Objective To evaluate the clinical value of virtual US-CT or MRI navigation system for guidance of interventional procedures. Methods Virtual US-CT or MRI fusion navigation system was applied on 47 cases for guiding various interventional procedures. The operating method, success rate, clinical outcome,and complication of the navigating interventional technique were retrospectively analyzed. Thirty-eight cases of hepatic tumors underwent percutaneous needle biopsy and/or radiofrequency ablation (RFA); 4 cases of hepatic abscess underwent percutaneous abscess drainage, 5 cases of musculoskeletal diseases underwent biopsy, RFA or RFA with cementoplasty. Results For 38 cases of hepatic tumors who underwent RFA, 27 acquired complete ablation in one session, no recurrence after 3.0-6. 0 months (median time4. 8 months) follow-up; while the other 11 cases present with no significant change. Five cases of musculoskeletal diseases improved significantly after interventional therapy and pathological diagnoses were also acquired. Four cases of hepatic abscesses were cured after drainage. All cases were free of significant complication, except one local skin thermal damage. Conclusion Virtual US-CT or MRI navigation guiding technique provides mutual aid to different imaging modalities for guiding interventional procedure. After application of navigation system, those interventional procedures may become more convenient, more effective and safer.

Objective To evaluate distribution features of disrupted carotid plaque. Methods Forty-three subjects with duplex ultrasound evidence of 50% to 99% stenosis were retrospectively analyzed. Plaques were categorized as disrupted if there was MRI evidence of fibrous cap rupture. Quantity measured areas of the lumen (LA), wall (WA), and plaque components. The morphological parameters used were total vessel area, vessel burden index, eccentricity index. Mann-Whitney test and Chi-square test appropriate used SPSS (v. 12.0 ). Results There were 17 disrupted and 26 undisrupted lesions identified for comparison. Disrupted plaques showed a predominance of longer longitudinal length of large lip nucleus along the vessel wall (6 mm vs. 0 mm, U = 126, P <0.05 ), a large vessel burden (0.67 vs. 0.59, U =105, P <0.05), and high prevalence of thrombus (82.4% vs. 42.3 %, U = 132,P <0.05). In addition, disrupted plaques showed a different pattern of plaque distribution, having a more eccentric position of the lumen (3.68 vs. 2.79, U = 126, P < 0.05 ), a smaller lumen area (23.97 mm2 vs. 30. 18 mm2, U = 138, P<0.05) and a longer segment of stenosis when compared with the intact plaques. Conclusions Disrupted plaques have significantly different characteristics in terms of both axial and longitudinal distribution. A combination of multi-plane and multi-contrast high resolution MRI may provide valuable information about overall lesion morphology and its association to vulnerability.

Objective　To assess the CT manifestations and diagnostic value in the pancreatic tuberculosis(PTB)with review of the literatures. Methods　All cases of PTB proved by surgery or biopsy were examined with plain and enhanced CT scans. Results　The CT findings in one case with multiple-nodular type of PTB were diffuse enlargement of the pancreas with multiple, nodular, and low-density lesions; The nodular lesions had peripheral enhancement. 7 cases of local type of PTB encroached on pancreatic head. 4 cases showed local soft tissue masses with multiple flecked calcifications in 2 cases and mild enhancement in one case; Cystic masses was found in 2 cases, with mural calcification in 1 case and multiloculated cystic mass in 1 case, respectively; Massive pancreatic head calcification was demonstrated in one case. In these 8 cases of PTB, the lesion extended out of pancreas in 4 cases, including abdominal tuberculous lymph nodes, tuberculous peritonitis, and hepatosplenic tuberculosis. Conclusion　CT findings of PTB were various but had some characteristics. Pancreatic masses with multiple flecked calcification or mild enhancement could suggest the diagnosis. Abdominal tuberculosis accompanied with the pancreatic lesion, especially tuberculous lymph nodes, was highly suggestive of the diagnosis of PTB.

Objective To investigate the clinical value of coplanar template-assisted CT guided radioactive seeds implantation in the treatment of pancreatic carcinoma. Methods A total of 22 advanced pancreatic carcinoma patients underwent CT guided radioactive seeds implantation were retrospectively analyzed.Ten patients were treated with coplanar template-assisted with an average age of(65±10)years(48 to 77 years).Tweleve patients were treated without coplanar template assist with an average age of(68±13) years (47 to 84 years). The preoperative planning designs and postoperative dosimetry verifications were performed for all patients.The dose related parameters including D90,MPD,V100,V150and V200were compared between pre and post operation by t test. The operating time were also evaluated between the two groups. Results Overall the 22 patients were treated successfully without serious surgery-related complications. An average of 26 seeds were implanted in the coplanar template assisted implantation group,and 23 seeds were implanted in the non template-assisted implantation group. Preoperative V100in coplanar template group and non template group were(94.45 ± 1.32)% and(93.27 ± 1.37)% separately. Postoperative V100in both groups were(89.31 ± 2.58)% and(85.25 ± 4.35)% separately. Postoperative D90in both groups were (147.32±7.12)Gy and(149.25±4.86)Gy separately.Postoperative V150in both groups were(57.83±7.74)% and(63.97±7.75)% separately.Preoperative D90in both groups were(152.41±6.78)Gy and(153.30±7.79) Gy separately. Preoperative V150in both groups were(58.61 ± 14.11)% and(62.45 ± 6.49)% separately. Postoperative MPD in both groups were(87.64±10.60)Gy and(87.12±7.66)Gy separately.Postoperative V200in both groups were(34.12±7.67)%,(39.42±7.18)% separately.Preoperative MPD in both groups were (82.12±7.81)Gy and(83.43±4.86)Gy separately.Preoperative V200in both groups were(29.04±10.64)%, (36.11 ± 7.22)% separately. Compared with preoperative plans, the mean value of D90and V100decreased while the mean value of MPD and V200increased in postoperative verifications in both coplanar template assist CT guided radioactive seeds implantation group and non template-assisted group.However,there was no significant difference between pre and post operation except for V100(P<0.05). The operating time of coplanar template assist group and non template-assisted group were(44.3±12.4)min and(60.0±12.8)min respectively. The difference of operating time between two groups were statistically significant (P<0.05). Conclusion Compared with the treatment without template assist, coplanar template-assisted brachytherapy could be more accurate in preoperative plans optimization,and shorten the operation time and improve the patients'tolerance.

Objective To investigate the diagnostic value of dual-energy CT virtual non-contrast (VNC) technology for osteoporosis(OP). Methods Dual-energy CT images of 50 patients with lumbar traumas were collected prospectively.Patients who suffer from vertebral bodies fractures between lumbar 1 to 4, have internal metal fixations or underwent percutaneous vertebroplasty, or presented tumors or compromised bone metabolism induced by diseases or medications were excluded.The scanning range was from the upper edge of the 12th thoracic vertebral body to the lower edge of the first sacral vertebral body. The voltages of tubes A and B were 90 kV and Sn 150 kV,and the reference tubes currents were 220 mAs and 138 mAs. Image reconstruction was performed using Advanced Modeled Iterative Reconstruction (ADMIRE)with iterative strength of 3 and convolution kernel of Qr 40.The default parameters of the virtual non-contrast software were corrected by the standard recommended by the Bone Marrow software of the post-processing platform Syngo.via,and the CT value of calcium(contrast media CM),the CT value of mixed energy images(regular CT value,rCT),the calcium density(CaD)and the fat fraction(Fat)were measured. The bone mineral density (BMD) and T score of each lumbar vertebra from lumbar 1 to lumbar 4 were measured by dual energy X-ray absorptiometry(DXA).With T score less than or equal to the 2.5 standard deviation as the gold standard for the diagnosis of OP,correlations between CT measurements and vertebral BMDs were analyzed using Pearson correlation analysis and linear regression and the diagnostic values of different CT measurements for OP were compared using receiver operating characteristic curve. Results Each of the vertebral bodies was analyzed as a single unit.Fifty of them were osteoporotic and the rest 116 were non-osteoporotic.Except for Fat,the CT measurement parameters of the osteoporotic vertebral bodies were lower than those of the ones without osteoporosis, and the difference was statistically significant (P<0.01).CM,rCT and CaD were significantly correlated with BMD(r were 0.75,0.65,0.71,all P<0.01)and there was a linear relationship(F were 209.91,120.24,167.69,all P<0.01).Meanwhile,CM,rCT,CaD and T score were also significantly correlated (r were 0.74, 0.65, 0.70, all P<0.01) with a linear relationship (F were 195.04,120.29,156.37,all P<0.01).CM,rCT and CaD had relatively high concordance rates against the OP diagnosis gold standard (respectively 81.9%, 62.2% and 81.9%). CM and CaD had higher concordance rates than rCT,the difference being statistically significant(P<0.01),and by the CM less than 239.5 HU or CaD less than 10.9 mg/cm3standard, their sensitivities of diagnosing osteoporosis were respectively 86.0% and 84.0%,while the specificities,80.2% and 81.0%.After superimposing CM and CaD, the results did not improve the diagnosis efficiency of OP (pre-superposition diagnostic performance better than post-superposition (P<0.05). Conclusion The VNC technology on DECT can do both vertebral fractures diagnosis and osteoporosis assessment at the same time, thus optimizing the clinical examination process.

Objective To evaluate the value of MRI texture analysis (TA) in prediction of treatment response neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer patients. Methods Fifty nine histopathologically-proven rectal adenocarcinoma patients through biopsy treated with nCRT before total mesorectal excision were enrolled in this retrospective study.The first MRI examination (pre-nCRT MRI)was performed before nCRT,and the second one(early nCRT MRI)was performed at the third week of nCRT. The texture parameters values were measured, including mean value, standard deviation, skewness, kurtosis, uniformity, energy, and entropy. Tumoral downstaging was determined by comparing the pre-nCRT clinical T stage(cT stage) with the ypT stage. The patients were divided into downstaging and non downstaging group based on postoperative T staging. Parameters were compared between pre-and early nCRT in terms of averages using Wilcoxon signed-rank test. Downstaging and non downstaging groups were analyzed using Mann-Whitney U test.Multivariate logistic regression analysis was performed using the statistically significant parameters between the two groups as independent variables. ROC analysis was performed on the new independent variables obtained by multi-parameter logistic regression analysis and the single parameter independent variables. The diagnostic efficiency of the parameters were evaluated. Results T-downstaging were found in 28 patients after nCRT. The stdDeviation, kurtosis, and uniformity were significantly different between pre-and early nCRT (P<0.05). There was no significant difference in mean value, skewness, energy, and entropy between pre-and early nCRT (P>0.05). The pre-nCRT, uniformity, energy, entropy and the early nCRT mean value, entropy were significantly different in patients with downstaging vs. non downstaging (P<0.05). For the pre-nCRT stdDeviation,uniformity,energy,entropy and the early nCRT mean value,entropy,ROC analysis showed an area under curve(AUC) of 0.69, 0.76, 0.68, 0.67 and 0.65, 0.68, respectively. The multivariate logistic regression analysis for the four pre-nCRT independent variables(stdDeviation,uniformity,energy,entropy) achieved logical variable 1,and the logical variable 1 achieved an AUC of 0.78 to discriminate patients with T-downstaging from patients with non downstaging.The multivariate logistic regression analysis for the two early nCRT independent variables(mean value,entropy)achieved logical variable 2,and the logical variable 2 achieved an AUC of 0.69 to predict T-downstaging.Conclusion Pre-and early nCRT MRI TA in rectal cancer have the efficacy to predict treatment response.

Objective To analyze the pancreatic fat fraction based on magnetic resonance Dixon sequence and correlation with clinical factors. Methods A total of 95 cases of adult physical examinees who had underwent abdominal MRI were retrospectively studied. Age, blood pressure, height and weight were recorded for every subject,and BMI was then calculated.The venous blood sample were analyzed for fasting plasma glucose (FPC), total cholesterol (TC), triglycerides (TG), low density lipoprotein-cholesterol (LDL-c)and high density lipoprotein-cholesterol(HDL-c).All cases underwent water-fat separation T1WI,fat inhibition T2WI, DWI, and coronal T2WI scans. We measured PFF of all the examinees, subcutaneous fat area(SA),visceral fat area(VA),and total abdominal fat area(TA)on the images above 8 centimeter of L4 to L5 were also measured, subcutaneous fat percentage (SFP) and visceral fat percentage (VFP) were further calculated. PFF of the 95 cases ranged from 2.1% to 35.0%, and the median PFF was 8.9%. This cohort was divided into low-fat pancreas groups (PFF≤8.9%, n＝51) and high-fat pancreas group (PFF>8.9%, n＝44) according to the median PFF. Independent sample t test was used to test for differences in clinical index between the two groups, Pearson correlation coefficient was used to measure the strength of a linear association between clinical indexes and PFF. Results Excellent water only, fat only, in phase and out of phase images of all the 95 adults were obtained. Signals of MRI images of all pancreas were homogeneous, the anatomic structures of all images were sharp and clear, and all the images had no motion artifact. The levels of BMI, systolic blood pressure, TG, LDL-c, FPC, VA, TA, VFP of high-fat pancreas group were significantly higher than those of low-fat pancreas group, and SFP was lower (P<0.05). The differences in age, diastolic blood pressure, HDL-c, TC, and SA between the two groups were not statistically significant(P> 0.05). PFF was weakly to moderately positively correlated with age, BMI, systolic blood pressure, diastolic blood pressure, TG, LDL-c, FPG, SA, VA, TA and VFP (r=0.219 to 0.515, P<0.05), SFP was moderately negatively correlated with PFF(r=－0.434, P<0.01). Conclusions It's feasible and accurate to measure the PFF with Dixon technique. PFF have a certain correlation with age, BMI, blood pressure, abdominal fat area and blood lipid metabolism.

Objective To investigate the diagnostic value of random forest(RF)model based on CT images and clinical data for preoperative T staging of colorectal cancer. Methods Four hundred and fifty patients with colorectal cancer who were pathologically confirmed by surgery and underwent preoperative CT examinationinthe first hospital of Jilin university from January 2016 to July 2016 were included retrospectively(Stage≤T2,T3,and T4 each has 150 cases).According to the ratio of 2:1,the patients were divided into training set(300 cases)and test set(150 cases,stage ≤T2,T3,and T4 each has 50 cases)by computer random software. Each of 450 patients had one lesion. All the patients underwent preoperative abdominal and pelvic contrast-enhanced CT scan.The clinical,imaging and pathological data[gender,age, carcinoembryonic antigen (CEA) level, carbohydrate antigen 19-9 (CA19-9) expression, intestinal wall deformation, maximum diameter of tumorand thickness of intestinal wall, location, enhancement homogeneity and enhancement rate]of these patients were collected.The correlation between the collected factors and pathological T staging was analyzed by Spearman correlation analysis.The preoperative staging model of colorectal cancer was established by RF algorithm in the training set.Two kinds of methods(model and traditional method)were used to diagnose T stage of the patients in the test set.The accuracy of the two methods was calculated by postoperative pathological staging as the gold standard.The consistency test was used to evaluate the consistency of the RF model results with the pathological results. Results T-staging was positively correlated with CEA, CA19-9, intestinal wall deformation, tumor size and thickness of intestinal wall(r=0.449,0.291,0.624,0.573,0.386;P<0.05).Age,location,enhancement homogeneity and enhancement rate were slightly negatively correlated with T-staging(r=-0.115,-0.245,-0.120 and-0.339;P<0.05).The predictive results of the model in≤T2,T3,and T4 stage cancers were moderately and highly consistent with the standard of pathology,and the Kappa value were 0.769,0.615 and 0.800,respectively.The total accuracy rate of the model andthe traditional method are 80.7%(121/150)and 54.0%(81/150). Conclusion Application of random forest model based on multi-slice spiral CT images and clinical data can improve the diagnostic efficacy of preoperative T stage of colorectal cancer.

Objective To develop and validate one optimal MR radiomics model for lymph node (LN) re-evaluation of locally advanced rectal cancer (LARC) after neoadjuvant chemoradiotheray (NCRT). Methods Four hundred and seven patients with clinicopathologically confirmed LARC in Beijing Cancer Hospital were included in this study from July 2010 to June 2015. All patients received NCRT before surgery,and underwent T2WI and DWI before and after NCRT.These patients were chronologically divided in the primary cohort(300 patients)and independent validation cohort(107 patients).The predicting model was trained and validated using postoperative pathological findings as truth values. By using radiomics method, we extracted the features of the tumor and the largest LN before and after neoadjuvant therapy, combined different features of the tumor and/or the largest LN before and/or after neoadjuvant therapy,and constructed 4 different prediction models,compared the performance of four predicting models.The optimal model with the highest accuracy was validated in the independent cohort. Decision curve analysis was conducted to determine the clinical usefulness of the radiomics nomograms by quantifying the net benefits at different threshold probabilities in the validation dataset. Results In the primary cohort, the radiomics signatures from 4 models provided an AUC of 0.637, 0.709, 0.753, 0.835, respectively in LN re-evaluation after chemoradiotheray. The diagnostic efficacy of model 4 was much better than that of 1, 2 and 3 model. In the validation cohort, the radiomics signatures provided an AUC of 0.795 for LN re-evaluation after chemoradiotheray. The sensitivity, specificity, positive predictive value, negative predictive value were 0.813, 0.693, 0.531, 0.897, respectively (95% CI: 0.694 to 0.896, 0.647 to 0.911, 0.582 to 0.786, 0.361 to 0.621, 0.792 to 0.952). While the probability of predicting N+ ranges from 17% to 80%, using the proposed radiomics model to predict N+ shows a greater advantage than either the scheme in which all patients were assumed to N+ or the scheme in which all patients are N-. Decision curve analysis demonstrated that the radiomics nomograms were clinically useful. Conclusion With a systematic analysis and comparison of both pre-and post-NCRT MRI data, we constructed an optimal individualized LN re-evaluation model based on MR radiomics, combing primary tumor and the largest LN features, compared with other models (only with pre/post tumor or pre/post largest LN features).

Objective To investigate the diagnostic values of radiomics model based on ADC map in differentiating benign from malignant lesions in suspicious breast findings with MRI breast imaging reporting and data system (BI-RADS) category 4. Methods Eighty eight patients (36 benign and 52 malignant)with diagnosis of MRI BI-RADS 4 in our hospital from December 2014 to December 2015 were retrospectively enrolled in this study.All the patients were proved by pathology and examined by sequence of T1WI,T2WI,DWI and dynamic contrast enhanced magnetic resonance imaging(DCE-MRI),and then were further sub-categorized into BI-RADS 4A, BI-RADS 4B, or BI-RADS 4C based on DCE-MRI sequence. Thus positive predictive value(PPV)of each sub-category were calculated and ROC were used to describe its efficiency in differential diagnosis.Radiomics features based on ADC map were generated automatically from Analysis-Kinetics(GE Healthcare).Sixty three of the 88 cases randomized-selected by computer were used to establish forecasting models and other 25 cases for validation. Kruskal-Wallis test and Spearman were introduced to reduce radiomics features that were highly correlated with others. Logistic linear regression(LLR)model was constructed based on the selected features by'glm'function in R software and then verified by 10-fold cross validation (repeat 10 times). ROC was curved to determine the diagnostic accuracy of the model.Results The PPV of BI-RADS 4A,4B,4C were 16.7%(2/12),59.6%(28/47),75.9% (22/29)respectively.Area under curve(AUC)of ROC was 0.650,sensitivity and specificity were 76.9% and 45.9% respectively. Three hundred and ninety six radiomics features were extracted automatically by software and 5 features (size zone variability, difference entropy, zone percentage, intensity variability and inverse difference moment)were left after redundancy reduction step.Cross-validation showed the accuracy of Logistic regression model was 80.0%(20/25),AUC was 0.790,sensitivity and specificity were 81.3% and 77.8% when cut-off was 0.45. Conclusion The radiomics model could provide important reference for differentiation between benign and malignant lesions in suspicious BI-RADS 4 findings.