Wi-Fi is a wireless communication technology that uses specific electromagnetic frequencies. The increasing use of Wi-Fi has raised public concerns about the impact of electromagnetic radiation on the environment and human health. Since the exposure level of the electromagnetic field (EMF) radiation differs between different locations, it is important to measure the strength of the EMF at various locations under observation. This study aimed to obtain specific values related to the radiofrequency and microwave EMF which is described by four specific parameters, that are 1) the frequency of the wave, 2) the electric field strength E, 3) the magnetic field strength H, and 4) the power density S. This study was carried out at the first floor area of Hamdan Tahir Library, Universiti Sains Malaysia Health Campus. Mapping of Wi-Fi signal and measurement of Wi-Fi radiation level was performed at four specific locations, that are Laptop zone 1, Laptop zone 2, Computer lab, and Cozy corner. The average radiation level was compared with the ICNIRP standard limit for public user. It was observed that the Wi-Fi signal was highest in Laptop zone 2 followed by Laptop zone 1 which displayed a moderate signal strength. Whereas moderate but lower signal level was detected in Computer lab zone and Cozy corner. The electric and magnetic fields as well as power density were found highest in Laptop zone 1, followed by Laptop zone 2, Cozy corner, and Computer lab. Comparison with standard ICNIRP limit showed that the radiation level is still far below the ICNIRP limit, which is only 2% of exposure level. To conclude, Laptop zone 2 exhibited the strongest Wi-Fi signal whereas Laptop zone 1 displayed the highest radiation level. However, the strength of the electric and magnetic fields as well as power density is still far below the ICNIRP limit.
The connectivity patterns among the DMN nodes when the brain is resting are still in great debate. Among the unknowns is whether a dominant node exists in the network and if any, how does it influences the other nodes. Resting state functional magnetic resonance imaging (rsfMRI) was utilized in data acquisition on 25 healthy male and female participants. The DMN nodes selected were posterior cingulate cortex (PCC), bilateral inferior parietal cortex (IPL) and medial prefrontal cortex (mPFC). Fully connected causal models were constructed comprising four DMN nodes. The time invariant covariance of the random fluctuations between nodes was then estimated to obtain the effective connectivity (EC) between the DMN nodes. The EC values among the DMN nodes were averaged over the participants using Bayesian Parameter Averaging (BPA). All the DMN nodes have self-inhibitory dynamics. All connections between nodes were significant (P > 0.9) with a condition for any of the two nodes, one node inhibited the others. The PCC which exhibited the highest signal intensity was in fact inhibited by others. Inter-hemispheric RIPC to LIPC connections acted the same way, with excitatory LIPC to RIPC and inhibitory RIPC to LIPC connections. The results also showed a stronger mPFC to RIPC connection in the right hemisphere (as compared to mPFC to LIPC connection in the left hemisphere) and a weaker PCC to RIPC connection in the right hemisphere (as compared to PCC to LIPC connection in the left hemisphere). PCC can be regarded as a dominant node among the four nodes, being connected to all other nodes in different ways. All the four nodes were significantly activated and connected to each other even though the brain was in a state of resting.
The whole-body fluorodeoxyglucose F18 (18F-FDG) and gallium-68 (Ga-68 DOTATATE) are the most common radiopharmaceutical use in PET/CT imaging for cancer staging. Although radiopharmaceutical for PET/CT examination has been acknowledged for its safety and efficacy, the internal dosimetry and effective dose (ED) from the examinations are rarely discussed. Hence, this study aimed to evaluate radiation ED for whole-body radiopharmaceuticals PET/CT concerning patients’ gender and their weight. A total of 82 oncology patients (44 males and 38 females) were collected retrospectively from Institut Kanser Negara, Putrajaya. Data, such as 18F-FDG and Ga-68 DOTATATE activity and patient demography (weight, height, age), were recorded and analyzed. Effective doses from both internal and external exposure were calculated using the coefficient
provided by the International Commission on Radiological Protection (ICRP) report. The total ED of 18F-FDG for male patients was 20.2 ± 8.6 mSv and for female patients were 19.0 ± 8.2 mSv while total whole-body ED for Ga-68 DOTATATE for male patients was 18.5 ± 7.0 mSv and 17.0 ± 5.6 mSv for female patients. The ratio for ED between male and female were 1:1 for both examinations ranged from 12.0 – 23 mSv. From this study, it indicated that the ED of Ga-68 DOTATATE was far lower when compared to the ED of 18F-FDG by a factor of 0.7. Therefore, it is crucial to optimize the PET/CT protocol dose in order to uphold the dose as low as reasonably achievable (ALARA).
The increasing use of wireless communication devices, particularly Wi-Fi has raised public concerns on the exposure to electromagnetic field (EMF) and its possible effect on human health. As the exposure level of the EMF radiation varies between different locations, measurement of the EMF strength at various locations is vital. In this study, we aimed to measure the EMF exposure which is described by four specific parameters, specifically 1) the frequency of the wave, 2) the electric field strength E, 3) the magnetic field strength H, and 4) the power density S. This study was performed at the second floor in Nurani hostel block in Desasiswa Murni Nurani, Universiti Sains Malaysia Health Campus. Mapping of Wi-Fi signal and measurement of Wi-Fi radiation level was performed at four specific locations, that are in a student room, television room, prayer room, and ironing room. The average radiation level was compared with the standard limit set by International Commission on Non-Ionizing Radiation Protection (ICNIRP). It was observed that the strength of Wi-Fi signal was highest in students’ room followed by television room. Both of these rooms exhibited high signal strength. While moderate but lower signal level was observed in prayer room followed by ironing room. The electromagnetic field and power density were found highest in students’ room, followed by television room, prayer room, and ironing room. Comparison with standard ICNIRP limit showed that the radiation level is still far below the acceptable limit, which is only 2% of the exposure level. To conclude, students’ room exhibited the strongest Wi-Fi signal and the highest radiation level. However, the radiation level especially power density is still far below the ICNIRP limit.
The advancement of internet nowadays have drives the university students place great reliance on the internet for almost all matter. However, if the internet is heavily used, it may have a detrimental effect which could contribute to an Internet Addiction Disorders (IAD) among university students. IAD could create problem in developing relationships like normal people and appear to have low quality of memory. Thus, this is definitely not good to students. Knowing that by listening to Quran verse has a potential to improve the memory, hence this study is carried out. The study utilized a brain-computer interface Emotiv EPOC+, multichannel electroencephalography (EEG) detection during dual N-back tasks (spatial and verbal) where subjects were given with load level from 2-back to 3-back. Five (5) out of two hundred (200) participants of USIM’s students (20-23 years old) were recruited to continue with the brain scan experiment after getting a high score which indicated their severe level of addiction in a screening addiction test, Young’s Internet Addiction Test. Subjects were administered with a pre‐ and post‐tests to analyze and evaluate the effects of implementing Quran listening in their dailies for two months. The behavioral assessment exhibited accuracy increment between pre- and post- tests by 13.4% from 9.4%. While the EEG power value showed there were significant differences (p=0.002) in brainwaves between the pre- and the post- tests for 2 back; as the dominant brainwave found at the frontal and prefrontal cortex for delta and theta bands. The research revealed that the theta power band presented as the most dominant brain wave associated with N-back task for the enhancement of working memory which influence by the listening to Surah in Al-Quran.
In radiography, radiation workers are responsible to protect patients and their caregivers from adverse effects of X-rays during diagnostic procedures. The X-ray examination rooms are designated as controlled areas where only authorised persons are allowed to enter. However, sometimes radiographers allow next in-line patients’ and caregivers in X-ray examination room and ask them to stand behind the mobile lead shielding when exposure is on. The objectives of this study were to determine the amount of scatter radiation dose at different heights with respect to the floor in the X-ray examination room and to educate and increase the awareness of radiation workers about the scattered radiation in minimizing the unnecessary radiation dose to patient’s caregivers. Siemens Multix Top X-ray system was used. Kyoto Kagaku PBU-50 whole body phantom was scanned. The phantom (torso) was positioned for anteroposterior (AP) lumbar projection on the examination table. The nanoDot OSLDs were fixed behind the lead shielding at different heights (120, 130, 140, 150, 160 and 170 cm) with respect to the floor 2.5 meters away from the central ray of X-ray beam. The phantom was exposed using different tube voltages 68 kVp, 79 kVp and 90 kVp at a constant tube current of 32 mAs fixing a 100 cm source to image distance (SID). Scatter radiation doses measured at different heights were different for each exposure. The highest scattered radiation dose measured was 6.4 mGy at 130 cm height for 79 kVp exposure. In conclusion the measured scattered radiation doses were within the acceptable annual dose limits as recommended by NCRP 116 and ICRP 103 for patient caregiver. However, a smallest amount of radiation dose may increase the risk of cancer. Thus, the negligence must not be overlooked because it exposes the caregiver to unnecessary radiation.
Many studies have been carried out to produce magnetic resonance imaging (MRI) phantoms as alternative to water phantom. Among the important properties of a phantom are the T1 and T2 relaxation times. The objective of this study is to investigate the T1 and T2 characteristics of the agarose gel phantoms with different relaxation modifier (gadolinium (III) oxide, Gd2O3) concentrations or [Gd2O3]. Six agarose gel phantoms were prepared with different [Gd2O3]. The T1 (fixed echo time (TE) and different repetition time (TR)) and T2 (fixed TR and different TE) measurements on all phantoms were conducted using the 3-T MRI system via spin echo (SE) and turbo spin echo (TSE) sequences, respectively. The signal-to-noise ratio (SNR) of all phantoms was calculated using Image-J software by implementing the region of interest (ROI) analysis. The SNR against TR and SNR against TE curves were fitted to the exponential equations for saturation, T1 and T2 determination. For every phantom, T1 curve demonstrated that the SNR increased exponentially with increasing TR, while T2 curves showed that the SNR decreased exponentially with increasing TE. Gd2O3 was found to successfully act as the relaxation modifier for the T1 but not the T2 curves. The T1 curve started to show saturated SNR (SNRo) and increasing SNRo for TR > 1000 ms and [Gd2O3] = 0.005 g/ml or higher. These behaviours are explained based on the dipole-dipole interaction that increases in phantoms with higher [Gd2O3], thus shortening the T1 relaxation. However, a systematic change in the T2 parameters with increasing [Gd2O3] was not observed. While Gd2O3 has significant effects on T1 relaxation parameters, the T2 relaxation parameters were minimally affected. With a shorter T1, the Gd2O3 added agarose gel can potentially be used as test phantom in fast imaging sequence, e.g. gradient echo pulse sequences.
The Malaysian Association of Medical Physics (MAMP) was set up in the year 2000 to promote and further develop the field that was relatively new in Malaysia. The article briefly summarises key developments in medical physics since the first discovery of x-rays in 1895. The resulted rapid progress in the field was also highlighted and related to the pace of development in Malaysia. Key activities organised by MAMP were also addressed. The international practices related to the field and the profession were highlighted and compared to the current status in Malaysia. Although the field has progressed well in the country, there are several gaps identified to further improve the field and the profession in Malaysia.
Music is one of the suggested interventions that can reduce stress caused by pain from mammography procedures. The different types of music might affect the anxiety level during a mammogram screening. Thus, the study aimed to determine the anxiety level of women who underwent mammogram screening according to different types of music. A cross-sectional study was conducted on 60 women by using the purposive sampling technique in the radiology department at randomly selected private hospitals in Klang Valley from November 2018 to November 2019. Respondents were randomly divided based on the day of mammogram screening into two groups; namely slow and upbeat music. Descriptive analysis was used to determine the anxiety level for each group and T-test analysis was used to compare the significance of anxiety level between both groups. A total of 60 respondents had participated in this study with a total of 30 (50.0%) respondents allocated in slow music, while another 30 (50.0%) respondents were allocated in upbeat music. Patients who underwent mammography screening while listening to slow music had a high anxiety level (70.0%) as compared to upbeat music group (63.3%). There was no significant effect for music, t (60) = -0.54, p = 0.59, despite slow music (M = 1.70, SD = 0.47) attaining higher anxiety level than the upbeat music (M = 1.63, SD = 0.49). Upbeat music has the potential in reducing the anxiety level of women undergoing mammography screening.
The radiographer's role in the imaging field is producing the best image to diagnose. Hence, this study is conducted to justify the ability of radiographers in terms of diagnostic performance and visual search patterns during radiographic image interpretation based on their experience. The musculoskeletal radiographic images were chosen as radiographers are expected to perform image interpretation in the red dot system as one of the expanded and extended roles of the radiographer. Sensitivity and specificity in the detection of abnormality are measured. The gaze plot, fixation count and duration are compared between groups of radiographers by using an eye tracker. 19 radiographic images consist of upper and lower extremities are used as stimuli in this study. The result from this study shows no significant difference in terms of sensitivity and specificity with a p-value of 0.818 and 0.146 respectively. For visual search pattern, two images have significant different in term of fixation count (Image 1, p = 0.017; Image 2, p = 0.042) and two images in fixation duration (Image 1, p = 0.001; Image 15, p = 0.021). The gaze plot is not different from an unstructured pattern and less coverage. In conclusion, the experience did not give an influence on the radiographic image interpretation. This may suggest that specific training in areas appropriate to the development of the radiographer could improve the image interpretation.
The aimed of this study is to estimate the entrance surface dose (ESD) of routine chest X-ray (CXR) examination and to compare the direct and indirect measurement. This study also extended to relate with the patients body thickness and established lifetime attributable risk (LAR) of the examinations. A total of 101 CXR examinations in posteroanterior (PA) projections were selected
as subjects and data, such as patient habitus and scanning acquisition parameters were recorded. The mean ESD value obtained from the TLD-100 and the software calculation was 0.31 mGy and 0.17 mGy, respectively. The percentage deviation obtained ranged from 25.5% to 61.3%. In comparison with the national diagnostic reference level (DRL), the mean values of ESD obtained from this study were lower by a factor of 3. Furthermore, it was observed that the mean absorbed dose of the adrenals, kidneys, lungs, oesophagus, and heart walls were lower as compared to the ESD value. The examinations were only associated with very low risk of cancer incidence and mortality. Hence, the results of this study suggested a need for standardisations of the personnel training to perform X-ray examinations according to ALARA principles.
This study investigated the effects of stochastic facilitation in healthy subjects with normal and low auditory working memory capacity (AWMC). Forty healthy volunteers were recruited in this study. They performed a backward recall task (BRT) in quiet and under four white noise intensity levels: 45, 50, 55, and 60 dB. Brain activations during the task were measured using functional magnetic resonance imaging (fMRI). The behavioral performance in both groups increased significantly in 50 and 55 dB white noise. The normal AWMC group (mean score = 48.70) demonstrated higher activation in the superior temporal gyrus and prefrontal cortex than the low AWMC group (mean score = 30.85). However, comparisons in the brain activation between groups for all noise levels were not statistically different. The results support previous findings that stochastic facilitation enhances cognitive performance in healthy individuals. The results also proposed that brain activity among healthy subjects is more or less similar, at least in the context of auditory working memory. These findings indicated that there were no differential effects of stochastic facilitation in healthy subjects with different AWMC.
Many recent studies focused on the patient’s safety from the administration of gadolinium-based contrast agents (GBCAs), their concentration, the dose of administration and their effects on the image quality. The present study was aimed at evaluating the effects of reduced GBCAs (gadobutrol and gadoterate meglumine) volume on the image quality by using phantoms. Eight (8) human brain mimicking phantom made of nickel chloride (NiCl2) doped agarose gel were added with 0.00500 ml (100% volume), 0.00350 ml (75% volume), 0.00250 ml (50% volume) and 0.00125 ml (25% volume) of gadobutrol, 0.0100 ml (100% volume), 0.0075 ml (75% volume), 0.0050 ml (50% volume) and 0.0025 ml (25% volume) of gadoterate meglumine. The phantoms were scanned using a 1.5-T and a 3 T-MRI system. Signal-to-noise ratio (SNR) and the contrast agents enhancement were evaluated quantitatively and qualitatively. The 50% volume of gadobutrol and gadoterate meglumine at 3 T showed greater enhancement when compared with 50% and 100% volumes of gadobutrol and gadoterate meglumine at 1.5 T. It can be concluded that the volume of gadobutrol and gadoterate meglumine contrast agents can be reduced when using a higher field system