Tav tus vaj huam sib luag Detectors ua lub luag haujlwm tseem ceeb hauv Digital RadioBraphy (raws li lawv cov duab zoo ncaj qha cuam tshuam qhov tseeb thiab ua haujlwm ntawm kev kuaj mob. Qhov zoo ntawm cov vaj huam sib luag tiaj tiaj nta yog feem ntau ntsuas los ntawm kev hloov pauv kev ua haujlwm (MTF) thiab Quantum hloov nyiaj ua haujlwm (DQE). Cov hauv qab no yog cov ncauj lus kom ntxaws ntxaws ntawm ob qhov ntsuas thiab qhov cuam tshuam uas cuam tshuam DQE:
1, Kev Hloov Hloov Hloov (MTF)
Kev hloov pauv kev hloov pauv (MTF) yog lub peev xwm ntawm cov txheej txheem kom luam cov spatial zaus ntau ntawm cov khoom xav tau. Nws muaj kev cuam tshuam cov kev xav lub zog muaj peev xwm paub qhov txawv cov duab. Cov kev xav zoo tshaj plaws yuav tsum tau 100% luam ntawm cov ntsiab lus ntawm lub zog, vim yog ntau yam kev xav paub lub peev xwm ntawm cov ntsiab lus ntawm cov khoom uas xav tau. Rau cov xaim hluav taws xob xoo hluav taws xob, txhawm rau ntsuas lawv xam cov kev ntsuas zoo, nws yog qhov tsim nyog yuav tsum xam cov qauv ua ntej uas tsis muaj kev cuam tshuam thiab muaj kev cuam tshuam rau lub system.
2, Quantum hloov nyiaj ua haujlwm (Dqe)
Quantx hloov nyiaj ua tau zoo (Dqe) yog ib qho qhia ntawm cov txheej txheem kev sib tw ntawm cov duab qhia thiab suab nrov los ntawm cov lus tawm tswv yim rau cov zis tawm, qhia raws li feem pua. Nws qhia txog qhov rhiab, suab nrov, xoo hluav taws xob, thiab ceev daws teeb meem ntawm cov vaj huam sib luag tiaj tiaj. Qhov siab dua DQE tus nqi, lub zog ua kom muaj zog dua lub peev xwm kom paub qhov txawv ntawm cov ntaub so ntswg ceev.
Yam cuam tshuam rau DQE
Txheej ntawm cov khoom siv scintillation: hauv Amorphous silicon tiaj tus vaj huam sib luag detectors, cov txheej txheej ntawm cov khoom tseem ceeb cuam tshuam rau DQE. Muaj ob hom scintillator txheej khoom: Cesium iodide (CSI) thiab gadolinium oxysulfide (GD ₂ a s). Cesium iodide muaj lub peev xwm muaj zog dua los hloov cov X-rays rau pom lub teeb tshaj gadolinium oxysulfide, tab sis ntawm tus nqi siab dua. Ua Cesium iodide rau hauv ib tus qauv cej paus tuaj yeem txhim kho cov peev xwm ntes tau x-rays thiab txo lub teeb tawg. The detector coated with gadolinium oxysulfide has a fast imaging rate, stable performance, and lower cost, but its conversion efficiency is not as high as that of cesium iodide coating.
TISTORS: Txoj hauv kev pom lub teeb tsim los ntawm scinterillators tau hloov pauv hluav taws xob tuaj yeem hloov kho hluav taws xob kuj tseem tuaj yeem cuam tshuam DQE. Nyob rau hauv tiaj tus vaj huam sib luag detectors nrog cov qauv ntawm Cesium iodide (lossis gadolinium oating yam tsis tau npaj tseg, uas pom tau lub teeb liab, uas pom tau tias tsis muaj lub teeb liab, uas pom tau tias tsis muaj lub teeb liab, nrog tsis muaj lub photon poob rau hauv nruab nrab, uas tsis muaj lub photon ploj hauv nruab nrab, uas tsis muaj tseeb dqe. Nyob rau hauv amorphous selenium tiaj tus vaj huam sib luag cov txheej txheem ntawm cov khoom siv hluav taws xob yog nyob ntawm qhov muaj peev xwm ntawm lub peev xwm ntawm cov amorphou selenium txheej los tsim cov nqi.
Ib qho ntxiv, rau tib hom vaj huam sib luag tiaj tus ntes, nws cov dqe tau sib txawv ntawm ntau qhov kev daws teeb meem sib txawv. Tus DQE heev yog siab, tab sis nws tsis txhais tau tias DQE yog qhov siab ntawm qhov kev daws teeb meem. Qhov kev xam cov lus rau DQE yog: DQE = s ² × × × / (NPS
3, kev sib piv ntawm Amorphous Silicon thiab Amorphous Selenium tiaj tus Vaj Huam Sib Luag Detectors
Kev ntsuas kev ntsuas tau ntawm cov koom haum thoob ntiaj teb tau qhia tias Amorphous sielonal detectors muaj MTF zoo heev. Raws li cov kev sib cav sib ceg ua rau muaj kev cuam tshuam ntau dua, lub pob zeb ntawm Amorphous silicon ncaj qha txo peev xwm txo tau tseem yuav tseem tuav tau zoo MTF tseem ceeb. Qhov no yog ze rau cov kev xav txog kev ua lub ntsiab cai ntawm amorphous selenium tiaj tus vaj huam sib luag tsis pom Xoo cov cim hluav taws xob. Amorphous Selenium tiaj tus Vaj Huam Sib Luag tsis tsim cov teeb pom kev lossis tawg pom kev pom kev zoo nkauj, yog li ntawd lawv tuaj yeem ua tiav cov kev daws teeb meem ntau dua thiab cov duab zoo dua.
Hauv cov ntsiab lus, cov duab zoo ntawm lub tiaj tus vaj huam sib luag ntes ntes tau cuam tshuam los ntawm ntau yam MTF thiab DQE yog ob qho kev ntsuas ntsuas qhov tseem ceeb. Nkag siab thiab paub cov ntsuas no cov ntsuas no cuam tshuam nrog DQE tuaj yeem pab peb xaiv cov kev pom zoo zoo thiab kuaj mob.
Lub Sijhawm Post: Dec-17-2024