發(fā)布時(shí)間：2018-02-15 08:51

  本文關(guān)鍵詞： 肝疾病 肝 體層攝影術(shù) X線計(jì)算機(jī) 迭代重建算法 圖像增強(qiáng) 輻射劑量 質(zhì)量控制　出處：《中國(guó)醫(yī)學(xué)影像學(xué)雜志》2015年01期 　論文類型：期刊論文

【摘要】：目的比較迭代模型重建(IMR)技術(shù)在不同輻射劑量條件下對(duì)肝臟CT增強(qiáng)掃描圖像質(zhì)量的影響,探討IMR技術(shù)在不同輻射劑量條件下在肝臟CT增強(qiáng)掃描中的價(jià)值。資料與方法 54例行上腹部CT增強(qiáng)掃描患者,根據(jù)不同門靜脈期掃描方案分為A組29例(120 k V,250 m As)和B組25例(80 k V,500 m As)。采用濾波反投影(FBP)重建技術(shù)和IMR技術(shù)重建門靜脈期原始數(shù)據(jù),得到4組圖像,包括A1組(120 k V,FBP)、A2組(120 k V,IMR)、B1組(80 k V,FBP)和B2組(80 k V,IMR),比較各組圖像質(zhì)量客觀評(píng)價(jià)指標(biāo)圖像噪聲、圖像信噪比(SNR)、對(duì)比噪聲比(CNR)和主觀評(píng)價(jià)指標(biāo)低對(duì)比分辨率、圖像失真及診斷信心度,并計(jì)算有效輻射劑量。結(jié)果 B組有效輻射劑量較A組降低42.7%(t=15.27,P0.001)。A2組圖像噪聲低于A1組,B2組圖像噪聲低于B1組,而B2組SNR及CNR較其他3組均顯著增高(F噪聲=81.98、FSNR=65.19、FCNR=37.42,P0.001)。各組低對(duì)比分辨率評(píng)分A2B2A1B1(χ2=58.21,P0.001),各組圖像失真評(píng)分A1B1A2B2(χ2=12.94,P0.001),B2組與A1組、B1組間差異有統(tǒng)計(jì)學(xué)意義(P0.05);各組診斷信心評(píng)分A2A1B2B1(χ2=34.06,P0.001),A1組與B2組間差異無統(tǒng)計(jì)學(xué)意義(P0.05),其余組間差異有統(tǒng)計(jì)學(xué)意義(P0.05)。結(jié)論與FBP比較,IMR技術(shù)不同輻射劑量掃描均可以降低肝臟CT增強(qiáng)掃描圖像噪聲并能提高圖像質(zhì)量,改變效果尤以80 k V、500 m As CT掃描明顯。
[Abstract]:Objective to compare the effects of iterative model reconstruction (IMR) technique on the quality of liver CT enhanced scanning images under different radiation doses. To investigate the value of IMR technique in liver CT enhanced scanning under different radiation doses. Materials and methods 54 patients with upper abdominal CT enhanced scanning were performed. According to different portal phase scanning schemes, 29 patients in group A were divided into two groups: group A (n = 29) and group B (n = 25), and group B (n = 25) were divided into two groups: group A (n = 29) and group B (n = 25). The original data of portal vein phase were reconstructed by filtering backprojection technique and IMR technique, and 4 groups of images were obtained. Group A1 (120 kV) and group B2 (80 kV) were compared with each other in terms of image quality, image noise, image signal-to-noise ratio (SNR), contrast noise ratio (CNR) and subjective evaluation index, low contrast resolution, image distortion and diagnostic confidence. Results the effective radiation dose in group B was 42.7 lower than that in group A. the image noise in group A was lower than that in group A (15.27) P 0.001. A2 was lower than that in group B _ 1, and that in group B _ 2 was lower than that in group B _ 1. The SNR and CNR of group B2 were significantly higher than those of other three groups (P < 0.05). The low contrast resolution score A 2B 2A 1B 1 (蠂 2 58.21g P 0.001) and the image distortion score A 1B 1A 2B 2 (蠂 2 12.94U P 0.001B 2) were significantly higher than those of group A1 (P 0.05), and the diagnostic confidence score A 2A 1B 2B 1 (蠂 2 34.06n P 0.001B 1) was significantly higher than that of the other three groups (P < 0.05). The diagnostic confidence score of each group was A2A1B2B1 (蠂 2 34.06P 0.001B 1) and the diagnostic confidence score (A2A1B2B1) was significantly higher than that of the other three groups (蠂 2 12.94U P 0.001 P 0.001); the diagnostic confidence score of each group was A2A1B2B1 (蠂 2 34.06P 0.001B 1). There was no significant difference (P 0.05) between the other groups. Conclusion compared with FBP, different doses of FBP can reduce the noise and improve the image quality of liver CT enhanced scanning. The change effect was especially obvious in 80 kV as 500 m as CT scan.
【作者單位】： 南方醫(yī)科大學(xué);廣東省人民醫(yī)院 廣東省醫(yī)學(xué)科學(xué)院放射科;飛利浦中國(guó)影像研究院;廣州市第一人民醫(yī)院放射科;
【基金】：國(guó)家自然科學(xué)基金項(xiàng)目(81271569,81271654)
【分類號(hào)】：R816.5;R575
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本文編號(hào)：1512897