| Project/Area Number |
01570587
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Radiation science
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| Research Institution | Kyoto University |
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Principal Investigator |
NAKANO Yoshihisa Kyoto University, Radiology. Licurer, 医学部, 構師 (70115898)
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| Co-Investigator(Kenkyū-buntansha) |
MINATO Kotarou Kyoto University, Medical Intornatics Associate Professor, 医学部, 助教授 (00127143)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1990: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1989: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Radiographs / Pata compression / CRT / CRT診断 |
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| Research Abstract |
We investigated a clinically safe compression ratio of radiographs. Fifty-four 2048 square digitized radiographs were compressed with non-uniform block coding method and displayed in a 1000-line CRT or in a laser printer films. Ninety two pairs of compressed and original images trimmed into 1024 square ROIs were observed by 3 radiologists on the displaying windows optimum for each pair of images. The differnces between compressed and original images were evaluated with the following results : (1) Using the ratio of 12, some differences were recognized on both anatomic and pathologic structures in 60% on CRTs and 79% on films. (2) With the ratio of 8, some differences were recognized on anatomic structures in 7% and 10% respectively. (3) With the ratio of 5, no differences were found on anatomical structures. We concluded that the data compression ratio 5 is the absolutely safe and the ratio 8 is a relatively safe in clinical diagnosis.
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