提出一种超声图像中胎儿头围自动测量的新方法.利用机器学习的随机森林(random forests,RFs)算法自动检测感兴趣区域(region of interest,ROI),通过图像局部相位对称(phase symmetry,PS)检测头围边缘,使用非迭代椭圆拟合算法拟合出头围...提出一种超声图像中胎儿头围自动测量的新方法.利用机器学习的随机森林(random forests,RFs)算法自动检测感兴趣区域(region of interest,ROI),通过图像局部相位对称(phase symmetry,PS)检测头围边缘,使用非迭代椭圆拟合算法拟合出头围椭圆.与医生手动拟合测量的结果对比,145个头像的平均相对偏差为-3.86 mm,表明该方法可以鲁棒的自动检测胎儿头围.展开更多
AIM:To determine the usefulness of arrival time parametric imaging(AtPI) using contrast-enhanced ultrasonography(CEUS) with Sonazoid in evaluating early response to sorafenib for hepatocellular carcinoma(HCC).METHODS:...AIM:To determine the usefulness of arrival time parametric imaging(AtPI) using contrast-enhanced ultrasonography(CEUS) with Sonazoid in evaluating early response to sorafenib for hepatocellular carcinoma(HCC).METHODS:Fourteen advanced HCC patients who received sorafenib 400/800 mg/d for at least 4 wk and were followed up by CEUS were enrolled in this study.CEUS was performed before treatment and 2 and 4 wk after treatment,and images of the target lesion in the arterial phase were recorded for each patient.The images were analyzed by AtPI.Color mapping(CM) images obtained by AtPI were compared before and after the treatment.In these CM images,the mean arrival time of the contrast agent in the region of interest from the starting point [mean time(MT)] was calculated.In each patient,differences between MT before and MT 2 and 4 wk after the treatment were compared with responses evaluated 4-8 wk after the treatment by dynamic computed tomography(CT),and statistical analysis was performed.Modified response evaluation criteria in solid tumors was used for the response evaluation.RESULTS:In CM images both 2 and 4 wk after the treatment,delays in the arrival time of the contrast agent were noted in 8 of the 14 patients.In the other 6 patients,no color changes were observed in the tumor,or red and/or yellow increase,suggesting a decrease in blood flow velocity between images 2 and 4 wk after the treatment and those before the treatment.Dynamic CT could be performed 4-8 wk after the treatment in 13 of the 14 patients.Median differences in the MT were 1.13 s and 1.015 s,2 and 4 wk after the treatment,respectively,in the 8 patients who showed stable disease(SD)/partial response(PR) on dynamic CT.Median differences in the MT were-0.39 s and-0.95 s,2 and 4 wk after the treatment,respectively,in the 5 patients who showed progressive disease(PD).Differences in the median MT between SD/PR and PD groups were significant 2 and 4 wk after the treatment with P = 0.019 and P = 0.028,respectively.CONCLUSION:AtPI by CEUS using Sonazoid is suggested to be useful for evaluating early responses to sorafenib.展开更多
文摘AIM:To determine the usefulness of arrival time parametric imaging(AtPI) using contrast-enhanced ultrasonography(CEUS) with Sonazoid in evaluating early response to sorafenib for hepatocellular carcinoma(HCC).METHODS:Fourteen advanced HCC patients who received sorafenib 400/800 mg/d for at least 4 wk and were followed up by CEUS were enrolled in this study.CEUS was performed before treatment and 2 and 4 wk after treatment,and images of the target lesion in the arterial phase were recorded for each patient.The images were analyzed by AtPI.Color mapping(CM) images obtained by AtPI were compared before and after the treatment.In these CM images,the mean arrival time of the contrast agent in the region of interest from the starting point [mean time(MT)] was calculated.In each patient,differences between MT before and MT 2 and 4 wk after the treatment were compared with responses evaluated 4-8 wk after the treatment by dynamic computed tomography(CT),and statistical analysis was performed.Modified response evaluation criteria in solid tumors was used for the response evaluation.RESULTS:In CM images both 2 and 4 wk after the treatment,delays in the arrival time of the contrast agent were noted in 8 of the 14 patients.In the other 6 patients,no color changes were observed in the tumor,or red and/or yellow increase,suggesting a decrease in blood flow velocity between images 2 and 4 wk after the treatment and those before the treatment.Dynamic CT could be performed 4-8 wk after the treatment in 13 of the 14 patients.Median differences in the MT were 1.13 s and 1.015 s,2 and 4 wk after the treatment,respectively,in the 8 patients who showed stable disease(SD)/partial response(PR) on dynamic CT.Median differences in the MT were-0.39 s and-0.95 s,2 and 4 wk after the treatment,respectively,in the 5 patients who showed progressive disease(PD).Differences in the median MT between SD/PR and PD groups were significant 2 and 4 wk after the treatment with P = 0.019 and P = 0.028,respectively.CONCLUSION:AtPI by CEUS using Sonazoid is suggested to be useful for evaluating early responses to sorafenib.
