Pitch hauv CT yog dab tsi?
Pitch hauv CT yog dab tsi?

Video: Pitch hauv CT yog dab tsi?

Video: Pitch hauv CT yog dab tsi?
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(p) Cov suab (hauv xam tomography) yog qhov piv ntawm tus neeg mob lub rooj nce mus rau tag nrho nominal beam dav rau CT scan. Cov suab qhov xwm txheej hais txog qhov ntim ceev ceev mus rau cov ntu thinnest uas tuaj yeem tsim kho dua tshiab. Suab = lub rooj txav ntawm ib qho kev sib hloov / ntu sib tsoo.

Raws li, helical suab yog dab tsi?

Helical suab yog ib qho kev ntsuas ntawm qhov kev ncua deb (kwv yees rau lub helical axis) cais ob lub ntsiab lus ntawm a helix tom qab ua tiav "tig" (nruab 2pi radians) [1]. Cov suab ntawm 3.6- helix (ib alpha helix nrog 3.6 residues ib "tig") yog kwv yees li 5.4 angstroms [2].

Ib sab saum toj, dab tsi yog daim thickness hauv CT? Txiav thickness thiab hlais increment yog lub hauv paus ntsiab lus uas nyob ib puag ncig CT /MRI cov duab. Txiav thickness hais txog (feem ntau axial) daws teeb meem ntawm scan (2 hli hauv cov duab). Txiav Kev nce ntxiv yog hais txog kev txav ntawm lub rooj / tshuab luam ntawv rau kev tshuaj xyuas tom ntej hlais (siv los ntawm 1 mm mus rau 4 mm nyob rau hauv cov duab).

Tom qab ntawd, ib tug kuj yuav nug, yuav ua li cas yog pitch xam nyob rau hauv CT?

Ib daim CT (SSCT) Lub sij hawm ntes suab yog siv thiab txhais raws li lub rooj nyob deb tau mus nyob rau hauv ib tug 360 ° gantry rotation muab faib los ntawm beam collimation 2. Piv txwv li, yog hais tias lub rooj mus 5 mm nyob rau hauv ib tug kev sib hloov thiab lub beam collimation yog 5 mm ces. suab 5 hli / 5 hli = 1.0.

Dab tsi yog Sinogram hauv CT?

A sinogram yog ib txoj kev x-ray tshwj xeeb uas yog ua kom pom qhov txawv txav ntawm qhov qhib (sinus) hauv lub cev, tom qab txhaj tshuaj ntawm qhov sib piv media (x-ray dye) rau hauv qhov qhib. Tsis muaj kev txwv kev noj zaub mov ua ntej a sinogram.

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