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Objective To investigate the feasibility of AccuLearning system for the auto-segmentation of target areas and organs-at-risk(OAR)for total marrow and lymphoid irradiation(TMLI)in children.Methods Thirty pediatric patients who underwent TMLI since 2018 to 2022 were selected.The patients were immobilized in the supine position,and their CT images were acquired on the Philips Brilliance Big Bore CT scanner.After the target areas and OAR were manually delineated and modified,the CT images and manually delineated contours were imported into AccuLearning system for training,validation,and testing of the auto-segmentation model.The auto-segmentation results in 6 TMLI patients in the test set were evaluated in terms of Dice similarity coefficient(DSC),95%Hausdorff distance and average surface distance.Results On the test set with 6 cases,except for the lens that was difficult to be delineated automatically,the DSC values was above 0.70 for all other target areas and OAR,with only one patient having a DSC value of 0.59 for the stomach.The average DSC value for the stomach in all 6 patients was 0.76,and the average DSC values for the other organs were above 0.80.Conclusion The target areas and OAR automatically delineated with the model can meet the requirements of clinical planning after simple modifications.
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ObjectiveTo reduce the effective dose and maintain the image quality by adjusting the image processing parameters in the lumbar spine examinations.Methods This study investigated the influence of image processing parameters on image quality of Philips DR system by evaluating image quality of CDRAD 2.0 phantom.The parameters include detail contrast enhancement,noise compensation,unsharp masking and unsharp masking kernel.The entrance surface dose of phantom was measured by solidose meter.A synthetical parameters optimization project was proposed by analyzing the results of the investigation.This project was also testified by phantoms.ResultsImportant effects were the main effects of DCE,unsharp masking and kernel at the clinically used tube potential of 70 kVp( F =91.45,373.79,429.88,P ＜ 0.05).These effects indicated an increase of the 1QF about 20 units with increasing unsharp masking,while an increase of DCE and kernel led to decrease of IQF about 10 and 21 units.When the tube potential was increased to 85 kV,keeping the settings of the process parameters unchanged,the IQF increased.The results showed statically significant difference ( t =5.31,P ＜ 0.05 ).ConclusionIt is possible to lower the effective dose to the patient by the use of a higher tube potential and maintain a good image quality,and it will have little influence on clinic diagnosis through the most optimal setting of the process parameters.
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Objective The imaging quality and irradiation dose were compared between scatter filtering template performance and conventional grid in digital radiography.MethodsImages of contrast-detail phantom and ROC statistic phantom corrected with scatter filtering template method and grid were obtained,respectively.The image quality factors(IQF)and sihnal detection probability values(Pdet)and imaging dose were analyzed by ANOVA,SNK and t test statistics for the two methods of scatter removing.ResultsThe difference of IQF and signal detection probability of images corrected by scatter filtering template technique and conventional snd Was statistically significant.ConclusionsIn digital radiography,STFF can effectively filter scattering,improve image quality without increasing the exposure.With the same image quality.it can reduce the entrance surface dose by about 30% than filter grid.In order to effectively filter scattering,improve the quality of X-ray image,and reduce the patient dose.STFF is an alternative method.