Wahyu Setiabudi
Guru Besar Jurusan Fisika, Fakultas MIPA Universitas Diponegoro

Published : 17 Documents
Articles

Found 17 Documents
Search

UPAYA PENINGKATAN KUALITAS CITRA MRI DENGAN PEMBERIAN MEDIA KONTRAS Suhardi, Suhardi; Setiabudi, Wahyu; Anam, Choirul
BERKALA FISIKA Vol 16, No 1 (2013): Berkala Fisika
Publisher : BERKALA FISIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (339.054 KB)

Abstract

Improvement the image quality of magnetic resonance imaging (MRI) carried out bycontrast media has been done. It was expected to obtain a better image quality so thatinterpretation of MRI images more valid. Contrast media were used gadolinium 5 mmol/10 ml perpatient. Number of patients 10 people with tumor of the head, and each uses a 6 slices. MRI usedAIRIS II with 0.3 Tesla magnetic field, Kodak Dry View 8900, densitometry, and Film. In thisstudy, the image resulted with and without contrast media were measured its density andcompared. It was resulted that the image density in normal  tissues no change, with and withoutcontrast media. While the tumor area with and without contrast media, the density decreased byan average of 0,56. The addition of contrast media, the presence of tumor will appear moreclearly.Keywords: Contrast Media, gadolinium, MRI
KAJIAN RADIOGRAFI DIGITAL TULANG TANGAN Susilo, Susilo; Setiabudi, Wahyu; Kusminarto, Kusminarto; Suparta, G. B.
BERKALA FISIKA Vol 16, No 1 (2013): Berkala Fisika
Publisher : BERKALA FISIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (217.462 KB)

Abstract

Teknologi diagnostik medis yang digunakan pada unit radiologi di rumah sakit sudahcenderung bergeser dari teknologi analog berbasis film menjadi teknologi digital (filmless). Salahsatu cara membuat system radiografi tanpa film adalah dengan cara konversi digital menggunakantabung kedap cahaya (light tight tube). Dalam penelitian ini, kami telah mengkaji kemungkinanpemanfaatan sistem pencitraan radiografi digital sinar-x berbasis X-Ray Intensifying Screen(XRIS) dihubungkan dengan perangkat frame-grabber. Hasil eksperimen tahap awal untukmemperoleh radiograf tulang tangan menunjukkan bahwa sistem ini cukup dioperasikan padategangan anode-katode 50 kV, arus waktu filamen 50 mAs dan waktu paparan 0,1 detik untukmenghasilkan citra yang cukup dapat dilihat. Untuk sekali paparan, dimungkinkan memperolehbeberapa citra untuk obyek yang sama pada posisi tetap, tipa-tiap citra mengandung informasiradiografi berbeda ditunjukkan oleh distribusi tiap citra yang bervariasi. Hasil ini menunjukkanbahwa sistem ini diharapkan lebih efisien dan lebih efektif dibandingkan dengan metodekonvensional berbasis film, dan dapat dikembangkan untuk diagnose mineral tulang.Kata kunci: radiografi digital; filmless; sinar-x; tulang tangan
STUDI UJI ALTERNATIF KUALITAS MINYAK GORENG BERDASARKAN PERUBAHAN POLARISASI CAHAYA TERIMBAS Susan, Ade Ika; Firdausi, K Sofjan; Setiabudi, Wahyu
BERKALA FISIKA Vol 14, No 4 (2011): Berkala Fisika
Publisher : BERKALA FISIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (210.16 KB)

Abstract

AbstractIn this research, we report the quality of several cooking oils before and after heating. The parameter of quality was based on electrooptics characteristic or, so called, the change ofpolarization angle induced by external electric field. In this examination, it was used threedifferent brands of cooking oils. The samples were heated in the time interval between 0-120minutes. The electrooptics characteristic was determined by measuring the change ofpolarization angle of light as it passed through the oil while it was applied by external electricfield. The field was produced by two parallel plates connected to different potential between 0-9kV. The light source was diode laser atλ = 650 nm and λ = 532 nm. The quality of oil was then determined by average polarization angle per potential difference, i.e. α ≡ Δθ/ΔV. Based on the result of observation, the fresh oil before heated has smaller change of polarization angle thanoil after heated, which is in agreement to the previous study. The longer heating time is, morefree radicals are produced, which leads to higher polarization. It shows also that the change ofpolarization depends on the wavelength.  From two diode lasers, the effective wavelength toproduce higher number free radicals is obtained by 532 nm. The increasing average ofpolarization angle is linearly to the increasing of heating time. It is obvious that the electroopticsparameter could be proposed as an alternative quality test of cooking oil.Keyword: Cooking oil quality, Change of polarization angle, electrooptics
Laju paparan dan dosis radiasi dari pasien terapi kelainan kelenjar tiroid dengan pemberian radiofarmaka Iodium-131 Mutohar, Ahmad; Setiabudi, Wahyu; Shintawati, Rini
Youngster Physics Journal Vol 6, No 1 (2017): Youngster Physics Journal Januari 2017
Publisher : Jurusan Fisika, Fakultas Sains dan Matematika, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (820.478 KB)

Abstract

Research about exposure and dose rate from patients with thyroid gland disorders therapy who received radiopharmaceutical Iodine-131 is done by direct measurement using a survey meter. In this study, the exposure rate collected from 37 patients who received doses of radiopharmaceutical therapy with activity ≤ 30 mCi and 13 patients who received doses of radiopharmaceutical therapy with activity> 30 mCi. Exposure rate of each patient was subsequently changed in the form of the dose rate. The results obtained that all patients who received a dose of a radiopharmaceutical with activity ≤ 30 mCi, produce dose rate below the maximum extent permitted to leave the hospital.  While patients who received doses with activity > 30 mCi, produce a dose rate above generate maximum extent permitted to leave the hospital. Besides that, the research also analyzed the reduction of dose rate from each patient. A decrease of dose rate (within 1 hour after administration of radiopharmaceutical) is affected by the excretion rate and rate of uptake of iodine in the blood.  Specially, patient who received a dose with activity > 30 mCi, efective half-life value is determined from a decrease of the dose rate each patient. The results obtained that effective half-life of I-131 in the body of every patient in the range of 6 to 14 hours. Patient H had the shortest effective half-life and patient M has longest effective half-life. The difference of effective half-life of I-131 affected by  biological elimination/ biological half-life of each patients.Keywords: Exposure rate, dose rate, Iodine-13 therapy patients, effective half-life
SIMULASI MONTE CARLO UNTUK MENENTUKAN DOSIS SINAR-X 6 MV PADA KETAKHOMOGENAN MEDIUM JARINGAN TUBUH Rizani, Alfian; Setiabudi, Wahyu; Anam, Choirul
BERKALA FISIKA Vol 15, No 2 (2012): Berkala Fisika
Publisher : BERKALA FISIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (258.831 KB)

Abstract

Study on dose distribution of human body at 6 MV X-ray beam has been done using Monte Carlo Simulation. This study is aimed to define dose distribution of soft tissues, lungs andbones also corrections factor due to tissue inhomogeneity.The study was conducted by Monte Carlo Simulation using EGSnrc software, i.e.BEAMnrc and DOSXYZnrc. The linear accelerator head was simulated by BEAMnrc  with SSD100 cm and field size 10 x 10 cm . The calculating of radiation dose distribution at homogen andnonhomogen phantom that have size 40 x 40 x 40 cm in tissues of human body, such as softtissues, lungs and bones were made by using DOSXYZnrc. Nonhomogen phantom of human bodywas made by insert lungs or bones with thickness 10 cm in soft tissues at depth of 5 cm – 14 cm.It is obtained that the dose distribution of soft tissue and water phantom have samecharacteristic which both of them have maximum dose (D ) at depth of 1,5 cm. Inserting of lungswith a thickness of 10 cm in soft tissue results to the increasing of dose until 12,2 % and insertingof bones with the same thickness with lungs results to decreasing of dose until 10,3 %. The rangeof correction factor due to inserting lungs is 1,00–1,27 and for bone is 0,81–1,05.Keywords:Monte Carlo Simulation, PDD (Percentage Depth Dose), corrections factor
Studi Uniformitas Dosis Radiasi CT Scan pada Fantom Kepala yang Terletak pada Sandaran Kepala Retnoningsih, Dwi Siwi; Anam, Choirul; Setiabudi, Wahyu
JURNAL SAINS DAN MATEMATIKA Volume 20 Issue 2 Year 2012
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3070.95 KB)

Abstract

The research on the impact of tube current and  tube voltage  on uniformity of the point dose in the head phantom was placed on the table, had been conducted. The research was carried out on the CT Scan machine, Siemens Somatom Emotion 6. The detector used was CT dose profiler and Piranha Electrometer 556. The phantom was head phantom with PMAA material with diameter 16 cm and length 15 cm. The measurement of point dose carried out by using axial mode. The measurement conducted in five points inside the head phantom. In this research, the tube current and tube voltage were varied. The results show that the point dose on the head phantom was placed on the table is non-uniform. At the bottom of the phantom, the dose is lower to below 50% than at the top of the phantom.   Keywords: CT Scan, Dose uniformity, Point Dose, CTDI
Pengaruh Perubahan Tegangan Tabung (kVp) Terhadap CT Number dan Uniformitasnya pada Pesawat CT Scan S., Anugrah Ariyani; Setiabudi, Wahyu; Anam, Choirul
JURNAL SAINS DAN MATEMATIKA Volume 20 Issue 3 Year 2012
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2813.475 KB)

Abstract

An examination of consistency of CT numbers and its uniformity due to variation of the tube voltage has been done. The examination was conducted using water and polyethyelene phantoms as a test object. The method of scanning, which are  axial  scanning  and helical scanning. The scanning was taken 5 (five) slices with slice thickness of 5 mm. Variations in  tube voltage used were 80 kV, 120 kV and 140 kV.  The tube current 160 mA and time scanning 2 seconds. It was obtained that the increase in voltage from 80 kV to 140 kV led to increase the value of CT number both for water and polyethylene phantoms. The uniformity of CT number for all ROI varies, but still within the range of tolerance limits. The CT number for the water phantom does not exceed 0 ± 5 HU and for polyethylene phantom does not exceed -300 to -100 HU..   Keywords: CT Scan, CT number, uniformity, tube voltage (kV)
Analisis Perubahan Kurva Percentage Depth Dose (PDD) dan Dose Profile untuk Radiasi Foton 6MV pada Fantom Thoraks Prasetyo, Nur Dwi; Setiabudi, Wahyu; Anam, Choirul
JURNAL SAINS DAN MATEMATIKA Volume 20 Issue 4 Year 2012
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3349.766 KB)

Abstract

The study of thickness variation of the soft tissue in the wall of thoracic phantom to the shifting of Percentage Depht Dose (PDD) curve and Dose Profile have been done by using Monte Carlo Simulation. The linac head was designed using BEAMnrc software, whereas modeling of water and thoracic phantom using DOSXYZnrc software. The field size of beam radiation 10 x10 cm2 and the distance of source to  phantom surface (SSD) 100 cm. The water phantom in cubic shape with a size  40x40x40 cm3. The thoracic phantom was designed in cubic shape, with the compositions: soft tissue, bone and lung. The thickness of the soft tissue in the wall of throcic phantom was varied 1-5 cm. This variation shows the thickness layer of the wall of the real patients. The results of comparation between monte carlo simulation and the  actual measurement, show that 6 MV photon delivered by linac at Kensaras Hospital Semarang was generated using energy electron about  5.7 MeV. The variation of soft tissue thickness change  the PDD curve and the dose profile curve. The variation of soft tissue thickness change the dose in the lung (depth 10 cm)  at about 3,84% - 5,59%   Keywords: Monte Carlo Simulation, Percentage Depht Dose (PDD), Dose profle, Tissue inhomogeneity    Telah dilakukan studi pengaruh ketebalan jaringanlunak pada fantom thoraks terhadap perubahan bentuk kurva  Percentage Depht Dose (PDD) dan Dose Profile untuk berkas foton energi 6MV menggunakan Simulasi Monte Carlo. Pembuatan model treatment head linac dilakukan menggunakan program BEAMnrc, sedang permodelan fantom air maupun fantom thoraks menggunakan DOSXYZnrc. Luas lapangan yang digunakan 10x10 cm2, dengan source to skin distance (SSD) sebesar 100 cm. Fantom air didesain berukuran 40x40x40 cm3. Fantom thoraks didesain berbentuk kubus dengan komposisi jaringan lunak, tulang, dan paru-paru. Jaringan lunak bagian depan (asterior) divariasi ketebalannya 1-5 cm. Variasi ini menggambarkan ketebalan jaringan lunak dinding thoraks pasien. Hasil perbandingan antara simulasi dan pengukuran menunjukan bahwa foton 6 MV yang dihasilkan pesawat linac RS Kensaras Semarang menggunakan energi elektron pembangkit mendekati 5,7 MeV. Variasi ketebalan jaringan lunak pada dinding fantom thoraks memberikan perubahan kurva PDD dan juga kurva profil dosis. Variasi ketebalan jaringan lunak tersebut mengubah besarnya dosis pada paru-paru (pada kedalaman 10 cm) sebesar 3,84% - 5,59% Kata kunci : Simulasi Monte Carlo, Percentage Depht Dose (PDD), Dose Profile, Inhomogenitas Jaringan.
Evaluasi Ketebalan Irisan (Slice Thickness) pada Pesawat CT-Scan Single Slice Makmur, I Wayan Ari; Setiabudi, Wahyu; Anam, Choirul
JURNAL SAINS DAN MATEMATIKA Volume 21 Issue 2 Year 2013
Publisher : JURNAL SAINS DAN MATEMATIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3895.227 KB)

Abstract

An evaluation of the value of the slice thickness due to changes in tube voltage and tube current on the CT scan have been performed. The evaluation is done by making images using CT performance test phantom. Testing is done by performing three scanning on each slice. Exposure factors used were 120 kVp-60 mA, 160 mA 120-kVp, 140-kVp 60 mA, and 140 kVp 160 mA. Nominal beam width were 2 mm, 3 mm, 5 mm, 7 mm, and 10 mm. Once the axial image was obtained (on the area for slice thickness determination),  then calculated the average CT number on the region of interest (ROI). After it was made graphs to determine the value of FWHM which indicates the magnitude of the thickness of the slice. From the test results obtained that changes in tube voltage and tube current does not affect the value of the thickness of the slice. Also found that the value of slice thickness for each thickness, greater than the nominal beam width.   Keywords: Phantom CT Performance Test, Slice Thickness, CT-Scan    Telah dilakukan evaluasi terhadap nilai slice thickness terhadap perubahan tegangan tabung dan arus tabung pada pesawat CT scan. Pengujian dilakukan dengan membuat citra menggunakan fantom CT performance test. Pengujian dilakukan dengan melakukan eksposi sebanyak tiga kali pada tiap-tiap slice. Faktor eksposi yang digunakan yaitu 120 kVp-60 mA, 120 kVp-160 mA, 140 kVp-60 mA, dan 140 kVp-160 mA. Slice thickness yang diuji adalah ketebalan 2 mm, 3 mm, 5 mm, 7 mm, dan 10 mm. Setelah didapatkan citra aksial pada bagian daerah uji slice thickness, maka diambil beberapa lokasi ROI dan dihitung rerata CT Number, kemudian nilai tersebut dibuat grafik dan ditentukan nilai FWHM yang menunjukkan besarnya slice thickness. Dari hasil pengujian diketahui perubahan tegangan tabung dan arus tabung tidak berpengaruh terhadap nilai slice thickness. Hasil pengukuran diketahui bahwa nilai slice thickness untuk masing-masing ketebalan, lebih besar dibanding nominal beam width. Kata kunci : Simulasi Monte Carlo, Percentage Depht Dose (PDD), Dose Profile, Inhomogenitas Jaringan.
Penentuan persentase uptake radiofarmaka Tc99m Sulfur Colloid pada sidik hati (Liver scan) Setiabudi, Wahyu; Nazir, Fadil; Ni’amah, Istifadatun
Youngster Physics Journal Vol 6, No 1 (2017): Youngster Physics Journal Januari 2017
Publisher : Jurusan Fisika, Fakultas Sains dan Matematika, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (555.098 KB)

Abstract

Based on data from the World Health Organization, showed that liver disease in Indonesia is in endemic high ranks. Early diagnosis of liver disease is very necessary for prevention and minimize the risk of liver disease. Research has been conducted on 28 patients on the biodistribution test of the liver scan using in vivo nuclear medicine technique that aims to determine the accumulation of counts Tc99m Sulfur Colloid in the body's metabolism, the percentage uptake activity in the heart, spleen, kidney, bladder, and liver as the target organ. The study was conducted using Tc99m obtained from elution of Mo99 generator and mixed with sulfur colloid. Tc99m allows a radiopharmaceutical can be detected and known location and sulfur colloid to determine where the target of radiopharmaceutical is accumulated. Liver scan is performed by injecting Tc99m Sulfur Colloid intravenously into the patient's arm as much as 2- 6mCi. Furthermore, the anterior posterior planar imaging in abdominal cavity at 5 minutes and 1 hour after injection of the patient by using a gamma camera. Determining the state of liver function can be seen from the percentage uptake activity at 5 minutes and 1 hour, the shape and size of the heart which can be evaluated from the image obtained. Biodistribution of  Tc99m Sulfur Colloid showed a high percentage of the liver after 5 minutes and 1 hour. Based on the value percentage uptake activity obtained, there were 18 patients with a normal liver and 10 patients with abnormal liver. Keywords: Tc99m Sulfur Colloid, liver scan, nuclear medicine, gamma camera