bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of magnetic susceptibility artefact induced by personal care product with gold nanoparticles on brain magnetic resonance (MRI) images
Authors: Zaini N S , Mohd Z , Karim M K A 
Published: June 2019

Abstract
MRI is an important diagnostic imaging tool as it provides excellent soft tissue contrast resolution. Artefact in MRI is an undesirable appearance in the image that affect the image quality and may hinder true diagnosis of the pathological events. Gold in bulk form does not cause any artefact in MRI as it is diamagnetic whereas in its nanoscale version, it was proven to pose magnetic properties. Previous studies also shown that some personal care products (PCPs) produce artefact in MR images due to the presence of metallic compounds in the PCP. Hence, this study was conducted to investigate the effect of PCP with gold nanoparticles (AuNPs) on brain MRI images. The study was conducted using 1.5 Tesla MRI system where moisturiser and compact powder with AuNPs were tested. The products were applied onto the micropore tape attached to the MRI water phantom. The phantom was placed in an RF coil at the isocentre of the MRI bore and scanned using T1-weighted fast-spin-echo (FSE), T2-weighted FSE and fluid attenuated inversion recovery (FLAIR) sequences. The images were evaluated using Visual Grading Analysis (VGA) checklist by two radiologists. Based on the VGA score, brain MRI images in moisturiser group were all scored ‘1’ which indicate minimal artefact with only loss of fine details seen. Whereas, brain MRI images of compact powder group were all scored ‘0’ which indicate no artefact seen. Therefore, it can be concluded that PCP with AuNPs produce little to no artefact on brain MRI images, thus, there will be no need for the patient who wears PCP with AuNPs to clean their face prior to brain MRI examination.
Assessment of radiation effective dose from lung cancer screening pilot project in Institut Kanser Negara: A preliminary finding
Authors: Karim M K A , Rahim N A , Mustafa S N S , Sabarudin A , Ibahim M J 
Published: June 2019

Abstract
The aim of this study is to evaluate effective dose received by participants from Lung Cancer Screening program in Institut Kanser Negara (IKN), Putrajaya. This retrospective study was performed between April 2016 - December 2016 where all scanning acquisition protocols and dose information from forty (40) participants were recorded and investigated. The screening process involves two types of imaging technique, the Dual Energy Subtraction (DES) Chest Xray and Low-Dose Computed Tomography (LDCT) imaging technique. Participant’s effective dose (ED) from DES and MSCT were analysed by using PCXMC (Version 2.0, Finland) and CT-EXPO (Version 2.3, Germany) software, respectively. It was observed that the mean ( ± SD) value for DES (at 60 kV), DES (at 120 kV) and MSCT examinations were 0.006 ± 0.005 mSv, 0.018 ± 0.005 mSv and 1.558 ± 0.129 mSv, respectively. In a whole, the total cumulative ED values for participants were ranged from 1.376 mSv to 1.986 mSv. It was summarized that both optimized techniques were useful for screening needs and the ED value from this study were lower when compared to other established reference.
Direct and indirect entrance surface dose measurement in X-ray diagnostics using nanoDot OSL dosimeters
Authors: Musa Yahaya , Hashim Suhairul , Khalis Abdul Karim Muhammad 
Published: June 2019

Abstract
This study investigated the suitability of nanoDot optically stimulated luminescence (OSL) dosimeters for entrance surface dose (ESD) measurements in common X-ray diagnostics. OSL dosimetry system supplied by Landauer Inc, (Glenwood, IL, USA) consisting of nanoDot OSL dosimeters and microStar reader were used. ESDs were measured with nanoDots placed on whole-body anthropomorphic phantom (for direct measurements) and in free air without backscatter material (for indirect measurements) in accordance with the IAEA Technical Report Series No. 457. Measurements were carried out in five X-ray projections including AP abdomen, AP chest, PA chest, AP thoracic spine and AP skull. The mean ESD for each projection was evaluated from multiple measurements with three different field sizes. Mean ESDs (direct measurements) for AP abdomen, AP chest, PA chest, AP thoracic spine and AP skull were 4.3 mGy, 0.7 mGy, 0.3 mGy, 6.8 mGy and 2.8 mGy respectively. While in the case of indirect measurements, the corresponding mean ESD values were 4.8 mGy, 0.7 mGy, 0.2 mGy, 7.2 mGy and 3.7 mGy respectively. The results were found to be within IAEA and European Commission (EC) diagnostic reference levels (DRLs) range. The percentage difference of the ESDs measured by direct and indirect methods in all projections were between 0 to 40%. It was affirmed that nanoDot OSL dosimeter is a good candidate for ESD measurement in common radiographic examinations, while taking into account the effect of energy dependence.
Development of light scattering methods for urinary stones diagnosis
Authors: Warty Y , Fitri L A , Haryanto F , Herman  
Published: June 2019

Abstract
The Kidney stones in the urinary tract area formed due to many factors. Most medical cases, this disease was diagnosed after the order of millimeters or centimeters. The purpose of this study was to characterize standard polystyrene solutions with light scattering techniques as a calibration tool that will be used to characterize urine crystals. The first stage begins with a literature review and optical settings. The second stage, the arrangement, and components of the tool were validated by measuring the aperture width based on the experiment and measuring the most appropriate cuvette to be used in the sample. The third stage, polystyrene was dissolved with 10 ml of tetrahydrofuran and measured by variations in molecular weight and concentration of polystyrene. The molecular weight of polystyrene was 4000, 90000, 200000, 400000 and 900000 grams/mol. The results showed the width of the gap according to the experiment was 0.05 mm. The cuvette which has a diffraction width value similar to the measurement without cuvette (Blank) measured from the central beam axis to dark 1 was a cuvette diameter of 27 mm. The results of the polystyrene solution showed a diffraction width change in the polystyrene solution for each molecular weight and concentration change. The higher the molecular weight and concentration, the smaller the diffraction width.
Clustering technique to determinate signal-to-noise ratio of Rhizophora spp. binderless and araldite resin particleboard as phantom material on computed tomography images
Authors: Marashdeh M W , Abubaker A , Suwais K M , Alshipli M , Oglat A A , Tajuddin A A 
Published: June 2019

AbstractThe signal-to-noise ratio (SNR) is an important measure of the quality of computed tomography (CT) images. In this study, a new clustering method is proposed to calculate the SNR ratio of CT image. Multi- Objective Simulated Annealing clustering is used for the comparison based on segmentation parameters such as SNR ratio. Two samples are used in this study as phantom materials, namely,Rhizophora Spp.binderless and araldite resin particleboard, with dimension of 20 cm x 20 cm. For each scanned datum, ImageJ software is utilised as the combination method to analyse CT images. Results shows that the automatic clustering algorithm improves the SNR results of the sample images. In addition, the SNR value of images using MOSA clustering is higher than that of normal CT images.
Intra-vendor clinical SPECT/CT system activity validation of 99mTc in phantom studies
Authors: Yousef M , Mansor S 
Published: June 2019

Abstract
This study was to establish various conversion factors and its impact on the quantitative accuracy of an absolute activity in phantom between 2 variant clinical SPECT/CT system from the same vendors in different centre. Multiple series of uniform phantom scans were performed with 370 MBq filled activity in the uniform phantom using different isotropic voxel sizes (64 × 64 × 64, 128 × 128 × 128, and 256 × 256 × 256). For activity validation purpose, single anthropomorphic phantom scan with different activities ratios for different organs (0:0:1:10, lung: spine: background: liver), matrix sizes and iterations were performed. Various conversion factor (in cps/Bq or Bq/cps) estimated from various matrix sizes (CF64, CF128, and CF256) were applied to generate the activity concentration of distribution in SPECT/CT images. The measured activities for background and liver were then compared to an absolute activity distribution and reported as a percentage difference, while for lung and spine region were reported as activity relative errors percentage. The identical methods were replicated in the other system and the differences between the system were evaluated. Both systems produced an identical trend of CF curves over the different iterations number and voxel sizes. Both systems were capable to estimate the activity distribution within 10% and 15% of error for the liver and background respectively using 256 × 256 × 256 voxel sizes. Furthermore, the relative error percentage was within 10 to 15% of error. Different variant of SPECT/CT system from the same vendor could be able to estimate an accurate activity distribution in phantom according to an identical procedure of CF establishment.
Channelized Hotelling observer assessing microcalcification detectability on 2D mammography: a first application to study the impact of tube voltage
Authors: Wigati K T , Vancoillie L , Salomon E , Zhang G , Cockmartin L , Marshall N , Bosmans H , Soejoko D S , Bliznakova K , Petrov D 
Published: June 2019

Abstract
This work was aimed to assess the detectability of microcalcifications as a function of tube voltage in 2D mammography using an in-house developed Channelized Hotelling Observer (CHO). The images of a 3D structured phantom, containing acrylic beads of different diameters in water and inserted signals (microcalcifications, spiculated and non-spiculated mass models) were assessed. Images had been acquired on a Siemens Mammomat Inspiration system at 5 different tube voltage levels (28-32 kVp) under AEC setting. The detectability of microcalcifications was analyzed in terms of percentage correctly detected signals (PC) as well as diameter threshold (dtr), using the CHO and human observers. Two Laguerre-Gauss and 8 Gabor channels were included in the two-layers CHO. The model and human observer results were retrieved from a 4-alternative forced choice (4-AFC) study. At 28 kVp and 32 kVp, the diameter thresholds dtr of microcalcifications together with their 95% confidence intervals (CI95) were 0.114 [0.110-0.118] mm and 0.119 [0.116-0.122] mm for the CHO, and 0.110 [0.093-0.127] mm and 0.123 [0.111-0.134] mm for the human observers. The Pearson correlation (r) between the PC values of model and human observer was more than 0.934. The in-house developed CHO and the human observer scores correlated very well for the application on 2D digital mammography acquired with different tube voltages. The overlapping range of CI95 of the dtr for the tested kVp shows that the tube voltage setting does not significantly affect the detectability of microcalcifications neither by the CHO nor by the human observers.
Determination of conversion factors of SPECT hot images respect to hot objects in bone medium: preliminary study using in house phantom
Authors: Hastari P T , Nurlely  , Soejoko D S 
Published: June 2019

Abstract
The purpose was to determine conversion factors (CF) of SPECT hot images respect to the original size of hot objects in the bone medium. In house phantom has been made in the form of a cubical acrylic (37cm x 15cm x 15cm) provided with cylindrical channel filled with bovine bone powder with the diameter (1.5; 3.5; 5.4; 7.4 cm). As hot objects, a mixture of bone powder and 99mTc source with various activity and diameter were embedded in filled bone channels. Image acquisitions were carried using Intevo Symbia E Siemens SPECT/CT and LEHR collimator, with surface collimator distance 9.6 cm. There were 6 different in activities and diameter of hot objects in each channel. Conversion factor (CF) was defined as the ratio between FWHM of hot object image profile and the original hot object size. CF value for each diameter channel was varied with the activity and size of the object diameter. The source activities used were 0.1-0.2 mCi and the observed object diameters were 7-12 mm. For hot object size less than resolution stated in SPECT specifications (4 mm), CF values were in the range 1.7-3.4 for 1.5 cm and 3.5 cm channel diameter. For hot objects diameter, 7.5-12 mm, CF value was mostly independent of channel diameters, with the value of (1.1 ± 0.2). This preliminary study informs that CF values of SPECT hot images independent with the size of the host bone medium. Whereas for object diameter ≤ 7.5 mm very relatively higher and influenced by the size of the host bone medium.
Comparison of SPECT quick QC between using in-house hot phantom and Jaszczak phantom: A preliminary study
Authors: Aida A , Prajitno P , Soejoko D S 
Published: June 2019

Abstract
Quality control in nuclear medicine imaging is very imprortant which regularly carried out before running exam. The most important in QC is to evaluate QC parameter on SPECT images. Phantoms can be useful for evaluate QC parameters. The phantom was designed to quick QC SPECT system. Hot image from in-house hot phantom and cold image from Jaszczak phantom were used in this study with increasing activity concentration in in-house and Jaszczak phantom. This research is aimed to compare measurement results QC parameters of local uniformity and contrast on SPECT image generated with in-house and Jaszczak phantom. Measurement results from in-house hot phantom showed that lowest activity (0.99 MBq/mL) generated hardly visualized hot image for small diameter object (4.2 and 5.6 mm), and starting to be visible for 8.6 mm object with contrast value of 46.44. The same trend occurred to cold images generated by Jaszczak phantom, at lowest activity (0.068 MBq/mL) the ROI 8.6 mm on diameter object of 15.9 mm give rise to nearly the same contrast of that in hot image. No significant difference was found between local uniformity measured with in-house hot phantom and Jaszczak phantom. In-house hot phantom was robust and can be used as quick QC tool for SPECT system.
Verification and evaluation of radiation-beam parameters of high-energy linear accelerator with gantry rotation
Authors: Joan M , Saminathan S , Manickam R , Chougule A 
Published: June 2019

Abstract
The radiation beam from a linear accelerator originates from the acceleration of the electrons in the accelerating structure. As the gantry rotates together with the accelerating structure, it is at different orientations with respect to the magnetic field of Earth. The deviations in the path of the electron beam due to the changes in the magnetic fields are corrected by steering coils surrounding the accelerating structure. In the present investigation, all deviations in photon and electron beam parameters of a high energy linear accelerator with gantry rotation are checked. The central axis dose is measured using a parallel-plate ionization chamber placed in the fabricated phantom via parallel-plate chamber holder. To measure the beam flatness and symmetry, a dosimetric plate designed to hold a radiosensitive film is used. The evaluation performed using the fabricated phantom confirms the accuracy of the dose delivered to patients at various gantry angles.
Correlation between CT Number shift and tissue temperature change during radiofrequency ablation: an ex-vivo study using bovine liver
Authors: Leng Lee Dong , How Wong Yin , Long Cheah Peng , Tan Daryl , Sing Lim Kok , Che Ahmad Azlan , Sulaiman Norshazriman , Johan Jeet Abdullah Basri , Hong Yeong Chai 
Published: June 2019

Abstract
Current post-RFA (radiofrequency ablation) evaluation of unresectable liver tumours relies on visual inspection of non-enhancing tissues on the contrasted CT (computed tomography) images. This research investigated the correlation between CT number shift (dHU) and tissue temperature change (dT) during real-time CT-guided RFA of ex-vivo bovine livers. The study aimed to develop a non-invasive CT thermometry method to guide clinicians in assessing ablation outcome. 10 liver samples were individually ablated for 12 minutes using a RFA electrode, powered by an impedance-controlled RF generator (Cool-tipTM, Metronic, USA) and subsequently cooled for 15 minutes. An optical fiber inscribed with 4 equally spaced Fiber Bragg Gratings (FBG) was inserted sideward through the liver to measure 4 temperature points at the grating positions. CT scans were performed at interval of 3 minutes from 0 to 27 minute. CT numbers at the grating positions were manually extracted, and dHU and dT were computed and plotted to investigate the relationship. From the results, CT number decreased as temperature increased during RFA, and vice versa. A negative linear relationship (y = -0.66x + 1.23, R2 = 0.925) between dHU and dT was observed. The thermal sensitivity was determined as -0.66 ± 0.03 HU/˚C. The strong correlation between dHU and dT during RFA could be used to estimate tissue temperature based on the CT number measured during real time CT-guided RFA. This approach would help the interventionalists in determining the ablation outcome hence improving treatment efficacy.
Evaluation of organ doses following prostate treatment with permanent brachytherapy seeds: a Geant4 Monte Carlo simulation study
Authors: Fahmi M R , Hashikin N A A , Yeong C H , Guatelli S , Ng K H , Malaroda A , Rosenfeld A B , Perkins A C 
Published: June 2019

Abstract
This study aimed to evaluate the absorbed doses received by the organs at risk (OARs) following prostate treatment with permanent Iodine-125 (125I) brachytherapy seeds. In order to simulate an enlarged abnormal prostate due to malignancy, the MIRD5 adult male anthropomorphic phantom (readily available in the Geant4 Monte Carlo package) was modified by increasing the prostate volume to 35 cm3. The permanent seeds were constructed with an outer cylindrical dimension of 4.5 mm (length) × 0.8 mm (diameter). The effects of various activity per seed (0.5, 0.6 and 0.8 mCi), number of seeds (62, 78, 94 and 110 seeds) and radionuclides, i.e. Palladium-103 (103Pd), 125I and Cesium-131 (131Cs), towards the absorbed dose to the OARs (i.e. rectum, urinary bladder and both testicles) were investigated. In this study, prostate dose of up to 237 Gy was simulated, which resulted in 11 Gy dose to rectum, 7 Gy to urinary bladder and 4 Gy to each testicle. The doses were considered as reasonable, given the low dose rate nature of the treatment, allowing tissue repair for the OARs. Optimal seeds arrangement was found to consist of 78 or fewer seeds, as it resulted in the lowest dose to the OARs. For similar prostate dose, 103Pd resulted in the lowest dose to the OARs, followed by 125I and 131Cs. Permanent seed brachytherapy allows high dose to be delivered to the prostate, while ensuring minimal dose to the OARs.
Dosimetry analysis of homemade bolus using propylene glycol for photon MegaVoltage and electron radiation therapy
Authors: Rancangkapti N , Hariyanto A P , Mariyam F U , Almira L , Endarko  , Haris B 
Published: June 2019

Abstract
Bolus is widely used to protect and reduce irradiation in organ at risk in the process of radiotherapy. Generally, the bolus was made from polymer material due to had property is similar or equivalent to tissue. This study aimed to determine the density, transmission factor, effective mass attenuation coefficient on bolus with radiation of photons and electrons. The bolus material (B) was used Propylene Glycol (PG), Silicon Rubber (SR) and Aluminium Powder (Al), and had four types of bolus namely B - PG 24%, B - PG 24%; SR 8%, B - PG 24%; SR 8%; Al 0,5%, and B - PG 24%; SR 8%; Al 1,5% with dimensions of 11 × 11 cm and thickness of 1 and 1.5 cm. The bolus density is evaluated through the mass of each volume. The measured data revealed that all of the boluses have density values which are similar to tissue or water and air in the range from 0,864 - 1,202 g/cm3. For dosimetry testing, the bolus is irradiated using Linear Accelerator with 6 and 10 MV for photon source and 6 and 12 MeV for an electron source. The results showed that B - PG 24%; SR 8%; Al 1.5% for dosimetry testing both 6 and 10 MV photons obtained properties that resemble soft tissue. Meanwhile, for both dosimetry testing of 12 MeV electrons, the B - PG 24%; SR 8% with addition silicone rubber and aluminum have nature closest to soft tissue. All of the boluses that have been fabricated have properties similar to soft tissue for photon therapy whereas the addition of more aluminum making a bolus has features as a shield on the process of radiotherapy.
The characteristics of small field beam quality and output factor of 6 MV FFF
Authors: Azzi A , Ryangga D , Pawiro SA 
Published: June 2019

Abstract
Flattening filter free linear accelerator (FFF LINAC) has been installed in Indonesia. To ensure the accuracy of FFF irradiation, we evaluate the characteristic of FFF in regular and small fields. We employed the Monte Carlo (MC) simulation of FFF LINAC 6 MV as a standard reference in this study. Then, we compared the calculation of FFF beam at central and lateral axis to the measurement and TPS at 10 × 10, 1 × 1, 2 × 2, 3 × 3, 4 × 4 cm2 field sizes. Output factor (OF) and beam quality such that TPR20,10 and penumbra of FFF LINAC were evaluated. TPR20,10(S) for 10 × 10 cm2 was 0.01 differ between MC and measurement whereas it varied from 0.588 to 0.703 for small fields. Dose difference of lateral axis was agreed within 3% except for the penumbra region. Output factor of small fields measurement indicated that field size of 1 × 1 cm2 had a large discrepancy to MC according to this works. The TPR20,10(10) of MC, TPS, and measurement was not a significant difference, while the OF was tending to a large deviation in 1 × 1 cm2. The results showed that our FFF LINAC could be used for small field until 2 × 2 cm2.
Determination of composite field correction factor kpcsr,msr for Tomotherapy
Authors: Fitriandini A , Wibowo W E , Pawiro S A 
Published: June 2019

Abstract
The purpose of this study is to determine the correction factor of the composite field (kpcsr,msr
) of Tomotherapy for head and neck cases and to investigate the influence parameters of the pcsr field. This study employed Exradin A1SL and A 16 as the investigated chambers, and EBT3 as the reference dosimeter. The pcsr fields were created based on cylindrical water solid phantom. The results of this study show that the kpcsr,msr
values for both detectors increased with increasing field width (jaw), decreasing complexity level, and increasing pitch value. The yielded results indicate several factors affecting the kpcsr,msr
values: target homogeneity, volume averaging effect, thread effect, and the difference of general recombination at the different field width. These results represent that kpcsr,msr
is specific and depends on the parameters of the composite field. The kpcsr,msr
values for head and neck cases vary from 0.978-1.028. This variation implies that the determination of pcsr field should be according to the parameters used in clinical conditions. Due to the different position of the chamber and the film, the target should have excellent dose homogeneity to avoid the different response of the detectors.