Geometric unsharpness yog hais txog qhov poob ntawm lub ntsiab lus uas yog tshwm sim los ntawm geometric yam ntawm cov khoom siv hluav taws xob thiab teeb tsa. Nws tshwm sim vim cov hluav taws xob tsis yog los ntawm ib qho chaw tab sis dhau ntawm ib cheeb tsam.
Dab tsi yog qhov laj thawj tseem ceeb ntawm geometric unsharpness?
Geometric unsharpness yog tshwm sim los ntawm yam ntawm lub geometry ntawm X-ray beamOb lub ntsiab tseem ceeb ua si ib txhij: qhov pom tseeb qhov chaw loj thiab qhov sib piv ntawm cov khoom-zaj duab xis nrug (OFD) thiab tsom-iav nrug (FFD). … Khaws qhov piv txwv FFD: OFD siab yuav txo qis geometric unsharpness.
Koj suav geometric unsharpness li cas?
Ug=F (t / d)
- Qhov ua kom yuam kev yog nco ntsoov ntsuas mus-thiab-los ntawm sab saum toj-sab ntawm tus qauv rau tus t/d. Yog tias qhov no yog ib daim tuab, qhov sib txawv tuaj yeem ua tau zoo los ntawm ntu nyias …… …
- Tsis txhob hnov qab siv tib qhov ntsuas UNITS rau txhua qhov kev suav. (inch lossis mm, thiab lwm yam)
- Maximum Geometric Unsharpness:
Dab tsi yog qhov geometric hauv radiography?
Geometric yam muaj xws li qhov loj ntawm thaj tsam ntawm lub hauv paus chiv keeb ntawm cov hluav taws xob, qhov chaw-rau-ntaus (zaj duab xis) nrug, qhov ntsuas-rau-ntaus (zaj duab xis) nrug, txav ntawm qhov chaw, cov qauv los yog lub tshuab ntes thaum raug, lub kaum sab xis ntawm qhov chaw thiab qee qhov tshwj xeeb thiab qhov hloov pauv sai ntawm cov qauv tuab lossis …
Isodose nkhaus yog dab tsi?
Ib qho isodose nkhaus (los yog contour) yog ib kab ntawm qhov nqus nqus tas mus liCov kab yog nyob rau hauv ib lub dav hlau thiab, rau ib kab hluav taws xob, nws cov nqi feem ntau cuam tshuam los ntawm tus nqi piv txwv yooj yim (e.g., 90 feem pua, 80 feem pua, thiab lwm yam) rau lub ncov absorbed koob tshuaj (los yog cov nto absorbed koob, rau x rays hauv qab no 400 kV) ntawm lub beam axis.
