„π‡§√◊ËÕ߇հ´‡√¬å§Õ¡æ‘«‡μÕ√å Automatic Tube Current Modulation for Computed Tomography

∫∑§«“¡ª√‘∑—»πå

√–∫∫°“√§«∫§ÿ¡ª√‘¡“≥°√–· À≈Õ¥Õ—μ‚π¡—μ‘

„π‡§√◊ËÕ߇հ´‡√¬å§Õ¡æ‘«‡μÕ√å Automatic Tube Current Modulation for Computed Tomography

 ÿ«‘™“ ‡™â“«ß»åæ“≥‘™¬å «∑.∫. (√—ß ’‡∑§π‘§)

»ÿ¿«√√≥ ®‘«–æß»å «∑.¡. (©“¬“‡«™»“ μ√å)

®“√ÿ«√√≥ ‡«’¬π¢π“π «∑.∫. (√—ß ’‡∑§π‘§)

‡√◊ËÕ߬àÕ

§«“¡μ√–Àπ—°„π‡√◊ËÕߧ«“¡ª≈Õ¥¿—¬∑“ß√—ß ’„π°“√μ√«®‡Õ°´‡√¬å§Õ¡æ‘«‡μÕ√å ´÷Ëß¡’ª√‘¡“≥√—ß ’ Ÿß∑”„Àâ

‡°‘¥°“√æ—≤π“√–∫∫°“√§«∫§ÿ¡ª√‘¡“≥°√–· À≈Õ¥‡Õ°´‡√¬å·∫∫Õ—μ‚π¡—μ‘„π‡§√◊ËÕ߇հ´‡√¬å§Õ¡æ‘«‡μÕ√å ‡æ◊ËÕ

°”°—∫°“√§«∫§ÿ¡ª√‘¡“≥√—ß ’∑’ˇÀ¡“– ¡°—∫¢π“¥√à“ß°“¬·≈–Õ«—¬«–„π°“√ ·°π ‚¥¬∑’Ë¿“æ√—ß ’∑’ˉ¥â¬—ß¡’§ÿ≥¿“æ

‡æ’¬ßæÕ ”À√—∫°“√·ª≈º≈ ∑—Èßπ’È¡’À≈—°°“√ ªí®®—¬·≈–·π«∑“ß∑’˧«√®–»÷°…“‡æ‘Ë¡‡μ‘¡‡æ◊ËÕ°“√„™âß“πÕ¬à“ß¡’ª√– ‘∑∏‘¿“æ Õ—π®–‡ªìπ¡“μ√∞“π„π°“√„Àâ∫√‘°“√∑“ß√—ß ’„π√–¥—∫ “°≈

§” ”§—≠: ‡Õ°´‡√¬å§Õ¡æ‘«‡μÕ√å, §«“¡ª≈Õ¥¿—¬∑“ß√—ß ’, √–∫∫§«∫§ÿ¡°√–· À≈Õ¥

Abstract

The concerning in radiation safety in CT scan with high dose lead to development of automatic tube current modulation. This system aim to control the radiation exposure optimize to the body size and organ to scan with the interpretationable image. However the principle, parameter and the using guideline is adding to learn for the effective use in the standard of radiology service.

Keywords: CT scan, radiation safety, automatic tube current modulation.

¿“§«‘™“√—ß ’«‘∑¬“ §≥–·æ∑¬»“ μ√廑√‘√“™æ¬“∫“≈

¡À“«‘∑¬“≈—¬¡À‘¥≈

∫∑π”

§«“¡°â“«Àπâ“∑“߇∑§‚π‚≈¬’¢Õ߇§√◊ËÕ߇հ´‡√¬å

§Õ¡æ‘«‡μÕ√å¡’°“√°â“«°√–‚¥¥μ—Èß·μàªï 1990 ∑”„Àâ¡’

°“√„Àâ∫√‘°“√¡“°„π∑—Ë«‚≈° ®π∑”„À⇰‘¥°“√°—ß«≈„®„π

¥â“πª√‘¡“≥√—ß ’∑’Ë„Àâ„πºŸâªÉ«¬ ‚¥¬¡’À≈—°§‘¥§◊Õ‡æ◊ËÕ°“√

«‘π‘®©—¬ºŸâªÉ«¬ “¡“√∂‰¥â√—∫ª√‘¡“≥√—ß ’¡“°°«à“§π

∑—Ë«‰ª‚¥¬‰¡à¡’¢âÕ∫àßÀâ“¡ °√–π—Èπ°Á¡’°“√æ—≤π“·π«∑“ß

¥â“π°“√≈¥ª√‘¡“≥√—ß ’∑’Ë„™â„π°“√μ√«®·μà°Á®–μâÕ߉¥â

¿ “ æ ∑ “ ß √— ß  ’ ∑’Ë ¡’ §ÿ ≥ ¿ “ æ ‡ æ’ ¬ ß æ Õ μà Õ ° “ √ «‘ π‘ ® ©— ¬

‡∑§‚π‚≈¬’Õ¬à“ß„À¡à∑’ˉ¥â√—∫§«“¡π‘¬¡„π°“√≈¥ª√‘¡“≥

√—ß ’„π‡§√◊ËÕ߇հ´‡√¬å§Õ¡æ‘«‡μÕ√剥ⷰà√–∫∫°“√

§«∫§ÿ¡ª√‘¡“≥°√–· À≈Õ¥‡Õ°´‡√¬åÕ—μ‚π¡—μ‘ ´÷Ëß μâÕß°“√°“√‡√’¬π√Ÿâ‡™‘ßÀ≈—°°“√·≈–‡Àμÿº≈„π°“√„™âß“π

∑’Ë¡“°¢÷Èπ ‚¥¬¡’¢Õ∫‡¢μ∑’Ë ”§—≠‰¥â·°à

1. √–∫∫°“√§«∫§ÿ¡ª√‘¡“≥°√–· À≈Õ¥

Õ—μ‚π¡—μ‘ (Automatic Tube Current Modulation;

ATCM)

°“√≈¥ª√‘¡“≥√—ß ’„π‡§√◊ËÕß CT  “¡“√∂∑”‰¥âÀ≈“¬

«‘∏’ °“√„™â√–∫∫ ATCM π—Èπ‡ª√’¬∫‡ ¡◊Õπ‡§√◊ËÕß¡◊Õ∑’Ë

™à«¬„π°“√ª√—∫ª√‘¡“≥√—ß ’∑’˺ŸâªÉ«¬®–‰¥â√—∫„ÀâÕ¬Ÿà„π ª√‘¡“≥∑’ˇÀ¡“– ¡‰¡à„Àâ¡“°‡°‘𧫓¡æÕ¥’ ·≈–‰¡à πâÕ¬®π∑”„Àâ¿“æ∑’ˉ¥â¡’§ÿ≥¿“æ∑’ËμË”®π¡’ªí≠À“„π°“√

·ª≈º≈ ´÷Ëß√–∫∫®–∑”°“√ª√—∫§à“°√–· „ÀâπâÕ¬≈ß„π

∫√‘‡«≥∑’Ë¡’§«“¡ “¡“√∂„π°“√≈¥∑Õπ√—ß ’∑’ËμË” ·≈–

‡æ‘Ë¡¡“°¢÷Èπ„π∫√‘‡«≥∑’Ë¡’§«“¡ “¡“√∂„π°“√≈¥∑Õπ∑’Ë Ÿß

‡™àπ „π∑√«ßÕ°√–∫∫®–„Àâ§à“ª√‘¡“≥°√–· ∑’ËπâÕ¬°«à“

∫√‘‡«≥™àÕß∑âÕß ‡ªìπμâπ √–∫∫ ATCM ®–∑”°“√

§” π « ≥ §à “ ª √‘ ¡ “ ≥ ° √ – ·   ‡ æ◊Ë Õ ™à « ¬ „ Àâ ¿ “ æ ∑’Ë ‰ ¥â ¡’

§ÿ≥¿“æ‡À¡“– ¡‡æ’¬ßæÕμàÕ°“√«‘π‘®©—¬ ∑”„Àâ√–¥—∫

 —≠≠“≥√∫°«π (noise) ¢Õß¿“æ¡’§«“¡§ß∑’Ë ´÷Ëß√–∫∫

ATCM ¢Õ߇§√◊ËÕ߇հ´‡√¬å§Õ¡æ‘«‡μÕ√åπ—Èπ®–¡’™◊ËÕ‡√’¬°

·≈–§à“∑’Ë„™â°”Àπ¥§ÿ≥¿“æμà“ß°—πμ“¡∫√‘…—∑ºŸâº≈‘μ

°“√„™âß“π°Á®–μà“ß°—πμ“¡ºŸâº≈‘μ

√–∫∫ ATCM Õ“»—¬‡∑§π‘§æ◊Èπ∞“π„π°“√ª√—∫

ª√‘¡“≥°√–· À≈Õ¥ÕÕ°‡ªìπ 2 ·∫∫À≈—°Ê§◊Õ °“√

ª√—∫§à“°√–· À≈Õ¥μ“¡°“√À¡ÿπ¢ÕßÀ≈Õ¥‡Õ°´‡√¬å

√Õ∫ºŸâªÉ«¬ (Angular Modulation) ·≈–°“√ª√—∫§à“°√–· 

À≈Õ¥μ“¡·π«¬“«¢Õß≈”μ—« (Z-Axis Modulation)

∫√‘…—∑ºŸâº≈‘μ®–‡≈◊Õ°„™â‡∑§π‘§∑’Ë·μ°μà“ß°—π∑—È߬—ß  “¡“√∂‡Õ“ Õ߇∑§π‘§¡“„™âß“π√à«¡°—π‰¥â‡æ◊ËÕ‡æ‘Ë¡

§«“¡ “¡“√∂„π°“√≈¥ª√‘¡“≥√—ß ’∑’Ë„ÀⷰຟâªÉ«¬

2. °“√ª√—∫§à“°√–· À≈Õ¥μ“¡°“√À¡ÿπ¢Õß À≈Õ¥‡Õ°´‡√¬å√Õ∫ºŸâªÉ«¬ (Angular Modulation)

‡∑§π‘§ Angular Modulation Õ“»—¬À≈—°°“√∑’ËÀ≈Õ¥

‡Õ°´‡√¬åÀ¡ÿπ√Õ∫μ—«ºŸâªÉ«¬®–∑”„Àâ§à“°“√≈¥∑Õπ√—ß ’

¢ÕߺŸâªÉ«¬„π·μà≈–¡ÿ¡μ“¡·π«·°π xy ‰¡à‡∑à“°—π ´÷Ëß

¥â“π∑’Ë¡’§«“¡Àπ“πâÕ¬°“√≈¥∑Õπ√—ß ’®–πâÕ¬°«à“¥â“π

∑’Ë¡’§«“¡Àπ“¡“°°«à“ ®÷ß„™âª√‘¡“≥√—ß ’∑’ËπâÕ¬°«à“¥â“π

μ“√“ß∑’Ë 1 · ¥ßμ—«Õ¬à“ß√–∫∫ ATCM ¢Õ߇§√◊ËÕ߇հ´‡√¬å§Õ¡æ‘«‡μÕ√宓°∫√‘…—∑ºŸâº≈‘μμà“ßÊ

Angular Z-Axis

∫√‘…—∑ºŸâº≈‘μ ™◊ËÕ¢Õß√–∫∫ §à“∑’Ë„™â°”Àπ¥§ÿ≥¿“æ

modulation modulation

GE Smart mA Noise index (NI) Yes Yes

Auto mA No Yes

Siemens CARE Dose 4D Quality reference mAs (QRM) Yes Yes

Toshiba Sure exposure 3D Standard deviation (S.D.) Yes Yes

Philips Dose right Maximum mAs/slice Yes Yes

∑’Ë¡’§«“¡Àπ“¡“°°«à“ °≈à“«§◊Õ¢≥–∑’ËÀ≈Õ¥‡Õ°´‡√¬å

‡§≈◊ËÕπ∑’Ë√Õ∫μ—«ºŸâªÉ«¬„π·π«·°π xy π—Èπ®–∑”°“√ª√—∫

§à“ª√‘¡“≥°√–· μ“¡§«“¡Àπ“¢ÕߺŸâªÉ«¬„π¡ÿ¡μà“ßÊ

‡™à𠧫“¡ “¡“√∂„π°“√≈¥∑Õπ√—ß ’∑“ߥâ“πÀπâ“„π·π«

Anteroposterior; AP πâÕ¬°«à“§«“¡ “¡“√∂„π°“√≈¥

∑Õπ√—ß ’¥â“π¢â“ß„π·π« Lateral; Lat √–∫∫®–∑”°“√

§”π«≥·≈–°”Àπ¥ª√‘¡“≥°√–· À≈Õ¥∑’Ë®–„Àâ„π¥â“π Lat ¡“°°«à“∑“ߥâ“π AP ‡ªìπμâπ

‡∑§π‘§ Angular Modulation ∂Ÿ°π”¡“„™â„π‡§√◊ËÕß GE single-detector helical CT §√—Èß·√°ª√–¡“≥ªï §.». 1994

‚¥¬æ◊Èπ∞“π¢Õß´Õøμå·«√å„π ¡—¬π—Èπ®–∑”°“√· «ßÀ“

¢âÕ¡Ÿ≈°“√≈¥∑Õπ√—ß ’®“°¿“æ∂à“¬∑“ß√—ß ’∑’Ë„™â ”À√—∫

°“√«“ß·ºπ„π à«π∑’Ë π„® ´÷Ëß√–∫∫®–∑”°“√§”π«≥

ª√‘¡“≥°√–· À≈Õ¥®“°¿“æ∂à“¬∑“ß√—ß ’‡æ◊ËÕ°“√

«“ß·ºπ∑—Èß®“°„π·π« AP ·≈– Lat ‡æ◊ËÕ„À≥⿓æ

‡Õ°´‡√¬å§Õ¡æ‘«‡μÕ√å∑’Ë¡’§à“ —≠≠“≥√∫°«π (Noise index)

§ß∑’Ëμ≈Õ¥∑—Èß¿“æ „π¢≥–∑’褈һ√‘¡“≥°√–· ®–∂Ÿ°

ª√—∫‡ª≈’ˬπ‰ªμ“¡§«“¡ “¡“√∂„π°“√¥Ÿ¥°≈◊π√—ß ’ μ“¡¡ÿ¡„π·π«·°π xy ¬°μ—«Õ¬à“߇™àπ  à«π∫√‘‡«≥À—«

‰À≈à„π·π« Lat ®–¡’§«“¡ “¡“√∂„π°“√¥Ÿ¥°≈◊π√—ß ’

¡“°°«à“·π« AP ¥—ßπ—Èπ§à“ª√‘¡“≥°√–· ∑’Ë√–∫∫®–

∑”°“√°“√‡≈◊Õ°„™â®“°∑“ߥâ“π Lat ®–¡“°°«à“∑“ߥâ“π AP ‡æ◊ËÕ„À≥⿓æ∑’Ë¡’§à“ —≠≠“≥√∫°«π§ß∑’Ëμ≈Õ¥∑—Èß

¿“æ ‡ªìπμâπ

¡’‡∑§π‘§ Angular Modulation Õ’°‡∑§π‘§∑’Ë∂Ÿ°„™â

´÷Ëß®–∑”°“√ª√—∫§à“°√–· À≈Õ¥„π≈—°…≥– real time

‡√’¬°«à“ Online angular modulation À≈Õ¥‡Õ°´‡√¬å®–

∑”°“√À¡ÿπ 180 Õß»“·√°‡æ◊ËÕ· «ßÀ“¢âÕ¡Ÿ≈°“√≈¥

∑Õπ√—ß ’®“°π—Èπ§”π«≥À“§à“ª√‘¡“≥°√–· ∑’ËμâÕß„™â

„π ·°π∂—¥¡“μ“¡·π«·°π xy ‚¥¬‰¡àμâÕß„™â¢âÕ¡Ÿ≈¢Õß

¿“æ∂à“¬∑“ß√—ß ’∑’Ë„™â„π°“√«“ß·ºπ ´÷Ëß®–μà“ß®“°√–∫∫

Angular Modulation ∑’Ë®”‡ªìπμâÕß„™â¢âÕ¡Ÿ≈®“°¿“æ∂à“¬

∑“ß√—ß ’∑’Ë„™â„π°“√«“ß·ºπ‡æ◊ËÕ§”π«≥À“§à“°√–· 

À≈Õ¥∑’Ë„Àâ„π·μà≈–¡ÿ¡

3. °“√ª√—∫§à“°√–· À≈Õ¥μ“¡·π«¬“«¢Õß

≈”μ—« (Z-Axis Modulation)

‡∑§π‘§ Z-Axis modulation §◊Õ‡∑§π‘§∑’Ë„™â§«∫§ÿ¡

°√–· À≈Õ¥μ“¡§«“¡ “¡“√∂„π°“√≈¥∑Õπ√—ß ’μ“¡

·π«¬“«¢ÕߺŸâªÉ«¬ (Z-Axis) ‡™à𠧫“¡ “¡“√∂„π°“√

≈¥∑Õπ√—ß ’¢ÕߺŸâªÉ«¬∫√‘‡«≥∑√«ßÕ°‡∑’¬∫°—∫§«“¡

 “¡“√∂„π°“√≈¥∑Õπ√—ß ’¢ÕߺŸâªÉ«¬∫√‘‡«≥Õÿâ߇™‘ß°√“π

∑”„Àâ§à“°√–· À≈Õ¥∑’Ë„™â„π∫√‘‡«≥∑√«ßÕ°®–∂Ÿ°ª√—∫

„ÀâπâÕ¬°«à“∫√‘‡«≥Õÿâ߇™‘ß°√“𠇪ìπμâπ √–∫∫®–Õ“»—¬

¢âÕ¡Ÿ≈®“°¿“æ∂à“¬∑“ß√—ß ’∑’Ë„™â„π°“√«“ß·ºπ‡æ◊ËÕ

§”π«≥°“√ª√—∫§à“°√–· À≈Õ¥„À≥⿓æ∑’Ë¡’§ÿ≥¿“æ

√Ÿª∑’Ë 2 · ¥ß§à“°√–· À≈Õ¥∑’Ë¡ÿ¡μà“ßÊ ¥â«¬‡∑§π‘§ Online Angular Modulation

√Ÿª∑’Ë 1 · ¥ß§à“°√–· À≈Õ¥∑’Ë¡ÿ¡μà“ßÊ ¥â«¬‡∑§π‘§ Angu- lar Modulation  à«π∑’ËÀπ“∑’Ë ÿ¥§◊Õ¥â“π¢â“ß (Lateral) ª√‘¡“≥√—ß ’∑’ËÕÕ°¡“®– Ÿß°«à“¥â“πÕ◊Ëπ

¢âÕ¡Ÿ≈®“°¿“æ∂à“¬∑“ß√—ß ’„™â„π°“√«“ß·ºπ‡æ◊ËÕ§”π«≥À“§à“

°√–· À≈Õ¥∑’Ë„Àâ„π·μà≈–¡ÿ¡

¿“¬„μâ§à“∑’Ë„™â°”Àπ¥§ÿ≥¿“æ¢Õß¿“æ 4. °“√π”√–∫∫ ATCM ‰ª„™âß“π

∫√‘…—∑ºŸâº≈‘μπ—Èπ®–¡’Àπâ“μà“ß°“√„™âß“π√–∫∫ ATCM

∑’Ë·μ°μà“ß°—π‰ª μ—«Õ¬à“߇™àπ‡§√◊ËÕ߇հ´‡√¬å§Õ¡æ‘«‡μÕ√å GE √ÿàπ Discovery(tm) CT750 HD √–∫∫®–„À⺟ℙâß“π

°”Àπ¥™à«ß¢Õߪ√‘¡“≥°√–· À≈Õ¥∑’Ë„™âß“π·≈–§à“

¥—™π’¢Õß —≠≠“≥√∫°«π (Noise index : NI) À“°

μâÕß°“√¿“æ∑’Ë¡’§ÿ≥¿“æ¡“°„π°“√μ√«®®–μâÕßμ—Èߧà“

¢Õß°√–· À≈Õ¥„Àâ‡æ’¬ßæÕ ·≈–μ—Èß§à“ NI „ÀâπâÕ¬´÷Ëß

¿“æ∑’ˉ¥â®–¡’§ÿ≥¿“æ¡“° ‡æ√“–¡’ —≠≠“≥√∫°«ππâÕ¬

·μàª√‘¡“≥√—ß ’Õ“® Ÿß‡°‘𧫓¡®”‡ªìπ §à“∑’ˇÀ¡“– ¡

∑’Ë ÿ¥π—Èπ ºŸâ„™âμâÕߧ”π÷ß∂÷ߪ√‘¡“≥√—ß ’∑’˺ŸâªÉ«¬‰¥â√—∫‡ªìπ

√Ÿª∑’Ë 4 · ¥ßÀπâ“μà“ß√–∫∫ ATCM „π‡§√◊ËÕ߇հ´‡√¬å§Õ¡æ‘«‡μÕ√å GE √ÿàπ Discovery(tm) CT750 HD

¿“æ∫π · ¥ßÀπâ“μà“ß°“√‡≈◊Õ°™à«ß°√–· À≈Õ¥·≈–§à“ NI

¿“æ≈à“ß · ¥ßÀπâ“μà“ß°“√®”≈Õß§à“°√–· À≈Õ¥∑’Ë„™â

√Ÿª∑’Ë 3 · ¥ßª√‘¡“≥°√–· À≈Õ¥¥â«¬‡∑§π‘§ Z-Axis modu- lation

 ”§—≠ §à“ª√‘¡“≥√—ß ’®–‡æ‘Ë¡À√◊Õ≈¥¢÷ÈπÕ¬Ÿà°—∫°“√μ—Èߧà“

¢ÕߺŸâ„™âß“π ·≈–‰¡à§«√μ—Èߧà“∑’ËμË”‡°‘π‰ª®π√—ß ’·æ∑¬å

‰¡à “¡“√∂·ª≈º≈‰¥â

®“°√Ÿª∑’Ë 4  “¡“√∂°”Àπ¥§à“μË” ÿ¥·≈– Ÿß ÿ¥

¢Õß°√–· À≈Õ¥‰¥â √–∫∫®–∑”°“√®”≈Õß°√–· 

À≈Õ¥∑’Ë„™â·≈–· ¥ß„πÀπâ“μà“ߢÕß mA Table ´÷Ëß  “¡“√∂¥Ÿ°“√®”≈Õß§à“ª√‘¡“≥°√–· ∑’Ë„™â·≈–Õ“®®–

∑”°“√ª√—∫μ—Èßæ“√“¡‘‡μÕ√åμà“ßʇæ◊ËÕ„À≥⿓æ∑’Ë¡’§ÿ≥

¿“æμ“¡∑’ËμâÕß°“√ ®–‡ÀÁπ‰¥â«à“°“√μ—Èß§à“°√–·  Ÿß ÿ¥

‡ ªì π ° “ √ °” À π ¥ §à “  Ÿ ß  ÿ ¥ ∑’Ë √ – ∫ ∫   “ ¡ “ √ ∂ ‡ ≈◊ Õ ° „ ™â ª√‘¡“≥°√–·  ¥—ßπ—ÈπÀ“°∑”°“√μ—Èß§à“°√–·  Ÿß ÿ¥‰¡à

‡æ’¬ßæÕ®–∑”„Àâ√–∫∫‰¡à “¡“√∂‡≈◊Õ°„™âª√‘¡“≥

°√–· ∑’ˇ撬ßæÕμàÕ°“√ √â“ß¿“æ∑’Ë¥’·≈–∑”„Àâ§ÿ≥¿“æ

¢Õß¿“æ∑’ˉ¥â¡’ —≠≠“≥√∫°«π¡“° μ—«Õ¬à“߇™àπ °“√

μ—Èß§à“¢Õß°√–· À≈Õ¥∑’Ë„™â„πºŸâªÉ«¬∑’Ë¡’¢π“¥„À≠à ‚¥¬

ª°μ‘·≈â«®–μâÕß„™âª√‘¡“≥°√–· À≈Õ¥¡“°°«à“ºŸâªÉ«¬

√Ÿª∑’Ë 5 · ¥ßμ“√“߇ª√’¬∫‡∑’¬∫§à“ª√‘¡“≥√—ß ’∑’ˉ¥â®“°

‡∑§π‘§°“√§«∫§ÿ¡ª√‘¡“≥°√–· À≈Õ¥∑’Ëμà“ß°—π

„π°“√μ√«®∫√‘‡«≥™àÕß∑âÕß·≈–Õÿâ߇™‘ß°√“π

∑’Ë¡’¢π“¥ª°μ‘‡æ◊ËÕ„À⇧√◊ËÕß “¡“√∂‡≈◊Õ°„™âª√‘¡“≥

°√–· ∑’ˇ撬ßæÕμàÕ°“√ √â“ß¿“æ ¥—ßπ—Èπ®÷ßμâÕßμ—Èߧà“

 Ÿß ÿ¥¢Õß°√–· À≈Õ¥„Àâ‡æ’¬ßæÕ ‡ªìπμâπ °“√μ—Èß§à“ NI

®–‡ªìπ°“√°”Àπ¥§à“ —≠≠“≥√∫°«π∑’ˬա√—∫‰¥â„π

¿“æÀ“°μ—Èß§à“ NI ∑’Ë Ÿß®π‡°‘π‰ª®–∑”„Àâ¿“æ∑’ˉ¥â¡’

 —≠≠“≥√∫°«π Ÿß·μຟâªÉ«¬®–‰¥â√—∫√—ß ’„πª√‘¡“≥∑’ËπâÕ¬

‡π◊ËÕß®“°√–∫∫®–∑”°“√≈¥§à“ª√‘¡“≥°√–· „ÀâπâÕ¬

√Ÿª∑’Ë 6 · ¥ß¿“æ∂à“¬∑“ß√—ß ’‡æ◊ËÕ°“√«“ß·ºπ‡ª√’¬∫‡∑’¬∫°—π√–À«à“ß°“√®—¥∑à“ºŸâªÉ«¬∑’Ëμ”·Àπàßμà“ß°—π

‡Õ° “√Õâ“ßÕ‘ß

1. GE Healthcare, (2012). Discovery(tm) CT750 HD operator manual.

2. Grey MM. (2011).Tube current modulation approaches: over- view, pratical issues and potential pitfalls [Slide presentation].

Retrived from http://www.aapm.org/meetings/2011CTS /docu- ments/McNittGrayTubeCurrnetModulationv4.pdf.

3. Kalra MK, Maher MM, Toth TL, Schmidt B, Westerman BL, Morgan HT, et al. (2004) Techniques and applications of auto- matic tube current modulation for CT. Radiology. 233:649-657.

4. Lee CH, Goo JM, Ye HJ, Ye SJ, Park CM, Chun EJ, et al.

(2008). Radiation dose modulation techniques in the multidetector CT era: from basics to practice. RadioGraphics.

28:1451-1459.

5. Lee SH, Yoon SW, Yoo SM, Ji YG, Kim KA, Kim SH, et al.

(2011) Comparison of image quality and radiation dose be-

≈ß·μà®–‰¡àπâÕ¬®πμË”°«à“§à“∑’˺Ÿâ„™â‰¥âμ—È߉«â À“°μ—Èß§à“ NI πâÕ¬®–∑”„Àâ¿“æ∑’ˉ¥â¡’ —≠≠“≥√∫°«ππâÕ¬·μຟâªÉ«¬

®–‰¥â√—∫ª√‘¡“≥√—ß ’∑’Ë¡“°μ“¡‰ª¥â«¬ ‡æ√“–©–π—Èππ—°

√—ß ’°“√·æ∑¬å®÷ß®”‡ªìπμâÕßμ°≈ß°—∫√—ß ’·æ∑¬å∂÷ß

§ÿ≥¿“æ¢Õß¿“æ∑’ˬա√—∫‰¥â·≈–∑”°“√μ—Èß§à“°“√„™â ß“π∑’ˇÀ¡“– ¡‡æ◊ËÕ„À⇰‘¥ª√–‚¬™πå Ÿß ÿ¥„π°“√„™âß“π

¡’ß“π«‘®—¬∑’Ë π—∫ πÿπ°“√π”√–∫∫ ATCM ‰ª„™â ß“π‡æ◊ËÕ≈¥ª√‘¡“≥√—ß ’∑’˺ŸâªÉ«¬®–‰¥â√—∫ ¥—ß√Ÿª∑’Ë 5 ´÷Ëß

· ¥ßº≈∑’ˉ¥â®“°°“√∑¥≈Õ߇¡◊ËÕ‡ª√’¬∫‡∑’¬∫ª√‘¡“≥

√—ß ’∑’˺ŸâªÉ«¬‰¥â√—∫√–À«à“ß°“√μ—Èß§à“ª√‘¡“≥°√–· À≈Õ¥

§ß∑’Ë°—∫°“√„™âß“π√–∫∫ ATCM ∫√‘‡«≥™àÕß∑âÕß·≈–Õÿâ߇™‘ß

°√“π⁵ ®–‡ÀÁπ«à“§à“ª√‘¡“≥√—ß ’∑’ˉ¥â√—∫®“°°“√„™âß“π

√–∫∫ ATCM ®–≈¥≈ß‚¥¬ª√–¡“≥ 45 ‡ªÕ√凴Áπμå¢Õß

°“√„™â§à“ª√‘¡“≥°√–· §ß∑’Ë ‚¥¬∑’˧ÿ≥¿“æ¢Õß¿“æ¡’

§«“¡„°≈⇧’¬ß°—π · ¥ß«à“∂â“„™â√–∫∫ ATCM ®–

 “¡“√∂≈¥ª√‘¡“≥√—ß ’∑’˺ŸâªÉ«¬‰¥â√—∫ ·≈–¿“æ∑’ˉ¥â¬—ß¡’

§ÿ≥¿“æ‡æ’¬ßæÕ ”À√—∫√—ß ’·æ∑¬å„π°“√·ª≈º≈

·¡â«à“°“√„™âß“π√–∫∫ ATCM ®–°àÕ„À⇰‘¥

ª√–‚¬™πå„π°“√„™âß“π ·μଗߧßμâÕߧ”π÷ß∂÷ߢâÕ§«√

√–«—ß„π°“√„™âß“π√–∫∫ ‡™àπ

- °“√‡≈◊Õ°„™â‚ª√‚μ§Õ≈„Àâ‡À¡“– ¡°—∫ºŸâªÉ«¬

„πºŸâªÉ«¬∑’ˇªìπ‡¥Á°μâÕ߇≈◊Õ°„™â‚ª‚μ§Õ≈‡¥Á°‡∑à“π—ÈπÀ“°

¡‘‡™àππ—Èπμ—«√–∫∫®–¡Õß«à“‡ªìπºŸâ„À≠à∑’Ë¡’¢π“¥μ—«‡≈Á°

Õ“®∑”„Àâ√–∫∫‡≈◊Õ°„™âª√‘¡“≥°√–· ∑’ˉ¡à‡À¡“– ¡ - °“√μ—Èß§à“™à«ß¢Õß°√–· À≈Õ¥„Àâ‡À¡“– ¡

°—∫ à«π∑’Ëμ√«®

- À≈’°‡≈’ˬ߰“√„™âß“π√–∫∫„πºŸâªÉ«¬∑’Ë¡’¢π“¥

„À≠à„π≈—°…≥–Õâ«π ‡æ√“–„πμ—«ºŸâªÉ«¬®–¡’§à“§«“¡

μà“ߢÕ߇π◊ÈÕ‡¬◊ËÕ∑’Ë¡“°æÕÕ¬Ÿà·≈â« ‰¡à®”‡ªìπ∑’Ë®–μâÕß„™â ª√‘¡“≥°√–· ∑’Ë¡“°®π‡°‘π‰ª

- √–«—ß°“√®—¥∑à“ºŸâªÉ«¬μâÕßÕ¬Ÿà°÷Ëß°≈“ßÕÿ‚¡ß§å (Iso-center) ‡æ√“–À“°®—¥∑à“ºŸâªÉ«¬„π≈—°…≥–∑’ËÕ¬Ÿà„°≈â À≈Õ¥‡Õ°´‡√¬å √–∫∫®–¡Õß«à“ºŸâªÉ«¬¡’¢π“¥„À≠à

∑”„À≥â√—∫ª√‘¡“≥√—ß ’¡“°°«à“ª°μ‘À√◊Õ∂â“Õ¬Ÿà‰°≈®“°

À≈Õ¥‡Õ°´‡√¬å √–∫∫®–¡Õß«à“ºŸâªÉ«¬¡’¢π“¥‡≈Á° ∑”„Àâ

‰¥â√—∫ª√‘¡“≥√—ß ’πâÕ¬°«à“ª°μ‘®π∑”„Àâ¿“æ∂à“¬∑“ß

√—ß ’¢“¥§ÿ≥¿“æ

Õ¬à“߉√°Á¥’°“√°”Àπ¥§à“æ“√“¡‘‡μÕ√åμà“ßÊ∑’Ë„™â„π

°“√ ·°πºŸâªÉ«¬®–∂Ÿ°°”À𥂥¬≈—°…≥–¢Õß¿“æ∑’Ë¡’

§ÿ≥¿“æμ“¡¡μ‘¢Õß√—ß ’·æ∑¬å¢Õß ∂“∫—ππ—ÈπÊ®–

 “¡“√∂„™â„π°“√·ª≈º≈‰¥â

 √ÿª

√–∫∫°“√§«∫§ÿ¡ª√‘¡“≥°√–· À≈Õ¥Õ—μ‚π¡—쑇ªìπ

√–∫∫∑’Ë∂Ÿ°π”¡“„™âß“πÕ¬à“ß·æ√àÀ≈“¬„πªí®®ÿ∫—π

‡ π◊Ë Õ ß ® “ ° √ – ∫ ∫ ¥— ß ° ≈à “ « ‡ ªì π μ— « ™à « ¬ ∑’Ë ¥’ „ π ° “ √ ≈ ¥ ª√‘¡“≥√—ß ’∑’Ëμ—«ºŸâªÉ«¬®–‰¥â√—∫®“°°“√μ√«®‡Õ°´‡√¬å

§Õ¡æ‘«‡μÕ√å ∂÷ß·¡â‡∑§‚π‚≈¬’®–¡’°“√æ—≤𓉪¡“°

·μà°“√‡≈◊Õ°∑’Ë®–„™âß“ππ—Èπ¬—ßÕ¬Ÿà„π°“√§«∫§ÿ¡¢ÕߺŸâ„™â π—°√—ß ’°“√·æ∑¬å®÷ß®”‡ªìπ∑’Ë®–μâÕß»÷°…“·≈–‡¢â“„®„π æ◊Èπ∞“π¢Õß√–∫∫‡æ◊ËÕ∑’Ë®–‰¥â∑”°“√„™âß“π√–∫∫‰¥â Õ¬à“߇μÁ¡∑’Ë·≈–¡’ª√– ‘∑∏‘¿“æ ‰¥â¿“æ∑’Ë¡’§ÿ≥¿“æ‡æ’¬ß æÕ ”À√—∫√—ß ’·æ∑¬å„π°“√·ª≈º≈ ‡æ◊ËÕ„À⇰‘¥ª√–‚¬™πå  Ÿß ÿ¥„π°“√μ√«®‚¥¬∑’Ë„™âª√‘¡“≥√—ß ’πâÕ¬∑’Ë ÿ¥

tween combined automatic tube current modulation and fixed tube current technique in CT of abdomen and pelvis. Acta Radiologica. 52:1101-1106.

6. Raman SP, Johnson PT, Deshmukh S, Mahesh M, Grant KL, Fishman EK. (2013). CT reduction applications: available tools

on the latest generation of CT scanners. J Am Coll Radiol. 10:

37-41.

7. Sookpeng S. (2015). Computed tomography automatic tube current modulation: principle and factor affecting radiation dose.

Songkla Med J. 33:197-206.