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Abstrak :
Penelitian ini bertujuan untuk mengetahui karakteristik material organik pengganti fantom polymethyl methacrylate (PMMA) dan fantom air dengan parameter backscatter factor (BSF) dan koefisien atenuasi linear (m). Pengukuran BSF dan m dilakukan menggunakan mobile X-Ray dengan faktor eksposi 40-120 kV dengan dua puluh variasi kualitas berkas pada tiga luas lapangan yang berbeda (untuk pengukuran BSF). Hasilnya, fantom organik memiliki nilai BSF yang mendekati fantom standar dengan deviasi < 8% dan < 10%, berturut-turut untuk fantom ekuivalen air dan PMMA. Sementara nilai m untuk fantom-ekuivalen air pada tegangan > 60 kV memiliki tingkat kesalahan < 15% untuk fantom ekuivalen air dan < 18% untuk fantom ekuivalen PMMA. ...... This research aims to verify physical characteristics of water and polymethyl methacrylate (PMMA)-equivalent phantom made of organic materials in terms of its interaction with diagnostic-range radiation. Backscatter factor (BSF) and linear attenuation coefficient (m) were selected as test parameters. Measurement of BSF and m has been performed using mobile x-ray beam with the exposure factor of 40 to 120 kV. For BSF, measurement has been carried out using twenty different beam qualities in three different field sizes. The final results show similarity between water equivalent-phantom and the literature with the error below 8% and below 10% for the PMMA equivalent-phantom. The results of m measurement for water equivalent phantom in the beam voltage above 60 kV shows error below 15% compared to standard water phantom. On the other hand, PMMA quivalent-phantom shows an error below 18%.

Abstrak :
Penelitian ini bertujuan untuk memperoleh lima komposisi bahan phantom ekuivalen jaringan dan membahas karakteristik interaksi radiasi phantom ekuivalen jaringan dengan bahan penyusunnya, yaitu campuran lilin batik (lilin gondorukem, lilin cecek, lilin parafin, dan lilin lebah) dan karbon aktif. . Komposisi yang diperoleh terdiri dari lima variasi bahan phantom ekuivalen jaringan, antara lain white matter brain (20% cecek wax, 20% karbon aktif, dan 60% gondorukem wax), grey matter brain (16% cecek wax, 16% karbon aktif, 68 % lilin gondorukem), otot (10% lilin cecek, 10% karbon aktif, 80% lilin gondorukem), lemak (10% lilin cecek, 10% karbon aktif, 80% lilin parafin), dan hati (40% tepung beras, 60 % lilin). Masing-masing bahan dibuat kemudian diuji menggunakan mesin x-ray dan dosimeter ruang pengion untuk mendapatkan nilai dosis permukaan masuk (ESD) dan faktor hamburan balik (BSF) pada kondisi sinar standar Radiation Quality Attenuated Beam 5 ( RQA 5). Pengukuran ESD dan BSF dilakukan dengan variasi ketebalan phantom dari 6 cm sampai 10 cm dan variasi lapangan 20 cm × 20 cm dan 25 cm × 25 cm. Nilai rata-rata ESD dan BSF cenderung meningkat pada ketebalan 6 cm hingga 8 cm untuk jaringan otak materi putih, otak materi abu-abu, otot, lemak, hati di bidang 20 cm × 20 cm masing-masing (5,31% ± 1,73%) ; (2,86% ± 2,01%); (1,81% ± 0,79%); (0,62% ± 2,24%); dan (1,34% ± 2,2%). Sedangkan bidang 25 cm × 25 cm mengalami peningkatan (4,86% ± 0,67%); (6,03% ± 5,25%); (0,98% ± 1,31%); (12,42% ± 5,71%); dan (3,81% ± 1,16%). Nilai ESD dan BSF untuk masing-masing jaringan dijenuhkan pada ketebalan 10 cm. ......This study aims to obtain five tissue equivalent phantom compositions and discuss the interaction characteristics of tissue equivalent phantom radiation with its constituent materials, namely a mixture of batik wax (gondorukem wax, cecek wax, paraffin wax, and beeswax) and activated carbon. . The composition obtained consisted of five variations of tissue equivalent phantom materials, including white matter brain (20% cecek wax, 20% activated carbon, and 60% gondorukem wax), gray matter brain (16% cecek wax, 16% activated carbon, 68 % gondorukem wax), muscle (10% cecek wax, 10% activated carbon, 80% gondorukem wax), fat (10% cecek wax, 10% activated carbon, 80% paraffin wax), and liver (40% rice flour, 60 % wax). Each material was made and then tested using an x-ray machine and an ionizing chamber dosimeter to obtain the value of the incoming surface dose (ESD) and backscattering factor (BSF) under standard beam conditions of Radiation Quality Attenuated Beam 5 (RQA 5). ESD and BSF measurements were carried out with variations in phantom thickness from 6 cm to 10 cm and field variations of 20 cm × 20 cm and 25 cm × 25 cm. The mean values ​​of ESD and BSF tended to increase at 6 cm to 8 cm thickness for white matter brain tissue, gray matter brain, muscle, fat, liver in the areas of 20 cm × 20 cm respectively (5.31% ± 1 ,73%); (2.86% ± 2.01%); (1.81% ± 0.79%); (0.62% ± 2.24%); and (1.34% ± 2.2%). While the area of ​​25 cm × 25 cm experienced an increase (4.86% ± 0.67%); (6.03% ± 5.25%); (0.98% ± 1.31%); (12.42% ± 5.71%); and (3.81% ± 1.16%). ESD and BSF values ​​for each tissue were saturated at a thickness of 10 cm.

Abstrak :
Terdapat kekhawatiran yang tumbuh di masyarakat umum serta bidang medis dan scientist tentang paparan radiasi dari prosedur sinar-x diagnostik dalam kasus wanita hamil yang menjalani pemeriksaan radiografi dimana embrio/janin berada dekat ataupun masuk dalam lapangan radiasi, misalnya pemeriksaan radiografi thoraks dan abdomen. Penelitian ini dilakukan untuk estimasi dosis janin pada pemeriksaan thoraks dan abdomen untuk kepentingan penilaian risiko janin dan manfaat pada review justifikasi. Estimasi dosis janin didapatkan dengan mengalikan antara Normalized Uterine Dose (NUD) dengan Entrance Surface Dose (ESD). NUD didapatkan dari kalkulasi software Xdose, sedangkan ESD didapatkan dari hasil bacaan Thermoluminescence Dosimetry (TLD) yang diletakkan pada titik berkas utama permukaan phantom posterior dengan tebal phantom 17 cm untuk pemeriksaan thoraks dengan arah penyinaran posterior-anterior dan pada titik berkas anterior permukaan phantom untuk pemeriksaan abdomen dengan arah penyinaran anterior-posterior. ESD juga bisa didapatkan dari hasil perkalian antara incident air kerma dengan backscatter factor. Pemeriksaan thorak dilakukan dengan tegangan tabung 55, 60, 66, 70 dan 77 kV dengan beban tabung 10 mAs sedangkan pemeriksaan abdomen dilakukan dengan tegangan tabung 60, 66, 70, 77, 81 dan 85 kV dengan beban tabung 10 mAs. Dosis janin yang didapat pada pemeriksaan thoraks antara 1,92x10-5 ? 2,79x10-5 mGy sedangkan pada pemeriksaan abdomen dosis janin yang didapat antara 0,054 ? 0,975 mGy. Dosis janin yang didapat masih berada dibawah nilai batas dosis menurut The International Commission on Radiological Protection (ICRP) yaitu 100 mGy. ......There has been growing concern on public, as well as scientific and medical communities, about radiation exposures from diagnostic X-ray procedures in the case of pregnant women who undergo radiological examinations when the embryo/fetus is near or included in the X-ray field, for example thorax and abdomen radiographic examinations. This research was conducted to estimate fetal doses in thorax and abdomen examination for risk-benefit considerations as justification review. Fetal doses estimation were obtained by multiplying Normalized Uterine Dose (NUD) with Entrance Surface Dose (ESD). NUDs were obtained using calculation software XDose while ESDs were obtained from Thermoluminescence Dosimetry (TLD) placed on the posterior center beam of phantom surface with 17 cm thickness for thorax examinations posterior-anterior projection and on anterior center beam of phantom surface for abdomen examinations anterior-posterior examinations. ESD can also be obtained by multiplying incident air kerma with backscatter factor. Thorax examination performed with a tube voltage of 55, 60, 66, 70 and 77 kV and 10 mas, while the abdominal examination performed with a tube voltage of 60, 66, 70, 77, 81 and 85 kV and 10 mas. From thorax examination fetal doses between 1.92 x10-5 to 2.79 x10-5 mGy and from abdomen examination fetal doses between 0.054 to 0.975 mGy. Fetal doses obtained were less than the dose limit value according to The International Commission on Radiological Protection (ICRP) of 100 mGy.