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"Computed Tomography Dose Index (CTDI) merupakan konsep utama dalam dosimetri CT scan. Berdasarkan rekomendasi IAEA di TRS 457, CTDI dapat diukur di udara dan di fantom khusus CTDI. Ukuran dan massa fantom cukup besar sehingga akan menyulitkan dalam mobilisasi. Dalam penelitian ini dilakukan pengukuran CTDI untuk mengetahui faktor fantom pesawat Siemens Sensation 64. Faktor fantom adalah perbandingan CTDIw terhadap CTDIair. Fantom yang digunakan adalah fantom berbahan polymethil methacrylic (PMMA) berdiameter 16 cm sebagai fantom kepala dan 32 cm sebagai fantom tubuh. Detektor yang digunakan adalah Xi CT Platinum dan Xi Base Unit sebagai elektrometer. Estimasi dosis efektif dihitung berdasarkan nilai CTDIair pengukuran yang dikoreksi dengan perangkat lunak ImPACT CT Dosimetry Patient Calculator version 1.0.4. Nilai faktor fantom yang diperoleh untuk fantom kepala dan tubuh secara berturut-turut ialah 0.702 dan 0.357. Estimasi dosis efektif satu fase (rata-rata ± deviasi standar) ialah: kepala rutin 2.01 ± 0.11 mSv, kepala trauma 2.53 ± 0.16 mSv, thorak 3.4 2 ± 0.79 mSv, abdomen 5.99 ± 2.16 mSv, dan pelvis 2.12 ± 0.99 mSv. Faktor konversi DLP displai scanner terhadap dosis efektif: kepala rutin 0.0021 mSv/mGy.cm, kepala trauma 0.0022 mGy.cm, thorak 0.0182 mSv/mGy.cm, abdomen 0.0151 mSv/mGy.cm, dan pelvis 0.0118 mSv/mGy.cm.

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Computed Tomography Dose Index (CTDI) is primary dosimetric concept in CT scan. Based on IAEA TRS 457 recommendation, CTDI can be measured free in air and by using phantom. Phantom size and mass are huge, thus it will complicate the mobilization. This research conducted CTDI measurement to find out the Siemens Sensation 64 phantom factor. Phantom factor is a ratio between CTDIw over CTDIair. A Polymethyl Methacrylic (PMMA) phantom was used in this research, which has 16 cm of diameter for head phantom and 32 cm of diameter for body phantom. The Xi CT Platinum detector was used in this research and Xi base unit is as an electrometer. The estimation of effective dose was calculated using CTDIair value and ImPACT CT Dosimetry Patient Calculator version 1.0.4. In this research was found out that the phantom factors are 0.702 for head phantom and 0.357 for body phantom. The estimation of effective dose for one phase (mean ± standard deviation): head routine 2.01 ± 0.11 mSv, head trauma 2.53 ± 0.16 mSv, thorax 3.4 2 ± 0.79 mSv, abdomen 5.99 ± 2.16 mSv, and pelvis 2.12 ± 0.99 mSv. DLP on scanner display to effective dose conversion factors: head routine 0.0021 mSv/mGy.cm, head trauma 0.0022 mSv/mGy.cm, thorax 0.0182 mSv/mGy.cm, abdomen 0.0151 mSv/mGy.cm, and pelvis 0.0118 mSv/mGy.cm."

"Perkiraan nilai dosis yang diterima pasien ( CTDI ) yang langsung ditampilkan pada monitor CT setiap selesai pemeriksaan akan diketahui ketepatan nilainya dengan pengukuran langsung menggunakan pencil ion chamber dan pengukuran tidak langsung menggunakan TLD (Thermolumescence Dosimeter ) yang ditempatkan pada objek phantom dan dibandingkan dengan nilai dosis referensi yang telah ditetapkan, sehingga diharapkan mendapatkan informasi nilai dosis yang sebenarnya.Analisis variasi parameter kV, mAs, dan pitch untuk menentukan berapa rentang nilai parameter optimum untuk mendapatkan nilai dosis pasien (CTDI/mAs) yang minimum namun tidak mengesampingkan kualitas pencitraan hasil CT. Scan yang baik guna menunjang diagnosa, pengukuran langsung maupun tidak langsung dengan menggunakan fantom kepala dan perut.Pengukuran tidak langsung dengan menggunakan TLD (Thermolumescence Dosimeter ) pada menunjukan hasil yang tidak jauh berbeda dengan pengukuran langsung dengan menggunakan pencil ion chamber, dapat ditunjukkan dengan hubungan sifat kelinearan antara pitch dan dosis (CTDI/mAs).

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An estimation dose (CTDI) received by the patient which is directly displayed on the CT monitor on every examination will be able to known it?s precisien by direct measurement using pencil ion chamber and the indirect measurement using TLD placed on the object (phantom) and compared with the value of dose reference, so the real dose rate will be known.

The variant analysis of kV, mAs and pitch parameters to justify the range of optimal parameter value, it is used to get the minimum patient dose rate (CTDI/mAs) while the image quality for supporting the diagnose still on the right value, directly or not directly using head and abdomen phantom.

Indirect measurement using TLD show unsignificant result if compared with the ion chamber. This value is shown by a relative variant parameter using stright pitch and dose ( CTDI/mAs)."

"Computed Tomography (CT) Scanner merupakan alat pencitraan diagnostik yang memberikan informasi citra medis untuk menunjang pengobatan pasien, namun tanpa disadari pemanfaatan radiasinya dapat menimbulkan efek negatif pada organ sensitif sekitar. Penelitian ini dilakukan untuk mengukur dosis organ sensitif (mata, tiroid, dan payudara) menggunakan fantom Rando pada CT Scanner area thorax. Untuk memudahkan penelitian ini, TLD rod 100 digunakan sebagai dosimeter, dimana kV dan pitch dijadikan sebagai variasi parameter penelitian. Hasil menunjukkan bahwa nilai paparan dosis tertinggi pada tiap kualitas berkas berturut-turut dari 80, 120, dan 140 kV yaitu payudara kanan (1,72±0,34 mGy), tiroid kanan (6,25±0,16 mGy), dan payudara kiri (10,78±0,76 mGy). Pada variasi pitch nilai paparan dosis tertinggi secara berturut-turut dari 4, 6, dan 8 yaitu payudara kiri (6,19±0,02 mGy), tiroid kanan (6,25±0,16 mGy), dan payudara kanan (5,08±0,85 mGy). Dapat disimpulkan bahwa nilai dosis payudara pada CT Thorax lebih tinggi dibandingkan dengan mamografi, namun keduanya tidak melebihi nilai batas dosis yang ditetapkan International Commission on Radiological Protection (ICRP) yaitu 5 Gy.

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Computed Tomography (CT) Scanner is an instrument of medical imaging using radiation to support treatment for patient, but the radiation may give a negative effect around sensitive organs. The research meant to measure dose for sensitive organs at thorax area (eyes, thyroid, and breast) using CT Scanner with rando phantom as an object. To ease this experiment, TLD rod 100 used as dosimetry, which kV and pitch as a parameter variation. The result showed that the highest dose for kV variation upon each sequent beam quality from 80, 120, and 140 kV are right breast (1,72±0,34 mGy), right thyroid (6,25±0,16 mGy), and left breast (10,78±0,76 mGy). Towards pitch variation the highest exposure dose value in sequently from 4, 6, and 8 are left breast (6,19±0,02 mGy), right thyroid (6,25±0,16 mGy), and right breast (5,08±0,85 mGy). As a conclusion, the dose on breast from CT Thorax is higher than the one from mammography but both are bellow dose value limit from International Commission on Radiological Protection (ICRP) which is 5 Gy."

"Tujuan penelitian ini adalah untuk melakukan pengukuran CTDI dan dosis efektif pada 3 mesin CT dengan pengujian abdominal terhadap pasien pediatrik dan dewasa menggunakan phantom CT yang dibuat dan detector pensil CT serta electrometer RADCAL. Phantom CT dibuat berdasarkan standar US-FDA untuk CT. Pengujian Computed Tomography (CT) yang dilakukan menggunakan 2 CT phantom yang berbeda, diameter 32 cm (pasien dewasa) dan diameter 16 cm (pasien pediatrik). Pengukuran CTDI dan perhitungan dosis efektif radiasi menunjukkan bahwa terdapat dosis pasien pediatrik yang lebih tinggi signifikan dibandingkan dengan dosis pasien dewasa pada perlakuan yang sama. Hal ini menandakan pentingnya penentuan secara hati-hati parameter teknis scan dan justifikasi yang kuat terhadap penggunaan pengujian CT pada pasien pediatrik.

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A study has been performed to measure CTDI and effective dose on 3 CT machines pertinent to abdominal examination to adult and pediatric patients using fabricated CT phantom and RADCAL pencil detector and electrometer. The CT phantom was tailored according US-FDA standard. Computed tomographic (CT) examinations have been performed using two different CT phantoms, 32 cm (adult) and 16 cm (pediatric) diameter. Computed tomographic (CT) examinations and radiation effective dose showed significant higher pediatric dose as compared to adult patient dose at the same examinations. This indicates the importance of careful selection of technical scan parameters and strong justification of the use of CT examination on pediatric patient."

"CT-scan abdomen merupakan opsi dalam penegakan diagnosis terkait dengan dugaan penyakit yang diderita pasien menggunakan radiasi pengion, namun resiko radiasi pada organ sensitif di sekitar area abdomen dapat menimbulkan kekhawatiran tersendiri. Maka dari itu, dilakukan penelitian untuk menunjukkan seberapa besar dosis radiasi yang diterima organ sensitif (gonad, payudara, tiroid dan mata) pada pelaksanaan pemeriksaan CT abdomen, dengan fantom rando sebagai objek pemeriksaan dan TLD rod sebagai penangkap radiasi. Pelaksanaan pemeriksaan dilakukan dengan memvariasikan kV (80,120 dan 140) dan nilai pitch (4,6 dan 8). Dosis radiasi terbesar didapatkan pada gonad dengan 7,67 mGy dan terendah pada tiroid kanan dengan 0,01 mGy. Sehingga, dapat disimpulkan bahwa pemeriksaan CT-scan abdomen tidak menimbulkan efek langsung.

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CT-scan for abdomen area is an examination option in diagnosis that related to patient’s disease, but the radiation risk that appears on sensitive organs near abdomen area need to be concern. Therefore, a research was done to show how much radiation dose for organs received (gonad, breasts, thyroids, and eyes) in CT-scan examination for abdomen, using rando phantom as an object and TLD rod as dosemeter. The variation of examination was done for kV (80, 120, and 140) and pitch (4, 6, and 8). The result show that gonad had received the highest radiation dose with 7,674 mGy (tube’s voltage was 140 kV, pitch 6). So, it can be concluded that examination with CT-scan did not give deterministic effect to sensitive organs."

"X-ray computed tomography (CT) has been playing an important role in current medical practice for diagnostic procedure. Beside its delicate technology, the 'hidden' software of CT image reconstruction has contributed almost half of total cost of a CT-scanner unit. Since Algebraic Reconstruction Technique (ART) is a basic to understand an iterative method of CT image reconstruction algortihm, and since it is difficult to find a clear description of fan beam ART algorithm in university literatures, it is important to develop an own algorithm and to begin a basic systematic research of this iterative method. After a long term of trial and error work, the research had succeded in developing an ART algorithm for third generation CT image reconstruction. By comparing the result of the research with more popular technique like Filtered Back Projection (FBP), the algorithm has been proved applicable to reconstruct a low dimension object matrix (32x32 and 64x64). By the resulted computer program, then basically a simple and low cost third generation CT-scanner can be designed for medical physics or biomedical imaging research. Finding a way of shortening the massive number of iterations process then, will be able to open the possibility of using the software for higher object matrix dimensions."

""The book offers a comprehensive and user-oriented description of the theoretical and technical system fundamentals of computed tomography (CT) for a wide readership, from conventional single-slice acquisitions to volume acquisition with multi-slice and cone-beam spiral CT. It covers in detail all characteristic parameters relevant for image quality and all performance features significant for clinical application. Readers will thus be informed how to use a CT system to an optimum depending on the different diagnostic requirements. This includes a detailed discussion about the dose required and about dose measurements as well as how to reduce dose in CT. All considerations pay special attention to spiral CT and to new developments towards advanced multi-slice and cone-beam CT. For the third edition most of the contents have been updated and latest topics like dual source CT, dual energy CT, flat detector CT and interventional CT have been added. The enclosed CD-ROM again offers copies of all figures in the book and attractive case studies, including many examples from the most recent 64-slice acquisitions, and interactive exercises for image viewing and manipulation. This book is intended for all those who work daily, regularly or even only occasionally with CT: physicians, radiographers, engineers, technicians and physicists. A glossary describes all the important technical terms in alphabetical order. The enclosed DVD again offers attractive case studies, including many examples from the most recent 64-slice acquisitions, and interactive exercises for image viewing and manipulation"--Back cover."

"Tujuan: Penelitian ini dilakukan untuk mendapatkan data profil kanalis fallopii segmen mastoid dan korda timpani sebelum operasi mastoidektomi untuk mengurangi angka morbiditas cedera kanalis fallopii akibat operasi. Metode: Pada penelitian retrospektif ini dilakukan rekonstruksi High-Resolution Computed Tomography tulang temporal terhadap 100 tulang temporal normal pada 50 pasien yang menjalani pemeriksaan CT scan kepala dan leher, yang diambil dari raw-data mulai Desember 2012 sampai Februari 2013. Rekonstruksi dilakukan dengan parameter ketebalan irisan 0,6 cm, increment 0,3 cm, Kernel filter Very Sharp (H70s), Window setting Osteo/Mastoid, menggunakan pesawat MDCT Somatom Definition Flash Dual Source 128 slice. Hasil dan diskusi: Bentuk kanalis fallopii segmen mastoid paling banyak ditemukan tipe lurus sebanyak 75%, defleksi terhadap bidang sagital dan defleksi terhadap bidang horizontal anatomi paling banyak ditemukan tidak terdapat defleksi sebanyak 62% dan 68%. Percabangan korda timpani paling banyak ditemukan intratemporal sebanyak 75%, yang tersering pada 1/3 distal kanalis fallopii segmen mastoid. Sudut korda timpani yang dibentuk korda timpani terhadap kanalis fallopii segmen mastoid paling banyak ditemukan antara 16 sampai 30 derajat sebanyak 37,3%. Ukuran korda timpani yang minimal tervisualisasi adalah 0,04 cm. Kesimpulan: Proporsi defleksi kanalis fallopii segmen mastoid terhadap bidang sagital dan horizontal adalah tidak terdapat defleksi.

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Objectives: This research was conducted to obtain profile data of mastoid segment of fallopian canal and tympanic cord before masteidectomy to reduce the morbidity rate of surgery-related fallopian canal injury.

Material and method: In this retrospective study reconstruction of High Resolution Computed Tomography of the temporal bone in 100 normal temporal bone in 50 patients who underwent a CT scan of the head and neck, were taken from the raw-data from December 2012 to February 2013. Reconstruction is done by parameters slice thickness 0,6 cm, increment 0,3 cm, Kernel filter Very Sharp (H70s), Window setting Osteo/Mastoid,using MDCT Somatom Definition Flash Dual Source 128 slice.

Result: Mastoid segment of fallopian canal commonly found type of straight as much as 75%, deflection of the sagittal plane and the horizontal field of anatomy most commonly found there was no deflection were 62% and 68%, respectively. Branching chordate tympani most commonly found intratemporal as much as 75%, which is common in 1/3 distal of mastoid segmen fallopian canal. The angled formed by chorda tympani and mastoid segment fallopian canal is most prevalent among 16 to 30 degrees as much as 37.3%. The minimum size of the chorda tympani is 0.04 cm.

Conclusion: Proportion of deflection mastoid segment facial canal of the sagittal and horizontal plane there is no deflection."

"Penelitian ini merupakan penelitian dengan menggunakan desain potong lintang (comparative cross sectional) yang bertujuan untuk menilai dan membandingkan ketebalan lapisan serabut saraf retina/retinal nerve fiber layer (RNFL) peripapil antara kelompok normal dan kelompok glaukoma dengan cup disk ratio (CDR) vertikal 0,4 sampai dengan 0,7 di poliklinik mata Rumah Sakit Cipto Mangunkusumo (RSCM) kirana. Sebanyak 40 mata kelompok normal dan 34 mata kelompok glaukoma mengikuti pemeriksaan Humphrey field analyzer dan Optical Coherence Tomography (OCT). Kemudian ketebalan RNFL peripapil kelompok normal dan glaukoma dianalisis untuk mendapatkan perbandingan ketebalan RNFL peripapil antara kelompok normal dan glaukoma. Pada penelitian ini didapatkan hasil tidak ada perbedaan perubahan ketebalan lapisan serabut saraf retina peripapil seiring dengan penambahan CDR vertikal namun secara klinis ketebalan RNFL peripapil pada kelompok glaukoma lebih tipis dibandingkan kelompok normal dengan CDR vertikal yang sama kecuali pada kuadran temporal.

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This was a comparative cross-sectional study. The purpose of this study was to assess and compare the peripapillary retinal nerve fiber layer (RNFL) thickness between the normal and glaucoma eyes with vertical cup disc ratio (CDR) 0.4 to 0.7 in eye clinic Cipto Mangunkusumo Hospital (RSCM) Kirana. A total of 40 eyes of normal group and 34 eyes of glaucoma following Humphrey field analyzer examination and Optical Coherence Tomography (OCT). Peripapillary RNFL thickness between normal and glaucoma eyes were analysed and compared each other. The result of this study was no difference in changes of peripapillary RNFL along with the progression of vertical CDR but clinically, peripapillary RFNL thickness in glaucoma group is thinner than that of normal group with the same vertical CDR except in temporal quadr."

"Electrical Impedance Tomography (EIT) merupakan salah satu teknik tomografi yang memanfaatkan distribusi konduktivitas dari objek yang diamati. Teknik pencitraan ini tidak menghasilkan radiasi karena menggunakan arus listrik bolak-balik orde lemah dan berfrekuensi tinggi. Arus akan diinjeksikan kedalam phantom yang berisi 16 elektroda yang terbuat dari tembaga yang dilapisi lapisan silver conductive paint. Tembaga yang digunakan berukuran 4 x 2 cm dengan ketebalan 0.5 mm. Tegangan akan diukur pada elektroda lainnya yang kemudian data tersebut akan diolah oleh perangkat lunak EIDORS menjadi hasil rekonstruksi citra. Pengontrolan elektroda yang akan diinjeksi arus dan diukur teganganya dilakukan oleh 16 channel multiplekser dan demultiplekser. Proses akuisisi data pada penelitian ini menggunakan perangkat NI ELVIS II dengan bantuan perangkat lunak LabVIEW. Sistem ini mampu melakukan proses rekonstruksi citra untuk objek plastik berbentuk silinder dengan diameter terkecil 2.5 cm.

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Electrical Impedance Tomography is one of tomography method which is based on distribution of electrical conductivity from the object. This method doesn’t produce harmful radiation because it is use constant low amplitude and high frequency AC current. On this method current will be injected to the phantom by 16 electrodes which made from copper that coated by silver conductive paint. The copper’s size is 4 x 2 cm and 0.5 mm thickness. Voltage will be measured on adjacent electrodes and then EIDORS will proccess it into image reconstruction. Data aqcuisition system are processed by NI ELVIS II with LabVIEW software. This system is able to process image reconstruction from cylindrical plastic object which has minimum size 2.5 cm of diameter"