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Abstrak :
ABSTRAK
Sampai sekarang mamografi merupakan program skrining utama untuk deteksi dini kanker payudara khususnya untuk kaum wanita, akan tetapi pemberian informasi tentang dosis yang diterima pasien masih jarang dilakukan. Padahal payudara merupakan salah satu organ sensitif terhadap radiasi pengion karena mampu menginduksi kanker. Sehingga perlu dilakukan estimasi dosis pasien pada pemeriksaan mamografi untuk mengetahui nilai dosis yang diterima oleh payudara. Estimasi dosis dilakukan dengan menggunakan perhitungan Mean Glandular Dose (MGD) pada mamografi Computed Radiography (CR). Dengan melakukan koreksi terhadap kualitas citra pada prosentase (%) glandularity, yaitu prosentase (%) glandularity 25-49% dan 1-24%. Nilai prosentase (%) glandularity dievaluasi oleh radiolog. Dari hasil estimasi didapatkan total rerata MGD pada seluruh proyeksi pemeriksaan payudara 1,65 mGy pada rerata ketebalan kompresi 48,85 mm. MGD yang diperoleh masih di bawah limit berdasarkan rekomendasi FDA, ACR dan MQSA yaitu < 3 mGy per eksposi pada ketebalan 45 mm. MGD dipengaruhi oleh kombinasi antara ketebalan kompresi, kV, HVL dan prosentase (%) glandularity.

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ABSTRACT
Currently, mammography is the primary screening program for breast cancer early detection for women, but information about the doses received by patient are still rare. Breast is a sensitive organ to ionizing radiation since it can include cancer. Therefore it is necessary to estimate the patient dose during mammography examinations. Estimated doses calculations were performed using in term of mean glandular dose (MGD) using Mammography Computed Radiography (CR). Image quality correction was done based on the most frequent percentage (%) glandularity from all samples, which are 25-45% and 1-24% glandularity. Percentage (%) glandularity was evaluated by radiologist. Estimated of total average MGD all off projection at the breast examination 1,65 mGy on the mean compression of thickness 48,85 mm. Mean Glandular Dose obtained during measurement are still under recommendation of the FDA, ACR and MSQA which is < 3 mGy per eksposure. From measurement and calculation, the MGD is influenced by compression of thickness, kV, HVL and percentage (%) glandularity.

Abstrak :
Penelitian ini bertujuan mengevaluasi karakter sistem DR menggunakan fantom in-house untuk mengetahui respon detektor DR. Pesawat DR GE Brivo DRF di eksposi untuk mengetahui karakter linearitas detektor, sensitifitas detektor, dan kualitas citra. Karakterisasi linearitas meninjau hubungan antara nilai piksel dan dosis, sedangkan sensitifitas meninjau hubungan antara dosis dan nilai eksposi (DEI). Karakter kualitas citra dievaluasi dengan parameter linearitas kontras (CL), konsistensi kontras (CV), dan MTF. Parameter CL, CV, dan MTF dievaluasi dengan variasi kVp, mAs, pada tiga simulasi anatomi. Hasil karakterisasi linearitas pada DR GE menunjukkan hubungan linier positif antara dosis dan nilai piksel, begitupun pada karakter sensitifitas. Nilai CL pada abdomen tidak dipengaruhi faktor eksposi sementara pada toraks dan kranial, nilai CL akan naik seiring kenaikan kVp dan lebih stabil pada mAs yang rendah.Karakter konsistensi kontras (CV) pada abdomen lebih stabil ketika nilai mAs rendah, sementara pada toraks dan kranial, nilai CV tidak dipengaruhi faktor eksposi. Karakter MTF 10% dan 50% pada abdomen, toraks, dan kranial menunjukkan hasil hampir identik pada tiap variasi namun lebih stabil pada keadaan mAs yang tinggi. Fantom in-house yang telah dibuat direkomendasikan untuk digunakan pada 70 kVp pada representasi anatomi abdomen, 120 kVp atau 115 kVp untuk mensimulasikan pemeriksaan thorax dan 65 kVp atau 80 kVp pada simulasi pemeriksaan cranial. ......The aim of this study is evaluating DR system character using in-house phantom to identify DR detector responses. DR GE Brivo DRF modality was exposed to discover detector linearity, detector sensitivity, and also image quality character. Linearity character was characterized by plotting the correlation between dose and DEI, while sensitivity was characterized by plotting the correlation between dose and pixel value. Character of image quality was determined by contrast linearity(CL), contrast consistency (CV), and MTF. These parameters were evaluated within exposing variaton such as kVp, mAs, and anatomy simulation. The detector sensitivity test results positive linearity correlation between dose and pixel value. Thiss is as same as result of detecteor lienarity test. Character of contrast linearity on abdomen simulations results no correlation within exposing factors (kVp and mAs), meanwhile CL value on thorax and cranial tend to increase as kVp increasing. Character of contrast consistency in thorax simulation has no correlation with exposing factors, meanwhile CV value in abdomen and cranial simulation seems more stable on low mAs. Characters MTF 10% and MTF 50% on three anatomies showed almost identic results for each condition, however MTF values were more stable when they are on high mAs. The constructed in-house phantom was recommended to be used at 70 kVp when representing the abdominal anatomy, 120 kVp or 115 kVp for thorax examination and 65 kVp or 80 kVp in cranial examination simulation.

Abstrak :
This completely updated second edition of Radiation exposure and image quality in x-ray diagnostic radiology provides the reader with detailed guidance on the optimization of radiological imaging. The basic physical principles of diagnostic radiology are first presented in detail, and their application to clinical problems is then carefully explored. The final section is a supplement containing tables of data and graphical depictions of X-ray spectra, interaction coefficients, characteristics of X-ray beams, and other aspects relevant to patient dose calculations. In addition, a complementary CD-ROM contains a user-friendly Excel file database covering these aspects that can be used in the reader’s own programs.