Radiation Biology, Radiotherapy & Radiodiagnosis - Scholarly Publications
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- ItemOpen AccessThe accuracy of ultrasonography in the diagnosis of breast pathology in symptomatic women(2012) Irurhe, NK; Adekola, OO; Awosanya, GOG; Adeyomoye, AO; Olowoyeye, OA; Awolola, NA; Olajide, TO
- ItemOpen AccessAnalysis of Efficiency of Different Antennas for Microwave Ablation using Simulation and Experimental Methods.(Elsevier, 2018-02-05) Ibitoye, AZ; Orotoye, T; Nwoye, EO; Aweda, MAThe objective of this study is to analyze the efficiency of different antennas proposed for microwave ablation therapy using numerical simulation and experimental approach. The simulation was done with COMSOL MULTIPHYSICS software to design antenna prototypes and evaluate its reflection coefficient, power dissipation distribution, power dissipation density, specific absorption rate and temperature distribution in tissue. Antennas were fabricated from a 50 X RG405/U semi-rigid coaxial cable to match the geometric prototypes generated during simulation. Ex vivo bovine livers were ablated with the fabricated antennas using 50Wfor 5 and 10 min. Ablation diameters, ablation lengths and aspect ratios were determined. Sleeved antenna produced lowest reflection coefficient, high power dissipation, low power dissipation density, high SAR and high temperature in the simulation. Sleeved antenna provides excellent localization, large ablative diameter, low backward heating and high aspect ratio than single slot, dual slot and monopole antennas.
- ItemOpen AccessAnalysis of the velocity profile of the popliteal artery and its relevance during blood flow studies(2017) Olowoyeye, O; Chiu, S; Leung, G; Wright, G; Moody, A
- ItemOpen AccessAssessing limb ischemia using Doppler in a person with diabetes(2009) Olowoyeye, OA; Adewole, OA; Lawani, EO
- ItemOpen AccessAssessment of Noise Level Distributions in Lagos Metropolis and the Potential for Adverse Health Effects(2017-06) Ibitoye, AZ; Awda, MA; Ofojebe, PCElevated sound pressure levels can lead to sleep disturbance,annoyance, hearing impairment, speech interference, and severe stresson the auditory and nervous systems if sound levels are continuous and greaterthan international standard limits. The aim of this study was to evaluatethe noise level distributions in Lagos, Nigeria. We selected 32 locations across the Lagos metropolis for this study. A digital sound meter capable of measuring32 dB–130 dB was used. At each location, minimum and maximum noiselevels were determined. Measurements were taken in morning (8–10 a.m.),afternoon (2–4 p.m.), and evening (6–8 p.m.) periods. The obtained valueswere presented as mean ± standard deviation in decibels (dB). The highest average sound pressure level was found to be 90.3 ± 15.3 dB, while the lowestvalue was 55.30 ± 4.6 dB. There was no statistically significant difference in thenoise level distributions in the three monitoring sessions (p = .74). Noise leveldistributions in the city exceeded the acceptable standard limits set by the World Health Organization. Health effects related to incessant exposures tohigh noise levels are likely to be common and may result in negative impactson the well-being of the inhabitants of the city.
- ItemOpen AccessCardiovascular and psychiatric characteristics associated with oxidative stress markers among adolescents with bipolar disorder.(2015) Hatch, J; Andreazza, A; Olowoyeye, O; Rezin, GT; Moody, A; Goldstein, BI
- ItemOpen AccessCommon Factors Affecting Radiographic Diagnostic Quality in X-Ray Facilities in Lagos(2012) Edeh, VI; Olowoyeye, OA; Irurhe, NK; Abonyi, LC; Arogundade, RA; Awosanya, GOG; Eze, CU; Omiyi, ODObjective: To determine the common factors that affect the diagnostic quality of radiographs in radiodiagnostic centers in Lagos state, Nigeria. Methods: Self-administered questionnaires containing both open and close-ended questions were distributed to the supervising radiographers in radiodiagnostic centers within the Lagos metropolis. The questions asked included the film/reject ratio in each center and reasons why each film was rejected. Results: Faulty x-ray machines, movement on the part of the patient, poor darkroom film processing, and suboptimal radiographic techniques were the main reasons respondents identified as factors commonly responsible for the production of faulty films. In some cases, more than one of these factors was responsible. Conclusion: There is a need to routinely ensure that x-ray machines are properly calibrated in order to reduce the rate of film rejects in our x-ray facilities. In addition, equipment that is old and cannot be properly calibrated should be replaced. This would guarantee optimum performance and reduce radiation dose to patients and personnel. Younger radiographers should also be open to mentoring by older colleagues so they can acquire useful tips on how to reduce the production of films with unacceptable diagnostic quality. They should be encouraged to attend continuing education programs for improved expertise. Also, quality control and maintenance programs such as the reject film analysis or regular equipment maintenance should be enforced in radiodiagnostic centers.
- ItemOpen AccessCompliance Rate of Adequate Filling of Radiology Request Forms in a Lagos University Teaching Hospital(2012) Irurhe, NK; Sulaymon, FA; Olowoyeye, Omodele; Adeyomoye, AARadiology request forms are essential communication tools used by hospitals and doctors referring patients for radiological investigations, however, their importance is highly underestimated. The clinician is required to give brief clinical history by filling the reason for referral as this helps radiologists to better understand the patient’s condition; so that the required expertise can be utilized. The aim of the research is to evaluate the adequacy of patient data and clinical information filled in the request forms sent to the Radiodiagnosis Department by the referring clinicians. Descriptive study design was used to find out the compliance rate of filling radiology request forms as indicated by referring physicians. The average number of request forms received on a daily basis in the Radiodiagnosis department of Lagos University Teaching Hospital (LUTH) was 62. A non probabilistic Quota sampling method was used to select 300 request forms over a period of 3 months which are representation of variety of examinations from different departments within LUTH. The study revealed a relatively high number of uncompleted fields in the radiology request forms in LUTH.
- ItemOpen AccessCraniopharyngioma causing visual loss in an adult(2007) Olowoyeye, OA; Bankole, OB
- ItemOpen AccessCross-sectional associations between dietary intake and carotid intima media thickness in type 2 diabetes : baseline data from a randomised trial(2017) Chiavaroli, L; Mirrahimi, A; Ireland, C; Mitchell, S; Sahye-Pudaruth, S; Coveney, J; Olowoyeye, O; Patel, D; de Souza, RJ; Augustin, LSA; Bashyam, B; Pichika, SC; Bianco Mejia, S; Nishi, SK; Leiter, LA; Josse, RG; McKeown-Eyssen, G; Moody, AR; Kendall, CWC; Sievenpiper, JL; Jenkins, DJA
- ItemOpen AccessCT-detected Intracranial Hemorrhage Among Patients With Head Injury in Lagos, Nigeria(2013) Eze, CU; Abonyi, LC; Olowoyeye, OA; Njoku, J; Ohagwu, C; Babalola, S
- ItemOpen AccessDesign and Evaluation of Structural Shielding of a Typical Radiotherapy Facility Using EGSnrc Monte Carlo Code(Wolters Kluwer, 2022-03-31) Ibitoye, A. Z.; Adedokun, M. B.; Orotoye, T. A.; Udo, G. B.Purpose: This study aimed to evaluate the shielding integrity of a typical radiotherapy facility using the Monte Carlo (MC) method. Materials and Methods: EGSnrc MC code was used to design a radiotherapy bunker with appropriate materials and thicknesses. A concrete density of 2.36 g/cm3 was used as a shielding material for primary and secondary barriers. The lead slab was used in the entrance door. The complex geometries of the bunker were modeled by using the egs++ application code embedded in the software. Phase‑space generated from a linac machine built with BEAMnrc codes was used as a source of 18 MV X‑ray beam set at 100 cm source–surface distance with a field size of 40 cm × 40 cm. Energy deposited in each geometrical region was evaluated and analyzed. Results: Energy deposited at the entrance door, supervised and controlled areas were found to be approximately 0%. No significant difference in the energy deposition on the geometries was observed when the gantry angles were set at either 90° or 270° (P = 1). Conclusion: The findings in this study revealed that the EGSnrc MC code can be used as a veritable tool in the design and evaluation of structural shielding efficiency in a radiotherapy facility.
- ItemOpen AccessDuplex Imaging in diagnosing chronic venous insufficiency(2006) Olowoyeye, OA; Soyebi, KO
- ItemOpen AccessDuplex ultrasonographic findings in patients with suspected DVT(2010) Olowoyeye, OA; Awosanya, GOG; Soyebi, KO
- ItemOpen AccessEffects of Ascorbic Acid Intake on the Intima-Media Thickness and Blood Flow Velocities of the Carotid Artery in Patients With Sickle Cell Anemia(2011) Olowoyeye, Omodele; Jaja, SI; Kehinde, MO; Awosanya, GO; Irurhe, NK; Adeyomoye, AA; Soyebi, KO; Arogundade, RA; Adekunle, OM; Soneye, BK; Tubi, OOThis study aims to investigate and compare the effects of six-week oral vitamin C supplementation on blood velocities, intima-media thickness, and cross-sectional diameter (CSD) of the common carotid artery of sickle cell anemia (SCA) and non–sickle cell anemia (NSCA) subjects using sonography. Results showed that the CSD and end-diastolic velocity were significantly higher (P < .002 and P < .001, respectively) in the SCA subjects than in the NSCA subjects in the presupplementation phase. Calculated resistivity index (RI) was significantly lower in the SCA subjects (P < .003). Vitamin C supplementation had a slight effect on all the measured parameters in the NSCA subjects but caused a significant increase in peak systolic velocity (PSV) (P < .02) and RI (P < .01) in SCA. A comparison of change in each measured variable between the groups showed significant differences. Oral supplementation with vitamin C should be encouraged in patients with SCA as prophylaxis against endothelial damage, thereby preventing vaso-occlusive crises and their associated morbidity.
- ItemOpen AccessEvaluation of Compliance to Radiation Safety Standard Amongst Radiographers in Radiodiagnostic Centres in South West, Nigeria.(2012) Adejumo, SB; Irurhe, NK; Olowoyeye, OA; Ibitoye, AZ; Eze, CU; Omiyi, OD
- ItemOpen AccessEvaluation of temperature distributions during microwave ablation of ex vivo bovine liver using two types of antennas.(2019-03) Ibitoye, AZ; Nwoye, EO; Saseyi, AO; Adeneye, SO; Adedokun, MB; Aweda, MAIntroduction: Temperature distributions during microwave ablation are dependent on the antenna types, antenna geometry, tissue properties, input power and ablation. All these factors can significantly affect the coagulation region, ablation length, ablation diameter, aspect ratio, backward heating (comic effect), and degree of necrosis. Temperature distributions during microwave ablation procedures determine the effectiveness of ablating tumours in tissue. Objective: The aim of this study is to evaluate temperature distributions during microwave ablation using sleeved and dual slot antennas. Materials and Methods: In this study, sleeved and dual slot antennas were designed using COMSOL MULTIPHYSICS software version 4.4. Temperature distributions were analyzed at 10 mm and 20 mm from the antennas’ surfaces. Dualslot and sleeved antennas were fabricated from 0.085’ 50 Ω semi-rigid coaxial cable to conform to numerical simulation. The antennas were applied on ex vivo bovine liver. Thermometer probes were placed at 10 mm and 20 mm from the antennas’ surfaces with the input powers set at 30, 50 and 80 W for 300 s. Before each ablation, the initial temperature was recorded whereas subsequent measurements were recorded at 50 s intervals. Numerical simulation and experimental obtained data were analyzed and compared using the student's t-test statistical tool. Results: The findings in this study showed that temperatures produced at the two points of measurements by the sleeved antenna were greater than that of the dual-slot antenna in simulation and experimental procedures. Also, there was no significant difference between simulation and experimentally results for dual-slot antenna and sleeved antenna (p = 0.25). Conclusion: In conclusion, the sleeved antenna has the potential to ablate a tumour faster above the tumoricidal temperatures at the same position than the dual-slot antenna.
- ItemOpen AccessEvaluation of the performance of designed coaxial antennas for hyperthermia using simulation and experimental methods(Sciendo, 2021-03-31) Ibitoye, AZ; Ogese, CO; Adedokun, MB; Habeebu, MYM; Nwoye, EO; Aweda, MAIntroduction: Antenna geometries and tissue properties affect microwave energy distributions during microwave ablation procedures. There is a paucity of information on the potential of antenna fabricated from a thick semi-rigid coaxialcable in the field of microwave thermal therapy. This study aimed at comparing the performance of two dual-slotantennas designed from different semi-rigid coaxial cables for the ablation of a liver tumour using numerical simulationand experimental validation methods. Materials and Methods: COMSOL Multiphysics software was used for designing dual-slot antennas and as well as toevaluate microwave energy deposition and heat distribution in the liver tissue. Experimental validations were conductedon the ex-vivo bovine livers to validate the simulation results. Results: Thick antenna developed in this study produced a higher sphericity index, larger ablation diameter and reducedbackward heating along the antenna shaft than the existing one. The experimental validation results also indicatesignificant differences between the two antennas in terms of ablation diameters (p = 0.04), ablation lengths (p = 0.02)and aspect ratios (p = 0.02). Conclusion: Based on the findings in this study, an antenna fabricated from a thick coaxial cable has ahigher potential oflocalizing microwave energy in the liver than conventional antennas.
- ItemOpen AccessFetal Kidney Length as an Independent Estimator of Gestational Age: A Cohort Study of a Population of Yoruba Women in Lagos Nigeria(2019) Eze, CU; Upeh, ER; Olowoyeye, OA
- ItemOpen AccessInfantile subdural empyema: The role of brain sonography and percutaneous subdural tapping in a resource-challenged region(2014) Kanu, OO; Nnoli, C; Olowoyeye, O; Ojo, O; Esezobor, C; Adeyomoye, A; et al