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Objective:To evaluate the diagnostic performance of a radiomics model based on dynamic contrast-enhanced MRI (DCE-MRI) and diffusion weighted imaging (DWI) in small breast cancer (≤ 20 mm in greatest dimension), and to compare the results with those of an experienced radiologist’s interpretation.Methods:A total of 205 small breast lesions in 192 consecutive female patients from June 2016 to January 2018 at Renji Hospital, School of Medicine, Shanghai Jiaotong University, were retrospectively enrolled in the study. All lesions (≤ 20 mm in greatest dimension) were confirmed by surgical pathological results. The lesions were divided into a training set (116 lesions) and an independent test set (89 lesions). Based on preoperative breast DCE-MRI and DWI data, a radiomics model was built using gradient boosting decision tree (GBDT). The GBDT model was applied to the test set for differentiation between malignant and benign small breast lesions. Cases of the test set were also evaluated by an experienced radiologist for benign and malignant diseases differentiation. ROC curve was used to assess the diagnostic performance for the GBDT model and the radiologist evaluation, respectively. Differences in the area under the ROC curve (AUC) were analyzed by the DeLong test. Differences in sensitivity, specificity and accuracy were evaluated by the McNemar test. Kappa values were used to assess the agreement between different evaluation methods.Results:The AUC of the GBDT model (0.950) showed no significant difference from that of the radiologist’s evaluation based on DCE-MRI combing DWI data (0.935) ( Z=0.499, P=0.618). However, it showed the AUC of GBDT model was significantly higher than that of evaluation based on DCE-MRI (0.874) or DWI (0.832) alone ( Z=2.024， P=0.043； Z=2.772， P=0.006). The sensitivity, specificity and accuracy of the best cutoff point of GBDT model were 90.0%, 89.8% and 89.9% respectively. The sensitivity, specificity and accuracy of evaluation based on DCE-MRI combined with DWI were 97.5%, 79.6% and 87.6% respectively. There was no significant difference in diagnostic performance between the two methods (χ 2=0.800,2.286 and 0.083, P>0.05). Conclusions:A radiomics model based on DCE-MRI and DWI images provided good diagnostic performance in small breast cancer. The results of radiomics were favorably comparable with those of experienced radiologist evaluation based on the combination of DCE-MRI and DWI data.
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Objective To explore the evaluation value of MRI parameters and immunohistochemistry in the neoadjuvant chemotherapy (NAC)for the HER-2 positive breast cancer.Methods 7 6 patients with locally advanced HER-2 positive breast cancer were analyzed retrospectively.According to the postoperative pathology,patients were divided into pathological complete response (PCR)group and non-PCR (Non-PCR)group.First,univariate and multivariate Logistic regression analysis were used to analyze the predictors of PCR,and then we assessed the evaluation value of the assessment model which was built on multivariate logistic regression.Results Univariate regression analysis showed that menstrual status,ER expression,K-i 67 expression,ADC value,tumor diameter, ΔADC%(NAC2－NAC0),ΔD%(NAC0－NAC2) had predictive value for PCR;the parameters ΔADC% and ΔD%,the expression of ER and K-i 67 were independent predictors of PCR based on multivariate Logistic regression analysis.The AUC of the assessment model model was 0.873.Conclusion Based on the heterogeneity of breast cancer,combine MRI with immunohistochemistry parameters could improve the prediction in the middle of NAC,and provide imaging basis for the adj ustment of follow-up chemotherapy regimen.
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Objective To study the values of change of diameter (ΔD%)on DCE-MRI and ΔD% combined with ADC for the therapeutic effect evaluation in the neoadjuvant chemotherapy(NAC)of each subtype of breast cancer.Methods 121 women with invasive breast cancer were enrolled in this study,including 56 cases of Luminal A type,42 cases of Luminal B type,13 cases of Her-2 type and 10 cases of triple negative type.Results Imaging evaluation results obtained by single applying DCE-MRI was analyzed with the pathological results after surgery for the consistency,and the Kappa values of Luminal A,Luminal B,Her-2 and triple negative type were 0.594,0.617,0.401,0.690,0.800,respectively.When combining ΔD% with ΔADC%,the Kappa values were 0.844,0.792,0.854, 0.847 and 0.800,respectively.The sensitivity of combined parameters in evaluating pCR after NAC was significantly increased in Luminal type cancers,however,with a slightly increasing in Her-2 type,and constant in triple negative type.Conclusion ΔD% combining with ΔADC% is better than single parameter in evaluating pCR for Luminal and Her-2 types cancer,but not for triple negative type.
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Objective To investigate the feasibility of quantitatively evaluating angiogenesis in liver tumors by using flat detector computed tomography (FDCT) in the angiography suite.Methods The VX2 liver tumor model was established in 25 rabbits,and then FDCT examination was performed for each animal.After reconstructing the blood volume (BV) perfusion map,BV values of the hepatic tumor and parenchyma were measured respectively.All experimental rabbits were sacrificed after FDCT,and the corresponding tumor specimens were collected for measuring microvessel density (MVD) and vascular endothelial growth factor (VEGF) expression level.The relationships of BV values with MVD and VEGF expression in liver tumors were analyzed.Results Of the 25 experimental rabbits,FDCT examination was successfully accomplished in 22(88.0％).Both the hepatic parenchyma and tumor lesions could be clearly visualized on BV perfusion map.The hepatic tumor was characterized by a hyperperfusion rim with a hypoperfusion center,known as rim-like enhancement pattern,on BV perfusion map.BV values bore a close relationship to both MVD grade and VEGF grade (P＜0.05 in both),while MVD grade had a parallel relationship with VEGF grade (r=0.504,P＜ 0.001).Conclusion It is feasible to use FDCT in the angiography suite to quantitatively assess the angiogenesis of liver tumors.It may be helpful for interventional treatment of liver tumors.
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Objective To evaluate the feasibility of diffusion kurtosis imaging (DKI)in the diagnosis and aggressiveness assessment of prostate cancer.Methods The MR data with multi-b-value diffusion-weighted imaging (DWI)of 30 male patients with prostate cancer were retrospectively analyzed.D maps and K maps were generated from the DKI model and ADC maps were obtained using the conventional monoexponential model.Differences in the D,K and ADC values between prostate cancer and benign peripheral zone (PZ)tissues,among tumors with different Gleason scores were analyzed.P<0.05 was considered statistical significance.Results ADC and D values were significantly lower in the prostate cancers than in the benign PZs (P <0.001).K values were significantly greater in the prostate cancers than in the benign PZs (P <0.001).ADC,D and K values were different significantly among the tumors with Glea-son scores of 6,7 and ≥8 (P <0.001,P =0.01 5 and P <0.001,respectively).Conclusion The DKI model can better describe the signal intensity attenuation with b values increasing,which is helpful for diagnosing and grading prostate cancer.K value may be used to quantitatively evaluate the complicated microstructure of prostate cancer.
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Objective To evaluate the effect of low-dose colonic CT scanning in image quality and lesion revealing with different noise idex.Methods Model group:in order to find the optimal scanning parameter range,small simulated polyps in pig colon was prepared and mA was modulated by regulating noise index.Images were reprocessed with CT colonography and Raysum reconstructions.Image quality and the lesion revealing situation were evaluated and scored based on both reconstructive and axial images.The study of patient group was prospective and continuous.All positive cases were comfirmed by biopsy or surgery pathology.Two groups of patients were enrolled.First group(39 cases from January 2007 to June 2007):patients were divided into three sub-groups randomly(15 cages with NI=10,13 cases with NI:13,11 cases with NI=16),while NI was not changed with position.Second group(32 cases from Jury 2007 to January 2008):patients were scanned and NI was changed with different position(NI=10,20).The average X-ray radiation values of two patient groups were compared with standard values.All data were processed with rank sum tesL Results First group:when NI=10,the average scores of axial and constructive images were 4.2 and 2.4 respectively,when NI=13,those were 3.2 and 2.5 respectively,When NI=16.those were 2.9 and 2.7 respectively.and the average CTDlw were 17.51,12.90 and 5.94 mGy respectively.When NI increased,the average scores of axial decreased(H=20.01,P＜0.01),the average scores of constructive images did not changed(H=0.81,P＞0.05).Second group:when NI=10,the average scores of axial and constructive images were respectively 3.6 and 2.3,when NI=20,those were 2.2 and 2.3 respectively,and the average CTDIw was 11.63 mGy.When NI increased from 10 to 20,the average scores of axial decreased(H=20.84,P＜0.01),the average scores of constructive images did not decreased(H=0.29,P＞0.05).In the first group,the average CTDIw wag reduced by 35.0%,52.1%and 77.9%respectively when NI was 10,13 and 16.In the second group,the average CTDIw Was reduced by 56.8%.Conclusions Auto-mA low-dose CT scanning could reduce X-ray radiation obviously,while not affecting image quality.