A SIMPLE METHOD FOR CALIBRATING PIXEL VALUES OF THE CT LOCALIZER RADIOGRAPH FOR CALCULATING WATER-EQUIVALENT DIAMETER AND SIZE-SPECIFIC DOSE ESTIMATE
| Autor: | Geoff Dougherty, Takatoshi Toyoda, Idam Arif, Choirul Anam, Naoki Sato, Rena Widita, Toshioh Fujibuchi, Freddy Haryanto |
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| Rok vydání: | 2017 |
| Předmět: |
Adult
Male AP projection Radiography Radiation Dosage Water equivalent Imaging phantom 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Calibration Humans Radiology Nuclear Medicine and imaging Projection (set theory) Retrospective Studies Physics Radiation Radiological and Ultrasound Technology Pixel Phantoms Imaging business.industry Public Health Environmental and Occupational Health Water General Medicine 030220 oncology & carcinogenesis Female Tomography Tomography X-Ray Computed Nuclear medicine business |
| Zdroj: | Radiation Protection Dosimetry. 179:158-168 |
| ISSN: | 1742-3406 0144-8420 |
| DOI: | 10.1093/rpd/ncx241 |
| Popis: | The purpose of this study is to establish the relationship between the pixel value (I) of the CT localizer radiograph and water-equivalent thickness (tw) in a straightforward procedure. We used a body CTDI phantom, which was scanned in the AP and LAT projections. After transformation from the pixel values of the images to tw, water-equivalent diameter (Dw) and size-specific dose estimate were calculated on an anthropomorphic phantom and 30 patients retrospectively. We found a linear correlation between I and tw, with R2 ≥ 0.980. The Dw values based on the CT localizer radiograph were comparable to those calculated using axial images. The Dw difference for the anthropomorphic phantom between AP projection and axial images was 5.4 ± 4.2%, and between LAT projection and axial images was 6.7 ± 5.3%. The Dw differences for the patients between CT localizer radiograph and axial images was 2.3 ± 3.2%. |
| Databáze: | OpenAIRE |
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