OptimizedtubecurrentselectionforconsistentimagequalityanddosereductioninMDCTcardiacima
发布时间:2008-04-30
浏览次数:3562次
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WeiweiQi,XiangkeDu,Jianyingli,YunShen;Beijing/CN
Purpose:Tointroduceandclinicallyevaluateabolus-trackingscan(BTS)basedtubecurrent(mA)selectionmethodinMDCTcoronaryartery(CTA)imagingtoobtainpreciseandconsistentimagequalityandtooptimizedoseutilizationforpatientpopulations.
MethodsandMaterials:Wefirstestablishedcorrelationbetweentheimagenoisesofbolustracking(BT)andCTAscansatfixedmAusingourstandardcardiacscanprotocolwith64-rowMDCT.Thiscorrelationwasthenconvertedtoformaformulatodeterminethepatient-dependentmAforgettingadesiredandconsistentCTAimagenoisebasedonthemeasuredBTSimagenoiseforindividualpatient.Subsequently,100cardiacpatientswerescannedwithindividuallyadjustedmAselectedusingtheformulaforachievingnoiseof28HUwhichwasdeterminedtobeclinicallyadequatebasedonanalyzingexistingCTAimages.
Results:TheaveragenoiseforCTAimagesof100patientswithBTS-basedmAselectionwasfoundtobe28.5HUandthestandarddeviationofimagenoisewasabout2HU,whichwasmuchsmallerthanthe5HUforthegroupofpatientswithfixedmA.ThelowestCTDIvol,fortheBTS-basedmAgroupwasonly25%thatofthefixedmAgroup,andtheaverageimagescoresfromthetwogroupsshowednostatisticaldifference.
Conclusion:AdjustingmAindividuallybasedonbolus-trackingscannoiseanalysisisanaccurateandpracticalmethodtoobtainconsistentimagequalityfordifferentcardiacpatientsandprovidesdosereductionforsmallerpatientscomparedtotheuseoffixedmA.