ct扫描中管电压对辐射剂量和ct值与灌注结果的影响

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1、天津医科大学硕士学位论文．2．784，P=0．009)，PS(t-"-3．439，JP=0．002)，阱(t=-2．115，P=0．048)，均具有统计学差异。校准后低管电压组各参数与标准管电压组相比，BV(t-"．2．015，P=0．068)，BF(t-"．1．996，P=0．055)，PS(t--．3．039，P=0．132)，HAF(，=一1．139，P--0．052)，均没有统计学差异。两组患者有效剂量有显著差异，，=．4．21，p=O．001；低管电压组有效剂量降低33％。结论：不同管电压下灌注参数结果存在差异，应用公式2对低管电压下扫描所得数据校正后，所得灌注值与标准管电压结

2、果相一致，且辐射剂量大幅降低。关键词：CT；管电压；管电流；低剂量；CT值；CT灌注III天津医科人学硕士学位论文AbstractPartIInfluenceofTubeVoltageandTubeCurrentonRadiationDoseandCTAttenuation：Low—doseCTStudyObjective：ThepurposewastoassesstheinfluenceoftubevoltageandtubecurrentonCTattenuationmeasurement，radiationdose，andimagequalityusingserialsolutio

3、nswithdifferentiodineconcentrations．MaterialsandMethods：Infuse4mlcontrastmedium(Ultravist，370mgI／ml，Bayer)foreachtimeinto1000mlnormalsodium，anddraw5mlsolutionswithasyringeaftermiscebene．Twenty—fivesyringeswithdifferentsolutionswerefixedontheCTcalibrationwaterphantomwiththediameterof20cm．Fifteenpr

4、otocolswithdifferenttubevoltages(120kV，100kV，and80kV)andtubecurrents(250mA，200mA，150mA，100mA，and50mA)werescanned．TheotherSCanparametersincludedaxialscanmodeand1s／rotforgantryrotation．NoothertechniqueforradiationdoseadjustmentWasadopted．TheCTdataweretransferredtoAdvantageWorkstation4．4forGE．Region

5、ofinterest(ROI)with10mm2weredrowntomeasuretheCTattenuationsofserialSOlutionsunderdifferentscansettings．Imageswithstandardsettingof120kVand250mAweremeasuredfirsttoselecttheserialsolutions，CTattenuationsofwhichwerefrom0HUto450HUwithincrementof5HU．113solutionswerebroughtintothestudy，andCTattenuation

6、underothersettingsweremeasuredandrecorded．ThechangesoftubevoltageandtubecurrentinfluenceonCTattenuationwereanalyzed，andtherelationshipswerecalculated．CTdoseindexs(CTDIvol，mGy)wererecordedanddoselengthproduct(DLP，mGy·cm)werecalculated．Results：CTattenuationswithfixedtubevoltageanddifferenttubecurre

7、ntwerenotdifferent(120kV,F=0．001，P21．000；100kV,F=0．008，P=1．000；80kV,F=0．075，P=0．990)．However，CTattenuationswithfixedtubecurrentanddifferentvoltagetubeweredifferent(250mA，H=17．906，p=0．000；200mA，H=17．688，p=0．000；150mm，H=