ABSTRACT
Objective:To investigate the application value of baseline MRI multi-parametric imaging radiomics in prediction of neoadjuvant chemoradiotherapy (NCR) efficacy of rectal mucinous adenocarcinoma (RMAC).Methods:Retrospective analysis was performed in the Sixth Affiliated Hospital of Sun Yat-sen University from August 2012 to October 2018. A total of 79 patients were included in this study, including 52 males and 27 females, aged 20-78 years (median age 52 years). According to the classification criteria of pathological regression, all patients were divided into NCR responsiveness group ( n=31) and nonresponsiveness group ( n=48). And 701 imaging features of T 2WI, diffusion weighted imaging (DWI) and enhanced T 1WI images of baseline MRI were extracted, and feature subsets were selected by repeatability analysis and feature dimensionality reduction to construct the radiomics prediction model. The tumor features from baseline MRI between the NCR responsiveness group and the nonresponsiveness group were compared, and the features of P<0.05 were combined with the radiomics to construct a model. Using pathology as the gold standard, the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficiency of the prediction model, and the area under the curve (AUC), 95% confidence interval, sensitivity and specificity were calculated, and the DeLong test was used to compare the diagnostic efficacy of different prediction models. Results:By comparing the conventional tumor imaging characteristics of the NCR responsiveness group and the nonresponsiveness group, the differences in lymph node stage and mucinous nodule status between the two groups were statistically significant (χ2 =6.040, 5.870, P<0.05). The AUC of ROC curves based on T 2WI, DWI, and enhanced T 1WI radiomics were 0.816, 0.821, and 0.819, respectively, which were higher than those of conventional tumor characteristics (lymph node staging, mucinous nodule status) (AUC=0.607), and the differences were statistically significant ( Z=-2.391, -2.580 and -2.717, P<0.05). Among the joint prediction models of T 2WI, DWI and contrast-enhanced T 1WI radiomics and conventional tumor features, the DWI combined model had the largest AUC (0.843), and there was no statistically significant difference between the three combined models (all P>0.05). Conclusion:The baseline T 2WI, DWI, and contrast-enhanced T 1WI radiomics model can be used to predict the NCR efficacy of RMAC, which is better than the predictive efficacy of conventional features, and the combination with conventional features can further improve the predictive efficacy.
ABSTRACT
To build a CT-based radiomics predictive mode to evaluate the differentiation degree of the esophageal squamous carcinoma. Methods: A total of 160 patients with surgical pathology, complete clinical data and chest CT scanning before operation were retrospectively collected from January 2008 to August 2016. All patients were assigned randomly to a primary data set and an independent validation. Texture analysis was performed on CT images, while the carcinomas were performed by manual segmentation to extract the radiomics features. Radiomics features were extracted and 9 radiomics signatures were finally selected after dimension reduction. Radiomics features were extracted and established via Matlab. Multivariable logistic regression analysis was performed to build the predictive model. A 10-fold cross-validation was used for selecting parameters in the least absolute shrinkage and selection operator (LASSO) model by minimum criteria. The receiver operating characteristic (ROC) curves and areas under ROC curve (AUC) were used to compare the model performance in the primary validation and the independent validation for evaluating the differentiation degree of esophageal squamous carcinoma. Results: Radiomics signature showed great effect in discriminating primary data set and independent validation. The predictive model had a good performance in primary data set. The AUC was 0.791, the sensitivity was 81.6%, and specificity was 72.3%. In the independent validation, the AUC was 0.757, the sensitivity was 70.0%, and the specificity was 73.0%. Conclusion: The predictive model can be used for evaluating the differentiation degree of esophageal squamous carcinoma efficiently, which can be helpful to clinicians in diagnosis and choice of treatment for esophageal squamous carcinoma.
Subject(s)
Humans , Carcinoma, Squamous Cell , Esophageal Neoplasms , ROC Curve , Retrospective Studies , Tomography, X-Ray ComputedABSTRACT
Objective To investigate the effect of tube voltage and iodine concentration of contrast medium (CM) on abdominal dynamic enhanced CT image quality.Methods Six miniature pigs underwent repeated upper abdomen dynamic contrast-enhanced CT scans in 4 scanning protocols with different concentration of CM and tube voltage,namely,protocol 1,CM with iodine concentration of 270 milligrams iodine per milliliter (mg/ml) and 80 kV tube voltage;protocol 2,270 mg/ml and 120 kV;protocol 3,370 mg/ml and 80 kV and protocol 4,370 mg/ml and 120 kV.The same iodine dose (600 mg/ml) and iodine delivery rate (IDR) (920 mg/s) were used in all protocols.The CM with iodine concentration of 270 mg/ml were injected at a flow rate of 3.4 ml/s,and 370 mg/ml CM injected at 2.5 ml/s.Image reconstruction was performed with iterative reconstruction (iDose4) in protocol 1 and 3,filtered back projection (FBP) was used in protocol 2 and 4.A subjective scoring system for image quality,image noise and sharpness was conducted by 2 radiologists independently.The measured values (peak of enhanced CT values,image noise of aorta,inferior vena cava,portal vein,hepatic vein and liver parenchyma) as well as the calculated values [their time-to-peak,signal-to-noise (SNR) and contrast-to-noise (CNR) ratios] were compared between among 4 protocols.The CT volume dose index (CDTIvol) and dose length product (DLP) were recorded from the CT console after each scanning.Factorial designed ANOVA was used for comparison of enhanced CT values of vessels and liver parenchyma,noise,SNR and CNR.The Kruskal-Wallis test was used for comparison of values among the 4 protocols,including the time-to-peak enhancement of vessels and liver parenchyma,the subjective scores of image quality indices.Result There was no significant differences in subjective scores of the image quality,image noise and image sharpness (P＞0.05).The scored were more than 3,and the images with 4 scanning protocols were all acceptable for diagnosis.There was no significant differences between protocol 1 and 3,protocol 2 and 4 in the peak enhancement CT values of aorta [(729±46) HU vs.(707±59)HU,(515±84)HU vs.(513±53)HU],inferior vena cava [(366±95)HU vs.(368±92)HU,(282±39)HU vs.(262 ± 67)HU],portal vein [(213± 18)HU vs.(201 ±29)HU,(180±21)HU vs.(176±27)HU],hepatic vein [(207±18)HU vs.(193±10)HU,(179±24)HU vs.(170±14)HU] and liver parenchyma [(128±7) HU vs.(127±4) HU,(135±5)HU vs.(135±6)HU] (P＞0.05).But the CT values of vessels (aorta,inferior vena cava,portal vein and hepatic vein) in protocol 1 and 3 were significantly higher than those in protocol 2 and 4 (P＜0.05),the CT values of liver parenchyma in protocol 1 and 3 were significantly lower than values in protocol 2 and 4 (P＜0.05).The image noises of vessels were higher in protocol 1 and 3 than noises in other protocols (P＜0.05),but there was no significant difference in liver parenchyma noise among protocols (P＞0.05).No significant differences were observed on the peak times,SNR and CNR in aorta,inferior vena cava,portal vein,hepatic vein and liver parenchyma among 4 protocols (P＞0.05).The CDTIvol and DLP were 199.67 mGy,1 597.4 mGy· cm respectively in protocol 1 and 3,585.12 mGy and 4 680.9 mGy· cm in protocol 2 and 4 (scanning with 120 kV).Conclusions CM with different iodinated concentration could achieve the same enhancement in the abdominal vessels and liver parenchyma by using the proper scan protocols,which have the same IDR and iodine dose per kilogram body weight.Higher vessel enhanced peak values were achieved when using the protocols with 80 kV tube voltage than 120 kV.By using a low dose protocol of 80 kV tube voltage with the iterative reconstruction algorithm,the quality of image can be warranted.