章輝慶,邱曉暉,劉藝超,夏俊立,劉海燕
·論著·
·全科醫(yī)生技能發(fā)展·
雙源CT“雙低方案”在冠狀動(dòng)脈CT血管成像檢查中的可行性研究
章輝慶*,邱曉暉,劉藝超,夏俊立,劉海燕
目的 探討雙源CT低管電壓低對(duì)比劑濃度(雙低方案)在冠狀動(dòng)脈CT血管成像(CTA)檢查中的可行性。方法 選擇2014年9月—2015年6月在亳州市人民醫(yī)院行冠狀動(dòng)脈CTA檢查的50例臨床疑似或確診冠心病且體質(zhì)指數(shù)(BMI)≤30.0 kg/m2的患者,隨機(jī)分成兩組,A組采用管電壓100 kV及320 mgI/ml碘克沙醇為對(duì)比劑;B組采用管電壓80 kV及270 mgI/ml碘克沙醇為對(duì)比劑,每組25例。所有冠狀動(dòng)脈CTA檢查由西門子第二代Definition Flash雙源CT完成,掃描范圍135 mm,采用自動(dòng) mAs技術(shù),對(duì)比劑劑量50 ml,注射速率5.0 ml/s。對(duì)圖像進(jìn)行質(zhì)量評(píng)分及客觀評(píng)價(jià)。測量升主動(dòng)脈(AO)根部的CT值及圖像噪聲,計(jì)算圖像信噪比(SNR),測量并計(jì)算左冠狀動(dòng)脈主干(LM)、左冠狀動(dòng)脈前降支(LAD)近段、左冠狀動(dòng)脈回旋支(LCX)近段、右冠狀動(dòng)脈(RCA)近段的對(duì)比度噪聲比(CNR)。記錄兩組的有效輻射劑量(ED)。結(jié)果 兩組圖像質(zhì)量評(píng)分及各血管段評(píng)分間差異無統(tǒng)計(jì)學(xué)意義(P0.05)。B組AO、LM、LAD近段、LCX近段、RCA近段CT值高于A組(P<0.05)。B組的圖像噪聲大于A組(P<0.05);兩組SNR及LM、LAD近段、LCX近段、RCA近段的CNR比較,差異均無統(tǒng)計(jì)學(xué)意義(P0.05)。B組ED低于A組(P<0.05)。結(jié)論 在80 kV、270 mgI/ml雙低條件下行冠狀動(dòng)脈CTA檢查,能明顯降低對(duì)患者的ED及碘攝入量的同時(shí),圖像質(zhì)量能夠滿足臨床診斷要求;對(duì)于BMI≤30.0 kg/m2的患者,行雙源CT“雙低方案”冠狀動(dòng)脈CTA檢查具有可行性及臨床借鑒意義。
血管造影術(shù);冠狀動(dòng)脈疾??;雙源;體層攝影術(shù),X線計(jì)算機(jī);輻射劑量;碘對(duì)比劑;低濃度
章輝慶,邱曉暉,劉藝超,等.雙源CT“雙低方案”在冠狀動(dòng)脈CT血管成像檢查中的可行性研究[J].中國全科醫(yī)學(xué),2017,20(9):1127-1131.[www.chinagp.net]
ZHANG H Q,QIU X H,LIU Y C,et al.Feasibility study of dual-source coronary CT angiography under "double low scheme"[J].Chinese General Practice,2017,20(9):1127-1131.
隨著多排螺旋CT尤其是后64排CT的迅速發(fā)展,冠狀動(dòng)脈CT血管成像(CTA)檢查已成為篩查冠心病的首選檢查技術(shù)之一,其效果與冠狀動(dòng)脈數(shù)字減影血管造影(DSA)相當(dāng)[1-2]。然而,冠狀動(dòng)脈CTA檢查伴隨的高輻射劑量成為限制其進(jìn)一步推廣及應(yīng)用于常規(guī)篩查的關(guān)鍵問題之一。由于X線探測技術(shù)的發(fā)展,尤其是雙源CT的出現(xiàn),能夠有效減低噪聲干擾,有望在降低管電壓的同時(shí)降低對(duì)比劑濃度[3]。
以往通過降低管電壓(通常從120 kV降到100 kV,亦有降到80 kV以下的報(bào)道[3])以及自動(dòng)管電壓技術(shù)來降低對(duì)患者的有效輻射劑量的研究較多,并取得滿意的臨床效果[3-5]。本研究通過應(yīng)用管電壓100 kV、對(duì)比劑濃度320 mgI/ml及管電壓80 kV、對(duì)比劑濃度270 mgI/ml進(jìn)行冠狀動(dòng)脈CTA檢查,探究對(duì)體質(zhì)指數(shù)(BMI)≤30.0 kg/m2的患者采用超低管電壓、低對(duì)比劑濃度的“雙低方案”的可行性及臨床效果。
1.1 臨床資料 選擇2014年9月—2015年6月在亳州市人民醫(yī)院行冠狀動(dòng)脈CTA檢查的50例臨床疑似或確診冠心病患者。患者均無嚴(yán)重的心律不齊和心功能不全,無肝腎功能異常和甲狀腺功能亢進(jìn)癥,無過敏反應(yīng)等禁忌證,患者檢查時(shí)屏氣配合良好,并簽署X線輻射及碘對(duì)比劑知情同意書。隨機(jī)分成A、B兩組,每組25例,A組采用管電壓100 kV及320 mgI/ml碘克沙醇為對(duì)比劑;B組采用管電壓80 kV及270 mgI/ml碘克沙醇為對(duì)比劑?;颊連MI均≤30.0 kg/m2。
1.2 掃描設(shè)備及參數(shù) 所有冠狀動(dòng)脈CTA檢查由西門子第二代Definition Flash雙源CT完成。采集R-R間期30%~80%時(shí)相數(shù)據(jù),掃描范圍自頭向尾氣管隆突下135 mm,自動(dòng) mAs技術(shù)。經(jīng)肘正中靜脈注入50 ml非離子造影劑(A組320 mgI/ml碘克沙醇、B組270 mgI/ml碘克沙醇),管電壓A組100 kV、B組80 kV,注射速率5.0 ml/s,注射完畢后立即用30 ml 0.9%氯化鈉溶液沖洗。在升主動(dòng)脈根部采用Bolus Tracking技術(shù),當(dāng)達(dá)到100 Hu的閾值后延遲6 s啟動(dòng)掃描,采用自適應(yīng)前瞻性心電門控序列掃描技術(shù)。
1.3 圖像重建及后處理 每例患者的圖像均傳輸?shù)轿鏖T子Syngo.via圖像后處理工作站,工作站自動(dòng)生成最佳收縮期與舒張期圖像,圖像不滿意時(shí)在右側(cè)冠狀動(dòng)脈中段水平預(yù)覽并選擇最佳時(shí)相。重建層厚0.75 mm,重建間隔0.50 mm,中等軟組織算法(B30f)。圖像處理包括最大密度投影重組(MIP)、曲面重組(CPR)和容積重組(VR)。
本研究創(chuàng)新點(diǎn):
(1)降低管電壓的同時(shí)降低對(duì)比劑濃度,對(duì)患者的有效輻射劑量降至(1.9±0.6)mSv,實(shí)現(xiàn)了冠狀動(dòng)脈CT血管成像的“雙低方案”檢查;(2)降低管電壓的同時(shí)降低對(duì)比劑濃度能得到更高CT值的對(duì)比強(qiáng)化圖像,滿足了臨床檢查要求;(3)將體質(zhì)指數(shù)提高至30 kg/m2。
1.4 圖像質(zhì)量評(píng)分 由2名放射科副主任醫(yī)師先采用雙盲法對(duì)圖像質(zhì)量進(jìn)行評(píng)分,評(píng)分不一致時(shí),共同討論以達(dá)成一致意見。對(duì)嚴(yán)重鈣化血管段不進(jìn)行評(píng)價(jià)。不能診斷圖像的定義為:圖像質(zhì)量差,重建圖像上冠狀動(dòng)脈錯(cuò)位、管壁嚴(yán)重偽影[6]。根據(jù)美國心臟協(xié)會(huì)標(biāo)準(zhǔn),對(duì)冠狀動(dòng)脈行改良15段分段法評(píng)價(jià),右冠狀動(dòng)脈(RCA)為1~4段,左冠狀動(dòng)脈主干(LM)和左冠狀動(dòng)脈前降支(LAD)為5~10段,左冠狀動(dòng)脈回旋支(LCX)為11~15段,如果存在中間支則為16段[7-8]。圖像質(zhì)量評(píng)分分級(jí)標(biāo)準(zhǔn)為,Ⅰ級(jí):冠狀動(dòng)脈顯示清晰,圖像噪聲極小,管腔連續(xù)、完整,無階梯狀偽影,圖像質(zhì)量為優(yōu),評(píng)為4分;Ⅱ級(jí):圖像噪聲較小,管壁輕度偽影或冠狀動(dòng)脈分支CPR圖像見輕度階梯狀偽影,不影響診斷,圖像質(zhì)量良好,評(píng)為3分;Ⅲ級(jí):圖像噪聲較大,管壁中度偽影或CPR圖像中度階梯狀偽影,尚可做出診斷,圖像質(zhì)量中等,評(píng)為2分;Ⅳ級(jí):圖像噪聲大,重組圖像上冠狀動(dòng)脈錯(cuò)位、管壁嚴(yán)重偽影,不能診斷,圖像質(zhì)量較差,評(píng)為1分[9]。
1.5 圖像質(zhì)量的客觀評(píng)價(jià) 在升主動(dòng)脈(AO)根部(測量LM開口附近)盡可能大的感興趣區(qū)(ROI)測量相鄰3個(gè)層面的平均CT值。CT值的標(biāo)準(zhǔn)差(SD)值定義為圖像噪聲;圖像信噪比(SNR)為AO根部平均CT值/圖像噪聲;測量并計(jì)算LM、LAD近段、LCX近段、RCA近段冠狀動(dòng)脈對(duì)比度噪聲比(CNR)[10]。計(jì)算公式:CNR=(CTlumen-CTconnective tissue)/圖像噪聲;CTlumen為各部位冠狀動(dòng)脈ROI平均CT值,CTconnective tissue為冠狀動(dòng)脈血管周圍脂肪組織內(nèi)的平均CT值。
1.6 有效輻射劑量(ED) 本研究統(tǒng)計(jì)的ED僅為冠狀動(dòng)脈CTA檢查的輻射劑量,不包括定位像和觸發(fā)掃描的輻射劑量。通過雙源CT設(shè)備自動(dòng)計(jì)算得到容積CT劑量指數(shù)(CTDIvol)和劑量長度乘積(DLP),以DLP×轉(zhuǎn)換系數(shù)k得出估計(jì)ED。參考?xì)W洲CT質(zhì)量標(biāo)準(zhǔn)指南[11],轉(zhuǎn)換系數(shù)k=0.014 mSv·mGy-1·cm-1。
2.1 臨床資料比較 兩組患者的性別、年齡、BMI、心率比較,差異均無統(tǒng)計(jì)學(xué)意義(P0.05,見表1)。
表1 兩組患者臨床資料比較
注:a為χ2值;BMI=體質(zhì)指數(shù)
2.2 圖像質(zhì)量評(píng)分 兩組圖像質(zhì)量評(píng)分、各血管段評(píng)分間差異無統(tǒng)計(jì)學(xué)意義(P0.05,見表2及圖1~2)。
2.3 圖像質(zhì)量的客觀評(píng)價(jià) B組AO、LM、LAD近段、LCX近段、RCA近段CT值高于A組,差異有統(tǒng)計(jì)學(xué)意義(P<0.05,見表3)。B組圖像噪聲較A組增加,差異有統(tǒng)計(jì)學(xué)意義(P<0.05);A組和B組的SNR及LM、LAD近段、LCX近段、RCA近段的CNR比較,差異均無統(tǒng)計(jì)學(xué)意義(P0.05,見表4);冠狀動(dòng)脈與周圍組織對(duì)比度良好(見圖1~2)。
表2 兩組圖像質(zhì)量評(píng)分比較
注:a為u值
表3 兩組患者圖像CT值比較
注:AO=升主動(dòng)脈,LM=左冠狀動(dòng)脈主干,LAD=左冠狀動(dòng)脈前降支,LCX=左冠狀動(dòng)脈回旋支,RCA=右冠狀動(dòng)脈
表4 兩組圖像質(zhì)量的客觀評(píng)價(jià)比較
注:SNR=圖像信噪比,CNR=對(duì)比度噪聲比
注:患者,女,62歲,陣發(fā)性心悸,體質(zhì)指數(shù)(BMI)為21.5 kg/m2,心率為62次/min,有效輻射劑量(ED)為3.07 mSv;A為容積重組(VR)圖像,清晰顯示冠狀動(dòng)脈各分支血管,各段血管腔連續(xù)完整;B為RCA的曲面重組(CPR)圖像,顯示右冠狀動(dòng)脈(RCA)4段呈輕度階梯狀改變(評(píng)為3分),其余冠狀動(dòng)脈節(jié)段無階梯狀偽影(評(píng)為4分);C為左冠狀動(dòng)脈(LCA)的CPR圖像;D為左冠狀動(dòng)脈回旋支(LCX)的CPR圖像
圖1 A組冠狀動(dòng)脈CTA檢查圖像
Figure 1 Coronary artery CTA images of group A
圖2 B組冠狀動(dòng)脈CTA檢查圖像
Figure 2 Coronary artery CTA images of group B
注:患者,女,68歲,反復(fù)心悸8年;BMI為22.5 kg/m2,心率為68次/min,ED為1.46 mSv,冠狀動(dòng)脈顯示清晰,各段血管腔連續(xù)完整,冠狀動(dòng)脈無階梯狀偽影(評(píng)為4分);A為VR圖像,清晰顯示冠狀動(dòng)脈各分支血管;B為RCA的CPR圖像;C為LCA的CPR圖像;D為LCX的CPR圖像
2.4 兩組ED比較 A、B組ED分別為(4.5±0.6)、(1.9±0.6)mSv,B組ED低于A組,差異有統(tǒng)計(jì)學(xué)意義(t=15.337,P<0.05)。
目前冠狀動(dòng)脈CTA檢查已成為臨床評(píng)估冠狀動(dòng)脈疾病的首選檢查方法,與冠狀動(dòng)脈造影(CAG)檢查結(jié)果具有一致性,尤其是對(duì)于中重度血管狹窄的評(píng)估,甚至可以替代CAG[2,12-13]。如何在得到最佳診斷圖像的同時(shí)把輻射風(fēng)險(xiǎn)降到最低、如何安全高效使用對(duì)比劑,是目前許多研究者關(guān)心的課題[3-5,7,14-15]。本研究通過降低管電壓及對(duì)比劑濃度進(jìn)行冠狀動(dòng)脈CTA檢查,探討對(duì)BMI≤30.0 kg/m2的患者采用 “雙低方案”的可行性。
3.1 臨床資料 A、B組的管電壓均較120 kV低,因過胖的患者可能影響檢查效果及成功率,故本研究入選的患者BMI≤30.0 kg/m2。對(duì)于低劑量冠狀動(dòng)脈CTA檢查在BMI30.0 kg/m2的患者中應(yīng)用,需今后進(jìn)一步探討。本組研究未對(duì)心率做具體規(guī)定,兩組平均心率間無明顯差異。
3.2 冠狀動(dòng)脈CTA檢查掃描方式、管電壓及對(duì)比劑濃度對(duì)ED的影響 冠狀動(dòng)脈CTA檢查分為心電門控下前瞻性掃描及回顧性掃描,前者為目前冠狀動(dòng)脈CTA檢查時(shí)減少ED最有效的方法[16]。本研究A、B組均采用心電門控下前瞻性掃描,管電壓分別為100、80 kV,ED分別為(1.9±0.6)(4.5±0.6)mSv,較管電壓為120 kV和回顧性掃描研究的ED低[4,7,11,16],與管電壓為80 kV研究的ED相當(dāng)[14-15]。
目前臨床應(yīng)用的CT對(duì)比劑一般為非離子型低滲透性對(duì)比劑,相對(duì)于離子型對(duì)比劑已經(jīng)明顯減少了對(duì)比劑不良反應(yīng),大劑量高濃度對(duì)比劑可加重腎臟負(fù)荷,尤其在有腎病等基礎(chǔ)疾病的患者中應(yīng)用時(shí)增加了其過敏反應(yīng)和對(duì)比劑腎病的發(fā)生率[17-18]。對(duì)此類患者使用碘對(duì)比劑應(yīng)慎重,必須行此檢查的患者應(yīng)選擇等滲低濃度的碘對(duì)比劑及做好水化等預(yù)防工作,以保護(hù)腎臟功能。通過降低管電壓,減少了康普頓散射效應(yīng),使含碘對(duì)比劑的CT值提高,從而增加了血管與其周圍組織結(jié)構(gòu)的對(duì)比,使得減少含碘對(duì)比劑用量及降低對(duì)比劑濃度成為可能,潘昌杰等[14]、CAO等[15]、吳永娟等[19]報(bào)道,低濃度碘對(duì)比劑的應(yīng)用能使ED、碘攝入量、碘使用總量明顯降低,本研究B組使用的碘對(duì)比劑為低濃度的等滲270 mgI/ml碘克沙醇,其ED明顯低于A組。
3.3 降低管電壓及對(duì)比劑濃度對(duì)圖像質(zhì)量的影響 本研究對(duì)于圖像質(zhì)量的評(píng)價(jià)分為圖像質(zhì)量評(píng)分和圖像質(zhì)量的客觀評(píng)價(jià)。有研究報(bào)道,管電壓從120 kV降到100 kV,冠狀動(dòng)脈TCA檢查圖像能夠滿足臨床診斷的要求,同時(shí)ED明顯降低[3,10]。有研究報(bào)道冠狀動(dòng)脈增強(qiáng)CT值達(dá)到250~300 Hu即可滿足診斷要求[20],本研究B組冠狀動(dòng)脈CT值達(dá)500 Hu以上,較A組的CT值高,提示降低管電壓的同時(shí)降低對(duì)比劑濃度,能得到更高CT值的對(duì)比強(qiáng)化圖像。國際心血管CT指導(dǎo)委員會(huì)建議,行冠狀動(dòng)脈CTA檢查時(shí),對(duì)于體質(zhì)量<85 kg或BMI<30.0 kg/m2的患者應(yīng)盡可能優(yōu)先選擇100 kV的管電壓[21]。本研究患者BMI≤30.0 kg/m2,B組較A組的管電壓更低,且兩組圖像質(zhì)量評(píng)分及圖像質(zhì)量的SNR、CNR間無明顯差異。提示低劑量的圖像質(zhì)量能夠滿足臨床診斷要求,因而低管電壓結(jié)合濃度為270 mgI/ml碘對(duì)比劑具有較好的應(yīng)用前景。
本研究的局限性:(1)本研究的入選樣本量偏少,需要在今后研究中進(jìn)一步擴(kuò)大樣本量;(2)本研究患者BMI≤30.0 kg/m2,對(duì)于BMI30.0 kg/m2肥胖患者是否能夠用該低劑量方法有待于進(jìn)一步研究;(3)未對(duì)兩組碘對(duì)比劑具體攝入量以及對(duì)腎功能的影響情況進(jìn)行研究;(4)兩組圖像的部分診斷結(jié)果沒有與冠狀動(dòng)脈導(dǎo)管造影進(jìn)行對(duì)照研究。
綜上所述,雙源CT“雙低方案”冠狀動(dòng)脈CTA檢查圖像質(zhì)量能夠滿足臨床診斷要求,具有臨床應(yīng)用可行性;建議BMI≤30.0 kg/m2的患者,采用雙源CT“雙低方案”冠狀動(dòng)脈CTA檢查,減少對(duì)患者的ED及碘攝入量,以使該檢查技術(shù)能廣泛應(yīng)用于臨床常規(guī)檢查、體檢及各種術(shù)前評(píng)估等。
作者貢獻(xiàn):章輝慶進(jìn)行課題的構(gòu)思與設(shè)計(jì),文章的可行性分析,文獻(xiàn)、資料的收集、整理,數(shù)據(jù)分析、撰寫論文并對(duì)文章負(fù)責(zé);邱曉暉參與課題申請(qǐng)及監(jiān)督管理;劉藝超、夏俊立、劉海燕負(fù)責(zé)具體病例篩選、患者冠狀動(dòng)脈CT血管成像檢查、圖像后處理及相關(guān)數(shù)據(jù)采集工作。
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[1] JOHNSON T R,NIKOLAOU K,BUSCH S,et al.Diagnostic accuracy of dual-source computed tomography in the diagnosis of coronary artery disease[J].Invest Radiol,2007,42(10):684-691.DOI:10.1097/RLI.0b013e31806907d0.
[2]SINGH S,JIN J Y.Diagnostic efficacy of CT angiography in coronary artery disease[J].J Southeast Univ(Med Sci Edi),2014,33(3):247-254.DOI:10.1016/j.jse.2013.12.018.
[3]曹劍,易妍,王怡寧,等.70kV超低管電壓低對(duì)比劑用量冠狀動(dòng)脈CTA研究[J].放射學(xué)實(shí)踐,2014,29(6):589-592.DOI:10.13609/j.cnki.1000-0313.2014.06.003. CAO J,YI Y,WANG Y N,et al.Preliminary study on ultra low tube voltage(70kV)sequential scan with low-volume contrast medial protocol for dual-source CT coronary angiography[J].Radiologic Practice,2014,29(6):589-592.DOI:10.13609/j.cnki.1000-0313.2014.06.003.
[4]YIN W H,LU B,GAO J B,et al.Effect of reduced X-ray tube voltage,low iodine concentrationcontrast medium,and sinogram-affirmed iterative reconstruction on image quality and radiationdose at coronary CT angiography:results of the prospective multicenter REALISE trial[J].J Cardiovasc Comput Tomogr,2015,9(3):215-224.DOI:10.1016/j.jcct.2015.01.010.
[5] 張俊,韓丹,何波,等.智能最佳管電壓掃描技術(shù)在雙源CT冠狀動(dòng)脈成像中的應(yīng)用價(jià)值[J].中華放射學(xué)雜志,2015,49(4):288-292. ZHANG J,HAN D,HE B,et al.Intelligent optimum tube voltage technology at dual-source CT coronary artery angiography[J].Chin J Radiol,2015,49(4):288-292.
[6] BRENNER D J,HALL E J.Computed tomography-an increasing source of radiation exposure[J].N Engl J Med,2007,357(22):2277-2284.DOI:10.1056/NEJMra072149.
[7] LABOUNTY T M,LEIPSIC J,POUHER R,et al.Coronary CT angiography of patients with a normal body mass index using 80 kVp versus 100 kVp:a prospective,muhicenter,muhivendor randomized trial[J].AJR Am J Roentgenol,2011,197(5):W860-867.DOI: 10.2214/AJR.11.6787.
[8] 王怡寧,曹劍,孔令燕,等.高靈敏度探測器結(jié)合迭代重建在低管電壓冠狀動(dòng)脈CT血管成像的價(jià)值[J].中華放射學(xué)雜志,2014,48(2):109-113.DOI:10.3760/cma.j.issn.1005-1201.2014.02.006. WANG Y N,CAO J,KONG L Y,et al.Radiation dose reduction of coronary CT angiography at low tube voltage on all integrated circuit detector with iterative reconstruction[J].Chin J Radiol,2014,48(2):109-113.DOI:10.3760/cma.j.issn.1005-1201.2014.02.006.
[9] LESCHKA S,STOLZMANN P,SCHMID F T,et al.Low kilovohage cardiac dual-source CT:attenuation,noise,and radiation dose[J].Eur Radiol,2008,18(9):1809-1817.DOI:10.1007/s00330-008-0966-1.
[10] RIPSWEDEN J,BFISMAR T B,HOLM J,et al.Impact on image quality and radiation exposure in coronary CT angiography:100 kVp versus 120 kVp[J].Acta Radiol,2010,51(8):903-909.DOI:10.3109/02841851.2010.504740.
[11] HAUSLEITER J,MARTINOFF S,HADAMITZKY M,et al.Image quality and radiation exposure with a low tube voltage protocol for coronary CT angiography results of the PROTECTION Ⅱ Trial[J].JACC Cardiovasc Imaging,2010,3(11):1113-1123.DOI:10.1016/j.jcmg.2010.08.016.
[12] JOHNSON T R,NIKOLAOU K,BUSCH S,et al.Diagnostic accuracy of dual-source computed tomography in the diagnosis of coronary artery disease[J].Invest Radiol,2007,42(10):684-691.DOI:10.1097/RLI.0b013e31806907d0.
[13] YIN W H,LU B,HOU Z H,et al.Detection of coronary artery stenosis with sub-milliSievert radiation dose by prospectively ECG-triggered high-pitch spiral CT angiography and iterative reconstruction[J].Eur Radiol,2013,23(11):2927-2933.DOI:doi:10.1007/s00330-013-2920-0.
[14] 潘昌杰,王濤,錢農(nóng),等.等滲低濃度對(duì)比劑冠狀動(dòng)脈CT低劑量成像的初步研究[J].中華放射學(xué)雜志,2014,48(10):800-804.DOI:10.3760/cma.j.issn.1005-1201.2014.10.004. PAN C J,WANG T,QIAN N,et al.Preliminary study of low-dose CT coronary angiography by using low concentration isotonic contrast agent[J].Chin J Radiol,2014,48(10):800-804.DOI:10.3760/cma.j.issn.1005-1201.2014.10.004.
[15] CAO J X,WANG Y M,LU J G,et al.Radiation and contrast agent doses reductions by using 80-kV tube voltage in coronary computed tomographic angiography:a comparative study[J].Eur J Radiol,2014,83(2):309-314.DOI:10.1016/j.ejrad.2013.06.032.
[16] KOPLAY M,CELIK M,AVCI A,et al.Comparison between prospectively electrocardiogram-gated high-pitch mode and retrospectively electrocardiogram-gated mode for dual-source ct coronary angiography[J].Pol J Radiol,2015,80(12):561-568.DOI:10.12659/PJR.895232.
[17] KRUMMEL T,F(xiàn)ALLER A L,BAZIN D,et al.Contrast-induced nephropathy[J].Presse Med,2010,39(7/8):807-814.
[18] MEHRAN R,NIKOLSKY E.Contrast-induced nephropathy:definition,epidemiology,and patients at risk[J].Kidney Int,2006,100(Suppl):S11-15.DOI:10.1038/sj.ki.5000368.
[19] 吳永娟,畢純龍,雍敏,等.雙源CT Flash模式雙低劑量掃描聯(lián)合SAFIRE在冠狀動(dòng)脈成像中的可行性研究[J].臨床放射學(xué)雜志,2016,35(1):142-146. WU Y J,BI C L,YONG M,et al.The feasibility study of both double low dose and safire on dual source ct coronary angiography with flash scan mode[J].J Clin Radiol,2016,35(1):142-146.
[20] JOSEPH SCHOEPF U.CT of the heart:principles and applications[M].New York:Humana Press,2005:377-380.
[21] ABBARA S,ARBAB- ZADEH A,CALLISTER T Q,et al.SCCT guidelines for performance of coronary computed tomographic angiography:a report of the society of ardiovascular computed tomography guide-lines committee[J].J Cardiovasc Comput Tomogr,2009,3(3):190-204.DOI:10.1016/j.jcct.2009.03.004.
(本文編輯:趙躍翠)
Feasibility Study of Dual-source Coronary CT Angiography under "Double Low Scheme"
ZHANGHui-qing*,QIUXiao-hui,LIUYi-chao,XIAJun-li,LIUHai-yan
MedicalImagingCenter,People′sHospitalofBozhou,Bozhou236800,China
*Correspondingauthor:ZHANGHui-qing,Associatechiefphysician;E-mail:zhq7611@sohu.com
Objective To evaluate the feasibility of low tube voltage and low concentration of contrast agent(double low) in dual-source coronary CT angiography(CTA).Methods Fifty people suspected with and diagnosed with coronary heart disease and body mass index(BMI) less than 30.0 kg/m2,who underwent coronary CTA examination in People′s Hospital of Bozhou from September 2014 to June 2015,were selected and randomly divided into group A and group B and each group had 25 cases.Group A used 100 kV tube voltage and contrast material Iodixanol of 320 mgI/ml;and group B used 80 kV tube voltage and contrast material Iodixanol of 270 mgI/ml.All the coronary CTA examination was performed with dual-source CT of second-generation Definition Flash of SIEMENS,scanning range was 135 mm,automatic mAs technology,contrast dose was 50 ml and the flow rate was 5.0 ml/s.The quality of the image was scored and objectively evaluated.The CT value and image noise of the ascending aortic root(AO) were measured,the signal to noise ratio(SNR) of the image was calculated,the contrast to noise ratio(CNR) of left main coronary artery(LM),proximal left anterior descending coronary artery(LAD) and proximal left circumflex coronary artery(LCX) and proximal right coronary artery(RCA) was measured and calculated.The effective radiation dose(ED) of the two groups was recorded.Results There was no significant difference in the score of the image quality and the total score of vascular segments between the two groups(P0.05).The CT value of AO,LM,proximal LAD,proximal LCX,and proximal RCA in group B was significantly higher than that in group A(P<0.05).The image noise of group B was bigger than that of group A(P<0.05);there was no significant difference in the SNR of the images and CNR of LM,proximal LAD,proximal LCX,and proximal RCA between two groups(P0.05).ED of group B was significantly lower than that of group A(P<0.05).Conclusion Coronary CTA under conditions of 80 kV and 270 mgI/ml can obviously reduce the effective radiation dose and iodine intake of the patients,at the same time the quality of the image can meet the requirement of clinical diagnosis.For patients with BMI no more than 30.0 kg/m2,the dual-source coronary CTA scanning under "double low scheme " is feasibility and clinically useful.
Angiography;Coronary artery disease;Dual-source;Tomography,X-ray computed;Radiation dosage;Iodine contrast agent;Low concentration
亳州市科技局科技創(chuàng)新立項(xiàng)課題(By201507)
R 816.2
A
10.3969/j.issn.1007-9572.2017.09.020
2016-11-20;
2017-01-22)
236800安徽省亳州市人民醫(yī)院影像中心
*通信作者:章輝慶,副主任醫(yī)師;E-mail:zhq7611@sohu.com