Yuav ua li cas koj xam cov dav hlau hauv pixel nyeem?
Yuav ua li cas koj xam cov dav hlau hauv pixel nyeem?

Video: Yuav ua li cas koj xam cov dav hlau hauv pixel nyeem?

Video: Yuav ua li cas koj xam cov dav hlau hauv pixel nyeem?
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Txhawm rau txiav txim siab ib pixel qhov loj hauv nyeem los yog kev taw qhia zaus, siv qhov no qauv : FOVf/Nf Lub teb ntawm saib nyob rau hauv lub zaus encoding kev taw qhia muab faib los ntawm tus naj npawb ntawm cov kauj ruam nyob rau hauv lub zaus encoding kev taw qhia sib npaug ib pixel qhov loj me nyob rau hauv qhov kev taw qhia zaus.

Hauv qhov no, koj ua li cas xam pixel loj hauv MRI?

Pixel loj tuaj yeem xam los ntawm kev faib qhov chaw saib los ntawm matrix qhov loj (e.g. FOV 320, Matrix 320x320, Pixel loj = 320/320 = 1 mm. Muaj ob qhov kev daws teeb meem siv hauv MRI rau zus tau tej cov duab ob seem i.e. yooj yim daws teeb meem thiab theem daws teeb meem.

Kuj Paub, dav hlau daws teeb meem yog dab tsi? Nws muaj qhov ntev muab nrog ob axes hauv mm, dictating in- dav hlau qhov chaw daws teeb meem . Pixel qhov ntau thiab tsawg nyob rau hauv kev kho mob MRI ntawm mm (piv txwv li, 1 3 1 mm2) rau sub-mm. Lub voxel yog lub ntim ntim, txhais hauv 3D qhov chaw. Lub pixel loj (FOV / matrix) txiav txim siab hauv- dav hlau daws teeb meem.

Tsis tas li ntawd, koj pom thaj tsam pixel li cas?

Rau txiav txim tus thaj tsam pixel (siv qhov no rau 2D sequences), siv qhov no qauv : cov ib pixel qhov loj me nyob rau hauv qhov kev nyeem los yog zaus kev taw qhia lub sij hawm ib pixel qhov loj me nyob rau theem kev taw qhia sib npaug ntawm thaj tsam pixel.

Qhov kev daws teeb meem ntawm MRI yog dab tsi?

Rau qhov zoo sib xws SNR tus nqi, scanners nrog tus nqi siab ntawm B0 thiab ntau tus coil receiver channel yuav tsim cov duab nrog ntau dua spatial daws teeb meem thiab sib piv (6). Niaj hnub no, feem ntau MRI scanners siv rau kev kho mob muaj B0 qhov tseem ceeb ntawm 1.5 lossis 3 T thiab tuaj yeem ncav cuag ib txwm kev daws teeb meem 1.5 × 1.5 × 4mm3.

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