本文選題：低管電壓 + 適應(yīng)性統(tǒng)計迭代重建��； 參考：《放射學(xué)實踐》2017年09期

【摘要】：目的:評價低管電壓結(jié)合適應(yīng)性統(tǒng)計迭代重建(ASIR)對腹部體模低劑量掃描圖像質(zhì)量的影響,探討適合臨床應(yīng)用的腹部低劑量掃描方案。方法:采用100kVp、120kVp分別對體模進行重復(fù)掃描,應(yīng)用自動管電流調(diào)節(jié)(ATCM)技術(shù),100kVp掃描時預(yù)設(shè)噪聲指數(shù)(NI)分別為11、12、13、14、15、16、17、18、19、20,每組圖像均進行30%、50%、70%、90%ASIR重建。120kVp組為常規(guī)劑量組,掃描時預(yù)設(shè)NI為11,30%ASIR重建,測量不同掃描條件下肝臟、脊柱的CT值、客觀噪聲,并計算信噪比(SNR),記錄不同掃描條件下的CT容積劑量指數(shù)(CTDIvol)。由兩位高年資醫(yī)師采用盲法對所有序列圖像進行主觀評價。結(jié)果:100kVp條件下,隨著NI增大,CTDIvol明顯下降;同一NI條件下隨著ASIR比例增加,圖像噪聲減少,SNR增加;NI≥17時圖像質(zhì)量下降,無法滿足臨床診斷要求;NI=15、70%ASIR組圖像噪聲、SNR與120kVp常規(guī)組差異無統(tǒng)計學(xué)意義(P0.05),主觀評分相當,但輻射劑量較常規(guī)組下降43.8%。NI=15、90%ASIR組及NI=16、90%ASIR組的圖像噪聲及信噪比優(yōu)于常規(guī)組(P0.05),但圖像質(zhì)量主觀評分下降。結(jié)論:低管電壓結(jié)合ASIR可以在降低輻射劑量的同時保證圖像質(zhì)量滿足臨床診斷要求。輻射劑量明顯降低時,需要增加ASIR在圖像重建中的權(quán)重。
[Abstract]:Objective: to evaluate the effect of low tube voltage combined with adaptive statistical iterative reconstruction (ASIRR) on the quality of low dose scan images of abdominal phantom, and to explore a suitable low dose scan scheme for clinical use.Methods: the phantom was scanned repeatedly by 100kVp1 120kVp, and the default noise index (NII) of 100kVp was 111212131515161718181920 respectively. Each group was reconstructed with 30507090ASIR. 120kVp was used as the routine dose group, and the default NI was 1130ASIR at the time of scanning.The CT value and objective noise of liver and spine were measured under different scanning conditions. The SNR was calculated and CT volumetric dose index (CTDIvoll) was recorded under different scanning conditions.All sequence images were evaluated subjectively by two senior doctors using blind method.Results under the condition of 1: 100kVp, with the increase of NI, CTDIvol decreased obviously, and under the same NI condition, with the increase of ASIR ratio, the image noise decreased and the image quality decreased with the increase of NI 鈮，

本文編號：1757141