology and treatment response. This study evaluates the potential of delta radiomics, the study of changes in radiomic features over time in response to treatment or disease progression, exploring the potential of delta radiomics to track temporal radiation changes in tumor morphology and microstructure. Methods: A cohort of 50 female CD1 nude mice was injected intracranially with G7 glioblastoma cells and divided into irradiated (IR) and non-irradiated (non-IR) groups. MRI scans were performed at baseline (week 11) and post-radiation (weeks 12 and 14), and radiomic features, including shape, histogram, and texture parameters, were extracted and analyzed to capture radiation-induced changes. The most robust features were those identified through intra-observer reproducibility assessment, ensuring reliability in feature selection. A machine learning model was developed to classify irradiated tumors based on delta radiomic features, and statistical analyses were conducted to evaluate feature feasibility, stability, and predictive performance. Results: Our findings demonstrate that delta radiomics effectively captured significant temporal variations in tumor characteristics. Delta radiomics features exhibited distinct patterns across different time points in the IR group, enabling machine learning models to achieve a high accuracy. Conclusions: Delta radiomics offers a robust, non-invasive method for monitoring the treatment of glioblastoma (GBM) following radiation therapy. Future research should prioritize the application of MRI delta radiomics to effectively capture short-term changes resulting from intratumoral radiation effects. This advancement has the potential to significantly enhance treatment monitoring and facilitate the development of personalized therapeutic strategies.

28 July 2022 in International Journal of General Medicine
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DADhafer M Alahmari
Dhafer M Alahmari
FAFahad M Alsahli
Fahad M Alsahli
SASami A Alghamdi
Sami A Alghamdi
OAOthman I Alomair
Othman I Alomair
AAAbdulrahman Alghamdi
Abdulrahman Alghamdi
MAMohammed J. Alsaadi
Mohammed J. Alsaadi
Purpose: Magnetic resonance imaging (MRI) is an important diagnostic method in modern clinical medicine. Patients’ ‎‎knowledge about MRI is of utmost importance for optimizing the workflow, ‎safety, and patient comfort and saving valuable time for the MRI department. This study investigates patient knowledge levels regarding MRI safety before an MRI examination. Patients and Methods: A cross-sectional survey was completed by 200 patients who required MRI. Recruitment occurred over eight weeks in ‎governmental and private hospitals in Saudi ‎Arabia; both hospitals and participants were selected randomly. The ‎questionnaire was given to the patients prior to ‎their MRI scans. Descriptive statistics and chi-square tests were performed to identify relationships between knowledge of MRI safety and selected demographic groupings (age, gender, education level, income level). It also evaluates their source of information and assesses the patient’s previous experience regarding MRI scans.‎ Results: The study sample consisted of 200 patients from 230 surveys distributed in ‎Saudi Arabia, and the response rate was ∼ 87%. Depending on the P-values of the chi-square statistical test to find the relationship between ‎socio-demographic factors and patient’ knowledge level, the results showed a significant association (p-value=0.006) between age and gender and the level of knowledge relating to MRI safety issues. A similar significance (p-value=0.042) is observed between the knowledge level of patients and their educational level and annual income. In addition, a highly significant association (p-value< 0.001) is found between education level or previous experience and whether people seek information about MRI safety. Conclusion: The study findings suggest that a complex combination of factors affects patient knowledge regarding MRI safety before an MRI examination. Hence, the hospital and radiological department must ‎‎provide the ‎patient with accurate information about MRI.‎

13 October 2020 in Egyptian Journal of Radiology and Nuclear Medicine
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AAAbdullah Dhaifallah Almutairi
Abdullah Dhaifallah Almutairi
HHHasyma Abu HassN
Hasyma Abu HassN
SSSUBAPRIYA SUPPIAH
SUBAPRIYA SUPPIAH
OAOthman I Alomair
Othman I Alomair
AAAbdulbaset Alshoaibi
Abdulbaset Alshoaibi
RMRozi Mahmud
Rozi Mahmud
Magnetic resonance imaging (MRI) is one of the diagnostic imaging modalities employing in lesion detection in neurological disorders such as multiple sclerosis (MS). Advances in MRI techniques such as double inversion recovery (DIR) made it more sensitive to distinguish lesions in the brain. To investigate the lesion load on different anatomical regions of the brain with MS using DIR, fluid attenuated inversion recovery (FLAIR) and T2-weighted imaging (T2WI) sequences. A total of 97 MS patients were included in our retrospective study, confirmed by neurologist. The patients were randomly selected from the major hospital in Saudi Arabia. All images were obtained using 3T Scanner (Siemens Skyra). The images from the DIR, FLAIR, and T2WI sequence were compared on axial planes with identical anatomic position and the number of lesions was assigned to their anatomical region. Comparing the lesion load measurement at various brain anatomical regions showed a significant difference among those three methods (p < 0.05). DIR is a valuable MRI sequence for better delineation, greater contrast measurements and the increasing total number of MS lesions in MRI, compared with FLAIR, and T2WI and DIR revealed more intracortical lesions as well; therefore, in MS patients, it is recommended to add DIR sequence in daily routine imaging sequences.